# -*- coding: utf-8 -*-
#Copyright (c) 2007, Playful Invention Company
#Copyright (c) 2008-13, Walter Bender
#Copyright (c) 2009-11 Raúl Gutiérrez Segalés
#Copyright (c) 2011 Collabora Ltd. <http://www.collabora.co.uk/>

#Permission is hereby granted, free of charge, to any person obtaining a copy
#of this software and associated documentation files (the "Software"), to deal
#in the Software without restriction, including without limitation the rights
#to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#copies of the Software, and to permit persons to whom the Software is
#furnished to do so, subject to the following conditions:

#The above copyright notice and this permission notice shall be included in
#all copies or substantial portions of the Software.

#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#THE SOFTWARE.

import pygtk
pygtk.require('2.0')
import gtk
import gobject
import pango
import pangocairo
from StringIO import StringIO

from gettext import gettext as _

try:
    import gst
    GST_AVAILABLE = True
except ImportError:
    # Turtle Art should not fail if gst is not available
    GST_AVAILABLE = False

import os
import subprocess

from math import atan2, pi
DEGTOR = 2 * pi / 360

import locale

from taconstants import (HORIZONTAL_PALETTE, VERTICAL_PALETTE, BLOCK_SCALE,
    MEDIA_SHAPES, STATUS_SHAPES, OVERLAY_SHAPES, TOOLBAR_SHAPES, TAB_LAYER,
    RETURN, OVERLAY_LAYER, CATEGORY_LAYER, BLOCKS_WITH_SKIN, ICON_SIZE,
    PALETTE_SCALE, PALETTE_WIDTH, SKIN_PATHS, MACROS, TOP_LAYER, BLOCK_LAYER,
    OLD_NAMES, DEFAULT_TURTLE, TURTLE_LAYER, EXPANDABLE, NO_IMPORT,
    TEMPLATES, PYTHON_SKIN, PALETTE_HEIGHT, STATUS_LAYER, OLD_DOCK,
    EXPANDABLE_ARGS, XO1, XO15, XO175, XO30, XO4, TITLEXY, CONTENT_ARGS,
    CONSTANTS, EXPAND_SKIN, PROTO_LAYER, EXPANDABLE_FLOW, SUFFIX)
from tapalette import (palette_names, palette_blocks, expandable_blocks,
    block_names, content_blocks, default_values, special_names, block_styles,
    help_strings, hidden_proto_blocks, string_or_number_args,
    make_palette, palette_name_to_index, palette_init_on_start)
from talogo import LogoCode, primitive_dictionary, logoerror
from tacanvas import TurtleGraphics
from tablock import Blocks, Block
from taturtle import Turtles, Turtle
from tautils import (magnitude, get_load_name, get_save_name, data_from_file,
    data_to_file, round_int, get_id, get_pixbuf_from_journal,
    movie_media_type, audio_media_type, image_media_type, save_picture,
    calc_image_size, get_path, hide_button_hit, show_button_hit, chooser,
    arithmetic_check, xy, find_block_to_run, find_top_block, journal_check,
    find_group, find_blk_below, data_to_string, find_start_stack,
    get_hardware, debug_output, error_output, data_to_string, convert,
    find_bot_block, restore_clamp, collapse_clamp, data_from_string,
    increment_name, get_screen_dpi)
from tasprite_factory import SVG, svg_str_to_pixbuf, svg_from_file
from sprites import Sprites, Sprite

if GST_AVAILABLE:
    from tagplay import stop_media

MOTION_THRESHOLD = 6
SNAP_THRESHOLD = 200
NO_DOCK = (100, 100)  # Blocks cannot be docked


class TurtleArtWindow():
    ''' TurtleArt Window class abstraction  '''
    timeout_tag = [0]
    _PLUGIN_SUBPATH = 'plugins'

    def __init__(self, canvas_window, path, parent=None,
                 mycolors=None, mynick=None, turtle_canvas=None,
                 running_sugar=True):
        self._loaded_project = ''
        self._sharing = False
        self.parent = parent
        self.turtle_canvas = turtle_canvas
        self.send_event = None  # method to send events over the network
        self.gst_available = GST_AVAILABLE
        self.running_sugar = False
        self.nick = None
        if type(canvas_window) == gtk.DrawingArea:
            self.interactive_mode = True
            self.window = canvas_window
            self.window.set_flags(gtk.CAN_FOCUS)
            self.window.show_all()
            if running_sugar:
                self.parent.show_all()
                self.running_sugar = True
                from sugar import profile
                self.nick = profile.get_nick_name()
            self._setup_events()
        else:
            self.interactive_mode = False
            self.window = canvas_window
            self.running_sugar = False
        self.activity = parent

        self.path = path
        self.load_save_folder = os.path.join(path, 'samples')
        self.py_load_save_folder = os.path.join(path, 'pysamples')
        self._py_cache = {}
        self.used_block_list = []  # Which blocks has the user used?
        self.save_folder = None
        self.save_file_name = None
        self.width = gtk.gdk.screen_width()
        self.height = gtk.gdk.screen_height()
        self.rect = gtk.gdk.Rectangle(0, 0, 0, 0)

        self.no_help = False
        self.last_label = None
        self._autohide_shape = True
        self.keypress = ''
        self.keyvalue = 0
        self._focus_out_id = None
        self._insert_text_id = None
        self._text_to_check = False
        self.mouse_flag = 0
        self.mouse_x = 0
        self.mouse_y = 0
        self.running_blocks = False

        try:
            locale.setlocale(locale.LC_NUMERIC, '')
        except locale.Error:
            debug_output('unsupported locale', self.running_sugar)
        self.decimal_point = locale.localeconv()['decimal_point']
        if self.decimal_point == '' or self.decimal_point is None:
            self.decimal_point = '.'

        self.orientation = HORIZONTAL_PALETTE

        self.hw = get_hardware()
        self.lead = 1.0
        if self.hw in (XO1, XO15, XO175, XO4):
            self.scale = 1.0
            self.entry_scale = 0.67
            if self.hw == XO1:
                self.color_mode = '565'
            else:
                self.color_mode = '888'
            if self.running_sugar and not self.activity.has_toolbarbox:
                self.orientation = VERTICAL_PALETTE
        else:
            self.scale = 1.0
            self.entry_scale = 1.0            
            self.color_mode = '888'  # TODO: Read visual mode from gtk image
        self._set_screen_dpi()        

        self.block_scale = BLOCK_SCALE[3]
        self.trash_scale = 0.5
        self.myblock = {}
        self.python_code = None
        self.nop = 'nop'
        self.loaded = 0
        self.step_time = 0
        self.hide = False
        self.palette = True
        self.coord_scale = 1
        self.buddies = []
        self._saved_string = ''
        self._saved_action_name = ''
        self._saved_box_name = ''
        self.dx = 0
        self.dy = 0
        self.media_shapes = {}
        self.cartesian = False
        self.polar = False
        self.metric = False
        self.overlay_shapes = {}
        self.toolbar_shapes = {}
        self.toolbar_offset = 0
        self.status_spr = None
        self.status_shapes = {}
        self.toolbar_spr = None
        self.palette_sprs = []
        self.palettes = []
        self.palette_button = []
        self.trash_stack = []
        self.selected_palette = None
        self.previous_palette = None
        self.selectors = []
        self.selected_selector = None
        self.previous_selector = None
        self.selector_shapes = []
        self.selected_blk = None
        self.selected_spr = None
        self.selected_turtle = None
        self.drag_group = None
        self.drag_turtle = 'move', 0, 0
        self.drag_pos = 0, 0
        self.dragging_canvas = [False, 0, 0]
        self.turtle_movement_to_share = None
        self.paste_offset = 20  # Don't paste on top of where you copied.

        self.block_list = Blocks(font_scale_factor=self.scale,
                                 decimal_point=self.decimal_point)
        if self.interactive_mode:
            self.sprite_list = Sprites(self.window)
        else:
            self.sprite_list = None

        self.canvas = TurtleGraphics(self, self.width, self.height)
        if self.hw == XO175 and self.canvas.width == 1024:
            self.hw = XO30
        if self.interactive_mode:
            self.sprite_list.set_cairo_context(self.canvas.canvas)

        self.turtles = Turtles(self.sprite_list)
        if self.nick is None:
            self.default_turtle_name = DEFAULT_TURTLE
        else:
            self.default_turtle_name = self.nick
        if mycolors is None:
            Turtle(self.turtles, self.default_turtle_name)
        else:
            Turtle(self.turtles, self.default_turtle_name, mycolors.split(','))
        self.active_turtle = self.turtles.get_turtle(self.default_turtle_name)
        self.active_turtle.show()

        self.canvas.clearscreen(False)

        CONSTANTS['titlex'] = int(-(self.canvas.width * TITLEXY[0]) / \
            (self.coord_scale * 2))
        CONSTANTS['leftx'] = int(-(self.canvas.width * TITLEXY[0]) / \
            (self.coord_scale * 2))
        CONSTANTS['rightx'] = 0
        CONSTANTS['titley'] = int((self.canvas.height * TITLEXY[1]) / \
            (self.coord_scale * 2))
        CONSTANTS['topy'] = int((self.canvas.height * (TITLEXY[1] - 0.125)) / \
            (self.coord_scale * 2))
        CONSTANTS['bottomy'] = 0
        CONSTANTS['leftpos'] = int(-self.canvas.width / (self.coord_scale * 2))
        CONSTANTS['toppos'] = int(self.canvas.height / (self.coord_scale * 2))
        CONSTANTS['rightpos'] = int(self.canvas.width / (self.coord_scale * 2))
        CONSTANTS['bottompos'] = int(-self.canvas.height / \
                                          (self.coord_scale * 2))
        CONSTANTS['width'] = int(self.canvas.width / self.coord_scale)
        CONSTANTS['height'] = int(self.canvas.height / self.coord_scale)

        self._icon_paths = [os.path.join(self.path, 'icons')]
        self.turtleart_plugins = []

        self._init_plugins()
        self.lc = LogoCode(self)

        from tabasics import Palettes
        p = Palettes(self)
        self._setup_plugins()

        if self.interactive_mode:
            self._setup_misc()
            for name in palette_init_on_start:
                debug_output('initing palette %s' % (name), self.running_sugar)
                self.show_toolbar_palette(palette_names.index(name),
                                          init_only=False, regenerate=True,
                                          show=False)
            self.show_toolbar_palette(0, init_only=False, regenerate=True,
                                          show=True)
        self.saved_pictures = []
        self.block_operation = ''

    def _set_screen_dpi(self):
        dpi = get_screen_dpi()
        if self.hw in (XO1, XO15, XO175, XO4):
            dpi = 133  # Tweek because of XO display peculiarities
        font_map_default = pangocairo.cairo_font_map_get_default()
        font_map_default.set_resolution(dpi)

    def _tablet_mode(self):
        return False  # Sugar will autoscroll the window for me

    def _get_plugin_home(self):
        ''' Look in the execution directory '''
        path = os.path.join(self.path, self._PLUGIN_SUBPATH)
        if os.path.exists(path):
            return path
        else:
            return None

    def _get_plugins_from_plugins_dir(self, path):
        ''' Look for plugin files in plugin dir. '''
        plugin_files = []
        if path is not None:
            candidates = os.listdir(path)
            candidates.sort()
            for dirname in candidates:
                if os.path.exists(
                    os.path.join(path, dirname, dirname + '.py')):
                    plugin_files.append(dirname)
        return plugin_files

    def _init_plugins(self):
        ''' Try importing plugin files from the plugin dir. '''
        for plugin_dir in self._get_plugins_from_plugins_dir(
            self._get_plugin_home()):
            self.init_plugin(plugin_dir)

    def init_plugin(self, plugin_dir):
        ''' Initialize plugin in plugin_dir '''
        plugin_class = plugin_dir.capitalize()
        f = "def f(self): from plugins.%s.%s import %s; return %s(self)" \
            % (plugin_dir, plugin_dir, plugin_class, plugin_class)
        plugins = {}
        # NOTE: When debugging plugins, it may be useful to not trap errors
        try:
            exec f in globals(), plugins
            self.turtleart_plugins.append(plugins.values()[0](self))
            debug_output('Successfully importing %s' % (plugin_class),
                         self.running_sugar)
            # Add the icon dir to the icon_theme search path
            self._add_plugin_icon_dir(os.path.join(self._get_plugin_home(),
                                                   plugin_dir))
        except ImportError as e:
            debug_output('Failed to import %s: %s' % (plugin_class, str(e)),
                         self.running_sugar)
        except:
            debug_output('Failed to load %s' % (plugin_class),
                         self.running_sugar)

    def _add_plugin_icon_dir(self, dirname):
        ''' If there is an icon subdir, add it to the search path. '''
        icon_theme = gtk.icon_theme_get_default()
        icon_path = os.path.join(dirname, 'icons')
        if os.path.exists(icon_path):
            icon_theme.append_search_path(icon_path)
            self._icon_paths.append(icon_path)

    def _get_plugin_instance(self, plugin_name):
        ''' Returns the plugin 'plugin_name' instance '''
        list_plugins = self._get_plugins_from_plugins_dir(
            self._get_plugin_home())
        if plugin_name in list_plugins:
            number_plugin = list_plugins.index(plugin_name)
            return self.turtleart_plugins[number_plugin]
        else:
            return None

    def _setup_plugins(self):
        ''' Initial setup -- called just once. '''
        for plugin in self.turtleart_plugins:
            plugin.setup()

    def _start_plugins(self):
        ''' Start is called everytime we execute blocks. '''
        for plugin in self.turtleart_plugins:
            plugin.start()

    def stop_plugins(self):
        ''' Stop is called whenever we stop execution. '''
        for plugin in self.turtleart_plugins:
            plugin.stop()

    def clear_plugins(self):
        ''' Clear is called from the clean block and erase button. '''
        for plugin in self.turtleart_plugins:
            if hasattr(plugin, 'clear'):
                plugin.clear()

    def background_plugins(self):
        ''' Background is called when we are pushed to the background. '''
        for plugin in self.turtleart_plugins:
            plugin.goto_background()

    def foreground_plugins(self):
        ''' Foreground is called when we are return from the background. '''
        for plugin in self.turtleart_plugins:
            plugin.return_to_foreground()

    def quit_plugins(self):
        ''' Quit is called upon program exit. '''
        for plugin in self.turtleart_plugins:
            plugin.quit()

    def _setup_events(self):
        ''' Register the events we listen to. '''
        self.window.add_events(gtk.gdk.BUTTON_PRESS_MASK)
        self.window.add_events(gtk.gdk.BUTTON_RELEASE_MASK)
        self.window.add_events(gtk.gdk.POINTER_MOTION_MASK)
        self.window.add_events(gtk.gdk.KEY_PRESS_MASK)
        self.window.connect("expose-event", self._expose_cb)
        self.window.connect("button-press-event", self._buttonpress_cb)
        self.window.connect("button-release-event", self._buttonrelease_cb)
        self.window.connect("motion-notify-event", self._move_cb)
        self.window.connect("key-press-event", self._keypress_cb)

        target = [("text/plain", 0, 0)]
        self.window.drag_dest_set(gtk.DEST_DEFAULT_ALL, target,
                           gtk.gdk.ACTION_COPY | gtk.gdk.ACTION_MOVE)
        self.window.connect('drag_data_received', self._drag_data_received)

    def _drag_data_received(self, w, context, x, y, data, info, time):
        ''' Handle dragging of block data from clipboard to canvas. '''
        debug_output(data.data, True)
        if data and data.format == 8 and data.data[0:2] == '[[':
            self.process_data(data_from_string(data.data),
                              self.paste_offset)
            self.paste_offset += 20
            context.finish(True, False, time)
        elif data and data.format == 8 and \
             self.selected_blk is not None and \
             self.selected_blk.name == 'string':
            bounds = self._text_buffer.get_bounds()
            self._text_buffer.set_text(
                self._text_buffer.get_text(bounds[0], bounds[1]) + data.data)
            self.text_entry.set_buffer(self._text_buffer)
            context.finish(True, False, time)
        else:
            context.finish(False, False, time)

    def load_media_shapes(self):
        ''' Media shapes get positioned onto blocks '''
        for name in MEDIA_SHAPES:
            if name in self.media_shapes:
                continue
            if name[0:7] == 'journal' and not self.running_sugar:
                filename = 'file' + name[7:]
            else:
                filename = name
            # Try both images/ and plugins/*/images/
            for path in SKIN_PATHS:
                if os.path.exists(os.path.join(self.path, path,
                                               filename + '.svg')):
                    self.media_shapes[name] = svg_str_to_pixbuf(svg_from_file(
                            os.path.join(self.path, path, filename + '.svg')))
                    break

    def _setup_misc(self):
        ''' Misc. sprites for status, overlays, etc. '''
        self.load_media_shapes()
        for i, name in enumerate(STATUS_SHAPES):
            # Temporary hack to use wider shapes
            if name in ['print', 'help', 'status'] and self.width > 1024:
                self.status_shapes[name] = svg_str_to_pixbuf(svg_from_file(
                        os.path.join(self.path, 'images', name + '1200.svg')))
            else:
                self.status_shapes[name] = svg_str_to_pixbuf(svg_from_file(
                        os.path.join(self.path, 'images', name + '.svg')))
        self.status_spr = Sprite(self.sprite_list, 0, self.height - 200,
                                 self.status_shapes['status'])
        self.status_spr.hide()
        self.status_spr.type = 'status'
        self._autohide_shape = True

        for name in OVERLAY_SHAPES:
            self.overlay_shapes[name] = Sprite(self.sprite_list,
                                                int(self.width / 2 - 600),
                                                int(self.height / 2 - 450),
                                                svg_str_to_pixbuf(
                    svg_from_file("%s/images/%s.svg" % (self.path, name))))
            self.overlay_shapes[name].hide()
            self.overlay_shapes[name].type = 'overlay'

        if not self.running_sugar:
            # offset = 2 * self.width - 55 * len(TOOLBAR_SHAPES)
            offset = 55 * (2 + len(palette_blocks))
            for i, name in enumerate(TOOLBAR_SHAPES):
                self.toolbar_shapes[name] = Sprite(
                    self.sprite_list, i * 55 + offset, 0,
                    svg_str_to_pixbuf(svg_from_file(os.path.join(
                                self.path, 'icons', '%s.svg' % (name)))))
                self.toolbar_shapes[name].set_layer(TAB_LAYER)
                self.toolbar_shapes[name].name = name
                self.toolbar_shapes[name].type = 'toolbar'
            self.toolbar_shapes['stopiton'].hide()

    def set_sharing(self, shared):
        self._sharing = shared

    def sharing(self):
        return self._sharing

    def is_project_empty(self):
        ''' Check to see if project has any blocks in use '''
        return len(self.just_blocks()) == 1

    def _expose_cb(self, win=None, event=None):
        ''' Repaint '''
        self.do_expose_event(event)
        return True

    def do_expose_event(self, event=None):
        ''' Handle the expose-event by drawing '''

        # Create the cairo context
        cr = self.window.window.cairo_create()

        # TODO: set global scale
        # find_sprite needs rescaled coordinates
        # sw needs new bounds set
        # cr.scale(self.activity.global_x_scale, self.activity.global_y_scale)

        if event is None:
            cr.rectangle(self.rect.x, self.rect.y,
                         self.rect.width, self.rect.height)
        else:
        # Restrict Cairo to the exposed area; avoid extra work
            cr.rectangle(event.area.x, event.area.y,
                         event.area.width, event.area.height)
        cr.clip()

        if self.turtle_canvas is not None:
            cr.set_source_surface(self.turtle_canvas)
            cr.paint()

        # Refresh sprite list
        self.sprite_list.redraw_sprites(cr=cr)

    def eraser_button(self):
        ''' Eraser_button (hide status block when clearing the screen.) '''
        if self.status_spr is not None:
            self.status_spr.hide()
        self._autohide_shape = True
        self.lc.find_value_blocks()  # Are there blocks to update?
        self.lc.prim_clear()
        self.display_coordinates()

    def run_button(self, time, running_from_button_push=False):
        ''' Run turtle! '''
        if self.running_sugar:
            self.activity.recenter()

        # Look for a 'start' block
        for blk in self.just_blocks():
            if find_start_stack(blk):
                self.step_time = time
                if self.running_sugar:
                    debug_output("running stack starting from %s" % (blk.name),
                                 self.running_sugar)
                if running_from_button_push:
                    self.selected_blk = None
                else:
                    self.selected_blk = blk
                self._run_stack(blk)
                return

        # If there is no 'start' block, run stacks that aren't 'def action'
        for blk in self.just_blocks():
            if find_block_to_run(blk):
                self.step_time = time
                if self.running_sugar:
                    debug_output("running stack starting from %s" % (blk.name),
                                 self.running_sugar)
                if running_from_button_push:
                    self.selected_blk = None
                else:
                    self.selected_blk = blk
                self._run_stack(blk)
        return

    def stop_button(self):
        ''' Stop button '''
        self.lc.stop_logo()
        # self._stop_plugins()

    def set_userdefined(self, blk=None):
        ''' Change icon for user-defined blocks after loading Python code. '''
        if blk is not None:
            if blk.name in PYTHON_SKIN:
                x, y = self._calc_image_offset('pythonon', blk.spr)
                blk.set_image(self.media_shapes['pythonon'], x, y)
                self._resize_skin(blk)

    def set_fullscreen(self):
        ''' Enter fullscreen mode '''
        if self.running_sugar:
            self.activity.fullscreen()
            self.activity.recenter()

    def set_cartesian(self, flag):
        ''' Turn on/off Cartesian coordinates '''
        if self.coord_scale == 1:
            self.draw_overlay('Cartesian_labeled')
        else:
            self.draw_overlay('Cartesian')
        return

    def set_polar(self, flag):
        ''' Turn on/off polar coordinates '''
        self.draw_overlay('polar')
        return

    def set_metric(self, flag):
        ''' Turn on/off metric coordinates '''
        self.draw_overlay('metric')
        return

    def draw_overlay(self, overlay):
        ''' Draw a coordinate grid onto the canvas. '''
        save_heading = self.canvas.heading
        self.canvas.heading = 0
        w = self.overlay_shapes[overlay].rect[2]
        h = self.overlay_shapes[overlay].rect[3]
        self.canvas.draw_surface(
            self.overlay_shapes[overlay].cached_surfaces[0],
            (self.canvas.width - w) / 2.,
            (self.canvas.height - h) / 2., w, h)
        self.canvas.heading = save_heading

    def update_overlay_position(self, widget, event):
        ''' Reposition the overlays when window size changes '''
        self.width = event.width
        self.height = event.height
        for name in OVERLAY_SHAPES:
            shape = self.overlay_shapes[name]
            showing = False
            if shape in shape._sprites.list:
                shape.hide()
                showing = True
            self.overlay_shapes[name] = Sprite(self.sprite_list,
                                                int(self.width / 2 - 600),
                                                int(self.height / 2 - 450),
                                                svg_str_to_pixbuf(
                    svg_from_file("%s/images/%s.svg" % (self.path, name))))
            if showing:
                self.overlay_shapes[name].set_layer(OVERLAY_LAYER)
            else:
                self.overlay_shapes[name].hide()
            self.overlay_shapes[name].type = 'overlay'
        self.cartesian = False
        self.polar = False
        self.metric = False
        self.canvas.width = self.width
        self.canvas.height = self.height
        self.canvas.move_turtle()

    def hideshow_button(self):
        ''' Hide/show button '''
        if not self.hide:
            for blk in self.just_blocks():
                blk.spr.hide()
            self.hide_palette()
            self.hide = True
        else:
            for blk in self.just_blocks():
                if blk.status != 'collapsed':
                    blk.spr.set_layer(BLOCK_LAYER)
            self.show_palette()
            self.hide = False
            if self.running_sugar:
                self.activity.recenter()
        self.inval_all()

    def inval_all(self):
        ''' Force a refresh '''
        if self.interactive_mode:
            self.window.queue_draw_area(0, 0, self.width, self.height)

    def hideshow_palette(self, state):
        ''' Hide or show palette  '''
        if not state:
            self.palette = False
            if self.running_sugar:
                self.activity.do_hidepalette()
            self.hide_palette()
        else:
            self.palette = True
            if self.running_sugar:
                self.activity.do_showpalette()
                self.activity.recenter()
            self.show_palette()

    def show_palette(self, n=None):
        ''' Show palette. '''
        if n is None:
            if self.selected_palette is None:
                n = 0
            else:
                n = self.selected_palette
        self.show_toolbar_palette(n)
        self.palette_button[self.orientation].set_layer(TAB_LAYER)
        self.palette_button[2].set_layer(TAB_LAYER)
        self._display_palette_shift_button(n)
        if not self.running_sugar or not self.activity.has_toolbarbox:
            self.toolbar_spr.set_layer(CATEGORY_LAYER)
        self.palette = True

    def hide_palette(self):
        ''' Hide the palette. '''
        self._hide_toolbar_palette()
        self.palette_button[self.orientation].hide()
        self.palette_button[2].hide()
        self.palette_button[3].hide()
        self.palette_button[4].hide()
        if not self.running_sugar or not self.activity.has_toolbarbox:
            self.toolbar_spr.hide()
        self.palette = False

    def move_palettes(self, x, y):
        ''' Move the palettes. '''
        for p in self.palettes:
            for blk in p:
                blk.spr.move((x + blk.spr.save_xy[0], y + blk.spr.save_xy[1]))
        for spr in self.palette_button:
            spr.move((x + spr.save_xy[0], y + spr.save_xy[1]))
        for p in self.palette_sprs:
            if p[0] is not None:
                p[0].move((x + p[0].save_xy[0], y + p[0].save_xy[1]))
            if p[1] is not None:
                p[1].move((x + p[1].save_xy[0], y + p[1].save_xy[1]))

        self.status_spr.move((x + self.status_spr.save_xy[0],
                              y + self.status_spr.save_xy[1]))

        # To do: set save_xy for blocks in Trash
        for blk in self.trash_stack:
            for gblk in find_group(blk):
                gblk.spr.move((x + gblk.spr.save_xy[0],
                               y + gblk.spr.save_xy[1]))

    def hideblocks(self):
        ''' Callback from 'hide blocks' block '''
        if not self.interactive_mode:
            return
        self.hide = False
        self.hideshow_button()
        if self.running_sugar:
            self.activity.do_hide_blocks()

    def showblocks(self):
        ''' Callback from 'show blocks' block '''
        if not self.interactive_mode:
            return
        self.hide = True
        self.hideshow_button()
        if self.running_sugar:
            self.activity.do_show_blocks()

    def resize_blocks(self, blocks=None):
        ''' Resize blocks or if blocks is None, all of the blocks '''
        if blocks is None:
            blocks = self.just_blocks()

        # Do the resizing.
        for blk in blocks:
            blk.rescale(self.block_scale)
        for blk in blocks:
            self._adjust_dock_positions(blk)

        # Resize the skins on some blocks: media content and Python
        for blk in blocks:
            if blk.name in BLOCKS_WITH_SKIN:
                self._resize_skin(blk)

        # Resize text_entry widget
        if hasattr(self, '_text_entry') and len(blocks) > 0:
            font_desc = pango.FontDescription('Sans')
            font_desc.set_size(
                int(blocks[0].font_size[0] * pango.SCALE * self.entry_scale))
            self._text_entry.modify_font(font_desc)

    def _shift_toolbar_palette(self, n):
        ''' Shift blocks on specified palette '''
        x, y = self.palette_sprs[n][self.orientation].get_xy()
        w, h = self.palette_sprs[n][self.orientation].get_dimensions()
        bx, by = self.palettes[n][0].spr.get_xy()
        if self.orientation == 0:
            dx = w - self.width
            dy = 0
            if bx - x > 0:
                dx *= -1
        else:
            dx = 0
            dy = h - self.height + ICON_SIZE
            if by - y > 0:
                dy *= -1
        for blk in self.palettes[n]:
            if blk.get_visibility():
                blk.spr.move_relative((dx, dy))

    def show_toolbar_palette(self, n, init_only=False, regenerate=False,
                             show=True):
        ''' Show the toolbar palettes, creating them on init_only '''
        # If we are running the 0.86+ toolbar, the selectors are already
        # created, as toolbar buttons. Otherwise, we need to create them.
        if (not self.running_sugar or not self.activity.has_toolbarbox) and \
           self.selectors == []:
            # First, create the selector buttons
            self._create_the_selectors()

        # Create the empty palettes that we'll then populate with prototypes.
        if self.palette_sprs == []:
            self._create_the_empty_palettes()

        # At initialization of the program, we don't actually populate
        # the palettes.
        if init_only:
            return

        if show:
            # Hide the previously displayed palette
            self._hide_previous_palette()
        else:
            save_selected = self.selected_palette
            save_previous = self.previous_palette

        self.selected_palette = n
        self.previous_palette = self.selected_palette

        # Make sure all of the selectors are visible. (We don't need to do
        # this for 0.86+ toolbars since the selectors are toolbar buttons.)
        if show and \
           (not self.running_sugar or not self.activity.has_toolbarbox):
            self.selected_selector = self.selectors[n]
            self.selectors[n].set_shape(self.selector_shapes[n][1])
            for i in range(len(palette_blocks)):
                self.selectors[i].set_layer(TAB_LAYER)

            # Show the palette with the current orientation.
            if self.palette_sprs[n][self.orientation] is not None:
                self.palette_sprs[n][self.orientation].set_layer(
                    CATEGORY_LAYER)
                self._display_palette_shift_button(n)

        # Create 'proto' blocks for each palette entry
        self._create_proto_blocks(n)

        if show or save_selected == n:
            self._layout_palette(n, regenerate=regenerate)
        else:
            self._layout_palette(n, regenerate=regenerate, show=False)
        for blk in self.palettes[n]:
            if blk.get_visibility():
                if hasattr(blk.spr, 'set_layer'):
                    blk.spr.set_layer(PROTO_LAYER)
                else:
                    debug_output('WARNING: block sprite is None' % (blk.name),
                                 self.running_sugar)
            else:
                blk.spr.hide()
        if n == palette_names.index('trash'):
            for blk in self.trash_stack:
                # Deprecated
                for gblk in find_group(blk):
                    if gblk.status != 'collapsed':
                        gblk.spr.set_layer(TAB_LAYER)

        if not show:
            if not save_selected == n:
                self._hide_previous_palette(palette=n)
            self.selected_palette = save_selected
            self.previous_palette = save_previous

    def regenerate_palette(self, n):
        ''' Regenerate palette (used by some plugins) '''
        if (not self.running_sugar or not self.activity.has_toolbarbox) and \
           self.selectors == []:
            return
        if self.palette_sprs == []:
            return

        save_selected = self.selected_palette
        save_previous = self.previous_palette
        self.selected_palette = n
        self.previous_palette = self.selected_palette

        if save_selected == n:
            self._layout_palette(n, regenerate=True)
        else:
            self._layout_palette(n, regenerate=True, show=False)

        for blk in self.palettes[n]:
            if blk.get_visibility():
                if hasattr(blk.spr, 'set_layer'):
                    blk.spr.set_layer(PROTO_LAYER)
                else:
                    debug_output('WARNING: block sprite is None' % (blk.name),
                                 self.running_sugar)
            else:
                blk.spr.hide()

        if not save_selected == n:
            self._hide_previous_palette(palette=n)
        self.selected_palette = save_selected
        self.previous_palette = save_previous

    def _display_palette_shift_button(self, n):
        ''' Palettes too wide (or tall) for the screen get a shift button '''
        if self.palette_sprs[n][self.orientation].type == \
                'category-shift-horizontal':
            self.palette_button[3].set_layer(CATEGORY_LAYER)
            self.palette_button[4].hide()
        elif self.palette_sprs[n][self.orientation].type == \
                'category-shift-vertical':
            self.palette_button[3].hide()
            self.palette_button[4].set_layer(CATEGORY_LAYER)
        else:
            self.palette_button[3].hide()
            self.palette_button[4].hide()

    def _create_the_selectors(self):
        ''' Create the palette selector buttons: only when running
        old-style Sugar toolbars or from GNOME '''
        svg = SVG()
        x, y = 50, 0  # positioned at the left, top
        for i, name in enumerate(palette_names):
            for path in self._icon_paths:
                if os.path.exists(os.path.join(path, '%soff.svg' % (name))):
                    icon_pathname = os.path.join(path, '%soff.svg' % (name))
                    break
            if icon_pathname is not None:
                off_shape = svg_str_to_pixbuf(svg_from_file(icon_pathname))
            else:
                off_shape = svg_str_to_pixbuf(svg_from_file(os.path.join(
                            self._icon_paths[0], 'extrasoff.svg')))
                error_output('Unable to open %soff.svg' % (name),
                             self.running_sugar)
            for path in self._icon_paths:
                if os.path.exists(os.path.join(path, '%son.svg' % (name))):
                    icon_pathname = os.path.join(path, '%son.svg' % (name))
                    break
            if icon_pathname is not None:
                on_shape = svg_str_to_pixbuf(svg_from_file(icon_pathname))
            else:
                on_shape = svg_str_to_pixbuf(svg_from_file(os.path.join(
                            self._icon_paths[0], 'extrason.svg')))
                error_output('Unable to open %son.svg' % (name),
                             self.running_sugar)

            self.selector_shapes.append([off_shape, on_shape])
            self.selectors.append(Sprite(self.sprite_list, x, y, off_shape))
            self.selectors[i].type = 'selector'
            self.selectors[i].name = name
            self.selectors[i].set_layer(TAB_LAYER)
            w = self.selectors[i].get_dimensions()[0]
            x += int(w)  # running from left to right

        # Create the toolbar background for the selectors
        self.toolbar_offset = ICON_SIZE
        self.toolbar_spr = Sprite(self.sprite_list, 0, 0,
            svg_str_to_pixbuf(svg.toolbar(2 * self.width, ICON_SIZE)))
        self.toolbar_spr.type = 'toolbar'
        self.toolbar_spr.set_layer(CATEGORY_LAYER)

    def _create_the_empty_palettes(self):
        ''' Create the empty palettes to be populated by prototype blocks. '''
        if len(self.palettes) == 0:
            for i in range(len(palette_blocks)):
                self.palettes.append([])

        # Create empty palette backgrounds
        for i in palette_names:
            self.palette_sprs.append([None, None])

        # Create the palette orientation button
        self.palette_button.append(Sprite(self.sprite_list, 0,
            self.toolbar_offset, svg_str_to_pixbuf(svg_from_file(
                        "%s/images/palettehorizontal.svg" % (self.path)))))
        self.palette_button.append(Sprite(self.sprite_list, 0,
            self.toolbar_offset, svg_str_to_pixbuf(svg_from_file(
                        "%s/images/palettevertical.svg" % (self.path)))))
        self.palette_button[0].name = _('orientation')
        self.palette_button[1].name = _('orientation')
        self.palette_button[0].type = 'palette'
        self.palette_button[1].type = 'palette'
        self.palette_button[self.orientation].set_layer(TAB_LAYER)
        self.palette_button[1 - self.orientation].hide()

        # Create the palette next button
        self.palette_button.append(Sprite(self.sprite_list, 16,
            self.toolbar_offset, svg_str_to_pixbuf(svg_from_file(
                        "%s/images/palettenext.svg" % (self.path)))))
        self.palette_button[2].name = _('next')
        self.palette_button[2].type = 'palette'
        self.palette_button[2].set_layer(TAB_LAYER)

        # Create the palette shift buttons
        dims = self.palette_button[0].get_dimensions()
        self.palette_button.append(Sprite(self.sprite_list, 0,
            self.toolbar_offset + dims[1], svg_str_to_pixbuf(svg_from_file(
                        "%s/images/palettehshift.svg" % (self.path)))))
        self.palette_button.append(Sprite(self.sprite_list, dims[0],
            self.toolbar_offset, svg_str_to_pixbuf(svg_from_file(
                        "%s/images/palettevshift.svg" % (self.path)))))
        self.palette_button[3].name = _('shift')
        self.palette_button[4].name = _('shift')
        self.palette_button[3].type = 'palette'
        self.palette_button[4].type = 'palette'
        self.palette_button[3].hide()
        self.palette_button[4].hide()

    def _create_proto_blocks(self, n):
        ''' Create the protoblocks that will populate a palette. '''
        # Reload the palette, but reuse the existing blocks
        # If a block doesn't exist, add it

        if not n < len(self.palettes):
            debug_output(
                '_create_proto_blocks: palette index %d is out of range' % (n),
                self.running_sugar)
            return

        for blk in self.palettes[n]:
            blk.spr.hide()
        old_blocks = self.palettes[n][:]
        self.palettes[n] = []
        for name in palette_blocks[n]:
            found_block = False
            for oblk in old_blocks:
                if oblk.name == name:
                    self.palettes[n].append(oblk)
                    found_block = True
                    break
            if not found_block:
                self.palettes[n].append(Block(
                        self.block_list, self.sprite_list, name, 0, 0,
                        'proto', [], PALETTE_SCALE))
                if name in hidden_proto_blocks:
                    self.palettes[n][-1].set_visibility(False)
                else:
                    if hasattr(self.palettes[n][-1].spr, 'set_layer'):
                        self.palettes[n][-1].spr.set_layer(PROTO_LAYER)
                        self.palettes[n][-1].unhighlight()
                    else:
                        debug_output('WARNING: block sprite is None' % (
                                self.palettes[n][-1].name), self.running_sugar)

            # Some proto blocks get a skin.
            if name in block_styles['box-style-media']:
                self._proto_skin(name + 'small', n, -1)
            elif name[:8] == 'template':  # Deprecated
                self._proto_skin(name[8:], n, -1)
            elif name[:7] == 'picture':  # Deprecated
                self._proto_skin(name[7:], n, -1)
            elif name in PYTHON_SKIN:
                self._proto_skin('pythonsmall', n, -1)
        return

    def _hide_toolbar_palette(self):
        ''' Hide the toolbar palettes '''
        self._hide_previous_palette()
        if not self.running_sugar or not self.activity.has_toolbarbox:
            # Hide the selectors
            for i in range(len(palette_blocks)):
                self.selectors[i].hide()
        elif self.selected_palette is not None and \
             not self.activity.has_toolbarbox:
            self.activity.palette_buttons[self.selected_palette].set_icon(
                palette_names[self.selected_palette] + 'off')

    def _hide_previous_palette(self, palette=None):
        ''' Hide just the previously viewed toolbar palette '''
        if palette is None:
            palette = self.previous_palette
        # Hide previously selected palette
        if palette is not None:
            if not palette < len(self.palettes):
                debug_output(
                    '_hide_previous_palette: index %d is out of range' % \
                        (palette), self.running_sugar)
                return
            for proto in self.palettes[palette]:
                proto.spr.hide()
            if self.palette_sprs[palette][self.orientation] is not None:
                self.palette_sprs[palette][self.orientation].hide()
            if not self.running_sugar or not self.activity.has_toolbarbox:
                self.selectors[palette].set_shape(
                    self.selector_shapes[palette][0])
            elif palette is not None and palette != self.selected_palette \
                 and not self.activity.has_toolbarbox:
                    self.activity.palette_buttons[palette].set_icon(
                        palette_names[palette] + 'off')
            if palette == palette_names.index('trash'):
                for blk in self.trash_stack:
                    for gblk in find_group(blk):
                        gblk.spr.hide()

    def _horizontal_layout(self, x, y, blocks):
        ''' Position prototypes in a horizontal palette. '''
        max_w = 0
        for blk in blocks:
            if not blk.get_visibility():
                continue
            w, h = self._width_and_height(blk)
            if y + h > PALETTE_HEIGHT + self.toolbar_offset:
                x += int(max_w + 3)
                y = self.toolbar_offset + 3
                max_w = 0
            (bx, by) = blk.spr.get_xy()
            dx = x - bx
            dy = y - by
            for g in find_group(blk):
                g.spr.move_relative((int(dx), int(dy)))
                g.spr.save_xy = g.spr.get_xy()
                if self.running_sugar and not self.hw in [XO1]:
                    g.spr.move_relative((self.activity.hadj_value,
                                         self.activity.vadj_value))
            y += int(h + 3)
            if w > max_w:
                max_w = w
        return x, y, max_w

    def _vertical_layout(self, x, y, blocks):
        ''' Position prototypes in a vertical palette. '''
        row = []
        row_w = 0
        max_h = 0
        for blk in blocks:
            if not blk.get_visibility():
                continue
            w, h = self._width_and_height(blk)
            if x + w > PALETTE_WIDTH:
                # Recenter row.
                dx = int((PALETTE_WIDTH - row_w) / 2)
                for r in row:
                    for g in find_group(r):
                        g.spr.move_relative((dx, 0))
                        g.spr.save_xy = (g.spr.save_xy[0] + dx,
                                         g.spr.save_xy[1])
                row = []
                row_w = 0
                x = 4
                y += int(max_h + 3)
                max_h = 0
            row.append(blk)
            row_w += (4 + w)
            (bx, by) = blk.spr.get_xy()
            dx = int(x - bx)
            dy = int(y - by)
            for g in find_group(blk):
                g.spr.move_relative((dx, dy))
                g.spr.save_xy = g.spr.get_xy()
                if self.running_sugar and not self.hw in [XO1]:
                    g.spr.move_relative((self.activity.hadj_value,
                                         self.activity.vadj_value))
            x += int(w + 4)
            if h > max_h:
                max_h = h
        # Recenter last row.
        dx = int((PALETTE_WIDTH - row_w) / 2)
        for r in row:
            for g in find_group(r):
                g.spr.move_relative((dx, 0))
                g.spr.save_xy = (g.spr.save_xy[0] + dx, g.spr.save_xy[1])
        return x, y, max_h

    def _layout_palette(self, n, regenerate=False, show=True):
        ''' Layout prototypes in a palette. '''
        if n is not None:
            if self.orientation == HORIZONTAL_PALETTE:
                x, y = 20, self.toolbar_offset + 5
                x, y, max_w = self._horizontal_layout(x, y, self.palettes[n])
                if n == palette_names.index('trash'):
                    x, y, max_w = self._horizontal_layout(x + max_w, y,
                                                          self.trash_stack)
                w = x + max_w + 25
                self._make_palette_spr(n, 0, self.toolbar_offset,
                                       w, PALETTE_HEIGHT, regenerate)
                if show:
                    self.palette_button[2].move((w - 20, self.toolbar_offset))
            else:
                x, y = 5, self.toolbar_offset + 15
                x, y, max_h = self._vertical_layout(x, y, self.palettes[n])
                if n == palette_names.index('trash'):
                    x, y, max_h = self._vertical_layout(x, y + max_h,
                                                        self.trash_stack)
                h = y + max_h + 25 - self.toolbar_offset
                self._make_palette_spr(n, 0, self.toolbar_offset,
                                       PALETTE_WIDTH, h, regenerate)
                if show:
                    self.palette_button[2].move((PALETTE_WIDTH - 20,
                                                 self.toolbar_offset))
            if show:
                self.palette_button[2].save_xy = \
                    self.palette_button[2].get_xy()
                if self.running_sugar and not self.hw in [XO1]:
                    self.palette_button[2].move_relative(
                        (self.activity.hadj_value, self.activity.vadj_value))
                self.palette_sprs[n][self.orientation].set_layer(
                    CATEGORY_LAYER)
                self._display_palette_shift_button(n)

    def _make_palette_spr(self, n, x, y, w, h, regenerate=False):
        ''' Make the background for the palette. '''
        if regenerate and not self.palette_sprs[n][self.orientation] is None:
            self.palette_sprs[n][self.orientation].hide()
            self.palette_sprs[n][self.orientation] = None
        if self.palette_sprs[n][self.orientation] is None:
            svg = SVG()
            self.palette_sprs[n][self.orientation] = \
                Sprite(self.sprite_list, x, y, svg_str_to_pixbuf(
                    svg.palette(w, h)))
            self.palette_sprs[n][self.orientation].save_xy = (x, y)
            if self.running_sugar and not self.hw in [XO1]:
                self.palette_sprs[n][self.orientation].move_relative(
                    (self.activity.hadj_value, self.activity.vadj_value))
            if self.orientation == 0 and w > self.width:
                self.palette_sprs[n][self.orientation].type = \
                    'category-shift-horizontal'
            elif self.orientation == 1 and h > self.height - ICON_SIZE:
                self.palette_sprs[n][self.orientation].type = \
                    'category-shift-vertical'
            else:
                self.palette_sprs[n][self.orientation].type = 'category'
            if n == palette_names.index('trash'):
                svg = SVG()
                self.palette_sprs[n][self.orientation].set_shape(
                    svg_str_to_pixbuf(svg.palette(w, h)))

    def _buttonpress_cb(self, win, event):
        ''' Button press '''
        self.window.grab_focus()
        x, y = xy(event)
        self.mouse_flag = 1
        self.mouse_x = x
        self.mouse_y = y
        self.button_press(event.get_state() & gtk.gdk.CONTROL_MASK, x, y)
        return True

    def button_press(self, mask, x, y):
        self.block_operation = 'click'

        # Find out what was clicked
        spr = self.sprite_list.find_sprite((x, y))

        # Unselect things that may have been selected earlier
        if self.selected_blk is not None:
            if self._action_name(self.selected_blk, hat=True):
                if self.selected_blk.values[0] == _('action'):
                    self._new_stack_block(self.selected_blk.spr.labels[0])
                self._update_action_names(self.selected_blk.spr.labels[0])
            elif self._box_name(self.selected_blk, storein=True):
                if self.selected_blk.values[0] == _('my box'):
                    self._new_storein_block(self.selected_blk.spr.labels[0])
                    self._new_box_block(self.selected_blk.spr.labels[0])
                self._update_storein_names(self.selected_blk.spr.labels[0])
                self._update_box_names(self.selected_blk.spr.labels[0])
            # Un-highlight any blocks in the stack
            grp = find_group(self.selected_blk)
            for blk in grp:
                if blk.status != 'collapsed':
                    blk.unhighlight()
            self._unselect_block()
            if self.running_sugar and self._sharing and \
               hasattr(self.activity, 'share_button'):
                self.activity.share_button.set_tooltip(
                    _('Select blocks to share'))
        self.selected_turtle = None

        # Almost always hide the status layer on a click
        if self._autohide_shape and self.status_spr is not None:
            self.status_spr.hide()
        elif spr == self.status_spr:
            self.status_spr.hide()
            self._autohide_shape = True

        self.dx = 0
        self.dy = 0
        self.dragging_canvas[1] = x
        self.dragging_canvas[2] = y
        if spr is None:
            if not self.running_blocks and not self.hw in (
                XO1, XO15, XO175, XO4):
                self.dragging_canvas[0] = True
            return True
        self.dragging_canvas[0] = False
        self.selected_spr = spr

        # From the sprite at x, y, look for a corresponding block
        blk = self.block_list.spr_to_block(spr)
        ''' If we were copying and didn't click on a block... '''
        if self.running_sugar and \
           (self.activity.copying or self.activity.sharing_blocks):
            if blk is None or blk.type != 'block':
                self.activity.restore_cursor()
        if blk is not None:
            if blk.type == 'block':
                self.selected_blk = blk
                self._block_pressed(x, y, blk)
            elif blk.type == 'trash':
                self._restore_from_trash(find_top_block(blk))
            elif blk.type == 'proto':
                if blk.name == 'restoreall':
                    self._restore_all_from_trash()
                elif blk.name == 'restore':
                    self.restore_latest_from_trash()
                elif blk.name == 'empty':
                    self._empty_trash()
                elif blk.name == 'trashall':
                    for b in self.just_blocks():
                        if b.type != 'trash':
                            if b.name == 'start':  # Don't trash start block
                                b1 = b.connections[-1]
                                if b1 is not None:
                                    b.connections[-1] = None
                                    b1.connections[0] = None
                                    self._put_in_trash(b1)
                            else:
                                self._put_in_trash(find_top_block(b))
                elif blk.name in MACROS:
                    self.new_macro(blk.name, x + 20, y + 20)
                else:
                    defaults = None
                    name = blk.name
                    # You can only have one instance of some blocks
                    if blk.name in ['start', 'hat1', 'hat2']:
                        if len(self.block_list.get_similar_blocks(
                                'block', blk.name)) > 0:
                            self.showlabel('dupstack')
                            return True
                    # We need to check to see if there is already a
                    # similarly default named stack
                    elif blk.name == 'hat':
                        similars = self.block_list.get_similar_blocks(
                            'block', blk.name)
                        # First look for a hat with _('action') as its label
                        found_the_action_block = False
                        bname = _('action')
                        if type(bname) == unicode:
                            bname = bname.encode('ascii', 'replace')
                        for sblk in similars:
                            cblk = sblk.connections[1]
                            if cblk is not None:
                                blabel = cblk.spr.labels[0]
                                if type(blabel) == unicode:
                                    blabel = blabel.encode('ascii', 'replace')
                                if bname == blabel:
                                    found_the_action_block = True
                        # If there is an action block in use, change the name
                        if len(similars) > 0 and found_the_action_block:
                            defaults = [_('action')]
                            if self._find_proto_name('stack', defaults[0]):
                                defaults[0] = increment_name(defaults[0])
                                while self._find_proto_name('stack_%s' % (
                                        defaults[0]), defaults[0]):
                                    defaults[0] = increment_name(defaults[0])
                                self._new_stack_block(defaults[0])
                    # If we autogenerated a stack prototype, we need
                    # to change its name from 'stack_foo' to 'stack'
                    elif blk.name[0:6] == 'stack_':
                        defaults = [blk.name[6:]]
                        name = 'stack'
                    # If we autogenerated a box prototype, we need
                    # to change its name from 'box_foo' to 'box'
                    elif blk.name[0:4] == 'box_':
                        defaults = [blk.name[4:]]
                        name = 'box'
                    # If we autogenerated a storein prototype, we need
                    # to change its name from 'storein_foo' to 'foo'
                    # and label[1] from foo to box
                    elif blk.name[0:8] == 'storein_':
                        defaults = [blk.name[8:], 100]
                        name = 'storein'
                    # storein my_box gets incremented
                    elif blk.name == 'storein':
                        defaults = [_('my box'), 100]
                        defaults[0] = increment_name(defaults[0])
                        while self._find_proto_name('storein_%s' % (
                                defaults[0]), defaults[0]):
                            defaults[0] = increment_name(defaults[0])
                        self._new_storein_block(defaults[0])
                        self._new_box_block(defaults[0])
                        name = 'storein'
                    # You cannot mix and match sensor blocks
                    elif blk.name in ['sound', 'volume', 'pitch']:
                        if len(self.block_list.get_similar_blocks(
                                'block', ['resistance', 'voltage',
                                          'resistance2', 'voltage2'])) > 0:
                            self.showlabel('incompatible')
                            return True
                    elif blk.name in ['resistance', 'voltage',
                                      'resistance2', 'voltage2']:
                        if len(self.block_list.get_similar_blocks(
                                'block', ['sound', 'volume', 'pitch'])) > 0:
                            self.showlabel('incompatible')
                            return True
                        if blk.name in ['resistance', 'resistance2']:
                            if len(self.block_list.get_similar_blocks(
                                    'block', ['voltage', 'voltage2'])) > 0:
                                self.showlabel('incompatible')
                                return True
                        elif blk.name in ['voltage', 'voltage2']:
                            if len(self.block_list.get_similar_blocks(
                                    'block', ['resistance',
                                              'resistance2'])) > 0:
                                self.showlabel('incompatible')
                                return True
                    blk.highlight()
                    self._new_block(name, x, y, defaults=defaults)
                    blk.unhighlight()
            return True

        # Next, look for a turtle
        t = self.turtles.spr_to_turtle(spr)
        if t is not None:
            # If turtle is shared, ignore click
            if self.remote_turtle(t.get_name()):
                return True
            self.selected_turtle = t
            self.canvas.set_turtle(self.turtles.get_turtle_key(t))
            self._turtle_pressed(x, y)
            return True

        # Finally, check for anything else
        if hasattr(spr, 'type'):
            if spr.type == 'selector':
                self._select_category(spr)
            elif spr.type in ['category', 'category-shift-horizontal',
                              'category-shift-vertical']:
                if hide_button_hit(spr, x, y):
                    self.hideshow_palette(False)
            elif spr.type == 'palette':
                if spr.name == _('next'):
                    i = self.selected_palette + 1
                    if i == len(palette_names):
                        i = 0
                    if not self.running_sugar or \
                       not self.activity.has_toolbarbox:
                        self._select_category(self.selectors[i])
                    else:
                        if self.selected_palette is not None and \
                           not self.activity.has_toolbarbox:
                            self.activity.palette_buttons[
                                self.selected_palette].set_icon(
                                palette_names[self.selected_palette] + 'off')
                        else:
                            # select radio button associated with this palette
                            self.activity.palette_buttons[i].set_active(True)
                        if not self.activity.has_toolbarbox:
                            self.activity.palette_buttons[i].set_icon(
                                palette_names[i] + 'on')
                        self.show_palette(i)
                elif spr.name == _('shift'):
                    self._shift_toolbar_palette(self.selected_palette)
                else:
                    self.orientation = 1 - self.orientation
                    self.palette_button[self.orientation].set_layer(TAB_LAYER)
                    self.palette_button[1 - self.orientation].hide()
                    self.palette_sprs[self.selected_palette][
                        1 - self.orientation].hide()
                    self._layout_palette(self.selected_palette)
                    self.show_palette(self.selected_palette)
            elif spr.type == 'toolbar':
                self._select_toolbar_button(spr)
            return True

    def _update_action_names(self, name):
        ''' change the label on action blocks of the same name '''
        if type(name) in [float, int]:
            return
        if type(name) == 'unicode':
            name = name.encode('ascii', 'replace')
        for blk in self.just_blocks():
            if self._action_name(blk, hat=False):
                if blk.spr.labels[0] == self._saved_action_name:
                    blk.spr.labels[0] = name
                    blk.values[0] = name
                if blk.status == 'collapsed':
                    blk.spr.hide()
                else:
                    blk.spr.set_layer(BLOCK_LAYER)
        self._update_proto_name(name, 'stack_%s' % (self._saved_action_name),
                                'stack_%s' % (name), 'basic-style-1arg')

    def _update_box_names(self, name):
        ''' change the label on box blocks of the same name '''
        if type(name) in [float, int]:
            return
        if type(name) == 'unicode':
            name = name.encode('ascii', 'replace')
        for blk in self.just_blocks():
            if self._box_name(blk, storein=False):
                if blk.spr.labels[0] == self._saved_box_name:
                    blk.spr.labels[0] = name
                    blk.values[0] = name
                if blk.status == 'collapsed':
                    blk.spr.hide()
                else:
                    blk.spr.set_layer(BLOCK_LAYER)
        self._update_proto_name(name, 'box_%s' % (self._saved_box_name),
                                'box_%s' % (name), 'number-style-1strarg')

    def _update_storein_names(self, name):
        ''' change the label on storin blocks of the same name '''
        if type(name) in [float, int]:
            return
        if type(name) == 'unicode':
            name = name.encode('ascii', 'replace')
        for blk in self.just_blocks():
            if self._box_name(blk, storein=True):
                if blk.spr.labels[0] == self._saved_box_name:
                    blk.spr.labels[0] = name
                    blk.values[0] = name
                if blk.status == 'collapsed':
                    blk.spr.hide()
                else:
                    blk.spr.set_layer(BLOCK_LAYER)
        self._update_proto_name(name, 'storein_%s' % (self._saved_box_name),
                                'storein_%s' % (name), 'basic-style-2arg',
                                label=1)

    def _update_proto_name(self, name, old, new, style, palette='blocks',
                           label=0):
        ''' Change the name of a proto block '''
        # The name change has to happen in multiple places:
        # (1) The proto block itself
        # (2) The list of block styles
        # (3) The list of proto blocks on the palette
        # (4) The list of block names
        if type(name) == unicode:
            name = name.encode('ascii', 'replace')
        if type(old) == unicode:
            old = old.encode('ascii', 'replace')
        if type(new) == unicode:
            new = new.encode('ascii', 'replace')

        if old == new:
            '''
            debug_output('update_proto_name: %s == %s' % (old, new),
                         self.running_sugar)
            '''
            return
        found = False

        if old in block_styles[style]:
            block_styles[style].remove(old)
        if not new in block_styles[style]:
            block_styles[style].append(new)

        if old in block_names:
            del block_names[old]
        if not new in block_names:
            block_names[new] = name

        i = palette_name_to_index(palette)
        for blk in self.palettes[i]:
            if blk.name == old:
                blk.name = new
                blk.spr.labels[label] = name
                blk.spr.set_layer(PROTO_LAYER)
                blk.resize()
                break  # Should only be one proto block by this name

        if old in palette_blocks[i]:
            palette_blocks[i].remove(old)
        if not new in palette_blocks[i]:
            palette_blocks[i].append(new)

        self.show_toolbar_palette(i, regenerate=True)

    def _action_name(self, blk, hat=False):
        ''' is this a label for an action block? '''
        if blk is None:
            return False
        if blk.name != 'string':  # Ignoring int/float names
            return False
        if blk.connections is None:
            return False
        if blk.connections[0] is None:
            return False
        if hat and blk.connections[0].name == 'hat':
            return True
        if not hat and blk.connections[0].name == 'stack':
            return True
        return False

    def _box_name(self, blk, storein=False):
        ''' is this a label for a storein block? '''
        if blk is None:
            return False
        if blk.name != 'string':  # Ignoring int names
            return False
        if blk.connections is None:
            return False
        if blk.connections[0] is None:
            return False
        if storein and blk.connections[0].name == 'storein':
            if blk.connections[0].connections[1] == blk:
                return True
            else:
                return False
        if not storein and blk.connections[0].name == 'box':
            return True
        return False

    def _select_category(self, spr):
        ''' Select a category from the toolbar '''
        i = self.selectors.index(spr)
        spr.set_shape(self.selector_shapes[i][1])
        if self.selected_selector is not None:
            j = self.selectors.index(self.selected_selector)
            if i == j:
                return
            self.selected_selector.set_shape(self.selector_shapes[j][0])
        self.previous_selector = self.selected_selector
        self.selected_selector = spr
        self.show_palette(i)

    def _select_toolbar_button(self, spr):
        ''' Select a toolbar button (Used when not running Sugar). '''
        if not hasattr(spr, 'name'):
            return
        if spr.name == 'run-fastoff':
            self.lc.trace = 0
            self.hideblocks()
            self.display_coordinates(clear=True)
            self.run_button(0)
        elif spr.name == 'run-slowoff':
            self.lc.trace = 1
            self.showblocks()
            self.run_button(3)
        elif spr.name == 'stopiton':
            self.stop_button()
            self.display_coordinates()
            self.showblocks()
            self.toolbar_shapes['stopiton'].hide()
        elif spr.name == 'eraseron':
            self.eraser_button()
        elif spr.name == 'hideshowoff':
            self.hideshow_button()

    def _put_in_trash(self, blk, x=0, y=0):
        ''' Put a group of blocks into the trash. '''
        self.trash_stack.append(blk)
        group = find_group(blk)
        for gblk in group:
            gblk.type = 'trash'
            gblk.rescale(self.trash_scale)
        blk.spr.move((x, y))
        for gblk in group:
            self._adjust_dock_positions(gblk)

        # And resize any skins.
        for gblk in group:
            if gblk.name in BLOCKS_WITH_SKIN:
                self._resize_skin(gblk)

        if self.selected_palette != palette_names.index('trash'):
            for gblk in group:
                gblk.spr.hide()

        # If there was a named hat or storein, remove it from the
        # proto palette, the palette name list, the block name list,
        # and the style list
        for gblk in group:
            if (gblk.name == 'hat' or gblk.name == 'storein') and \
               gblk.connections is not None and \
               gblk.connections[1] is not None and \
               gblk.connections[1].name == 'string':
                if gblk.name == 'hat':
                    self._remove_palette_blocks(
                        'stack_%s' % gblk.connections[1].values[0],
                        'basic-style-1arg')
                else:  # Only if it was the only one 
                    remove = True
                    similars = self.block_list.get_similar_blocks(
                        'block', 'storein')
                    for blk in similars:
                        if blk.connections is not None and \
                           blk.connections[1] is not None and \
                           blk.connections[1].name == 'string':
                            if blk.connections[1].values[0] == \
                               gblk.connections[1].values[0]:
                                remove = False
                    similars = self.block_list.get_similar_blocks(
                        'block', 'box')
                    for blk in similars:
                        if blk.connections is not None and \
                           blk.connections[1] is not None and \
                           blk.connections[1].name == 'string':
                            if blk.connections[1].values[0] == \
                               gblk.connections[1].values[0]:
                                remove = False
                    if remove:
                        self._remove_palette_blocks(
                            'box_%s' % gblk.connections[1].values[0],
                            'number-style-1strarg')
                        self._remove_palette_blocks(
                            'storein_%s' % gblk.connections[1].values[0],
                            'basic-style-2arg')

    def _remove_palette_blocks(self, name, style, palette='blocks'):
        ''' Remove blocks from palette and block, style lists '''
        i = palette_name_to_index('blocks')
        if name in palette_blocks[i]:
            palette_blocks[i].remove(name)
            for blk in self.palettes[i]:
                if blk.name == name:
                    blk.spr.hide()
                    self.palettes[i].remove(blk)
            self.show_toolbar_palette(i, regenerate=True)
        if name in block_styles[style]:
            block_styles[style].remove(name)
        if name in block_names:
            del block_names[name]

    def _restore_all_from_trash(self):
        ''' Restore all the blocks in the trash can. '''
        for blk in self.block_list.list:
            if blk.type == 'trash':
                self._restore_from_trash(blk)

    def restore_latest_from_trash(self):
        ''' Restore most recent blocks from the trash can. '''
        if len(self.trash_stack) == 0:
            return
        self._restore_from_trash(self.trash_stack[len(self.trash_stack) - 1])

    def _restore_from_trash(self, blk):
        group = find_group(blk)

        for gblk in group:
            if gblk.name == 'sandwichclampcollapsed':
                restore_clamp(gblk)
                self.resize_parent_clamps(gblk)

        for gblk in group:
            gblk.rescale(self.block_scale)
            gblk.spr.set_layer(BLOCK_LAYER)
            x, y = gblk.spr.get_xy()
            if self.orientation == 0:
                gblk.spr.move((x, y + PALETTE_HEIGHT + self.toolbar_offset))
            else:
                gblk.spr.move((x + PALETTE_WIDTH, y))
            gblk.type = 'block'

        for gblk in group:
            self._adjust_dock_positions(gblk)

        # And resize any skins.
        for gblk in group:
            if gblk.name in BLOCKS_WITH_SKIN:
                self._resize_skin(gblk)

        self.trash_stack.remove(blk)

    def _empty_trash(self):
        ''' Permanently remove all blocks presently in the trash can. '''
        for blk in self.block_list.list:
            if blk.type == 'trash':
                blk.type = 'deleted'
                blk.spr.hide()
        self.trash_stack = []

    def _in_the_trash(self, x, y):
        ''' Is x, y over a palette? '''
        if self.selected_palette is not None and \
           self.palette_sprs[self.selected_palette][self.orientation].hit(
            (x, y)):
            return True
        return False

    def _block_pressed(self, x, y, blk):
        ''' Block pressed '''
        if blk is not None:
            blk.highlight()
            self._disconnect(blk)
            self.drag_group = find_group(blk)
            (sx, sy) = blk.spr.get_xy()
            self.drag_pos = x - sx, y - sy
            for blk in self.drag_group:
                if blk.status != 'collapsed':
                    blk.spr.set_layer(TOP_LAYER)
            if self.running_sugar and \
               (self.activity.copying or self.activity.sharing_blocks):
                for blk in self.drag_group:
                    if blk.status != 'collapsed':
                        blk.highlight()
                self.block_operation = 'copying'
                if self.activity.copying:
                    self.activity.send_to_clipboard()
                else:
                    self.activity.share_blocks()
            if self.running_sugar and self._sharing and \
               hasattr(self.activity, 'share_button'):
                self.activity.share_button.set_tooltip(
                    _('Share selected blocks'))
            if len(blk.spr.labels) > 0:
                self._saved_string = blk.spr.labels[0]
                self._saved_action_name = self._saved_string
                self._saved_box_name = self._saved_string
            else:
                self._saved_string = ''

    def _unselect_block(self):
        ''' Unselect block '''
        # After unselecting a 'number' block, we need to check its value
        if self.selected_blk is None:
            return
        if self.selected_blk.name == 'number':
            if self._text_to_check:
                self._test_number()
        elif self.selected_blk.name == 'string':
            if self._text_to_check:
                self._test_string()
        self._text_to_check = False
        if self._action_name(self.selected_blk, hat=True):
            if self._saved_action_name == _('action'):
                self._new_stack_block(self.selected_blk.spr.labels[0])
            self._update_action_names(self.selected_blk.spr.labels[0])
        elif self._box_name(self.selected_blk, storein=True):
            if self._saved_box_name == _('my box'):
                self._new_storein_block(self.selected_blk.spr.labels[0])
                self._new_box_block(self.selected_blk.spr.labels[0])
            self._update_storein_names(self.selected_blk.spr.labels[0])
            self._update_box_names(self.selected_blk.spr.labels[0])
        self.selected_blk.unhighlight()
        self.selected_blk = None

    def _new_block(self, name, x, y, defaults=None):
        ''' Make a new block. '''
        x_pos = x - 20
        y_pos = y - 20
        if name in content_blocks:
            if defaults == None:
                defaults = default_values[name]
            newblk = Block(self.block_list, self.sprite_list, name, x_pos,
                           y_pos, 'block', defaults, self.block_scale)
        else:
            newblk = Block(self.block_list, self.sprite_list, name, x_pos,
                           y_pos, 'block', [], self.block_scale)

        # Add a 'skin' to some blocks
        if name in PYTHON_SKIN:
            if self.nop == 'pythonloaded':
                self._block_skin('pythonon', newblk)
            else:
                self._block_skin('pythonoff', newblk)
        elif name in block_styles['box-style-media']:
            if name in EXPAND_SKIN:
                if newblk.ex == 0:
                    newblk.expand_in_x(EXPAND_SKIN[name][0])
                if newblk.ey == 0:
                    newblk.expand_in_y(EXPAND_SKIN[name][1])
            self._block_skin(name + 'off', newblk)

        newspr = newblk.spr
        newspr.set_layer(TOP_LAYER)
        self.drag_pos = 20, 20
        newblk.connections = [None] * len(newblk.docks)
        if newblk.name in default_values:
            if defaults == None:
                defaults = default_values[newblk.name]
            for i, argvalue in enumerate(defaults):
                # skip the first dock position since it is always a connector
                dock = newblk.docks[i + 1]
                argname = dock[0]
                if argname == 'unavailable':
                    continue
                if argname == 'media':
                    argname = 'journal'
                elif argname == 'number' and \
                     (type(argvalue) is str or type(argvalue) is unicode):
                    argname = 'string'
                elif argname == 'string' and \
                     name in block_styles['number-style-1strarg'] and \
                     type(argvalue) in [int, float]:
                    argname = 'number'
                elif argname == 'bool':
                    argname = argvalue
                elif argname == 'flow':
                    argname = argvalue
                (sx, sy) = newspr.get_xy()
                if argname is not None:
                    if argname in content_blocks:
                        argblk = Block(self.block_list, self.sprite_list,
                                       argname, 0, 0, 'block', [argvalue],
                                       self.block_scale)
                    else:
                        argblk = Block(self.block_list, self.sprite_list,
                                       argname, 0, 0, 'block', [],
                                       self.block_scale)
                    argdock = argblk.docks[0]
                    nx = sx + dock[2] - argdock[2]
                    ny = sy + dock[3] - argdock[3]
                    if argname == 'journal':
                        self._block_skin('journaloff', argblk)
                    argblk.spr.move((nx, ny))
                    argblk.spr.set_layer(TOP_LAYER)
                    argblk.connections = [newblk, None]
                    newblk.connections[i + 1] = argblk
        self.drag_group = find_group(newblk)
        self.block_operation = 'new'
        if len(newblk.spr.labels) > 0 and newblk.spr.labels[0] is not None \
                and newblk.name not in ['', 'number', 'string']:
            if len(self.used_block_list) > 0:
                self.used_block_list.append(', ')
            if newblk.name in special_names:
                self.used_block_list.append(special_names[newblk.name])
            elif newblk.spr.labels[0] not in self.used_block_list:
                self.used_block_list.append(newblk.spr.labels[0])

    def new_macro(self, name, x, y):
        ''' Create a "macro" (predefined stack of blocks). '''
        macro = MACROS[name]
        macro[0][2] = x
        macro[0][3] = y
        top = self.process_data(macro)
        self.block_operation = 'new'
        self.drag_group = find_group(top)

    def process_data(self, block_data, offset=0):
        ''' Process block_data (from a macro, a file, or the clipboard). '''
        self._process_block_data = []
        for blk in block_data:
            if not self._found_a_turtle(blk):
                self._process_block_data.append(
                    [blk[0], blk[1], blk[2], blk[3], blk[4]])
        self._extra_block_data = []
        # Create the blocks (or turtle).
        blocks = []
        for i, blk in enumerate(self._process_block_data):
            if not self._found_a_turtle(blk):
                newblk = self.load_block(blk, offset)
                if newblk is not None:
                    blocks.append(newblk)
                    if newblk.spr is not None:
                        newblk.spr.set_layer(TOP_LAYER)
                else:
                    blocks.append(None)
        # Some extra blocks may have been added by load_block
        for blk in self._extra_block_data:
            self._process_block_data.append(blk)
            newblk = self.load_block(blk, offset)
            if newblk is not None:
                blocks.append(newblk)
                if newblk.spr is not None:
                    newblk.spr.set_layer(TOP_LAYER)

        # Make the connections.
        for i, blk in enumerate(blocks):
            if blk is None:
                continue
            cons = []
            # Normally, it is simply a matter of copying the connections.
            if blk.connections is None:
                if self._process_block_data[i][4] is not None:
                    for c in self._process_block_data[i][4]:
                        if c is None or c > (len(blocks) - 1):
                            cons.append(None)
                        else:
                            cons.append(blocks[c])
                else:
                    debug_output("connection error %s" % (
                            str(self._process_block_data[i])),
                                 self.running_sugar)
                    cons.append(None)
            elif blk.connections == 'check':
                # Convert old-style boolean and arithmetic blocks
                cons.append(None)  # Add an extra connection.
                for c in self._process_block_data[i][4]:
                    if c is None:
                        cons.append(None)
                    else:
                        cons.append(blocks[c])
                # If the boolean op was connected, readjust the plumbing.
                if blk.name in block_styles['boolean-style']:
                    if self._process_block_data[i][4][0] is not None:
                        c = self._process_block_data[i][4][0]
                        cons[0] = blocks[self._process_block_data[c][4][0]]
                        c0 = self._process_block_data[c][4][0]
                        for j, cj in enumerate(self._process_block_data[c0][4]):
                            if cj == c:
                                blocks[c0].connections[j] = blk
                        if c < i:
                            blocks[c].connections[0] = blk
                            blocks[c].connections[3] = None
                        else:
                            # Connection was to a block we haven't seen yet.
                            debug_output("Warning: dock to the future",
                                         self.running_sugar)
                else:
                    if self._process_block_data[i][4][0] is not None:
                        c = self._process_block_data[i][4][0]
                        cons[0] = blocks[self._process_block_data[c][4][0]]
                        c0 = self._process_block_data[c][4][0]
                        for j, cj in enumerate(self._process_block_data[c0][4]):
                            if cj == c:
                                blocks[c0].connections[j] = blk
                        if c < i:
                            blocks[c].connections[0] = blk
                            blocks[c].connections[1] = None
                        else:
                            # Connection was to a block we haven't seen yet.
                            debug_output("Warning: dock to the future",
                                         self.running_sugar)
            else:
                debug_output("Warning: unknown connection state %s" % \
                                  (str(blk.connections)),
                             self.running_sugar)
            blk.connections = cons[:]

        # Block sizes and shapes may have changed.
        for blk in blocks:
            if blk is None:
                continue
            self._adjust_dock_positions(blk)

        # Look for any stacks that need to be collapsed
        for blk in blocks:
            if blk is None:
                continue
            if blk.name == 'sandwichclampcollapsed':
                collapse_clamp(blk, False)

        # process in reverse order
        for i in range(len(blocks)):
            blk = blocks[-i - 1]
            if blk is None:
                continue
            if blk.name in EXPANDABLE_FLOW:
                if blk.name in block_styles['clamp-style-1arg'] or\
                   blk.name in block_styles['clamp-style-boolean']:
                    if blk.connections[2] is not None:
                        self._resize_clamp(blk, blk.connections[2])
                elif blk.name in block_styles['clamp-style']:
                    if blk.connections[1] is not None:
                        self._resize_clamp(blk, blk.connections[1])
                elif blk.name in block_styles['clamp-style-else']:
                    if blk.connections[2] is not None:
                        self._resize_clamp(blk, blk.connections[2], dockn=2)
                    if blk.connections[3] is not None:
                        self._resize_clamp(blk, blk.connections[3], dockn=3)

        # Eliminate None blocks from the block list
        blocks_copy = []
        for blk in blocks:
            if blk is not None:
                blocks_copy.append(blk)
        blocks = blocks_copy[:]

        # Resize blocks to current scale
        if self.interactive_mode:
            self.resize_blocks(blocks)

        if len(blocks) > 0:
            return blocks[0]
        else:
            return None

    def _adjust_dock_positions(self, blk):
        ''' Adjust the dock x, y positions '''
        if not self.interactive_mode:
            return
        (sx, sy) = blk.spr.get_xy()
        for i, c in enumerate(blk.connections):
            if i > 0 and c is not None and i < len(blk.docks):
                bdock = blk.docks[i]
                for j in range(len(c.docks)):
                    if j < len(c.connections) and c.connections[j] == blk:
                        cdock = c.docks[j]
                        nx = sx + bdock[2] - cdock[2]
                        ny = sy + bdock[3] - cdock[3]
                        c.spr.move((nx, ny))
                self._adjust_dock_positions(c)

    def _turtle_pressed(self, x, y):
        (tx, ty) = self.selected_turtle.get_xy()
        w = self.selected_turtle.spr.rect.width / 2
        h = self.selected_turtle.spr.rect.height / 2
        dx = x - tx - w
        dy = y - ty - h
        # if x, y is near the edge, rotate
        if not hasattr(self.lc, 'value_blocks'):
            self.lc.find_value_blocks()
        self.lc.update_values = True
        if (dx * dx) + (dy * dy) > ((w * w) + (h * h)) / 6:
            self.drag_turtle = ('turn',
                self.canvas.heading - atan2(dy, dx) / DEGTOR, 0)
        else:
            self.drag_turtle = ('move', x - tx, y - ty)

    def _move_cb(self, win, event):
        x, y = xy(event)
        self.mouse_x = x
        self.mouse_y = y
        self._mouse_move(x, y)
        return True

    def _share_mouse_move(self):
        ''' Share turtle movement and rotation after button up '''
        if self.sharing():
            nick = self.turtle_movement_to_share.get_name()
            self.send_event("r|%s" % (
                    data_to_string([nick, round_int(self.canvas.heading)])))
            if self.canvas.pendown:
                self.send_event('p|%s' % (data_to_string([nick, False])))
                put_pen_back_down = True
            else:
                put_pen_back_down = False
            self.send_event("x|%s" % (
                    data_to_string([nick, [round_int(self.canvas.xcor),
                                           round_int(self.canvas.ycor)]])))
            if put_pen_back_down:
                self.send_event('p|%s' % (data_to_string([nick, True])))
        self.turtle_movement_to_share = None

    def _mouse_move(self, x, y):
        ''' Process mouse movements '''

        if self.running_sugar and self.dragging_canvas[0]:
            dx = self.dragging_canvas[1] - x
            dy = self.dragging_canvas[2] - y
            self.dragging_canvas[1] = x
            self.dragging_canvas[2] = y
            self.activity.adjust_sw(dx, dy)
            return True

        self.block_operation = 'move'

        # First, check to see if we are dragging or rotating a turtle.
        if self.selected_turtle is not None:
            dtype, dragx, dragy = self.drag_turtle
            (sx, sy) = self.selected_turtle.get_xy()
            # self.canvas.set_turtle(self.selected_turtle.get_name())
            if dtype == 'move':
                dx = x - dragx - sx + self.selected_turtle.spr.rect.width / 2
                dy = y - dragy - sy + self.selected_turtle.spr.rect.height / 2
                self.selected_turtle.spr.set_layer(TOP_LAYER)
                tx, ty = self.canvas.screen_to_turtle_coordinates(sx + dx,
                                                                  sy + dy)
                if self.canvas.pendown:
                    self.canvas.setpen(False)
                    self.canvas.setxy(tx, ty, share=False)
                    self.canvas.setpen(True)
                else:
                    self.canvas.setxy(tx, ty, share=False)
                self.lc.update_label_value('xcor',
                                           self.canvas.xcor / self.coord_scale)
                self.lc.update_label_value('ycor',
                                           self.canvas.ycor / self.coord_scale)
            else:
                dx = x - sx - self.selected_turtle.spr.rect.width / 2
                dy = y - sy - self.selected_turtle.spr.rect.height / 2
                self.canvas.seth(int(dragx + atan2(dy, dx) / DEGTOR + 5) / \
                                     10 * 10, share=False)
                self.lc.update_label_value('heading', self.canvas.heading)
            self.turtle_movement_to_share = self.selected_turtle

        # If we are hoving, show popup help.
        elif self.drag_group is None:
            self._show_popup(x, y)
            return

        # If we have a stack of blocks selected, move them.
        elif self.drag_group[0] is not None:
            blk = self.drag_group[0]

            self.selected_spr = blk.spr
            dragx, dragy = self.drag_pos
            (sx, sy) = blk.spr.get_xy()
            dx = x - dragx - sx
            dy = y - dragy - sy

            # Take no action if there was a move of 0, 0.
            if dx == 0 and dy == 0:
                return

            self.drag_group = find_group(blk)

            # Prevent blocks from ending up with a negative x or y
            for blk in self.drag_group:
                (bx, by) = blk.spr.get_xy()
                if bx + dx < 0:
                    dx = -bx
                if by + dy < 0:
                    dy = -by

            # Calculate a bounding box and only invalidate once.
            minx = blk.spr.rect.x
            miny = blk.spr.rect.y
            maxx = blk.spr.rect.x + blk.spr.rect.width
            maxy = blk.spr.rect.y + blk.spr.rect.height

            for blk in self.drag_group:
                if blk.spr.rect.x < minx:
                    minx = blk.spr.rect.x
                if blk.spr.rect.x + blk.spr.rect.width > maxx:
                    maxx = blk.spr.rect.x + blk.spr.rect.width
                if blk.spr.rect.y < miny:
                    miny = blk.spr.rect.y
                if blk.spr.rect.y + blk.spr.rect.height > maxy:
                    maxy = blk.spr.rect.y + blk.spr.rect.height
                blk.spr.rect.x += dx
                blk.spr.rect.y += dy

            if dx < 0:
                minx += dx
            else:
                maxx += dx
            if dy < 0:
                miny += dy
            else:
                maxy += dy

            self.rect.x = minx
            self.rect.y = miny
            self.rect.width = maxx - minx
            self.rect.height = maxy - miny
            self.window.queue_draw_area(self.rect.x,
                                        self.rect.y,
                                        self.rect.width,
                                        self.rect.height)
        self.dx += dx
        self.dy += dy

    def _show_popup(self, x, y):
        ''' Let's help our users by displaying a little help. '''
        spr = self.sprite_list.find_sprite((x, y))
        blk = self.block_list.spr_to_block(spr)
        if spr and blk is not None:
            if self.timeout_tag[0] == 0:
                self.timeout_tag[0] = self._do_show_popup(blk.name)
                self.selected_spr = spr
            else:
                if self.timeout_tag[0] > 0:
                    try:
                        gobject.source_remove(self.timeout_tag[0])
                        self.timeout_tag[0] = 0
                    except:
                        self.timeout_tag[0] = 0
        elif spr and hasattr(spr, 'type') and (spr.type == 'selector' or \
                                               spr.type == 'palette' or \
                                               spr.type == 'toolbar'):
            if self.timeout_tag[0] == 0 and hasattr(spr, 'name'):
                self.timeout_tag[0] = self._do_show_popup(spr.name)
                self.selected_spr = spr
            else:
                if self.timeout_tag[0] > 0:
                    try:
                        gobject.source_remove(self.timeout_tag[0])
                        self.timeout_tag[0] = 0
                    except:
                        self.timeout_tag[0] = 0
        else:
            if self.timeout_tag[0] > 0:
                try:
                    gobject.source_remove(self.timeout_tag[0])
                    self.timeout_tag[0] = 0
                except:
                    self.timeout_tag[0] = 0

    def _do_show_popup(self, block_name):
        ''' Fetch the help text and display it.  '''
        if self.no_help:
            return 0
        if block_name in special_names:
            special_block_name = special_names[block_name]
        elif block_name in block_names:
            special_block_name = block_names[block_name][0]
        elif block_name in TOOLBAR_SHAPES:
            special_block_name = ''
        else:
            special_block_name = _(block_name)
        if block_name in help_strings:
            label = help_strings[block_name]
        else:
            label = special_block_name
        if self.last_label == label:
            return 0
        self.showlabel('help', label=label)
        self.last_label = label
        return 0

    def _buttonrelease_cb(self, win, event):
        ''' Button release '''
        x, y = xy(event)
        self.mouse_flag = 0
        self.mouse_x = x
        self.mouse_y = y
        self.button_release(x, y)
        if self.turtle_movement_to_share is not None:
            self._share_mouse_move()
        return True

    def button_release(self, x, y):
        if self.running_sugar and self.dragging_canvas[0]:
            self.dragging_canvas[0] = False
            self.dragging_canvas[1] = x
            self.dragging_canvas[2] = y
            self.activity.adjust_palette()
            return True

        # We may have been moving the turtle
        if self.selected_turtle is not None:
            (tx, ty) = self.selected_turtle.get_xy()
            k = self.turtles.get_turtle_key(self.selected_turtle)

            # Remove turtles by dragging them onto the trash palette.
            if self._in_the_trash(tx, ty):
                # If it is the default turtle, just recenter it.
                if k == self.default_turtle_name:
                    self._move_turtle(0, 0)
                    self.canvas.heading = 0
                    self.canvas.turn_turtle()
                    self.lc.update_label_value('heading', self.canvas.heading)
                else:
                    self.selected_turtle.hide()
                    self.turtles.remove_from_dict(k)
                    self.active_turtle = None
            else:
                self._move_turtle(
                    tx - self.canvas.width / 2. + \
                        self.active_turtle.spr.rect.width / 2.,
                    self.canvas.height / 2. - ty - \
                        self.active_turtle.spr.rect.height / 2.)
            self.selected_turtle = None
            if self.active_turtle is None:
                self.canvas.set_turtle(self.default_turtle_name)
            return

        # If we don't have a group of blocks, then there is nothing to do.
        if self.drag_group is None:
            return

        blk = self.drag_group[0]
        # Remove blocks by dragging them onto any palette.
        if self.block_operation == 'move' and self._in_the_trash(x, y):
            self._put_in_trash(blk, x, y)
            self.drag_group = None
            return

        # Pull a stack of new blocks off of the category palette.
        if self.block_operation == 'new':
            for gblk in self.drag_group:
                (bx, by) = gblk.spr.get_xy()
                if self.orientation == 0:
                    gblk.spr.move((bx + 20,
                                   by + PALETTE_HEIGHT + self.toolbar_offset))
                else:
                    gblk.spr.move((bx + PALETTE_WIDTH, by + 20))

        # Look to see if we can dock the current stack.
        self._snap_to_dock()
        for gblk in self.drag_group:
            if gblk.status != 'collapsed':
                gblk.spr.set_layer(BLOCK_LAYER)
        self.drag_group = None

        # Find the block we clicked on and process it.
        # Consider a very small move a click (for touch interfaces)
        if self.block_operation == 'click' or \
           (self.hw in [XO175, XO30, XO4] and \
            self.block_operation == 'move' and (
                abs(self.dx) < MOTION_THRESHOLD and \
                abs(self.dy < MOTION_THRESHOLD))):
            self._click_block(x, y)
        elif self.block_operation == 'copying':
            gobject.timeout_add(500, self._unhighlight_drag_group, blk)

    def _unhighlight_drag_group(self, blk):
            self.drag_group = find_group(blk)
            for gblk in self.drag_group:
                gblk.unhighlight()
            self.drag_group = None

    def remote_turtle(self, name):
        ''' Is this a remote turtle? '''
        if name == self.nick:
            return False
        if hasattr(self, 'remote_turtle_dictionary') and \
           name in self.remote_turtle_dictionary:
            return True
        return False

    def label_remote_turtle(self, name, colors=['#A0A0A0', '#C0C0C0']):
        ''' Add a label to remote turtles '''
        turtle = self.turtles.get_turtle(name)
        if turtle is not None:
            turtle.label_block = Block(self.block_list,
                                       self.sprite_list, 'turtle-label', 0, 0,
                                       'label', [], 2.0 / self.scale,
                                       colors)
            turtle.label_block.spr.set_label_attributes(12.0 / self.scale)
            if len(name) > 6:
                turtle.label_block.spr.set_label(name[0:4] + '…')
            else:
                turtle.label_block.spr.set_label(name)
            turtle.show()

    def _move_turtle(self, x, y):
        ''' Move the selected turtle to (x, y). '''
        self.canvas.xcor = x
        self.canvas.ycor = y
        self.canvas.move_turtle()
        if self.interactive_mode:
            self.display_coordinates()
        if self.running_sugar:
            self.selected_turtle.spr.set_layer(TURTLE_LAYER)
            self.lc.update_label_value('xcor',
                                       self.canvas.xcor / self.coord_scale)
            self.lc.update_label_value('ycor',
                                       self.canvas.ycor / self.coord_scale)

    def _click_block(self, x, y):
        ''' Click block: lots of special cases to handle... '''
        blk = self.block_list.spr_to_block(self.selected_spr)
        if blk is None:
            return
        self.selected_blk = blk

        if blk.name in ['string', 'number']:
            self._saved_string = blk.spr.labels[0]
            if not hasattr(self, '_text_entry'):
                self._text_entry = gtk.TextView()
                self._text_entry.set_justification(gtk.JUSTIFY_CENTER)
                self._text_buffer = self._text_entry.get_buffer()
                font_desc = pango.FontDescription('Sans')
                font_desc.set_size(
                    int(blk.font_size[0] * pango.SCALE * self.entry_scale))
                self._text_entry.modify_font(font_desc)
                self.activity.fixed.put(self._text_entry, 0, 0)
            self._text_entry.show()
            w = blk.spr.label_safe_width()
            if blk.name == 'string':
                count = self._saved_string.count(RETURN)
                self._text_buffer.set_text(
                    self._saved_string.replace(RETURN, '\12'))
                h = blk.spr.label_safe_height() * (count + 1)
            else:
                self._text_buffer.set_text(self._saved_string)
                h = blk.spr.label_safe_height()
            self._text_entry.set_size_request(w, h)
            bx, by = blk.spr.get_xy()
            if not self.running_sugar:
                by += self.activity.menu_height + 4  # FIXME: padding
            mx, my = blk.spr.label_left_top()
            self._text_entry.set_pixels_above_lines(my)
            bx -= int(self.activity.sw.get_hadjustment().get_value())
            by -= int(self.activity.sw.get_vadjustment().get_value())
            self.activity.fixed.move(self._text_entry, bx + mx, by + my * 2)
            self.activity.fixed.show()
            if blk.name == 'number':
                self._insert_text_id = self._text_buffer.connect(
                    'insert-text', self._insert_text_cb)
            self._focus_out_id = self._text_entry.connect(
                'focus-out-event', self._text_focus_out_cb)
            self._text_entry.grab_focus()

        elif blk.name in block_styles['box-style-media'] and \
             blk.name not in NO_IMPORT:
            self._import_from_journal(self.selected_blk)
            if blk.name == 'journal' and self.running_sugar:
                self._load_description_block(blk)

        elif blk.name == 'identity2' or blk.name == 'hspace':
            group = find_group(blk)
            if hide_button_hit(blk.spr, x, y):
                dx = -20
                blk.contract_in_x(-dx)
                # dx = blk.reset_x()
            elif show_button_hit(blk.spr, x, y):
                dx = 20
                blk.expand_in_x(dx)
            else:
                self._run_stack(blk)
                return
            for gblk in group:
                if gblk != blk:
                    gblk.spr.move_relative((dx * blk.scale, 0))

        elif blk.name == 'vspace':
            group = find_group(blk)
            if hide_button_hit(blk.spr, x, y):
                dy = -20
                blk.contract_in_y(-dy)
                # dy = blk.reset_y()
            elif show_button_hit(blk.spr, x, y):
                dy = 20
                blk.expand_in_y(dy)
            else:
                self._run_stack(blk)
                return
            for gblk in group:
                if gblk != blk:
                    gblk.spr.move_relative((0, dy * blk.scale))
            self._resize_parent_clamps(blk)

        elif blk.name in expandable_blocks:
            # Connection may be lost during expansion, so store it...
            blk0 = blk.connections[0]
            if blk0 is not None:
                dock0 = blk0.connections.index(blk)

            if hide_button_hit(blk.spr, x, y):
                dy = -20
                blk.contract_in_y(-dy)
                # dy = blk.reset_y()
            elif show_button_hit(blk.spr, x, y):
                dy = 20
                blk.expand_in_y(dy)
            else:
                self._run_stack(blk)
                return

            if blk.name in block_styles['boolean-style']:
                self._expand_boolean(blk, blk.connections[2], dy)
            else:
                self._expand_expandable(blk, blk.connections[1], dy)

            # and restore it...
            if blk0 is not None:
                blk.connections[0] = blk0
                blk0.connections[dock0] = blk
                self._cascade_expandable(blk)

            self._resize_parent_clamps(blk)

        elif blk.name in EXPANDABLE_ARGS or blk.name == 'nop':
            if show_button_hit(blk.spr, x, y):
                n = len(blk.connections)
                group = find_group(blk.connections[n - 1])
                if blk.name == 'myfunc1arg':
                    blk.spr.labels[1] = 'f(x, y)'
                    blk.spr.labels[2] = ' '
                    dy = blk.add_arg()
                    blk.primitive = 'myfunction2'
                    blk.name = 'myfunc2arg'
                elif blk.name == 'myfunc2arg':
                    blk.spr.labels[1] = 'f(x, y, z)'
                    dy = blk.add_arg(False)
                    blk.primitive = 'myfunction3'
                    blk.name = 'myfunc3arg'
                elif blk.name == 'userdefined':
                    dy = blk.add_arg()
                    blk.primitive = 'userdefined2'
                    blk.name = 'userdefined2args'
                    self._resize_skin(blk)
                elif blk.name == 'userdefined2args':
                    dy = blk.add_arg(False)
                    blk.primitive = 'userdefined3'
                    blk.name = 'userdefined3args'
                    self._resize_skin(blk)
                elif blk.name == 'loadblock':
                    dy = blk.add_arg()
                    blk.primitive = 'loadblock2'
                    blk.name = 'loadblock2arg'
                    self._resize_skin(blk)
                elif blk.name == 'loadblock2arg':
                    dy = blk.add_arg(False)
                    blk.primitive = 'loadblock3'
                    blk.name = 'loadblock3arg'
                    self._resize_skin(blk)
                else:
                    dy = blk.add_arg()
                for gblk in group:
                    gblk.spr.move_relative((0, dy))
                blk.connections.append(blk.connections[n - 1])
                argname = blk.docks[n - 1][0]
                argvalue = default_values[blk.name][len(
                        default_values[blk.name]) - 1]
                argblk = Block(self.block_list, self.sprite_list, argname,
                               0, 0, 'block', [argvalue], self.block_scale)
                argdock = argblk.docks[0]
                (bx, by) = blk.spr.get_xy()
                nx = bx + blk.docks[n - 1][2] - argdock[2]
                ny = by + blk.docks[n - 1][3] - argdock[3]
                argblk.spr.move((nx, ny))
                argblk.spr.set_layer(TOP_LAYER)
                argblk.connections = [blk, None]
                blk.connections[n - 1] = argblk
                if blk.name in block_styles['number-style-var-arg']:
                    self._cascade_expandable(blk)
                self._resize_parent_clamps(blk)
            elif blk.name in PYTHON_SKIN:
                self._import_py()
            else:
                self._run_stack(blk)
        elif blk.name == 'sandwichclampcollapsed':
            restore_clamp(blk)
            if blk.connections[1] is not None:
                self._resize_clamp(blk, blk.connections[1], 1)
            self._resize_parent_clamps(blk)
        elif blk.name == 'sandwichclamp':
            if hide_button_hit(blk.spr, x, y):
                collapse_clamp(blk, True)
                self._resize_parent_clamps(blk)
            else:
                self._run_stack(blk)
        else:
            self._run_stack(blk)

    def _resize_parent_clamps(self, blk):
        ''' If we changed size, we need to let any parent clamps know. '''
        nblk, dockn = self._expandable_flow_above(blk)
        while nblk is not None:
            self._resize_clamp(nblk, nblk.connections[dockn], dockn=dockn)
            nblk, dockn = self._expandable_flow_above(nblk)

    def _expand_boolean(self, blk, blk2, dy):
        ''' Expand a boolean blk if blk2 is too big to fit. '''
        group = find_group(blk2)
        for gblk in find_group(blk):
            if gblk not in group:
                gblk.spr.move_relative((0, -dy * blk.scale))

    def _expand_expandable(self, blk, blk2, dy):
        ''' Expand an expandable blk if blk2 is too big to fit. '''
        if blk2 is None:
            group = [blk]
        else:
            group = find_group(blk2)
            group.append(blk)
        for gblk in find_group(blk):
            if gblk not in group:
                gblk.spr.move_relative((0, dy * blk.scale))
        if blk.name in block_styles['compare-style'] or \
           blk.name in block_styles['compare-porch-style']:
            for gblk in find_group(blk):
                gblk.spr.move_relative((0, -dy * blk.scale))

    def _number_style(self, name):
        if name in block_styles['number-style']:
            return True
        if name in block_styles['number-style-porch']:
            return True
        if name in block_styles['number-style-block']:
            return True
        if name in block_styles['number-style-var-arg']:
            return True
        return False

    def _cascade_expandable(self, blk):
        ''' If expanding/shrinking a block, cascade. '''
        while self._number_style(blk.name):
            if blk.connections[0] is None:
                break
            if blk.connections[0].name in expandable_blocks:
                if blk.connections[0].connections.index(blk) != 1:
                    break
                blk = blk.connections[0]
                if blk.connections[1].name == 'myfunc2arg':
                    dy = 40 + blk.connections[1].ey - blk.ey
                elif blk.connections[1].name == 'myfunc3arg':
                    dy = 60 + blk.connections[1].ey - blk.ey
                else:
                    dy = 20 + blk.connections[1].ey - blk.ey
                blk.expand_in_y(dy)
                if dy != 0:
                    group = find_group(blk.connections[1])
                    group.append(blk)
                    for gblk in find_group(blk):
                        if gblk not in group:
                            gblk.spr.move_relative((0, dy * blk.scale))
                    if blk.name in block_styles['compare-style'] or \
                       blk.name in block_styles['compare-porch-style']:
                        for gblk in find_group(blk):
                            gblk.spr.move_relative((0, -dy * blk.scale))
            else:
                break

    def _run_stack(self, blk):
        ''' Run a stack of blocks. '''
        if not self.interactive_mode:
            # Test for forever block
            if len(self.block_list.get_similar_blocks('block', 'forever')) > 0:
                debug_output('WARNING: Projects with forever blocks \
may not terminate.', False)
        if self.status_spr is not None:
            self.status_spr.hide()
        self._autohide_shape = True
        if blk is None:
            return
        self.lc.find_value_blocks()  # Are there blocks to update?
        # Is there a savesvg block?
        if len(self.block_list.get_similar_blocks('block', 'savesvg')) > 0:
            if self.canvas.cr_svg is None:
                self.canvas.setup_svg_surface()
        self.running_blocks = True
        self._start_plugins()  # Let the plugins know we are running.
        top = find_top_block(blk)
        self.lc.run_blocks(top, self.just_blocks(), True)
        if self.interactive_mode:
            gobject.idle_add(self.lc.doevalstep)
        else:
            while self.lc.doevalstep():
                pass

    def _snap_to_dock(self):
        ''' Snap a block (selected_block) to the dock of another block
            (destination_block). '''
        selected_block = self.drag_group[0]
        best_destination = None
        d = SNAP_THRESHOLD
        self.inserting_block_mid_stack = False
        for selected_block_dockn in range(len(selected_block.docks)):
            for destination_block in self.just_blocks():
                # Don't link to a block that is hidden
                if destination_block.status == 'collapsed':
                    continue
                # Don't link to a block to which you're already connected
                if destination_block in self.drag_group:
                    continue
                # Check each dock of destination for a possible connection
                for destination_dockn in range(len(destination_block.docks)):
                    this_xy = self.dock_dx_dy(
                        destination_block, destination_dockn,
                        selected_block, selected_block_dockn)
                    if magnitude(this_xy) > d:
                        continue
                    d = magnitude(this_xy)
                    best_xy = this_xy
                    best_destination = destination_block
                    best_destination_dockn = destination_dockn
                    best_selected_block_dockn = selected_block_dockn
        if d < SNAP_THRESHOLD:
            # Some combinations of blocks are not valid
            if not arithmetic_check(selected_block, best_destination,
                                    best_selected_block_dockn,
                                    best_destination_dockn):
                return
            if not journal_check(selected_block, best_destination,
                                    best_selected_block_dockn,
                                    best_destination_dockn):
                return

            # Move the selected blocks into the docked position
            for blk in self.drag_group:
                (sx, sy) = blk.spr.get_xy()
                blk.spr.move((sx + best_xy[0], sy + best_xy[1]))

            blk_in_dock = best_destination.connections[best_destination_dockn]
            if self.inserting_block_mid_stack:
                # If there was already a block docked there, move it
                # to the bottom of the drag group.
                if blk_in_dock is not None and blk_in_dock != selected_block:
                    bot = find_bot_block(self.drag_group[0])
                    if bot is not None:
                        blk_in_dock.connections[0] = None
                        drag_group = find_group(blk_in_dock)
                        blk_in_dock.connections[0] = bot
                        bot.connections[-1] = blk_in_dock
                        dx = bot.spr.get_xy()[0] - \
                             self.drag_group[0].spr.get_xy()[0] + \
                             bot.docks[-1][2] - blk_in_dock.docks[0][2]
                        dy = bot.spr.get_xy()[1] - \
                             self.drag_group[0].spr.get_xy()[1] + \
                             bot.docks[-1][3] - blk_in_dock.docks[0][3]
                        # Move each sprite in the group associated
                        # with the block we are moving.
                        for gblk in drag_group:
                            gblk.spr.move_relative((dx, dy))
            else:
                # If there was already a block docked there, move it
                # to the trash.
                if blk_in_dock is not None and blk_in_dock != selected_block:
                    blk_in_dock.connections[0] = None
                    self._put_in_trash(blk_in_dock)

            # Note the connection in destination dock
            best_destination.connections[best_destination_dockn] = \
                selected_block

            # And in the selected block dock
            if selected_block.connections is not None:
                if best_selected_block_dockn < len(selected_block.connections):
                    selected_block.connections[best_selected_block_dockn] = \
                        best_destination

            # Are we renaming an action or variable?
            if best_destination.name in ['hat', 'storein'] and \
               selected_block.name == 'string' and best_destination_dockn == 1:
                name = selected_block.values[0]
                if best_destination.name == 'storein':
                    if not self._find_proto_name('storein_%s' % (name), name):
                        self._new_storein_block(name)
                    if not self._find_proto_name('box_%s' % (name), name):
                        self._new_box_block(name)
                else:  # 'hat'
                    # Check to see if it is unique...
                    unique = True
                    similars = self.block_list.get_similar_blocks(
                        'block', 'hat')
                    for blk in similars:
                        if blk == best_destination:
                            continue
                        if blk.connections is not None and \
                           blk.connections[1] is not None and \
                           blk.connections[1].name == 'string':
                            if blk.connections[1].values[0] == name: 
                                unique = False
                    if not unique:
                        while self._find_proto_name('stack_%s' % (name), name):
                            name = increment_name(name)
                        blk.connections[1].values[0] = name
                        blk.connections[1].spr.labels[0] = name
                        blk.resize()
                    self._new_stack_block(name)

            # Some destination blocks expand to accomodate large blocks
            if best_destination.name in block_styles['boolean-style']:
                if best_destination_dockn == 2 and \
                   (selected_block.name in block_styles['boolean-style'] or \
                    selected_block.name in block_styles['compare-style'] or \
                    selected_block.name in block_styles['compare-porch-style']
                    ):
                    dy = selected_block.ey - best_destination.ey
                    if selected_block.name in block_styles['boolean-style']:
                        # Even without expanding, boolean blocks are
                        # too large to fit in the lower dock position
                        dy += 45
                    best_destination.expand_in_y(dy)
                    self._expand_boolean(best_destination, selected_block, dy)
            elif best_destination.name in EXPANDABLE_FLOW:
                if best_destination.name in block_styles['clamp-style-1arg'] or\
                   best_destination.name in block_styles['clamp-style-boolean']:
                    if best_destination_dockn == 2:
                        self._resize_clamp(best_destination, self.drag_group[0])
                elif best_destination.name in block_styles['clamp-style'] or \
                     best_destination.name in block_styles[
                    'clamp-style-collapsible']:
                    if best_destination_dockn == 1:
                        self._resize_clamp(best_destination, self.drag_group[0])
                elif best_destination.name in block_styles['clamp-style-else']:
                    if best_destination_dockn == 2:
                        self._resize_clamp(
                            best_destination, self.drag_group[0], dockn=2)
                    elif best_destination_dockn == 3:
                        self._resize_clamp(
                            best_destination, self.drag_group[0], dockn=3)
            elif best_destination.name in expandable_blocks and \
                 best_destination_dockn == 1:
                dy = 0
                if (selected_block.name in expandable_blocks or
                    selected_block.name in block_styles[
                        'number-style-var-arg']):
                    if selected_block.name == 'myfunc2arg':
                        dy = 40 + selected_block.ey - best_destination.ey
                    elif selected_block.name == 'myfunc3arg':
                        dy = 60 + selected_block.ey - best_destination.ey
                    else:
                        dy = 20 + selected_block.ey - best_destination.ey
                    best_destination.expand_in_y(dy)
                else:
                    if best_destination.ey > 0:
                        dy = best_destination.reset_y()
                if dy != 0:
                    self._expand_expandable(
                        best_destination, selected_block, dy)
                self._cascade_expandable(best_destination)
        # If we are in an expandable flow, expand it...
        if best_destination is not None:
            self._resize_parent_clamps(best_destination)
        # Check for while nesting
        if best_destination is not None:
            while_blk = self._while_in_drag_group(self.drag_group[0])
            if while_blk is not None:
                self._check_while_nesting(best_destination,
                                          self.drag_group[0], while_blk)

    def _while_in_drag_group(self, blk):
        ''' Is there a contained while or until block? '''
        if blk.name in ['while', 'until']:
            return blk
        return find_blk_below(blk, ['while', 'until'])

    def _check_while_nesting(self, blk, dock_blk, while_blk):
        ''' Is there a containing while or until block? If so, swap them '''
        if blk.name in ['while', 'until']:
            if blk.connections[2] == dock_blk:
                self._swap_while_blocks(blk, while_blk)
        while blk.connections[-1] is not None:
            blk = blk.connections[-1]
            if blk.name in ['while', 'until']:
                if blk.connections[2] == dock_blk:
                    self._swap_while_blocks(blk, while_blk)
            dock_blk = blk

    def _swap_while_blocks(self, blk1, blk2):
        ''' Swap postion in block list of nested while blocks '''
        # Check to see if blk1 comes before blk2 in the block list.
        # If so, swap them.
        i1 = self.just_blocks().index(blk1)
        i2 = self.just_blocks().index(blk2)
        if i1 < i2:
            self.block_list.swap(blk1, blk2)

    def _disconnect(self, blk):
        ''' Disconnect block from stack above it. '''
        if blk is None:
            return
        if blk.connections is None:
            return
        if blk.connections[0] is None:
            return
        c = None
        blk2 = blk.connections[0]
        if blk in blk2.connections:
            c = blk2.connections.index(blk)
            blk2.connections[c] = None
        blk3, dockn = self._expandable_flow_above(blk)

        if blk2.name in block_styles['boolean-style']:
            if c == 2 and blk2.ey > 0:
                dy = -blk2.ey
                blk2.expand_in_y(dy)
                self._expand_boolean(blk2, blk, dy)
        elif blk2.name in expandable_blocks and c == 1:
            if blk2.ey > 0:
                dy = blk2.reset_y()
                if dy != 0:
                    self._expand_expandable(blk2, blk, dy)
                self._cascade_expandable(blk2)
        elif c is not None and blk2.name in EXPANDABLE_FLOW:
            if blk2.name in block_styles['clamp-style-1arg'] or\
               blk2.name in block_styles['clamp-style-boolean']:
                if c == 2:
                    self._resize_clamp(blk2, None, c)
            elif blk2.name in block_styles['clamp-style'] or \
                 blk2.name in block_styles['clamp-style-collapsible']:
                if c == 1:
                    self._resize_clamp(blk2, None)
            elif blk2.name in block_styles['clamp-style-else']:
                if c == 2 or c == 3:
                    self._resize_clamp(blk2, None, dockn=c)
        while blk3 is not None and blk3.connections[dockn] is not None:
            self._resize_clamp(blk3, blk3.connections[dockn], dockn=dockn)
            blk3, dockn = self._expandable_flow_above(blk3)
        blk.connections[0] = None

    def _resize_clamp(self, blk, gblk, dockn=-2):
        ''' If the content of a clamp changes, resize it '''
        if not self.interactive_mode:
            return
        if dockn < 0:
            dockn = len(blk.docks) + dockn
        y1 = blk.docks[-1][3]
        if blk.name in block_styles['clamp-style-else'] and dockn == 3:
            blk.reset_y2()
        else:
            blk.reset_y()
        dy = 0
        # Calculate height of drag group
        while gblk is not None:
            delta = int((gblk.docks[-1][3] - gblk.docks[0][3]) / gblk.scale)
            if delta == 0:
                dy += 21  # Fixme: don't hardcode size of stop action block
            else:
                dy += delta
            gblk = gblk.connections[-1]
        # Clamp has room for one "standard" block by default
        if dy > 0:
            dy -= 21  # Fixme: don't hardcode
        if blk.name in block_styles['clamp-style-else'] and dockn == 3:
            blk.expand_in_y2(dy)
        else:
            blk.expand_in_y(dy)
        y2 = blk.docks[-1][3]
        gblk = blk.connections[-1]
        # Move group below clamp up or down
        if blk.connections[-1] is not None:
            drag_group = find_group(blk.connections[-1])
            for gblk in drag_group:
                gblk.spr.move_relative((0, y2-y1))
        # We may have to move the else clamp group down too.
        if blk.name in block_styles['clamp-style-else'] and dockn == 2:
            if blk.connections[3] is not None:
                drag_group = find_group(blk.connections[3])
                for gblk in drag_group:
                    gblk.spr.move_relative((0, y2 - y1))

    def _expandable_flow_above(self, blk):
        ''' Is there an expandable flow block above this one? '''
        while blk.connections[0] is not None:
            if blk.connections[0].name in EXPANDABLE_FLOW:
                if blk.connections[0].name == 'ifelse':
                    if blk.connections[0].connections[2] == blk:
                        return blk.connections[0], 2
                    elif blk.connections[0].connections[3] == blk:
                        return blk.connections[0], 3
                else:
                    if blk.connections[0].connections[-2] == blk:
                        return blk.connections[0], -2
            blk = blk.connections[0]
        return None, None

    def _import_from_journal(self, blk):
        ''' Import a file from the Sugar Journal '''
        # TODO: check blk name to set filter
        if self.running_sugar:
            chooser(self.parent, '', self._update_media_blk)
        else:
            fname, self.load_save_folder = get_load_name('.*',
                                                         self.load_save_folder)
            if fname is None:
                return
            self._update_media_icon(blk, fname)

    def _load_description_block(self, blk):
        ''' Look for a corresponding description block '''
        if blk is None or blk.name != 'journal' or len(blk.values) == 0 or \
           blk.connections[0] is None:
            return
        _blk = blk.connections[0]
        dblk = find_blk_below(_blk, 'description')
        # Autoupdate the block if it is empty
        if dblk != None and (len(dblk.values) == 0 or dblk.values[0] is None):
            self._update_media_icon(dblk, None, blk.values[0])

    def _update_media_blk(self, dsobject):
        ''' Called from the chooser to load a media block '''
        self._update_media_icon(self.selected_blk, dsobject,
                                dsobject.object_id)

    def _update_media_icon(self, blk, name, value=''):
        ''' Update the icon on a 'loaded' media block. '''
        if blk.name == 'journal':
            self._load_image_thumb(name, blk)
        elif blk.name == 'audio':
            self._block_skin('audioon', blk)
        elif blk.name == 'video':
            self._block_skin('videoon', blk)
        else:
            self._block_skin('descriptionon', blk)
        if value == '':
            value = name
        if len(blk.values) > 0:
            blk.values[0] = value
        else:
            blk.values.append(value)
        blk.spr.set_label(' ')

    def _load_image_thumb(self, picture, blk):
        ''' Replace icon with a preview image. '''
        pixbuf = None
        self._block_skin('descriptionon', blk)

        if self.running_sugar:
            w, h = calc_image_size(blk.spr)
            pixbuf = get_pixbuf_from_journal(picture, w, h)
        else:
            if movie_media_type(picture):
                self._block_skin('videoon', blk)
                blk.name = 'video'
            elif audio_media_type(picture):
                self._block_skin('audioon', blk)
                blk.name = 'audio'
            elif image_media_type(picture):
                w, h = calc_image_size(blk.spr)
                pixbuf = gtk.gdk.pixbuf_new_from_file_at_size(picture, w, h)
            else:
                blk.name = 'description'
        if pixbuf is not None:
            x, y = self._calc_image_offset('', blk.spr)
            blk.set_image(pixbuf, x, y)
            self._resize_skin(blk)

    def _keypress_cb(self, area, event):
        ''' Keyboard '''
        keyname = gtk.gdk.keyval_name(event.keyval)
        keyunicode = gtk.gdk.keyval_to_unicode(event.keyval)
        if event.get_state() & gtk.gdk.MOD1_MASK:
            alt_mask = True
            alt_flag = 'T'
        else:
            alt_mask = False
            alt_flag = 'F'
        self._key_press(alt_mask, keyname, keyunicode)
        return keyname

    def _key_press(self, alt_mask, keyname, keyunicode):
        if keyname is None:
            return False

        self.keypress = keyname

        if alt_mask:
            if keyname == "p":
                self.hideshow_button()
            elif keyname == 'q':
                self.quit_plugins()
                if self.gst_available:
                    stop_media(self.lc)
                exit()
            elif keyname == 'g':
                self._align_to_grid()

        elif self.selected_blk is not None and \
             self.selected_blk.name != 'proto':
            self._process_keyboard_commands(keyname, block_flag=True)

        elif self.turtles.spr_to_turtle(self.selected_spr) is not None:
            self._process_keyboard_commands(keyname, block_flag=False)

        return True

    def _process_keyboard_commands(self, keyname, block_flag=True):
        ''' Use the keyboard to move blocks and turtle '''
        mov_dict = {'KP_Up': [0, 20], 'j': [0, 20], 'Up': [0, 20],
                    'KP_Down': [0, -20], 'k': [0, -20], 'Down': [0, -20],
                    'KP_Left': [-20, 0], 'h': [-20, 0], 'Left': [-20, 0],
                    'KP_Right': [20, 0], 'l': [20, 0], 'Right': [20, 0],
                    'KP_Page_Down': [-1, -1], 'Page_Down': [-1, -1],
                    'KP_Page_Up': [-1, -1], 'Page_Up': [-1, -1],
                    'KP_End': [0, 0], 'End': [0, 0],
                    'KP_Home': [0, 0], 'Home': [0, 0], 'space': [0, 0],
                    'Return': [-1, -1], 'Esc': [-1, -1]}

        if keyname not in mov_dict:
            return True

        if keyname in ['KP_End', 'End']:
            self.run_button(self.step_time)
        elif self.selected_spr is not None:
            if not self.lc.running and block_flag:
                blk = self.block_list.spr_to_block(self.selected_spr)
                if keyname in ['Return', 'KP_Page_Up', 'Page_Up', 'Esc']:
                    (x, y) = blk.spr.get_xy()
                    self._click_block(x, y)
                elif keyname in ['KP_Page_Down', 'Page_Down']:
                    if self.drag_group is None:
                        self.drag_group = find_group(blk)
                    self._put_in_trash(blk)
                    self.drag_group = None
                elif keyname in ['KP_Home', 'Home', 'space']:
                    block = self.block_list.spr_to_block(self.selected_spr)
                    if block is None:
                        return True
                    block.unhighlight()
                    block = self.block_list.get_next_block_of_same_type(
                                block)
                    if block is not None:
                        self.selected_spr = block.spr
                        block.highlight()
                else:
                    self._jog_block(blk, mov_dict[keyname][0],
                                         mov_dict[keyname][1])
            elif not block_flag:
                self._jog_turtle(mov_dict[keyname][0], mov_dict[keyname][1])
        return True

    def _jog_turtle(self, dx, dy):
        ''' Jog turtle '''
        if dx == -1 and dy == -1:
            self.canvas.xcor = 0
            self.canvas.ycor = 0
        else:
            self.canvas.xcor += dx
            self.canvas.ycor += dy
        self.active_turtle = self.turtles.spr_to_turtle(self.selected_spr)
        self.canvas.move_turtle()
        self.display_coordinates()
        self.selected_turtle = None

    def _align_to_grid(self, grid=20):
        ''' Align blocks at the top of stacks to a grid '''
        for blk in self.block_list.list:
            if blk.type == 'block':
                top = find_top_block(blk)
                if top == blk:
                    x = top.spr.get_xy()[0]
                    y = top.spr.get_xy()[1]
                    if x < 0:
                        dx = -x % grid
                    else:
                        dx = -(x % grid)
                    if y < 0:
                        dy = -y % grid
                    else:
                        dy = -(y % grid)
                    self._jog_block(top, dx, -dy)

    def _jog_block(self, blk, dx, dy):
        ''' Jog block '''
        if blk.type == 'proto':
            return
        if dx == 0 and dy == 0:
            return
        self._disconnect(blk)
        self.drag_group = find_group(blk)

        for blk in self.drag_group:
            (sx, sy) = blk.spr.get_xy()
            if sx + dx < 0:
                dx += -(sx + dx)
            if sy + dy < 0:
                dy += -(sy + dy)

        for blk in self.drag_group:
            (sx, sy) = blk.spr.get_xy()
            blk.spr.move((sx + dx, sy - dy))

        self._snap_to_dock()
        self.drag_group = None

    def _test_number(self):
        ''' Make sure a 'number' block contains a number. '''
        if hasattr(self, '_text_entry'):
            bounds = self._text_buffer.get_bounds()
            text = self._text_buffer.get_text(bounds[0], bounds[1])
            if self._focus_out_id is not None:
                self._text_entry.disconnect(self._focus_out_id)
                self._focus_out_id = None
            if self._insert_text_id is not None:
                self._text_buffer.disconnect(self._insert_text_id)
                self._insert_text_id = None
            self._text_entry.hide()
        else:
            text = self.selected_blk.spr.labels[0]
        self._number_check(text)

    def _number_check(self, text):
        text = text.strip()  # Ignore any whitespace
        if text == '':
            text = '0'
        if text in ['-', '.', '-.', ',', '-,']:
            num = 0
        elif text is not None:
            try:
                num = float(text.replace(self.decimal_point, '.'))
                if num > 1000000:
                    num = 1
                    self.showlabel("#overflowerror")
                elif num < -1000000:
                    num = -1
                    self.showlabel("#overflowerror")
                if int(num) == num:
                    num = int(num)
            except ValueError:
                num = 0
                self.showlabel("#notanumber")
        else:
            num = 0
        self.selected_blk.spr.set_label(str(num))
        try:
            self.selected_blk.values[0] = \
                float(str(num).replace(self.decimal_point, '.'))
        except ValueError:
            self.selected_blk.values[0] = float(str(num))
        except IndexError:
            self.selected_blk.values[0] = float(str(num))

    def _text_focus_out_cb(self, widget=None, event=None):
        self._text_to_check = True
        self._unselect_block()

    def _insert_text_cb(self, textbuffer, textiter, text, length):
        self._text_to_check = True
        if '\12' in text:
            self._unselect_block()

    def _test_string(self):
        if hasattr(self, '_text_entry'):
            if self._focus_out_id is not None:
                self._text_entry.disconnect(self._focus_out_id)
                self._focus_out_id = None
            bounds = self._text_buffer.get_bounds()
            text = self._text_buffer.get_text(bounds[0], bounds[1])
            self._text_entry.hide()
        else:
            text = self.selected_blk.spr.labels[0]
        self.selected_blk.spr.set_label(text.replace('\12', RETURN))
        self.selected_blk.resize()
        self.selected_blk.values[0] = text.replace(RETURN, '\12')
        self._saved_string = self.selected_blk.values[0]

    def load_python_code_from_file(self, fname=None, add_new_block=True):
        ''' Load Python code from a file '''
        id = None
        self.python_code = None
        if fname is None:
            fname, self.py_load_save_folder = get_load_name('.py',
                self.py_load_save_folder)
        if fname is None:
            return id
        try:
            f = open(fname, 'r')
            self.python_code = f.read()
            f.close()
            id = fname
        except IOError:
            error_output("Unable to read Python code from %s" % (fname),
                         self.running_sugar)
            return id

        # if we are running Sugar, copy the file into the Journal
        if self.running_sugar:
            if fname in self._py_cache:
                id = self._py_cache[fname]
            else:
                from sugar.datastore import datastore
                from sugar import profile

                dsobject = datastore.create()
                dsobject.metadata['title'] = os.path.basename(fname)
                dsobject.metadata['icon-color'] = \
                    profile.get_color().to_string()
                dsobject.metadata['mime_type'] = 'text/x-python'
                dsobject.metadata['activity'] = 'org.laptop.Pippy'
                dsobject.set_file_path(fname)
                try:
                    datastore.write(dsobject)
                    id = dsobject.object_id
                    debug_output("Copied %s to the datastore" % (fname),
                                 self.running_sugar)
                    # Don't copy the same file more than once
                    self._py_cache[fname] = id
                except IOError:
                    error_output("Error copying %s to the datastore" % (fname),
                                 self.running_sugar)
                    id = None
                dsobject.destroy()

            if add_new_block:
                # add a new block for this code at turtle position
                (tx, ty) = self.active_turtle.get_xy()
                self._new_block('userdefined', tx, ty)
                self.myblock[self.block_list.list.index(self.drag_group[0])] =\
                    self.python_code
                self.set_userdefined(self.drag_group[0])
                self.drag_group[0].values.append(id)
                self.drag_group = None
            # Save object ID in block value
            if self.selected_blk is not None:
                if len(self.selected_blk.values) == 0:
                    self.selected_blk.values.append(id)
                else:
                    self.selected_blk.values[0] = id
        else:
            if len(self.selected_blk.values) == 0:
                self.selected_blk.values.append(fname)
            else:
                self.selected_blk.values[0] = fname

        return id

    def load_python_code_from_journal(self, dsobject, blk=None):
        ''' Read the Python code from the Journal object '''
        self.python_code = None
        try:
            file_handle = open(dsobject.file_path, "r")
            self.python_code = file_handle.read()
            file_handle.close()
        except IOError:
            debug_output("couldn't open %s" % dsobject.file_path,
                         self.running_sugar)
        # Save the object id as the block value
        if blk is None:
            blk = self.selected_blk
        if blk is not None:
            if len(blk.values) == 0:
                blk.values.append(dsobject.object_id)
            else:
                blk.values[0] = dsobject.object_id

    def _import_py(self):
        ''' Import Python code into a block '''
        if self.running_sugar:
            chooser(self.parent, 'org.laptop.Pippy',
                    self.load_python_code_from_journal)
        else:
            self.load_python_code_from_file(fname=None, add_new_block=False)

        if self.selected_blk is not None:
            self.myblock[self.block_list.list.index(self.selected_blk)] = \
                self.python_code
            self.set_userdefined(self.selected_blk)

    def new_project(self):
        ''' Start a new project '''
        self.lc.stop_logo()
        self._loaded_project = ""
        # Put current project in the trash.
        while len(self.just_blocks()) > 0:
            blk = self.just_blocks()[0]
            top = find_top_block(blk)
            self._put_in_trash(top)
        self.canvas.clearscreen()
        self.save_file_name = None

    def is_new_project(self):
        ''' Is this a new project or was a old project loaded from a file? '''
        return self._loaded_project == ""

    def project_has_changed(self):
        ''' WARNING: order of JSON serialized data may have changed. '''
        try:
            f = open(self._loaded_project, 'r')
            saved_project_data = f.read()
            f.close()
        except:
            debug_output("problem loading saved project data from %s" % \
                              (self._loaded_project),
                         self.running_sugar)
            saved_project_data = ""
        current_project_data = data_to_string(self.assemble_data_to_save())

        return saved_project_data != current_project_data

    def load_files(self, ta_file, create_new_project=True):
        ''' Load a project from a file '''
        if create_new_project:
            self.new_project()
        self.process_data(data_from_file(ta_file))
        self._loaded_project = ta_file

    def load_file_from_chooser(self, create_new_project=True):
        ''' Load a project from file chooser '''
        _file_name, self.load_save_folder = get_load_name('.t[a-b]',
                                                     self.load_save_folder)
        if _file_name is None:
            return
        if not _file_name.endswith(SUFFIX):
            _file_name = _file_name + SUFFIX[1]
        self.load_files(_file_name, create_new_project)
        if create_new_project:
            self.save_file_name = os.path.basename(_file_name)
        if self.running_sugar:
            self.activity.metadata['title'] = os.path.split(_file_name)[1]

    def _found_a_turtle(self, blk):
        ''' Either [-1, 'turtle', ...] or [-1, ['turtle', key], ...] '''
        if blk[1] == 'turtle':
            self.load_turtle(blk)
            return True
        elif type(blk[1]) in [list, tuple] and blk[1][0] == 'turtle':
            if blk[1][1] == DEFAULT_TURTLE:
                if self.nick is not None and self.nick is not '':
                    self.load_turtle(blk, self.nick)
            else:
                self.load_turtle(blk, blk[1][1])
            return True
        return False

    def load_turtle(self, blk, key=1):
        ''' Restore a turtle from its saved state '''
        tid, name, xcor, ycor, heading, color, shade, pensize = blk
        self.canvas.set_turtle(key)
        self.canvas.setxy(xcor, ycor, pendown=False)
        self.canvas.seth(heading)
        self.canvas.setcolor(color)
        self.canvas.setshade(shade)
        self.canvas.setpensize(pensize)

    def load_block(self, b, offset=0):
        ''' Restore individual blocks from saved state '''
        if self.running_sugar:
            from sugar.datastore import datastore

        if b[1] == 0:
            return None
        # A block is saved as: (i, (btype, value), x, y, (c0,... cn))
        # The x, y position is saved/loaded for backward compatibility
        btype, value = b[1], None
        if type(btype) == tuple:
            btype, value = btype
        elif type(btype) == list:
            btype, value = btype[0], btype[1]

        # Replace deprecated sandwich blocks
        if btype == 'sandwichtop_no_label':
            btype = 'sandwichclamp'
            docks = []
            for d in b[4]:
                docks.append(d)
            docks.append(None)
            b[4] = docks
        elif btype == 'sandwichtop_no_arm_no_label':
            btype = 'sandwichclampcollapsed'
            docks = []
            for d in b[4]:
                docks.append(d)
            docks.append(None)
            b[4] = docks
        # FIXME: blocks after sandwich bottom must be attached to
        # sandwich top dock[2], currently set to None
        elif btype in ['sandwichbottom', 'sandwichcollapsed']:
            btype = 'vspace'
        # FIXME: blocks after sandwichtop should be in a sandwich clamp
        elif btype in ['sandwichtop', 'sandwichtop_no_arm']:
            btype = 'comment'

        # Some blocks can only appear once...
        if btype in ['start', 'hat1', 'hat2']:
            if self._check_for_duplicate(btype):
                name = block_names[btype][0]
                while self._find_proto_name('stack_%s' % (name), name):
                    name = increment_name(name)
                i = len(self._process_block_data) + len(self._extra_block_data)
                self._extra_block_data.append(
                    [i, ['string', name], 0, 0, [b[0], None]])
                # To do: check for a duplicate name
                self._new_stack_block(name)
                btype = 'hat'
                self._process_block_data[b[0]] = [
                    b[0], b[1], b[2], b[3], [b[4][0], i, b[4][1]]]
        elif btype  == 'hat':
            if b[4][1] < len(self._process_block_data):
                i = b[4][1]
                name = self._process_block_data[i][1][1]
            else:
                i = b[4][1] - len(self._process_block_data)
                name = self._extra_block_data[i][1][1]
            while self._find_proto_name('stack_%s' % (name), name):
                name = increment_name(name)
                if b[4][1] < len(self._process_block_data):
                    dblk = self._process_block_data[i]
                    self._process_block_data[i] = [dblk[0], (dblk[1][0], name),
                                                   dblk[2], dblk[3], dblk[4]]
                else:
                    dblk = self._extra_block_data[i]
                    self._extra_block_data[i] = [dblk[0], (dblk[1][0], name),
                                                 dblk[2], dblk[3], dblk[4]]
            self._new_stack_block(name)
        elif btype  == 'storein':
            if b[4][1] < len(self._process_block_data):
                i = b[4][1]
                name = self._process_block_data[i][1][1]
            else:
                i = b[4][1] - len(self._process_block_data)
                name = self._extra_block_data[i][1][1]
            if not self._find_proto_name('storein_%s' % (name), name):
                self._new_storein_block(name)
            if not self._find_proto_name('box_%s' % (name), name):
                self._new_box_block(name)

        if btype in content_blocks:
            if btype == 'number':
                try:
                    values = [round_int(value)]
                except ValueError:
                    values = [0]
            else:
                values = [value]
        else:
            values = []

        if btype in OLD_DOCK:
            check_dock = True
        else:
            check_dock = False
        if btype in OLD_NAMES:
            btype = OLD_NAMES[btype]

        blk = Block(self.block_list, self.sprite_list, btype,
                    b[2] + self.canvas.cx + offset,
                    b[3] + self.canvas.cy + offset,
                    'block', values, self.block_scale)

        # If it was an unknown block type, we need to match the number
        # of dock items. TODO: Try to infer the dock type from connections
        if blk.unknown and len(b[4]) > len(blk.docks):
            debug_output('%s: dock mismatch %d > %d' % (
                    btype, len(b[4]), len(blk.docks)), self.running_sugar)
            for i in range(len(b[4]) - len(blk.docks)):
                blk.docks.append(['unavailable', True, 0, 0])

        # Some blocks get transformed.
        if btype in block_styles['basic-style-var-arg'] and value is not None:
            # Is there code stored in this userdefined block?
            if value > 0:  # catch deprecated format (#2501)
                self.python_code = None
                if self.running_sugar:
                    # For security reasons, only open files found in
                    # Python samples directory
                    if os.path.exists(os.path.join(self.path, value)) and \
                            value[0:9] == 'pysamples':
                        self.selected_blk = blk
                        self.load_python_code_from_file(
                            fname=os.path.join(self.path, value),
                            add_new_block=False)
                        self.selected_blk = None
                    else:  # or files from the Journal
                        try:
                            dsobject = datastore.get(value)
                        except:  # Should be IOError, but dbus error is raised
                            dsobject = None
                            debug_output("couldn't get dsobject %s" % value,
                                         self.running_sugar)
                        if dsobject is not None:
                            self.load_python_code_from_journal(dsobject, blk)
                else:
                    self.selected_blk = blk
                    self.load_python_code_from_file(fname=value,
                                                    add_new_block=False)
                    self.selected_blk = None
                if self.python_code is not None:
                    self.myblock[self.block_list.list.index(blk)] = \
                        self.python_code
                    self.set_userdefined(blk)
        if btype == 'string' and blk.spr is not None:
            value = blk.values[0]
            if type(value) == unicode:
                value = value.encode('ascii', 'replace')
            blk.spr.set_label(value.replace('\n', RETURN))
        elif btype == 'start':  # block size is saved in start block
            if value is not None:
                self.block_scale = value
        elif btype in block_styles['box-style-media'] and blk.spr is not None:
            if btype in EXPAND_SKIN:
                if blk.ex == 0:
                    blk.expand_in_x(EXPAND_SKIN[btype][0])
                if blk.ey == 0:
                    blk.expand_in_y(EXPAND_SKIN[btype][1])
            if len(blk.values) == 0 or blk.values[0] == 'None' or \
               blk.values[0] is None or btype in NO_IMPORT:
                self._block_skin(btype + 'off', blk)
            elif btype in ['video', 'audio', 'description']:
                self._block_skin(btype + 'on', blk)
            elif self.running_sugar:
                try:
                    dsobject = datastore.get(blk.values[0])
                    if not movie_media_type(dsobject.file_path[-4:]):
                        w, h, = calc_image_size(blk.spr)
                        pixbuf = get_pixbuf_from_journal(dsobject, w, h)
                        if pixbuf is not None:
                            x, y = self._calc_image_offset('', blk.spr)
                            blk.set_image(pixbuf, x, y)
                        else:
                            self._block_skin('journalon', blk)
                    dsobject.destroy()
                except:
                    try:
                        w, h, = calc_image_size(blk.spr)
                        pixbuf = gtk.gdk.pixbuf_new_from_file_at_size(
                                     blk.values[0], w, h)
                        x, y = self._calc_image_offset('', blk.spr)
                        blk.set_image(pixbuf, x, y)
                    except:
                        debug_output("Couldn't open dsobject (%s)" % \
                              (blk.values[0]), self.running_sugar)
                        self._block_skin('journaloff', blk)
            else:
                if not movie_media_type(blk.values[0][-4:]):
                    try:
                        w, h, = calc_image_size(blk.spr)
                        pixbuf = gtk.gdk.pixbuf_new_from_file_at_size(
                                     blk.values[0], w, h)
                        x, y = self._calc_image_offset('', blk.spr)
                        blk.set_image(pixbuf, x, y)
                    except:
                        self._block_skin('journaloff', blk)
                else:
                    self._block_skin('journalon', blk)
            blk.spr.set_label(' ')
            blk.resize()
        elif btype in EXPANDABLE or btype in expandable_blocks or \
             btype in EXPANDABLE_FLOW or btype in EXPANDABLE_ARGS or \
             btype == 'nop':
            if btype == 'vspace' or btype in expandable_blocks:
                if value is not None:
                    blk.expand_in_y(value)
            elif btype == 'hspace' or btype == 'identity2':
                if value is not None:
                    blk.expand_in_x(value)
            elif btype in EXPANDABLE_FLOW:
                if value is not None:
                    if type(value) is int:
                        blk.expand_in_y(value)
                    else:  # thenelse blocks
                        blk.expand_in_y(value[0])
                        blk.expand_in_y2(value[1])
            elif btype == 'templatelist' or btype == 'list':
                for i in range(len(b[4]) - 4):
                    blk.add_arg()
            elif btype == 'myfunc2arg' or btype == 'myfunc3arg' or\
                 btype == 'userdefined2args' or btype == 'userdefined3args' or\
                 btype == 'loadblock2arg' or btype == 'loadblock3arg':
                blk.add_arg()
            if btype == 'myfunc3arg' or btype == 'userdefined3args' or \
               btype == 'loadblock3arg':
                blk.add_arg(False)
            if btype in PYTHON_SKIN:
                if self.nop == 'pythonloaded':
                    self._block_skin('pythonon', blk)
                else:
                    self._block_skin('pythonoff', blk)

        if self.interactive_mode:
            blk.spr.set_layer(BLOCK_LAYER)
        if check_dock:
            blk.connections = 'check'

        if self.running_sugar and len(blk.spr.labels) > 0 and \
                blk.name not in ['', ' ', 'number', 'string']:
            if len(self.used_block_list) > 0:
                self.used_block_list.append(', ')
            if blk.name in special_names:
                self.used_block_list.append(special_names[blk.name])
            elif blk.spr.labels[0] not in self.used_block_list:
                self.used_block_list.append(blk.spr.labels[0])
        return blk

    def _check_for_duplicate(self, name):
        ''' Is there already a block of this name? '''
        for blk in self.just_blocks():
            if blk.name == name:
                return True
        return False

    def load_start(self, ta_file=None):
        ''' Start a new project with a 'start' brick '''
        if ta_file is None:
            self.process_data([[0, "start", PALETTE_WIDTH + 20,
                                self.toolbar_offset + PALETTE_HEIGHT + 20,
                                [None, None]]])
        else:
            self.process_data(data_from_file(ta_file))

    def save_file(self, file_name=None):
        ''' Start a project to a file '''
        if self.save_folder is not None:
            self.load_save_folder = self.save_folder
        if file_name is None:
            file_name, self.load_save_folder = get_save_name(
                '.t[a-b]', self.load_save_folder, self.save_file_name)
        if file_name is None:
            return
        if not file_name.endswith(SUFFIX):
            file_name = file_name +  SUFFIX[1]
        data_to_file(self.assemble_data_to_save(), file_name)
        self.save_file_name = os.path.basename(file_name)
        if not self.running_sugar:
            self.save_folder = self.load_save_folder

    def assemble_data_to_save(self, save_turtle=True, save_project=True):
        ''' Pack the project (or stack) into a datastream to be serialized '''
        data = []
        blks = []

        if save_project:
            blks = self.just_blocks()
        else:
            if self.selected_blk is None:
                return []
            blks = find_group(find_top_block(self.selected_blk))

        for i, blk in enumerate(blks):
            blk.id = i
        for blk in blks:
            if blk.name in content_blocks:
                if len(blk.values) > 0:
                    name = (blk.name, blk.values[0])
                else:
                    name = (blk.name)
            elif blk.name in block_styles['basic-style-var-arg'] and \
                 len(blk.values) > 0:
                name = (blk.name, blk.values[0])
            elif blk.name in EXPANDABLE or blk.name in expandable_blocks or \
                 blk.name in EXPANDABLE_ARGS or blk.name in EXPANDABLE_FLOW:
                ex, ey, ey2 = blk.get_expand_x_y()
                if blk.name in block_styles['clamp-style-else']:
                    name = (blk.name, (ey, ey2))
                elif ex > 0:
                    name = (blk.name, ex)
                elif ey > 0:
                    name = (blk.name, ey)
                else:
                    name = (blk.name, 0)
            elif blk.name == 'start':  # save block_size in start block
                name = (blk.name, self.block_scale)
            else:
                name = (blk.name)
            if hasattr(blk, 'connections') and blk.connections is not None:
                connections = [get_id(cblk) for cblk in blk.connections]
            else:
                connections = None
            (sx, sy) = blk.spr.get_xy()
            # Add a slight offset for copy/paste
            if not save_project:
                sx += 20
                sy += 20
            data.append((blk.id, name, sx - self.canvas.cx,
                         sy - self.canvas.cy, connections))
        if save_turtle:
            for turtle in iter(self.turtles.dict):
                # Don't save remote turtles
                if not self.remote_turtle(turtle):
                    # Save default turtle as 'Yertle'
                    if turtle == self.nick:
                        turtle = DEFAULT_TURTLE
                    data.append((-1, ['turtle', turtle],
                                   self.canvas.xcor, self.canvas.ycor,
                                   self.canvas.heading, self.canvas.color,
                                   self.canvas.shade, self.canvas.pensize))
        return data

    def display_coordinates(self, clear=False):
        ''' Display the coordinates of the current turtle on the toolbar '''
        if clear:
            if self.running_sugar:
                self.activity.coordinates_label.set_text('')
                self.activity.coordinates_label.show()
            elif self.interactive_mode:
                self.parent.set_title('')
        else:
            x = round_int(float(self.canvas.xcor) / self.coord_scale)
            y = round_int(float(self.canvas.ycor) / self.coord_scale)
            h = round_int(self.canvas.heading)
            if int(x) == x and int(y) == y and int(h) == h:
                formatting = '%s: %d %s: %d %s: %d'
            else:
                formatting = '%s: %0.2f %s: %0.2f %s: %0.2f'
            if self.running_sugar:
                self.activity.coordinates_label.set_text(
                    formatting % (_('xcor'), x, _('ycor'), y,
                                              _('heading'), h))
                self.activity.coordinates_label.show()
            elif self.interactive_mode:
                formatting = '%s — ' + formatting
                self.parent.set_title(
                    formatting % (_('Turtle Art'), _('xcor'), x, _('ycor'), y,
                                  _('heading'), h))

    def showlabel(self, shp, label=''):
        ''' Display a message on a status block '''
        if not self.interactive_mode:
            debug_output(label, self.running_sugar)
            return
        # Don't overwrite an error message
        if not self._autohide_shape:
            return
        if shp in ['print', 'info', 'help']:
            self._autohide_shape = True
        else:
            self._autohide_shape = False
        if shp == 'syntaxerror' and str(label) != '':
            if str(label)[1:] in self.status_shapes:
                shp = str(label)[1:]
                label = ''
            else:
                shp = 'status'
        elif shp[0] == '#':
            shp = shp[1:]
            label = ''
        self.status_spr.set_shape(self.status_shapes[shp])
        self.status_spr.set_label_attributes(12.0, rescale=False)
        if shp == 'status':
            self.status_spr.set_label('"%s"' % (str(label)))
        else:
            self.status_spr.set_label(str(label))
        self.status_spr.set_layer(STATUS_LAYER)
        if shp == 'info':
            self.status_spr.move((PALETTE_WIDTH, self.height - 400))
        else:
            # Adjust vertical position based on scrolled window adjustment
            if self.running_sugar:
                self.status_spr.move((0, self.height - 200 + \
                    self.activity.sw.get_vadjustment().get_value()))
            elif self.interactive_mode:
                self.status_spr.move((0, self.height - 100))

    def calc_position(self, template):
        ''' Relative placement of portfolio objects (deprecated) '''
        w, h, x, y, dx, dy = TEMPLATES[template]
        x *= self.canvas.width
        y *= self.canvas.height
        w *= (self.canvas.width - x)
        h *= (self.canvas.height - y)
        dx *= w
        dy *= h
        return(w, h, x, y, dx, dy)

    def save_for_upload(self, file_name):
        ''' Grab the current canvas and save it for upload '''
        if not file_name.endswith(SUFFIX):
            ta_file = file_name + SUFFIX[1]
            image_file = file_name + '.png'
        else:
            ta_file = file_name
            image_file = file_name[0:-3] + '.png'
        
        data_to_file(self.assemble_data_to_save(), ta_file)
        save_picture(self.canvas, image_file)
        return ta_file, image_file

    def save_as_image(self, name="", svg=False):
        ''' Grab the current canvas and save it. '''
        if svg:
            suffix = '.svg'
        else:
            suffix = '.png'

        if not self.interactive_mode:
            save_picture(self.canvas, name[:-3] + suffix)
            return
        if self.running_sugar:
            if len(name) == 0:
                filename = 'turtleblocks' + suffix
            else:
                filename = name + suffix
            datapath = get_path(self.activity, 'instance')
        elif len(name) == 0:
            name = 'ta'
            if self.save_folder is not None:
                self.load_save_folder = self.save_folder
            filename, self.load_save_folder = get_save_name(
                suffix, self.load_save_folder, name)
            datapath = self.load_save_folder
        else:
            datapath = os.getcwd()
            filename = name + suffix
        if filename is None:
            return

        file_path = os.path.join(datapath, filename)
        if svg:
            if self.canvas.cr_svg is None:
                return
            self.canvas.svg_reset()
        else:
            save_picture(self.canvas, file_path)

        if self.running_sugar:
            from sugar.datastore import datastore
            from sugar import profile

            dsobject = datastore.create()
            if len(name) == 0:
                dsobject.metadata['title'] = "%s %s" % \
                    (self.activity.metadata['title'], _("image"))
            else:
                dsobject.metadata['title'] = name
            dsobject.metadata['icon-color'] = profile.get_color().to_string()
            if svg:
                dsobject.metadata['mime_type'] = 'image/svg+xml'
                dsobject.set_file_path(os.path.join(datapath, 'output.svg'))
            else:
                dsobject.metadata['mime_type'] = 'image/png'
                dsobject.set_file_path(file_path)
            datastore.write(dsobject)
            dsobject.destroy()
            self.saved_pictures.append((dsobject.object_id, svg))
            if svg:
                os.remove(os.path.join(datapath, 'output.svg'))
            else:
                os.remove(file_path)
        else:
            if svg:
                subprocess.check_output(
                    ['mv', os.path.join(datapath, 'output.svg'),
                     os.path.join(datapath, filename)])
            self.saved_pictures.append((file_path, svg))

    def just_blocks(self):
        ''' Filter out 'proto', 'trash', and 'deleted' blocks '''
        just_blocks_list = []
        for blk in self.block_list.list:
            if blk.type == 'block':
                just_blocks_list.append(blk)
        return just_blocks_list

    def just_protos(self):
        ''' Filter out 'block', 'trash', and 'deleted' blocks '''
        just_protos_list = []
        for blk in self.block_list.list:
            if blk.type == 'proto':
                just_protos_list.append(blk)
        return just_protos_list

    def _width_and_height(self, blk):
        ''' What are the width and height of a stack? '''
        minx = 10000
        miny = 10000
        maxx = -10000
        maxy = -10000
        for gblk in find_group(blk):
            (x, y) = gblk.spr.get_xy()
            w, h = gblk.spr.get_dimensions()
            if x < minx:
                minx = x
            if y < miny:
                miny = y
            if x + w > maxx:
                maxx = x + w
            if y + h > maxy:
                maxy = y + h
        return(maxx - minx, maxy - miny)

    # Utilities related to putting a image 'skin' on a block

    def _calc_image_offset(self, name, spr, iw=0, ih=0):
        ''' Calculate the postion for placing an image onto a sprite. '''
        _l, _t = spr.label_left_top()
        if name == '':
            return _l, _t
        _w = spr.label_safe_width()
        _h = spr.label_safe_height()
        if iw == 0:
            iw = self.media_shapes[name].get_width()
            ih = self.media_shapes[name].get_height()
        return int(_l + (_w - iw) / 2), int(_t + (_h - ih) / 2)

    def _calc_w_h(self, name, spr):
        ''' Calculate new image size '''
        target_w = spr.label_safe_width()
        target_h = spr.label_safe_height()
        if name == '':
            return target_w, target_h
        image_w = self.media_shapes[name].get_width()
        image_h = self.media_shapes[name].get_height()
        scale_factor = float(target_w) / image_w
        new_w = target_w
        new_h = image_h * scale_factor
        if new_h > target_h:
            scale_factor = float(target_h) / new_h
            new_h = target_h
            new_w = target_w * scale_factor
        return int(new_w), int(new_h)

    def _proto_skin(self, name, n, i):
        ''' Utility for calculating proto skin images '''
        x, y = self._calc_image_offset(name, self.palettes[n][i].spr)
        self.palettes[n][i].spr.set_image(self.media_shapes[name], 1, x, y)

    def _block_skin(self, name, blk):
        ''' Some blocks get a skin '''
        x, y = self._calc_image_offset(name, blk.spr)
        blk.set_image(self.media_shapes[name], x, y)
        self._resize_skin(blk)

    def _resize_skin(self, blk):
        ''' Resize the 'skin' when block scale changes. '''
        if blk.name in PYTHON_SKIN:
            w, h = self._calc_w_h('pythonoff', blk.spr)
            x, y = self._calc_image_offset('pythonoff', blk.spr, w, h)
        elif blk.name == 'journal':
            if len(blk.values) == 1 and blk.values[0] is not None:
                w, h = self._calc_w_h('', blk.spr)
                x, y = self._calc_image_offset('journaloff', blk.spr, w, h)
            else:
                w, h = self._calc_w_h('journaloff', blk.spr)
                x, y = self._calc_image_offset('journaloff', blk.spr, w, h)
        else:
            # w, h = self._calc_w_h('descriptionoff', blk.spr)
            w, h = self._calc_w_h('', blk.spr)
            # x, y = self._calc_image_offset('descriptionoff', blk.spr, w, h)
            x, y = self._calc_image_offset('', blk.spr, w, h)
        blk.scale_image(x, y, w, h)

    def _find_proto_name(self, name, label, palette='blocks'):
        ''' Look for a protoblock with this name '''
        if type(name) == unicode:
            name = name.encode('ascii', 'replace')
        if type(label) == unicode:
            label = label.encode('ascii', 'replace')
        i = palette_name_to_index(palette)
        for blk in self.palettes[i]:
            blk_label = blk.spr.labels[0]
            if type(blk.name) == unicode:
                blk.name = blk.name.encode('ascii', 'replace')
            if type(blk_label) == unicode:
                blk_label = blk_label.encode('ascii', 'replace')
            if blk.name == name and blk_label == label:
                return True
            # Check labels[1] too (e.g., store in block)
            if len(blk.spr.labels) > 1:
                blk_label = blk.spr.labels[1]
                if blk.name == name and blk_label == label:
                    return True
        return False

    def _new_stack_block(self, name):
        ''' Add a stack block to the 'blocks' palette '''
        if type(name) in [float, int]:
            return
        if type(name) == unicode:
            name = name.encode('ascii', 'replace')
        if name == _('action'):
            return
        # Choose a palette for the new block.
        palette = make_palette('blocks')

        # Create a new block prototype.
        primitive_dictionary['stack'] = self._prim_stack
        palette.add_block('stack_%s' % (name),
                          style='basic-style-1arg',
                          label=name,
                          string_or_number=True,
                          prim_name='stack',
                          logo_command='action',
                          default=name,
                          help_string=_('invokes named action stack'))
        self.lc.def_prim('stack', 1, primitive_dictionary['stack'], True)

        # Regenerate the palette, which will now include the new block.
        self.show_toolbar_palette(palette_name_to_index('blocks'),
                                  regenerate=True)

    def _new_box_block(self, name):
        ''' Add a box block to the 'blocks' palette '''
        if type(name) in [float, int]:
            return
        if type(name) == unicode:
            name = name.encode('ascii', 'replace')
        if name == _('my box'):
            return
        # Choose a palette for the new block.
        palette = make_palette('blocks')

        # Create a new block prototype.
        primitive_dictionary['box'] = self._prim_box
        palette.add_block('box_%s' % (name),
                          style='number-style-1strarg',
                          label=name,
                          string_or_number=True,
                          prim_name='box',
                          default=name,
                          logo_command='box',
                          help_string=_('named variable (numeric value)'))
        self.lc.def_prim('box', 1,
                             lambda self, x: primitive_dictionary['box'](x))

        # Regenerate the palette, which will now include the new block.
        self.show_toolbar_palette(palette_name_to_index('blocks'),
                                  regenerate=True)

    def _new_storein_block(self, name):
        ''' Add a storin block to the 'blocks' palette '''
        if type(name) in [float, int]:
            return
        if type(name) == unicode:
            name = name.encode('ascii', 'replace')
        if name == _('my box'):
            return
        # Choose a palette for the new block.
        palette = make_palette('blocks')

        # Create a new block prototype.
        primitive_dictionary['setbox'] = self._prim_setbox
        palette.add_block('storein_%s' % (name),
                          style='basic-style-2arg',
                          label=[_('store in'), name, _('value')],
                          string_or_number=True,
                          prim_name='storeinbox',
                          logo_command='storeinbox',
                          default=[name, 100],
                          help_string=_('stores numeric value in named \
variable'))
        self.lc.def_prim('storeinbox', 2,
                         lambda self, x, y: primitive_dictionary['setbox'](
                'box3', x, y))

        # Regenerate the palette, which will now include the new block.
        self.show_toolbar_palette(palette_name_to_index('blocks'),
                                  regenerate=True)

    def _prim_stack(self, x):
        ''' Process a named stack '''
        if type(convert(x, float, False)) == float:
            if int(float(x)) == x:
                x = int(x)
        if 'stack3' + str(x) not in self.lc.stacks or \
           self.lc.stacks['stack3' + str(x)] is None:
            raise logoerror("#nostack")
        self.lc.icall(self.lc.evline,
                      self.lc.stacks['stack3' + str(x)][:])
        yield True
        self.lc.procstop = False
        self.lc.ireturn()
        yield True

    def _prim_box(self, x):
        ''' Retrieve value from named box '''
        if type(convert(x, float, False)) == float:
            if int(float(x)) == x:
                x = int(x)
        try:
            return self.lc.boxes['box3' + str(x)]
        except KeyError:
            raise logoerror("#emptybox")

    def _prim_setbox(self, name, x, val):
        """ Define value of named box """
        if x is not None:
            if type(convert(x, float, False)) == float:
                if int(float(x)) == x:
                    x = int(x)
            self.lc.boxes[name + str(x)] = val
            self.lc.update_label_value('box', val, label=x)
        else:
            self.lc.boxes[name] = val
            self.lc.update_label_value(name, val)            

    def dock_dx_dy(self, block1, dock1n, block2, dock2n):
        ''' Find the distance between the dock points of two blocks. '''
        # Cannot dock a block to itself
        if block1 == block2:
            return NO_DOCK
        dock1 = block1.docks[dock1n]
        dock2 = block2.docks[dock2n]
        # Dock types include flow, number, string, unavailable
        # Dock directions: Flow: True -> in; False -> out
        # Dock directions: Number: True -> out; False -> in
        # Each dock point as an associated relative x, y position on its block
        d1type, d1dir, d1x, d1y = dock1[0:4]
        d2type, d2dir, d2x, d2y = dock2[0:4]
        # Cannot connect an innie to an innie or an outie to an outie
        if d1dir == d2dir:
            return NO_DOCK
        # Flow blocks can be inserted into the middle of a stack
        if d2type is 'flow' and dock2n is 0:
            if block1.connections is not None and \
               dock1n == len(block1.connections) - 1 and \
               block1.connections[dock1n] is not None:
                self.inserting_block_mid_stack = True
            elif block1.connections is not None and \
               block1.name in EXPANDABLE_FLOW and \
               block1.connections[dock1n] is not None:
                self.inserting_block_mid_stack = True
        # Only number blocks can be docked when the dock is not empty
        elif d2type is not 'number' or dock2n is not 0:
            if block1.connections is not None and \
               dock1n < len(block1.connections) and \
               block1.connections[dock1n] is not None:
                return NO_DOCK
            if block2.connections is not None and \
               dock2n < len(block2.connections) and \
               block2.connections[dock2n] is not None:
                return NO_DOCK
        # Only some dock types are interchangeable
        if d1type != d2type:
            # Some blocks will take strings or numbers
            if block1.name in string_or_number_args:
                if d2type == 'number' or d2type == 'string':
                    pass
            # Some blocks will take content blocks
            elif block1.name in CONTENT_ARGS:
                if d2type in content_blocks:
                    pass
            else:
                return NO_DOCK
        (b1x, b1y) = block1.spr.get_xy()
        (b2x, b2y) = block2.spr.get_xy()
        return ((b1x + d1x) - (b2x + d2x), (b1y + d1y) - (b2y + d2y))
