/**
 * This file is part of the HTML widget for KDE.
 *
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2004 Apple Computer, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
#include "rendering/render_canvas.h"
#include "render_layer.h"
#include "xml/dom_docimpl.h"

#include "khtmlview.h"
#include <kdebug.h>

#if APPLE_CHANGES
#include "khtml_part.h"
#endif

using namespace khtml;

//#define BOX_DEBUG
//#define SPEED_DEBUG

RenderCanvas::RenderCanvas(DOM::NodeImpl* node, KHTMLView *view)
    : RenderBlock(node)
{
    // Clear our anonymous bit.
    setIsAnonymous(false);
        
    // init RenderObject attributes
    setInline(false);

    m_view = view;
    // try to contrain the width to the views width

    m_minWidth = 0;
    m_height = 0;

    m_width = m_minWidth;
    m_maxWidth = m_minWidth;

    m_rootWidth = m_rootHeight = 0;
    m_viewportWidth = m_viewportHeight = 0;
    
    setPositioned(true); // to 0,0 :)

    m_printingMode = false;
    m_printImages = true;

    m_maximalOutlineSize = 0;
    
    m_selectionStart = 0;
    m_selectionEnd = 0;
    m_selectionStartPos = -1;
    m_selectionEndPos = -1;

    // Create a new root layer for our layer hierarchy.
    m_layer = new (node->getDocument()->renderArena()) RenderLayer(this);
}

RenderCanvas::~RenderCanvas()
{
}

void RenderCanvas::calcHeight()
{
    if (!m_printingMode && m_view)
    {
        m_height = m_view->visibleHeight();
    }
    else if (!m_view)
    {
        m_height = m_rootHeight;
    }
}

void RenderCanvas::calcWidth()
{
    // the width gets set by KHTMLView::print when printing to a printer.
    if(m_printingMode || !m_view)
    {
        m_width = m_rootWidth;
        return;
    }

    m_width = m_view ?
                m_view->frameWidth() + paddingLeft() + paddingRight() + borderLeft() + borderRight()
                : m_minWidth;

    if (style()->marginLeft().type==Fixed)
        m_marginLeft = style()->marginLeft().value;
    else
        m_marginLeft = 0;

    if (style()->marginRight().type==Fixed)
        m_marginRight = style()->marginRight().value;
    else
        m_marginRight = 0;
}

void RenderCanvas::calcMinMaxWidth()
{
    KHTMLAssert( !minMaxKnown() );

    RenderBlock::calcMinMaxWidth();

    m_maxWidth = m_minWidth;

    setMinMaxKnown();
}

//#define SPEED_DEBUG

void RenderCanvas::layout()
{
    KHTMLAssert(!view()->inLayout());
    
    if (m_printingMode)
       m_minWidth = m_width;

    setChildNeedsLayout(true);
    setMinMaxKnown(false);
    for (RenderObject *c = firstChild(); c; c = c->nextSibling())
        c->setChildNeedsLayout(true);

#ifdef SPEED_DEBUG
    QTime qt;
    qt.start();
#endif
    if ( recalcMinMax() )
	recalcMinMaxWidths();
#ifdef SPEED_DEBUG
    kdDebug() << "RenderCanvas::calcMinMax time used=" << qt.elapsed() << endl;
    qt.start();
#endif

#ifdef SPEED_DEBUG
    kdDebug() << "RenderCanvas::layout time used=" << qt.elapsed() << endl;
    qt.start();
#endif
    if (!m_printingMode) {
        m_viewportWidth = m_width = m_view->visibleWidth();
        m_viewportHeight = m_height = m_view->visibleHeight();
    }
    else {
        m_width = m_rootWidth;
        m_height = m_rootHeight;
    }

    RenderBlock::layout();

    int docw = docWidth();
    int doch = docHeight();

    if (!m_printingMode) {
        setWidth( m_viewportWidth = m_view->visibleWidth() );
        setHeight(  m_viewportHeight = m_view->visibleHeight() );
    }

    // ### we could maybe do the call below better and only pass true if the docsize changed.
    layoutPositionedObjects( true );

#ifdef SPEED_DEBUG
    kdDebug() << "RenderCanvas::end time used=" << qt.elapsed() << endl;
#endif

    layer()->setHeight(kMax(doch, m_height));
    layer()->setWidth(kMax(docw, m_width));
    
    setNeedsLayout(false);
}

bool RenderCanvas::absolutePosition(int &xPos, int &yPos, bool f)
{
    if ( f && m_view) {
	xPos = m_view->contentsX();
	yPos = m_view->contentsY();
    }
    else {
        xPos = yPos = 0;
    }
    return true;
}

void RenderCanvas::paint(PaintInfo& i, int _tx, int _ty)
{
#ifdef DEBUG_LAYOUT
    kdDebug( 6040 ) << renderName() << "(RenderCanvas) " << this << " ::paintObject() w/h = (" << width() << "/" << height() << ")" << endl;
#endif
    // 1. paint background, borders etc
    if (i.phase == PaintActionElementBackground) {
        paintBoxDecorations(i, _tx, _ty);
        return;
    }
    
    // 2. paint contents
    for (RenderObject *child = firstChild(); child; child = child->nextSibling())
        if (!child->layer() && !child->isFloating())
            child->paint(i, _tx, _ty);

    if (m_view)
    {
        _tx += m_view->contentsX();
        _ty += m_view->contentsY();
    }
    
    // 3. paint floats.
    if (i.phase == PaintActionFloat)
        paintFloats(i, _tx, _ty);
        
#ifdef BOX_DEBUG
    outlineBox(i.p, _tx, _ty);
#endif
}

void RenderCanvas::paintBoxDecorations(PaintInfo& i, int _tx, int _ty)
{
    // Check to see if we are enclosed by a transparent layer.  If so, we cannot blit
    // when scrolling, and we need to use slow repaints.
    DOM::ElementImpl* elt = element()->getDocument()->ownerElement();
    if (view() && elt) {
        RenderLayer* layer = elt->renderer()->enclosingLayer();
        if (layer->isTransparent() || layer->transparentAncestor())
            view()->useSlowRepaints();
    }
    
    if ((firstChild() && firstChild()->style()->visibility() == VISIBLE) || !view())
        return;

    // This code typically only executes if the root element's visibility has been set to hidden.
    // Only fill with a base color (e.g., white) if we're the root document, since iframes/frames with
    // no background in the child document should show the parent's background.
    if (elt || view()->isTransparent())
        view()->useSlowRepaints(); // The parent must show behind the child.
    else
        i.p->fillRect(i.r.x(), i.r.y(), i.r.width(), i.r.height(), 
                    view()->palette().active().color(QColorGroup::Base));
}

void RenderCanvas::repaintViewRectangle(const QRect& ur, bool immediate)
{
    if (m_printingMode || ur.width() == 0 || ur.height() == 0) return;

    QRect vr = viewRect();
    if (m_view && ur.intersects(vr)) {
        // We always just invalidate the root view, since we could be an iframe that is clipped out
        // or even invisible.
        QRect r = ur.intersect(vr);
        DOM::ElementImpl* elt = element()->getDocument()->ownerElement();
        if (!elt)
            m_view->repaintRectangle(r, immediate);
        else {
            // Subtract out the contentsX and contentsY offsets to get our coords within the viewing
            // rectangle.
            r.setX(r.x() - m_view->contentsX());
            r.setY(r.y() - m_view->contentsY());
            
            RenderObject* obj = elt->renderer();
            int frameOffset = (m_view->frameStyle() != QFrame::NoFrame) ? 2 : 0;
            r.setX(r.x() + obj->borderLeft()+obj->paddingLeft() + frameOffset);
            r.setY(r.y() + obj->borderTop()+obj->paddingTop() + frameOffset);
            obj->repaintRectangle(r, immediate);
        }
    }
}

QRect RenderCanvas::getAbsoluteRepaintRect()
{
    QRect result;
    if (m_view && !m_printingMode)
        result = QRect(m_view->contentsX(), m_view->contentsY(),
                       m_view->visibleWidth(), m_view->visibleHeight());
    return result;
}

void RenderCanvas::computeAbsoluteRepaintRect(QRect& r, bool f)
{
    if (m_printingMode) return;

    if (f && m_view) {
        r.setX(r.x() + m_view->contentsX());
        r.setY(r.y() + m_view->contentsY());
    }
}


static QRect enclosingPositionedRect (RenderObject *n)
{
    RenderObject *enclosingParent =  n->containingBlock();
    QRect rect(0,0,0,0);
    if (enclosingParent) {
        int ox, oy;
        enclosingParent->absolutePosition(ox, oy);
        rect.setX(ox);
        rect.setY(oy);
        rect.setWidth (enclosingParent->width());
        rect.setHeight (enclosingParent->height());
    }
    return rect;
}

void RenderCanvas::absoluteRects(QValueList<QRect>& rects, int _tx, int _ty)
{
    rects.append(QRect(_tx, _ty, m_layer->width(), m_layer->height()));
}

QRect RenderCanvas::selectionRect() const
{
    RenderObject *r = m_selectionStart;
    if (!r)
        return QRect();
    
    QRect selectionRect = enclosingPositionedRect(r);

    while (r && r != m_selectionEnd)
    {
        RenderObject* n;
        if ( !(n = r->firstChild()) ){
            if ( !(n = r->nextSibling()) )
            {
                n = r->parent();
                while (n && !n->nextSibling())
                    n = n->parent();
                if (n)
                    n = n->nextSibling();
            }
        }
        r = n;
        if (r) {
            selectionRect = selectionRect.unite(enclosingPositionedRect(r));
        }
    }

    return selectionRect;
}

void RenderCanvas::setSelection(RenderObject *s, int sp, RenderObject *e, int ep)
{
    // Check we got valid renderobjects. www.msnbc.com and clicking around, to find the case where this happened.
    if ( !s || !e )
    {
        kdWarning(6040) << "RenderCanvas::setSelection() called with start=" << s << " end=" << e << endl;
        return;
    }
    //kdDebug( 6040 ) << "RenderCanvas::setSelection(" << s << "," << sp << "," << e << "," << ep << ")" << endl;

#if APPLE_CHANGES
    // Cut out early if the selection hasn't changed.
    if (m_selectionStart == s && m_selectionStartPos == sp &&
        m_selectionEnd == e && m_selectionEndPos == ep){
        return;
    }

    // Record the old selected objects.  Will be used later
    // to delta again the selected objects.
    
    RenderObject *oldStart = m_selectionStart;
    int oldStartPos = m_selectionStartPos;
    RenderObject *oldEnd = m_selectionEnd;
    int oldEndPos = m_selectionEndPos;
    QPtrList<RenderObject> oldSelectedInside;
    QPtrList<RenderObject> newSelectedInside;
    RenderObject *os = oldStart;

    while (os && os != oldEnd)
    {
        RenderObject* no;
        if (!(no = os->firstChild())) {
            if ( !(no = os->nextSibling()) )
            {
                no = os->parent();
                while (no && !no->nextSibling())
                    no = no->parent();
                if (no)
                    no = no->nextSibling();
            }
        }
        if (os->selectionState() == SelectionInside && !oldSelectedInside.containsRef(os))
            oldSelectedInside.append(os);
            
        os = no;
    }
    clearSelection(false);
#else
    clearSelection();
#endif

    while (s->firstChild())
        s = s->firstChild();
    while (e->lastChild())
        e = e->lastChild();

    // set selection start
    if (m_selectionStart)
        m_selectionStart->setIsSelectionBorder(false);
    m_selectionStart = s;
    if (m_selectionStart)
        m_selectionStart->setIsSelectionBorder(true);
    m_selectionStartPos = sp;

    // set selection end
    if (m_selectionEnd)
        m_selectionEnd->setIsSelectionBorder(false);
    m_selectionEnd = e;
    if (m_selectionEnd)
        m_selectionEnd->setIsSelectionBorder(true);
    m_selectionEndPos = ep;

    // update selection status of all objects between m_selectionStart and m_selectionEnd
    RenderObject* o = s;
    
    while (o && o!=e)
    {
        if (o->style()->userSelect() != SELECT_NONE)
            o->setSelectionState(SelectionInside);
//      kdDebug( 6040 ) << "setting selected " << o << ", " << o->isText() << endl;
        RenderObject* no = 0;
        if (!(no = o->firstChild()))
            if ( !(no = o->nextSibling()) )
            {
                no = o->parent();
                while (no && !no->nextSibling())
                    no = no->parent();
                if (no)
                    no = no->nextSibling();
            }
#if APPLE_CHANGES
        if (o->selectionState() == SelectionInside && !newSelectedInside.containsRef(o))
            newSelectedInside.append(o);
#endif
            
        o=no;
    }
    
    if (s->style()->userSelect() != SELECT_NONE)
        s->setSelectionState(SelectionStart);
    if (e->style()->userSelect() != SELECT_NONE)
        e->setSelectionState(SelectionEnd);
    if (s == e && s->style()->userSelect() != SELECT_NONE)
        s->setSelectionState(SelectionBoth);

#if APPLE_CHANGES
    if (!m_view)
        return;

    newSelectedInside.remove (s);
    newSelectedInside.remove (e);
    
    QRect updateRect;

    // Don't use repaint() because it will cause all rects to
    // be united (see khtmlview::scheduleRepaint()).  Instead
    // just draw damage rects for objects that have a change
    // in selection state.
    
    // Are any of the old fully selected objects not in the new selection?
    // If so we have to draw them.
    // Could be faster by building list of non-intersecting rectangles rather
    // than unioning rectangles.
    QPtrListIterator<RenderObject> oldIterator(oldSelectedInside);
    bool firstRect = true;
    for (; oldIterator.current(); ++oldIterator){
        if (!newSelectedInside.containsRef(oldIterator.current())){
            if (firstRect){
                updateRect = enclosingPositionedRect(oldIterator.current());
                firstRect = false;
            }
            else
                updateRect = updateRect.unite(enclosingPositionedRect(oldIterator.current()));
        }
    }
    if (!firstRect){
        m_view->updateContents( updateRect );
    }

    // Are any of the new fully selected objects not in the previous selection?
    // If so we have to draw them.
    // Could be faster by building list of non-intersecting rectangles rather
    // than unioning rectangles.
    QPtrListIterator<RenderObject> newIterator(newSelectedInside);
    firstRect = true;
    for (; newIterator.current(); ++newIterator){
        if (!oldSelectedInside.containsRef(newIterator.current())){
            if (firstRect){
                updateRect = enclosingPositionedRect(newIterator.current());
                firstRect = false;
            }
            else
                updateRect = updateRect.unite(enclosingPositionedRect(newIterator.current()));
        }
    }
    if (!firstRect) {
        m_view->updateContents( updateRect );
    }
    
    // Is the new starting object different, or did the position in the starting
    // element change?  If so we have to draw it.
    if (oldStart != m_selectionStart || 
        (oldStart == oldEnd && (oldStartPos != m_selectionStartPos || oldEndPos != m_selectionEndPos)) ||
        (oldStart == m_selectionStart && oldStartPos != m_selectionStartPos)){
        m_view->updateContents( enclosingPositionedRect(m_selectionStart) );
    }

    // Draw the old selection start object if it's different than the new selection
    // start object.
    if (oldStart && oldStart != m_selectionStart){
        m_view->updateContents( enclosingPositionedRect(oldStart) );
    }
    
    // Does the selection span objects and is the new end object different, or did the position
    // in the end element change?  If so we have to draw it.
    if (oldStart != oldEnd && 
        (oldEnd != m_selectionEnd ||
        (oldEnd == m_selectionEnd && oldEndPos != m_selectionEndPos))){
        m_view->updateContents( enclosingPositionedRect(m_selectionEnd) );
    }
    
    // Draw the old selection end object if it's different than the new selection
    // end object.
    if (oldEnd && oldEnd != m_selectionEnd){
        m_view->updateContents( enclosingPositionedRect(oldEnd) );
    }
#else
    repaint();
#endif
}


#if APPLE_CHANGES
void RenderCanvas::clearSelection(bool doRepaint)
#else
void RenderCanvas::clearSelection()
#endif
{
    // update selection status of all objects between m_selectionStart and m_selectionEnd
    RenderObject* o = m_selectionStart;
    while (o && o!=m_selectionEnd)
    {
        if (o->selectionState()!=SelectionNone)
#if APPLE_CHANGES
            if (doRepaint)
#endif
                o->repaint();
        o->setSelectionState(SelectionNone);
        RenderObject* no;
        if ( !(no = o->firstChild()) )
            if ( !(no = o->nextSibling()) )
            {
                no = o->parent();
                while (no && !no->nextSibling())
                    no = no->parent();
                if (no)
                    no = no->nextSibling();
            }
        o=no;
    }
    if (m_selectionEnd)
    {
        m_selectionEnd->setSelectionState(SelectionNone);
        // check if selection is collapsed
        if (m_selectionStart != m_selectionEnd || m_selectionStartPos != m_selectionEndPos)
#if APPLE_CHANGES
            if (doRepaint)
#endif
                m_selectionEnd->repaint();
    }

    // set selection start & end to 0
    if (m_selectionStart)
        m_selectionStart->setIsSelectionBorder(false);
    m_selectionStart = 0;
    m_selectionStartPos = -1;

    if (m_selectionEnd)
        m_selectionEnd->setIsSelectionBorder(false);
    m_selectionEnd = 0;
    m_selectionEndPos = -1;
}

void RenderCanvas::selectionStartEnd(int& spos, int& epos)
{
    spos = m_selectionStartPos;
    epos = m_selectionEndPos;
}

QRect RenderCanvas::viewRect() const
{
    if (m_printingMode)
        return QRect(0,0, m_width, m_height);
    else if (m_view)
        return QRect(m_view->contentsX(),
            m_view->contentsY(),
            m_view->visibleWidth(),
            m_view->visibleHeight());
    else return QRect(0,0,m_rootWidth,m_rootHeight);
}

int RenderCanvas::docHeight() const
{
    int h;
    if (m_printingMode || !m_view)
        h = m_height;
    else
        h = m_view->visibleHeight();

    int lowestPos = lowestPosition();
    if( lowestPos > h )
        h = lowestPos;

    // FIXME: This doesn't do any margin collapsing.
    // Instead of this dh computation we should keep the result
    // when we call RenderBlock::layout.
    int dh = 0;
    for (RenderObject *c = firstChild(); c; c = c->nextSibling()) {
        dh += c->height() + c->marginTop() + c->marginBottom();
    }
    if( dh > h )
        h = dh;

    return h;
}

int RenderCanvas::docWidth() const
{
    int w;
    if (m_printingMode || !m_view)
        w = m_width;
    else
        w = m_view->visibleWidth();

    int rightmostPos = rightmostPosition();
    if( rightmostPos > w )
        w = rightmostPos;

    for (RenderObject *c = firstChild(); c; c = c->nextSibling()) {
        int dw = c->width() + c->marginLeft() + c->marginRight();
        if( dw > w )
            w = dw;
    }
    return w;
}

#if APPLE_CHANGES
// The idea here is to take into account what object is moving the pagination point, and
// thus choose the best place to chop it.
void RenderCanvas::setBestTruncatedAt(int y, RenderObject *forRenderer, bool forcedBreak)
{
    // Nobody else can set a page break once we have a forced break.
    if (m_forcedPageBreak) return;
    
    // Forced breaks always win over unforced breaks.
    if (forcedBreak) {
        m_forcedPageBreak = true;
        m_bestTruncatedAt = y;
        return;
    }
    
    // prefer the widest object who tries to move the pagination point
    int width = forRenderer->width();
    if (width > m_truncatorWidth) {
        m_truncatorWidth = width;
        m_bestTruncatedAt = y;
    }
}
#endif
