QwtPicker provides selections on a widget. More...
#include <qwt_picker.h>
Public Types | |
enum | RubberBand { NoRubberBand = 0, HLineRubberBand, VLineRubberBand, CrossRubberBand, RectRubberBand, EllipseRubberBand, PolygonRubberBand, UserRubberBand = 100 } |
enum | DisplayMode { AlwaysOff, AlwaysOn, ActiveOnly } |
enum | ResizeMode { Stretch, KeepSize } |
Public Slots | |
void | setEnabled (bool) |
Signals | |
void | activated (bool on) |
void | selected (const QPolygon &polygon) |
void | appended (const QPoint &pos) |
void | moved (const QPoint &pos) |
void | removed (const QPoint &pos) |
void | changed (const QPolygon &selection) |
Public Member Functions | |
QwtPicker (QWidget *parent) | |
QwtPicker (RubberBand rubberBand, DisplayMode trackerMode, QWidget *) | |
virtual | ~QwtPicker () |
void | setStateMachine (QwtPickerMachine *) |
const QwtPickerMachine * | stateMachine () const |
QwtPickerMachine * | stateMachine () |
void | setRubberBand (RubberBand) |
RubberBand | rubberBand () const |
void | setTrackerMode (DisplayMode) |
DisplayMode | trackerMode () const |
void | setResizeMode (ResizeMode) |
ResizeMode | resizeMode () const |
void | setRubberBandPen (const QPen &) |
QPen | rubberBandPen () const |
void | setTrackerPen (const QPen &) |
QPen | trackerPen () const |
void | setTrackerFont (const QFont &) |
QFont | trackerFont () const |
bool | isEnabled () const |
bool | isActive () const |
virtual bool | eventFilter (QObject *, QEvent *) |
QWidget * | parentWidget () |
const QWidget * | parentWidget () const |
virtual QRect | pickRect () const |
virtual void | drawRubberBand (QPainter *) const |
virtual void | drawTracker (QPainter *) const |
virtual QwtText | trackerText (const QPoint &pos) const |
QPoint | trackerPosition () const |
QRect | trackerRect (const QFont &) const |
QPolygon | selection () const |
Protected Member Functions | |
virtual QPolygon | adjustedPoints (const QPolygon &) const |
virtual void | transition (const QEvent *) |
virtual void | begin () |
virtual void | append (const QPoint &) |
virtual void | move (const QPoint &) |
virtual void | remove () |
virtual bool | end (bool ok=true) |
virtual bool | accept (QPolygon &) const |
virtual void | reset () |
virtual void | widgetMousePressEvent (QMouseEvent *) |
virtual void | widgetMouseReleaseEvent (QMouseEvent *) |
virtual void | widgetMouseDoubleClickEvent (QMouseEvent *) |
virtual void | widgetMouseMoveEvent (QMouseEvent *) |
virtual void | widgetWheelEvent (QWheelEvent *) |
virtual void | widgetKeyPressEvent (QKeyEvent *) |
virtual void | widgetKeyReleaseEvent (QKeyEvent *) |
virtual void | widgetEnterEvent (QEvent *) |
virtual void | widgetLeaveEvent (QEvent *) |
virtual void | stretchSelection (const QSize &oldSize, const QSize &newSize) |
virtual void | updateDisplay () |
const QWidget * | rubberBandWidget () const |
const QWidget * | trackerWidget () const |
const QPolygon & | pickedPoints () const |
QwtPicker provides selections on a widget.
QwtPicker filters all enter, leave, mouse and keyboard events of a widget and translates them into an array of selected points.
The way how the points are collected depends on type of state machine that is connected to the picker. Qwt offers a couple of predefined state machines for selecting:
While these state machines cover the most common ways to collect points it is also possible to implement individual machines as well.
QwtPicker translates the picked points into a selection using the adjustedPoints method. adjustedPoints is intended to be reimplemented to fixup the selection according to application specific requirements. (F.e. when an application accepts rectangles of a fixed aspect ratio only.)
Optionally QwtPicker support the process of collecting points by a rubberband and tracker displaying a text for the current mouse position.
#include <qwt_picker.h> #include <qwt_picker_machine.h> QwtPicker *picker = new QwtPicker(widget); picker->setStateMachine(new QwtPickerDragRectMachine); picker->setTrackerMode(QwtPicker::ActiveOnly); picker->setRubberBand(QwtPicker::RectRubberBand);
The state machine triggers the following commands:
The picker is active (isActive()), between begin() and end(). In active state the rubberband is displayed, and the tracker is visible in case of trackerMode is ActiveOnly or AlwaysOn.
The cursor can be moved using the arrow keys. All selections can be aborted using the abort key. (QwtEventPattern::KeyPatternCode)
Display mode
Controls what to do with the selected points of an active selection when the observed widget is resized.
The default value is Stretch.
Rubberband style
The default value is NoRubberBand.
QwtPicker::QwtPicker | ( | QWidget * | parent | ) | [explicit] |
Constructor
Creates an picker that is enabled, but without a state machine. rubberband and tracker are disabled.
parent | Parent widget, that will be observed |
QwtPicker::QwtPicker | ( | RubberBand | rubberBand, | |
DisplayMode | trackerMode, | |||
QWidget * | parent | |||
) | [explicit] |
Constructor
rubberBand | Rubberband style | |
trackerMode | Tracker mode | |
parent | Parent widget, that will be observed |
QwtPicker::~QwtPicker | ( | ) | [virtual] |
Destructor.
bool QwtPicker::accept | ( | QPolygon & | ) | const [protected, virtual] |
Validate and fixup the selection.
Accepts all selections unmodified
selection | Selection to validate and fixup |
Reimplemented in QwtPlotZoomer.
void QwtPicker::activated | ( | bool | on | ) | [signal] |
A signal indicating, when the picker has been activated. Together with setEnabled() it can be used to implement selections with more than one picker.
on | True, when the picker has been activated |
QPolygon QwtPicker::adjustedPoints | ( | const QPolygon & | points | ) | const [protected, virtual] |
Map the pickedPoints() into a selection().
adjustedPoints() maps the points, that have been collected on the parentWidget() into a selection(). The default implementation simply returns the points unmodified.
The reason, why a selection() differs from the picked points depends on the application requirements. F.e. :
The example below is for a rectangular selection, where the first point is the center of the selected rectangle.
QPolygon MyPicker::adjustedPoints(const QPolygon &points) const { QPolygon adjusted; if ( points.size() == 2 ) { const int width = qAbs(points[1].x() - points[0].x()); const int height = qAbs(points[1].y() - points[0].y()); QRect rect(0, 0, 2 * width, 2 * height); rect.moveCenter(points[0]); adjusted += rect.topLeft(); adjusted += rect.bottomRight(); } return adjusted; }
void QwtPicker::append | ( | const QPoint & | pos | ) | [protected, virtual] |
Append a point to the selection and update rubberband and tracker. The appended() signal is emitted.
pos | Additional point |
Reimplemented in QwtPlotPicker.
void QwtPicker::appended | ( | const QPoint & | pos | ) | [signal] |
void QwtPicker::begin | ( | ) | [protected, virtual] |
Open a selection setting the state to active
Reimplemented in QwtPlotZoomer.
void QwtPicker::changed | ( | const QPolygon & | selection | ) | [signal] |
A signal emitted when the active selection has been changed. This might happen when the observed widget is resized.
selection | Changed selection |
void QwtPicker::drawRubberBand | ( | QPainter * | painter | ) | const [virtual] |
Draw a rubberband, depending on rubberBand()
painter | Painter, initialized with clip rect |
void QwtPicker::drawTracker | ( | QPainter * | painter | ) | const [virtual] |
bool QwtPicker::end | ( | bool | ok = true |
) | [protected, virtual] |
Close a selection setting the state to inactive.
The selection is validated and maybe fixed by accept().
ok | If true, complete the selection and emit a selected signal otherwise discard the selection. |
Reimplemented in QwtPlotPicker, and QwtPlotZoomer.
bool QwtPicker::eventFilter | ( | QObject * | o, | |
QEvent * | e | |||
) | [virtual] |
Event filter.
When isEnabled() == true all events of the observed widget are filtered. Mouse and keyboard events are translated into widgetMouse- and widgetKey- and widgetWheel-events. Paint and Resize events are handled to keep rubberband and tracker up to date.
bool QwtPicker::isActive | ( | ) | const |
bool QwtPicker::isEnabled | ( | ) | const |
void QwtPicker::move | ( | const QPoint & | pos | ) | [protected, virtual] |
Move the last point of the selection The moved() signal is emitted.
pos | New position |
Reimplemented in QwtPlotPicker.
void QwtPicker::moved | ( | const QPoint & | pos | ) | [signal] |
A signal emitted whenever the last appended point of the selection has been moved.
pos | Position of the moved last point of the selection. |
const QWidget * QwtPicker::parentWidget | ( | ) | const |
Return the parent widget, where the selection happens.
QWidget * QwtPicker::parentWidget | ( | ) |
Return the parent widget, where the selection happens.
const QPolygon & QwtPicker::pickedPoints | ( | ) | const [protected] |
Return the points, that have been collected so far. The selection() is calculated from the pickedPoints() in adjustedPoints().
QRect QwtPicker::pickRect | ( | ) | const [virtual] |
Find the area of the observed widget, where selection might happen.
void QwtPicker::remove | ( | ) | [protected, virtual] |
void QwtPicker::removed | ( | const QPoint & | pos | ) | [signal] |
A signal emitted whenever the last appended point of the selection has been removed.
void QwtPicker::reset | ( | ) | [protected, virtual] |
Reset the state machine and terminate (end(false)) the selection
QwtPicker::ResizeMode QwtPicker::resizeMode | ( | ) | const |
QwtPicker::RubberBand QwtPicker::rubberBand | ( | ) | const |
QPen QwtPicker::rubberBandPen | ( | ) | const |
const QWidget * QwtPicker::rubberBandWidget | ( | ) | const [protected] |
void QwtPicker::selected | ( | const QPolygon & | polygon | ) | [signal] |
A signal emitting the selected points, at the end of a selection.
polygon | Selected points |
QPolygon QwtPicker::selection | ( | ) | const |
void QwtPicker::setEnabled | ( | bool | enabled | ) | [slot] |
En/disable the picker.
When enabled is true an event filter is installed for the observed widget, otherwise the event filter is removed.
enabled | true or false |
void QwtPicker::setResizeMode | ( | ResizeMode | mode | ) |
Set the resize mode.
The resize mode controls what to do with the selected points of an active selection when the observed widget is resized.
Stretch means the points are scaled according to the new size, KeepSize means the points remain unchanged.
The default mode is Stretch.
mode | Resize mode |
void QwtPicker::setRubberBand | ( | RubberBand | rubberBand | ) |
Set the rubberband style
rubberBand | Rubberband style The default value is NoRubberBand. |
void QwtPicker::setRubberBandPen | ( | const QPen & | pen | ) |
Set the pen for the rubberband
pen | Rubberband pen |
void QwtPicker::setStateMachine | ( | QwtPickerMachine * | stateMachine | ) |
Set a state machine and delete the previous one
stateMachine | State machine |
void QwtPicker::setTrackerFont | ( | const QFont & | font | ) |
Set the font for the tracker
font | Tracker font |
void QwtPicker::setTrackerMode | ( | DisplayMode | mode | ) |
Set the display mode of the tracker.
A tracker displays information about current position of the cursor as a string. The display mode controls if the tracker has to be displayed whenever the observed widget has focus and cursor (AlwaysOn), never (AlwaysOff), or only when the selection is active (ActiveOnly).
mode | Tracker display mode |
void QwtPicker::setTrackerPen | ( | const QPen & | pen | ) |
Set the pen for the tracker
pen | Tracker pen |
QwtPickerMachine * QwtPicker::stateMachine | ( | ) |
const QwtPickerMachine * QwtPicker::stateMachine | ( | ) | const |
void QwtPicker::stretchSelection | ( | const QSize & | oldSize, | |
const QSize & | newSize | |||
) | [protected, virtual] |
Scale the selection by the ratios of oldSize and newSize The changed() signal is emitted.
oldSize | Previous size | |
newSize | Current size |
QFont QwtPicker::trackerFont | ( | ) | const |
QwtPicker::DisplayMode QwtPicker::trackerMode | ( | ) | const |
QPen QwtPicker::trackerPen | ( | ) | const |
QPoint QwtPicker::trackerPosition | ( | ) | const |
QRect QwtPicker::trackerRect | ( | const QFont & | font | ) | const |
Calculate the bounding rectangle for the tracker text from the current position of the tracker
font | Font of the tracker text |
QwtText QwtPicker::trackerText | ( | const QPoint & | pos | ) | const [virtual] |
Return the label for a position.
In case of HLineRubberBand the label is the value of the y position, in case of VLineRubberBand the value of the x position. Otherwise the label contains x and y position separated by a ',' .
The format for the string conversion is "%d".
pos | Position |
Reimplemented in QwtPlotPicker.
const QWidget * QwtPicker::trackerWidget | ( | ) | const [protected] |
void QwtPicker::transition | ( | const QEvent * | e | ) | [protected, virtual] |
Passes an event to the state machine and executes the resulting commands. Append and Move commands use the current position of the cursor (QCursor::pos()).
e | Event |
void QwtPicker::updateDisplay | ( | ) | [protected, virtual] |
Update the state of rubberband and tracker label.
void QwtPicker::widgetEnterEvent | ( | QEvent * | event | ) | [protected, virtual] |
Handle a enter event for the observed widget.
void QwtPicker::widgetKeyPressEvent | ( | QKeyEvent * | ke | ) | [protected, virtual] |
Handle a key press event for the observed widget.
Selections can be completely done by the keyboard. The arrow keys move the cursor, the abort key aborts a selection. All other keys are handled by the current state machine.
Reimplemented in QwtPlotZoomer.
void QwtPicker::widgetKeyReleaseEvent | ( | QKeyEvent * | ke | ) | [protected, virtual] |
Handle a key release event for the observed widget.
Passes the event to the state machine.
void QwtPicker::widgetLeaveEvent | ( | QEvent * | event | ) | [protected, virtual] |
Handle a leave event for the observed widget.
void QwtPicker::widgetMouseDoubleClickEvent | ( | QMouseEvent * | me | ) | [protected, virtual] |
Handle mouse double click event for the observed widget.
Empty implementation, does nothing.
void QwtPicker::widgetMouseMoveEvent | ( | QMouseEvent * | e | ) | [protected, virtual] |
Handle a mouse move event for the observed widget.
void QwtPicker::widgetMousePressEvent | ( | QMouseEvent * | e | ) | [protected, virtual] |
Handle a mouse press event for the observed widget.
void QwtPicker::widgetMouseReleaseEvent | ( | QMouseEvent * | e | ) | [protected, virtual] |
Handle a mouse relase event for the observed widget.
Reimplemented in QwtPlotZoomer.
void QwtPicker::widgetWheelEvent | ( | QWheelEvent * | e | ) | [protected, virtual] |
Handle a wheel event for the observed widget.
Move the last point of the selection in case of isActive() == true