QwtPicker filters all mouse and keyboard events of a widget and translates them into an array of selected points. Depending on the QwtPicker::SelectionType the selection might be a single point, a rectangle or a polygon. The selection process is supported by optional rubberbands (rubberband selection) and position labels.
QwtPicker is useful for widgets where the event handlers canīt be overloaded, like for components of composite widgets. It offers alternative handlers for mouse and key events.
#include <qwt_picker.h> QwtPicker *picker = new QwtPicker(widget); picker->setCursorLabelMode(QwtPicker::ActiveOnly); connect(picker, SIGNAL(selected(const QPointArray &)), ...); // emit the position of clicks on widget picker->setSelectionFlags(QwtPicker::PointSelection | QwtPicker::ClickSelection); ... // now select rectangles picker->setSelectionFlags(QwtPicker::RectSelection | QwtPicker::DragSelection); picker->setRubberBand(QwtPicker::RectRubberBand);
The commands are initiated from a small state machine (QwtPickerMachine) that translates mouse and key events. There are a couple of predefined state machines for point, rect and polygon selections. The selectionFlags() control which one should be used. It is possible to use other machines by overloading stateMachine().
The picker is active (isActive()), between begin() and end(). In active state the rubberband is displayed, and the cursor label is visible in case of cursorLabelMode is ActiveOnly or AlwaysOn.
The cursor can be moved using the arrow keys. All selections can be aborted using the abort key. (QwtEventPattern::KeyPatternCode)
Definition at line 79 of file qwt_picker.h.
Public Types | |
enum | SelectionType { NoSelection = 0, PointSelection = 1, RectSelection = 2, PolygonSelection = 4 } |
enum | RectSelectionType { CornerToCorner = 64, CenterToCorner = 128, CenterToRadius = 256 } |
enum | SelectionMode { ClickSelection = 1024, DragSelection = 2048 } |
enum | RubberBand { NoRubberBand = 0, HLineRubberBand, VLineRubberBand, CrossRubberBand, RectRubberBand, EllipseRubberBand, PolygonRubberBand, UserRubberBand = 100 } |
enum | DisplayMode { AlwaysOff, AlwaysOn, ActiveOnly } |
enum | ResizeMode { Stretch, KeepSize } |
Signals | |
void | selected (const QPointArray &pa) |
void | appended (const QPoint &pos) |
void | moved (const QPoint &pos) |
void | changed (const QPointArray &pa) |
Public Member Functions | |
QwtPicker (QWidget *, const char *name=0) | |
QwtPicker (int selectionFlags, RubberBand rubberBand, DisplayMode cursorLabelMode, QWidget *, const char *name=0) | |
virtual | ~QwtPicker () |
virtual void | setSelectionFlags (int) |
int | selectionFlags () const |
virtual void | setRubberBand (RubberBand) |
RubberBand | rubberBand () const |
virtual void | setCursorLabelMode (DisplayMode) |
DisplayMode | cursorLabelMode () const |
virtual void | setResizeMode (ResizeMode) |
ResizeMode | resizeMode () const |
virtual void | setRubberBandPen (const QPen &) |
QPen | rubberBandPen () const |
virtual void | setCursorLabelPen (const QPen &) |
QPen | cursorLabelPen () const |
virtual void | setCursorLabelFont (const QFont &) |
QFont | cursorLabelFont () const |
bool | isEnabled () const |
virtual void | setEnabled (bool) |
bool | isActive () const |
virtual bool | eventFilter (QObject *, QEvent *) |
QWidget * | parentWidget () |
const QWidget * | parentWidget () const |
virtual QRect | pickRect () const |
const QPointArray & | selection () const |
virtual bool | event (QEvent *) |
Protected Member Functions | |
virtual bool | accept (QPointArray &selection) const |
virtual void | transition (const QEvent *) |
virtual void | begin () |
virtual void | append (const QPoint &) |
virtual void | move (const QPoint &) |
virtual bool | end (bool ok=TRUE) |
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 | drawRubberBand (const QRect &clipRect=QRect()) const |
virtual void | drawRubberBand (QPainter *, const QRect &rect, const QPointArray &) const |
virtual void | drawCursorLabel (const QRect &clipRect=QRect()) const |
virtual void | drawCursorLabel (QPainter *, const QRect &rect, const QPoint &, const QPointArray &) const |
virtual void | stretchSelection (const QSize &oldSize, const QSize &newSize) |
virtual QString | cursorLabel (const QPoint &pos) const |
virtual QwtPickerMachine * | stateMachine (int) const |
void | repaint (const QRect &rect=QRect()) |
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Definition at line 223 of file qwt_picker.h. Referenced by cursorLabelMode(). |
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Selection subtype for RectSelection This enum type describes the type of rectangle selections. It can be orīd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags().
The default value is CornerToCorner. Definition at line 149 of file qwt_picker.h. |
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Controls what to do with the selected points of an active selection when the observed widget is resized.
The default value is Stretch.
Definition at line 242 of file qwt_picker.h. Referenced by resizeMode(). |
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Rubberband style
The default value is NoRubberBand. Definition at line 193 of file qwt_picker.h. Referenced by rubberBand(). |
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Values of this enum type orīd together with a SelectionType value identifies which state machine should be used for the selection. The default value is ClickSelection.
Definition at line 163 of file qwt_picker.h. |
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This enum type describes the type of a selection. It can be orīd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags()
The default value is NoSelection. Definition at line 123 of file qwt_picker.h. |
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Constructor Creates an picker that is enabled, but where selection flags s set to NoSelection, rubberband and cursor label are disabled.
Definition at line 30 of file qwt_picker.cpp. |
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Constructor
Definition at line 46 of file qwt_picker.cpp. |
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Destructor.
Definition at line 54 of file qwt_picker.cpp. |
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Validate and fixup the selection. Accepts all selections unmodified
Reimplemented in QwtPlotZoomer. Definition at line 1124 of file qwt_picker.cpp. Referenced by end(). |
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Append a point to the selection and update rubberband and cursor label. The appended() signal is emitted.
Reimplemented in QwtPlotPicker. Definition at line 1082 of file qwt_picker.cpp. References appended(), drawCursorLabel(), and drawRubberBand(). Referenced by QwtPlotPicker::append(), and transition(). |
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A signal emitted when a point has been appended to the selection
Referenced by append(). |
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Open a selection setting the state to active
Reimplemented in QwtPlotZoomer. Definition at line 1013 of file qwt_picker.cpp. References cursorLabelMode(), drawCursorLabel(), and parentWidget(). Referenced by QwtPlotZoomer::begin(), and transition(). |
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A signal emitted when the active selection has been changed. This might happen when the observed widget is resized.
Referenced by stretchSelection(). |
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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 ī, ī. The format for the string conversion is "%d".
Reimplemented in QwtPlotPicker. Definition at line 408 of file qwt_picker.cpp. References rubberBand(). Referenced by drawCursorLabel(). |
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Definition at line 336 of file qwt_picker.cpp. |
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Definition at line 240 of file qwt_picker.cpp. References DisplayMode. Referenced by begin(), drawCursorLabel(), and end(). |
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Definition at line 365 of file qwt_picker.cpp. |
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Draw a cursor label. The default position of the label is top-right of the cursor. In case of a rubberband the label is placed not to conflict with the rubberband.
Definition at line 627 of file qwt_picker.cpp. References QwtText::boundingRect(), cursorLabel(), QwtText::draw(), isActive(), QwtText::makeText(), and rubberBand(). |
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Draw the cursor label. The cursor label is painted in Qt::XorROP mode, what means the first call paints the second erases the painted rubberband.
Definition at line 580 of file qwt_picker.cpp. References cursorLabelMode(), isActive(), parentWidget(), and pickRect(). Referenced by append(), begin(), end(), event(), eventFilter(), setCursorLabelFont(), setCursorLabelPen(), setEnabled(), widgetMouseMoveEvent(), and widgetWheelEvent(). |
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Draw a rubberband , depending on rubberBand() and selectionFlags()
Definition at line 472 of file qwt_picker.cpp. References QwtPainter::drawEllipse(), QwtPainter::drawLine(), QwtPainter::drawRect(), rubberBand(), and selectionFlags(). |
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Draw the rubberband. The rubberband is painted in Qt::XorROP mode, what means the first call paints the second erases the painted rubberband.
Definition at line 437 of file qwt_picker.cpp. References isActive(), parentWidget(), pickRect(), rubberBand(), and rubberBandPen(). Referenced by append(), end(), event(), eventFilter(), move(), and setRubberBandPen(). |
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Close a selection setting the state to inactive. The selection is validated and maybe fixed by QwtPicker::accept().
Reimplemented in QwtPlotPicker, and QwtPlotZoomer. Definition at line 1044 of file qwt_picker.cpp. References accept(), cursorLabelMode(), drawCursorLabel(), drawRubberBand(), and selected(). Referenced by QwtPlotPicker::end(), transition(), and widgetKeyPressEvent(). |
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Event Handler. Paint events for the observed widgets require to repaint rubberband an cursor label too. To delay them until the widget is repainted the event filter sends a QEvent::Paint to the picker, that is handled here.
Definition at line 702 of file qwt_picker.cpp. References drawCursorLabel(), and drawRubberBand(). |
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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 cursor label up to date.
Definition at line 728 of file qwt_picker.cpp. References drawCursorLabel(), drawRubberBand(), parentWidget(), repaint(), stretchSelection(), widgetKeyPressEvent(), widgetKeyReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetMousePressEvent(), widgetMouseReleaseEvent(), and widgetWheelEvent(). |
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A picker is active between begin() and end().
Definition at line 1133 of file qwt_picker.cpp. Referenced by drawCursorLabel(), drawRubberBand(), QwtPlotZoomer::widgetKeyPressEvent(), and widgetKeyPressEvent(). |
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Definition at line 306 of file qwt_picker.cpp. Referenced by setCursorLabelFont(), and setCursorLabelPen(). |
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Move the last point of the selection The moved() signal is emitted.
Reimplemented in QwtPlotPicker. Definition at line 1108 of file qwt_picker.cpp. References drawRubberBand(), and moved(). Referenced by QwtPlotPicker::move(), and transition(). |
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A signal emitted whenever the last appended point of the selection has been moved.
Referenced by move(). |
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Return the parent widget, where the selection happens.
Definition at line 155 of file qwt_picker.cpp. |
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Return the parent widget, where the selection happens.
Definition at line 145 of file qwt_picker.cpp. Referenced by begin(), QwtPlotPicker::canvas(), drawCursorLabel(), drawRubberBand(), eventFilter(), pickRect(), setEnabled(), transition(), and widgetKeyPressEvent(). |
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Find the area of the observed widget, where selection might happen.
Definition at line 1205 of file qwt_picker.cpp. References parentWidget(). Referenced by drawCursorLabel(), drawRubberBand(), widgetKeyPressEvent(), widgetMouseMoveEvent(), and widgetWheelEvent(). |
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Repaint cursor label and rubberband on top of the widget. Send a QEvent::Paint event to the picker
Definition at line 687 of file qwt_picker.cpp. Referenced by eventFilter(). |
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Definition at line 269 of file qwt_picker.cpp. References ResizeMode. |
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Definition at line 206 of file qwt_picker.cpp. References RubberBand. Referenced by QwtPlotPicker::cursorLabel(), cursorLabel(), drawCursorLabel(), and drawRubberBand(). |
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Definition at line 390 of file qwt_picker.cpp. Referenced by drawRubberBand(). |
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A signal emitting the selected points, at the end of a selection.
Referenced by end(). |
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Return Selected points.
Definition at line 1139 of file qwt_picker.cpp. Referenced by QwtPlotZoomer::end(), and QwtPlotPicker::end(). |
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Definition at line 184 of file qwt_picker.cpp. Referenced by drawRubberBand(), and QwtPlotPicker::end(). |
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Set the font for the cursor label
Definition at line 317 of file qwt_picker.cpp. References drawCursorLabel(), and isEnabled(). |
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Set the display mode of the cursor label. A cursor label dispays the current position of the cursor as a string. The display mode controls if the label has to be displayed whenever the observed widget has focus and cursor (AlwaysOn), never (AlwaysOff), or only when the selection is active (ActiveOnly).
Definition at line 227 of file qwt_picker.cpp. |
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Set the pen for the cursor label
Definition at line 347 of file qwt_picker.cpp. References drawCursorLabel(), and isEnabled(). |
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En/disable the picker. When enabled is TRUE an event filter is installed for the observed widget, otherwise the event filter is removed.
Definition at line 283 of file qwt_picker.cpp. References drawCursorLabel(), and parentWidget(). |
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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.
Definition at line 259 of file qwt_picker.cpp. |
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Set the rubberband style
Definition at line 197 of file qwt_picker.cpp. |
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Set the pen for the rubberband
Definition at line 376 of file qwt_picker.cpp. References drawRubberBand(). |
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Set the selection flags
Reimplemented in QwtPlotZoomer. Definition at line 173 of file qwt_picker.cpp. References stateMachine(). Referenced by QwtPlotZoomer::setSelectionFlags(). |
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Create a state machine depending on the selection flags.
Definition at line 121 of file qwt_picker.cpp. Referenced by setSelectionFlags(). |
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Scale the selection by the ratios of oldSize and newSize The changed() signal is emitted.
Definition at line 1153 of file qwt_picker.cpp. References changed(). Referenced by eventFilter(). |
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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()).
Definition at line 970 of file qwt_picker.cpp. References append(), begin(), end(), move(), parentWidget(), and QwtPickerMachine::transition(). Referenced by widgetKeyPressEvent(), widgetKeyReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetMousePressEvent(), widgetMouseReleaseEvent(), and widgetWheelEvent(). |
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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. Definition at line 904 of file qwt_picker.cpp. References end(), isActive(), QwtEventPattern::keyMatch(), parentWidget(), pickRect(), QwtPickerMachine::reset(), and transition(). Referenced by eventFilter(), and QwtPlotZoomer::widgetKeyPressEvent(). |
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Handle a key release event for the observed widget. Passes the event to the state machine.
Definition at line 958 of file qwt_picker.cpp. References transition(). Referenced by eventFilter(). |
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Handle mouse double click event for the observed widget. Empty implementation, does nothing.
Definition at line 861 of file qwt_picker.cpp. References transition(). Referenced by eventFilter(). |
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Handle a mouse move event for the observed widget. Move the last point of the selection in case of isActive() == TRUE
Definition at line 822 of file qwt_picker.cpp. References drawCursorLabel(), pickRect(), and transition(). Referenced by eventFilter(). |
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Handle a mouse press event for the observed widget. Begin and/or end a selection depending on the selection flags.
Definition at line 808 of file qwt_picker.cpp. References transition(). Referenced by eventFilter(). |
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Handle a mouse relase event for the observed widget. End a selection depending on the selection flags.
Reimplemented in QwtPlotZoomer. Definition at line 847 of file qwt_picker.cpp. References transition(). Referenced by eventFilter(), and QwtPlotZoomer::widgetMouseReleaseEvent(). |
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Handle a wheel event for the observed widget. Move the last point of the selection in case of isActive() == TRUE
Definition at line 876 of file qwt_picker.cpp. References drawCursorLabel(), pickRect(), and transition(). Referenced by eventFilter(). |