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 trackers.
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->setTrackerMode(QwtPicker::ActiveOnly); connect(picker, SIGNAL(selected(const SelectedPoints &)), ...); // 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 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)
Definition at line 83 of file qwt_picker.h.
Public Types | |
typedef QPointArray | SelectedPoints |
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 QwtPicker::SelectedPoints &pa) |
void | appended (const QPoint &pos) |
void | moved (const QPoint &pos) |
void | changed (const SelectedPoints &pa) |
Public Member Functions | |
QwtPicker (QWidget *parent) | |
QwtPicker (int selectionFlags, RubberBand rubberBand, DisplayMode trackerMode, QWidget *) | |
virtual | ~QwtPicker () |
virtual void | setSelectionFlags (int) |
int | selectionFlags () const |
virtual void | setRubberBand (RubberBand) |
RubberBand | rubberBand () const |
virtual void | setTrackerMode (DisplayMode) |
DisplayMode | trackerMode () const |
virtual void | setResizeMode (ResizeMode) |
ResizeMode | resizeMode () const |
virtual void | setRubberBandPen (const QPen &) |
QPen | rubberBandPen () const |
virtual void | setTrackerPen (const QPen &) |
QPen | trackerPen () const |
virtual void | setTrackerFont (const QFont &) |
QFont | trackerFont () 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 SelectedPoints & | selection () const |
virtual void | drawRubberBand (QPainter *) const |
virtual void | drawTracker (QPainter *) const |
Protected Member Functions | |
virtual bool | accept (SelectedPoints &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 *) |
QRect | trackerRect (QPainter *painter) const |
virtual void | stretchSelection (const QSize &oldSize, const QSize &newSize) |
virtual QString | trackerText (const QPoint &pos) const |
virtual QwtPickerMachine * | stateMachine (int) const |
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Definition at line 225 of file qwt_picker.h. |
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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 146 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 244 of file qwt_picker.h. |
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Rubberband style
The default value is NoRubberBand. Definition at line 195 of file qwt_picker.h. |
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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 160 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 120 of file qwt_picker.h. |
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Constructor Creates an picker that is enabled, but where selection flag is set to NoSelection, rubberband and tracker are disabled.
Definition at line 165 of file qwt_picker.cpp. |
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Constructor
Definition at line 180 of file qwt_picker.cpp. |
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Destructor.
Definition at line 188 of file qwt_picker.cpp. |
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Validate and fixup the selection. Accepts all selections unmodified
Reimplemented in QwtPlotZoomer. Definition at line 1144 of file qwt_picker.cpp. Referenced by end(). |
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Append a point to the selection and update rubberband and tracker. The appended() signal is emitted.
Reimplemented in QwtPlotPicker. Definition at line 1103 of file qwt_picker.cpp. References appended(). 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 1036 of file qwt_picker.cpp. References parentWidget(), and trackerMode(). 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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Draw a rubberband , depending on rubberBand() and selectionFlags()
Definition at line 573 of file qwt_picker.cpp. References QwtPainter::drawEllipse(), QwtPainter::drawLine(), QwtPainter::drawRect(), isActive(), pickRect(), rubberBand(), rubberBandPen(), and selectionFlags(). |
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Draw the tracker
Definition at line 670 of file qwt_picker.cpp. References QwtText::draw(), QwtText::makeText(), and trackerText(). |
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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 1068 of file qwt_picker.cpp. References accept(), selected(), and trackerMode(). Referenced by QwtPlotPicker::end(), transition(), and widgetKeyPressEvent(). |
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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 tracker up to date.
Definition at line 760 of file qwt_picker.cpp. References parentWidget(), stretchSelection(), widgetKeyPressEvent(), widgetKeyReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetMousePressEvent(), widgetMouseReleaseEvent(), and widgetWheelEvent(). |
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A picker is active between begin() and end().
Definition at line 1153 of file qwt_picker.cpp. Referenced by drawRubberBand(), QwtPlotZoomer::widgetKeyPressEvent(), widgetKeyPressEvent(), and widgetMouseMoveEvent(). |
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Definition at line 454 of file qwt_picker.cpp. |
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Move the last point of the selection The moved() signal is emitted.
Reimplemented in QwtPlotPicker. Definition at line 1125 of file qwt_picker.cpp. References 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 302 of file qwt_picker.cpp. |
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Return the parent widget, where the selection happens.
Definition at line 292 of file qwt_picker.cpp. Referenced by begin(), QwtPlotPicker::canvas(), eventFilter(), pickRect(), setEnabled(), transition(), and widgetKeyPressEvent(). |
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Find the area of the observed widget, where selection might happen.
Definition at line 1225 of file qwt_picker.cpp. References parentWidget(). Referenced by drawRubberBand(), widgetKeyPressEvent(), widgetMouseMoveEvent(), and widgetWheelEvent(). |
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Definition at line 416 of file qwt_picker.cpp. |
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Definition at line 353 of file qwt_picker.cpp. Referenced by drawRubberBand(), QwtPlotPicker::trackerText(), and trackerText(). |
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Definition at line 527 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 1159 of file qwt_picker.cpp. Referenced by QwtPlotZoomer::end(), QwtPlotPicker::end(), and stretchSelection(). |
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Definition at line 331 of file qwt_picker.cpp. Referenced by drawRubberBand(), and QwtPlotPicker::end(). |
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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 430 of file qwt_picker.cpp. References 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 406 of file qwt_picker.cpp. |
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Set the rubberband style
Definition at line 344 of file qwt_picker.cpp. |
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Set the pen for the rubberband
Definition at line 514 of file qwt_picker.cpp. |
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Set the selection flags
Reimplemented in QwtPlotZoomer. Definition at line 320 of file qwt_picker.cpp. References stateMachine(). Referenced by QwtPlotZoomer::setSelectionFlags(). |
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Set the font for the tracker
Definition at line 465 of file qwt_picker.cpp. |
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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).
Definition at line 374 of file qwt_picker.cpp. |
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Set the pen for the tracker
Definition at line 490 of file qwt_picker.cpp. |
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Create a state machine depending on the selection flags.
Definition at line 268 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 1173 of file qwt_picker.cpp. References changed(), and selection(). Referenced by eventFilter(). |
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Definition at line 479 of file qwt_picker.cpp. |
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Definition at line 387 of file qwt_picker.cpp. |
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Definition at line 503 of file qwt_picker.cpp. |
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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 545 of file qwt_picker.cpp. References rubberBand(). Referenced by drawTracker(). |
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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 979 of file qwt_picker.cpp. References append(), begin(), end(), move(), and parentWidget(). 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 910 of file qwt_picker.cpp. References end(), isActive(), QwtEventPattern::keyMatch(), parentWidget(), pickRect(), 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 967 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 870 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 833 of file qwt_picker.cpp. References isActive(), 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 819 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 856 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 885 of file qwt_picker.cpp. References pickRect(), and transition(). Referenced by eventFilter(). |