QwtPicker − QwtPicker provides selections on a widget.
#include <qwt_picker.h>
Inherits QObject, and QwtEventPattern.
Inherited by QwtPlotPicker, and QwtPolarPicker.
enum
RubberBand { NoRubberBand = 0,
HLineRubberBand, VLineRubberBand,
CrossRubberBand, RectRubberBand,
EllipseRubberBand, PolygonRubberBand,
UserRubberBand = 100 }
enum DisplayMode { AlwaysOff, AlwaysOn,
ActiveOnly }
Display mode.
enum ResizeMode { Stretch, KeepSize
}
Public Types inherited from QwtEventPattern
enum MousePatternCode {
MouseSelect1, MouseSelect2,
MouseSelect3, MouseSelect4,
MouseSelect5, MouseSelect6,
MousePatternCount }
Symbolic mouse input codes.
enum KeyPatternCode { KeySelect1,
KeySelect2, KeyAbort, KeyLeft,
KeyRight, KeyUp, KeyDown,
KeyRedo, KeyUndo, KeyHome,
KeyPatternCount }
Symbolic keyboard input codes.
void
setEnabled (bool)
En/disable the picker.
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)
QwtPicker
(QWidget *parent)
QwtPicker (RubberBand rubberBand, DisplayMode
trackerMode, QWidget *)
virtual ˜QwtPicker ()
Destructor.
void setStateMachine (QwtPickerMachine *)
const QwtPickerMachine * stateMachine () const
QwtPickerMachine * stateMachine ()
void setRubberBand (RubberBand)
RubberBand rubberBand () const
void setTrackerMode (DisplayMode)
Set the display mode of the tracker.
DisplayMode trackerMode () const
void setResizeMode (ResizeMode)
Set the resize mode.
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 *)
override
Event filter.
QWidget * parentWidget ()
Return the parent widget, where the selection happens.
const QWidget * parentWidget () const
Return the parent widget, where the selection happens.
virtual QPainterPath pickArea () const
virtual void drawRubberBand (QPainter *) const
virtual void drawTracker (QPainter *) const
virtual QRegion trackerMask () const
virtual QRegion rubberBandMask () const
virtual QwtText trackerText (const QPoint &pos)
const
Return the label for a position.
QPoint trackerPosition () const
virtual QRect trackerRect (const QFont &) const
QPolygon selection () const
Public Member Functions inherited from QwtEventPattern
QwtEventPattern ()
virtual ˜QwtEventPattern ()
Destructor.
void initMousePattern (int numButtons)
void initKeyPattern ()
void setMousePattern (MousePatternCode,
Qt::MouseButton button,
Qt::KeyboardModifiers=Qt::NoModifier)
void setKeyPattern (KeyPatternCode, int key,
Qt::KeyboardModifiers modifiers=Qt::NoModifier)
void setMousePattern (const QVector<
MousePattern > &)
Change the mouse event patterns.
void setKeyPattern (const QVector<
KeyPattern > &)
Change the key event patterns.
const QVector< MousePattern > &
mousePattern () const
const QVector< KeyPattern > &
keyPattern () const
QVector< MousePattern > &
mousePattern ()
QVector< KeyPattern > &
keyPattern ()
bool mouseMatch (MousePatternCode, const
QMouseEvent *) const
Compare a mouse event with an event pattern.
bool keyMatch (KeyPatternCode, const QKeyEvent
*) const
Compare a key event with an event pattern.
virtual
QPolygon adjustedPoints (const QPolygon &) const
Map the pickedPoints() into a selection()
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)
Close a selection setting the state to inactive.
virtual bool accept (QPolygon &) const
Validate and fix up the selection.
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 ()
Update the state of rubber band and tracker label.
const QwtWidgetOverlay * rubberBandOverlay ()
const
const QwtWidgetOverlay * trackerOverlay ()
const
const QPolygon & pickedPoints () const
QRect trackerRect (const QSize &) const
Protected Member Functions inherited from QwtEventPattern
virtual bool mouseMatch
(const MousePattern &, const QMouseEvent *) const
Compare a mouse event with an event pattern.
virtual bool keyMatch (const KeyPattern &,
const QKeyEvent *) const
Compare a key event with an event pattern.
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:
|
• |
Nothing |
QwtPickerTrackerMachine
|
• |
Single points |
QwtPickerClickPointMachine, QwtPickerDragPointMachine
|
• |
Rectangles |
QwtPickerClickRectMachine, QwtPickerDragRectMachine
|
• |
Polygons |
QwtPickerPolygonMachine
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 fix up 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 rubber band and tracker displaying a text for the current mouse position.
Example
#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:
|
• |
begin() |
Activate/Initialize the selection.
|
• |
append() |
Add a new point
|
• |
move() |
Change the position of the last point.
|
• |
remove() |
Remove the last point.
|
• |
end() |
Terminate the selection and call accept to validate the picked points.
The picker is active (isActive()), between begin() and end(). In active state the rubber band 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)
Warning
In case of QWidget::NoFocus the focus policy of the observed widget is set to QWidget::WheelFocus and mouse tracking will be manipulated while the picker is active, or if trackerMode() is AlwayOn.
Definition at line 103 of file qwt_picker.h.
Display mode.
See also
setTrackerMode(), trackerMode(), isActive()
Enumerator
AlwaysOff
Display never.
AlwaysOn
Display always.
ActiveOnly
Display only when the selection is active.
Definition at line 161 of file qwt_picker.h.
Controls what to do with the selected points of an active selection when the observed widget is resized.
The default value is QwtPicker::Stretch.
See also
setResizeMode()
Enumerator
Stretch
All points are scaled according to the new size,.
KeepSize
All points remain unchanged.
Definition at line 181 of file qwt_picker.h.
Rubber band style
The default value is QwtPicker::NoRubberBand.
See also
setRubberBand(), rubberBand()
Enumerator
NoRubberBand
No rubberband.
HLineRubberBand
A horizontal line ( only for QwtPickerMachine::PointSelection )
VLineRubberBand
A vertical line ( only for QwtPickerMachine::PointSelection )
CrossRubberBand
A crosshair ( only for QwtPickerMachine::PointSelection )
RectRubberBand
A rectangle ( only for QwtPickerMachine::RectSelection )
EllipseRubberBand
An ellipse ( only for QwtPickerMachine::RectSelection )
PolygonRubberBand
A polygon ( only for QwtPickerMachine::PolygonSelection )
UserRubberBand
Values >= UserRubberBand can be used to define additional rubber bands.
Definition at line 127 of file qwt_picker.h.
Constructor
Creates an picker that is enabled, but without a state machine. rubber band and tracker are disabled.
Parameters
parent Parent widget, that will be observed
Definition at line 169 of file qwt_picker.cpp.
Constructor
Parameters
rubberBand Rubber band
style
trackerMode Tracker mode
parent Parent widget, that will be observed
Definition at line 182 of file qwt_picker.cpp.
Destructor.
Definition at line 190 of file qwt_picker.cpp.
Validate and fix up the selection. Accepts all selections unmodified
Parameters
selection Selection to validate and fix up
Returns
true, when accepted, false otherwise
Reimplemented in QwtPlotZoomer.
Definition at line 1402 of file qwt_picker.cpp.
A signal indicating, when the picker has been activated. Together with setEnabled() it can be used to implement selections with more than one picker.
Parameters
on True, when the picker has been activated
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. :
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• |
A rectangular selection might need to have a specific aspect ratio only. | ||
|
• |
A selection could accept non intersecting polygons only. | ||
|
• |
... |
The example below is for a rectangular selection, where the first point is the center of the selected rectangle.
Example
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;
}
Parameters
points Selected points
Returns
Selected points unmodified
Definition at line 783 of file qwt_picker.cpp.
Append a point to the selection and update rubber band and tracker. The appended() signal is emitted.
Parameters
pos Additional point
See also
isActive(), begin(), end(), move(), appended()
Reimplemented in QwtPlotPicker, and QwtPolarPicker.
Definition at line 1339 of file qwt_picker.cpp.
A signal emitted when a point has been appended to the selection
Parameters
pos Position of the appended point.
See also
append(). moved()
Open a selection setting the state to active
See also
isActive(), end(), append(), move()
Reimplemented in QwtPlotZoomer.
Definition at line 1258 of file qwt_picker.cpp.
A signal emitted when the active selection has been changed. This might happen when the observed widget is resized.
Parameters
selection Changed selection
See also
stretchSelection()
Draw a rubber band, depending on rubberBand()
Parameters
painter Painter, initialized with a clip region
See also
rubberBand(), RubberBand
Definition at line 637 of file qwt_picker.cpp.
Draw the tracker
Parameters
painter Painter
See also
trackerRect(), trackerText()
Definition at line 732 of file qwt_picker.cpp.
Close a selection setting the state to inactive. The selection is validated and maybe fixed by accept().
Parameters
ok If true, complete the selection and emit a selected signal otherwise discard the selection.
Returns
true if the selection is accepted, false otherwise
See also
isActive(), begin(), append(), move(), selected(), accept()
Reimplemented in QwtPlotPicker, QwtPlotZoomer, and QwtPolarPicker.
Definition at line 1291 of file qwt_picker.cpp.
Event filter. When isEnabled() is 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 rubber band and tracker up to date.
Parameters
object Object to be
filtered
event Event
Returns
Always false.
See also
widgetEnterEvent(), widgetLeaveEvent(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent(), QObject::installEventFilter(), QObject::event()
Definition at line 912 of file qwt_picker.cpp.
A picker is active between begin() and end().
Returns
true if the selection is active.
Definition at line 1412 of file qwt_picker.cpp.
Returns
true when enabled, false otherwise
See also
setEnabled(), eventFilter()
Definition at line 400 of file qwt_picker.cpp.
Move the last point of the selection The moved() signal is emitted.
Parameters
pos New position
See also
isActive(), begin(), end(), append()
Reimplemented in QwtPlotPicker, and QwtPolarPicker.
Definition at line 1357 of file qwt_picker.cpp.
A signal emitted whenever the last appended point of the selection has been moved.
Parameters
pos Position of the moved last point of the selection.
See also
move(), appended()
Return the parent widget, where the selection happens.
Definition at line 263 of file qwt_picker.cpp.
Return the parent widget, where the selection happens.
Definition at line 273 of file qwt_picker.cpp.
Find the area of the observed widget, where selection might happen.
Returns
parentWidget()->contentsRect()
Reimplemented in QwtPolarPicker.
Definition at line 1493 of file qwt_picker.cpp.
Return the points, that have been collected so far. The selection() is calculated from the pickedPoints() in adjustedPoints().
Returns
Picked points
Definition at line 1422 of file qwt_picker.cpp.
Remove the last point of the selection The removed() signal is emitted.
See also
isActive(), begin(), end(), append(), move()
Definition at line 1378 of file qwt_picker.cpp.
A signal emitted whenever the last appended point of the selection has been removed.
Parameters
pos Position of the point, that has been removed
See also
remove(), appended()
Reset the state machine and terminate ( end(false) ) the selection
Definition at line 1322 of file qwt_picker.cpp.
Returns
Resize mode
See also
setResizeMode(), ResizeMode
Definition at line 362 of file qwt_picker.cpp.
Returns
Rubber band style
See also
setRubberBand(), RubberBand, rubberBandPen()
Definition at line 299 of file qwt_picker.cpp.
Calculate the mask for the rubber band overlay
Returns
Region for the mask
See also
QWidget::setMask()
Definition at line 526 of file qwt_picker.cpp.
Returns
Overlay displaying the rubber band
Definition at line 1600 of file qwt_picker.cpp.
Returns
Rubber band pen
See also
setRubberBandPen(), rubberBand()
Definition at line 473 of file qwt_picker.cpp.
A signal emitting the selected points, at the end of a selection.
Parameters
polygon Selected points
Returns
Selected points
See also
pickedPoints(), adjustedPoints()
Definition at line 792 of file qwt_picker.cpp.
En/disable the picker. When enabled is true an event filter is installed for the observed widget, otherwise the event filter is removed.
Parameters
enabled true or false
See also
isEnabled(), eventFilter()
Definition at line 376 of file qwt_picker.cpp.
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.
Parameters
mode Resize mode
See also
resizeMode(), ResizeMode
Definition at line 352 of file qwt_picker.cpp.
Set the rubber band style
Parameters
rubberBand Rubber band style The default value is NoRubberBand.
See also
rubberBand(), RubberBand, setRubberBandPen()
Definition at line 290 of file qwt_picker.cpp.
Set the pen for the rubberband
Parameters
pen Rubber band pen
See also
rubberBandPen(), setRubberBand()
Definition at line 460 of file qwt_picker.cpp.
Set a state machine and delete the previous one
Parameters
stateMachine State machine
See also
stateMachine()
Definition at line 230 of file qwt_picker.cpp.
Set the font for the tracker
Parameters
font Tracker font
See also
trackerFont(), setTrackerMode(), setTrackerPen()
Definition at line 411 of file qwt_picker.cpp.
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).
Parameters
mode Tracker display mode
Warning
In case of AlwaysOn, mouseTracking will be enabled for the observed widget.
See also
trackerMode(), DisplayMode
Definition at line 320 of file qwt_picker.cpp.
Set the pen for the tracker
Parameters
pen Tracker pen
See also
trackerPen(), setTrackerMode(), setTrackerFont()
Definition at line 436 of file qwt_picker.cpp.
Returns
Assigned state machine
See also
setStateMachine()
Definition at line 248 of file qwt_picker.cpp.
Returns
Assigned state machine
See also
setStateMachine()
Definition at line 257 of file qwt_picker.cpp.
Scale the selection by the ratios of oldSize and newSize The changed() signal is emitted.
Parameters
oldSize Previous size
newSize Current size
See also
ResizeMode, setResizeMode(), resizeMode()
Definition at line 1436 of file qwt_picker.cpp.
Returns
Tracker font
See also
setTrackerFont(), trackerMode(), trackerPen()
Definition at line 425 of file qwt_picker.cpp.
Calculate the mask for the tracker overlay
Returns
Region with one rectangle: trackerRect( trackerFont() );
See also
QWidget::setMask(), trackerRect()
Definition at line 515 of file qwt_picker.cpp.
Returns
Tracker display mode
See also
setTrackerMode(), DisplayMode
Definition at line 333 of file qwt_picker.cpp.
Returns
Overlay displaying the tracker text
Definition at line 1606 of file qwt_picker.cpp.
Returns
Tracker pen
See also
setTrackerPen(), trackerMode(), trackerFont()
Definition at line 449 of file qwt_picker.cpp.
Returns
Current position of the tracker
Definition at line 798 of file qwt_picker.cpp.
Calculate the bounding rectangle for the tracker text from the current position of the tracker
Parameters
font Font of the tracker text
Returns
Bounding rectangle of the tracker text
See also
trackerPosition()
Definition at line 812 of file qwt_picker.cpp.
Calculate the geometry of the tracker that is needed to display information of a specific size at the tracker position
Parameters
size Size
Returns
Bounding rectangle of the tracker
See also
trackerPosition()
Definition at line 844 of file qwt_picker.cpp.
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".
Parameters
pos Position
Returns
Converted position as string
Reimplemented in QwtPlotPicker, and QwtPolarPicker.
Definition at line 491 of file qwt_picker.cpp.
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() ).
Parameters
event Event
Definition at line 1195 of file qwt_picker.cpp.
Update the state of rubber band and tracker label.
Definition at line 1505 of file qwt_picker.cpp.
Handle a enter event for the observed widget.
Parameters
event Qt event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Definition at line 1037 of file qwt_picker.cpp.
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.
Parameters
keyEvent Key event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyReleaseEvent(), stateMachine(), QwtEventPattern::KeyPatternCode
Reimplemented in QwtPlotZoomer.
Definition at line 1131 of file qwt_picker.cpp.
Handle a key release event for the observed widget.
Passes the event to the state machine.
Parameters
keyEvent Key event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), stateMachine()
Definition at line 1183 of file qwt_picker.cpp.
Handle a leave event for the observed widget.
Parameters
event Qt event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Definition at line 1051 of file qwt_picker.cpp.
Handle mouse double click event for the observed widget.
Parameters
mouseEvent Mouse event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Definition at line 1083 of file qwt_picker.cpp.
Handle a mouse move event for the observed widget.
Parameters
mouseEvent Mouse event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Definition at line 1015 of file qwt_picker.cpp.
Handle a mouse press event for the observed widget.
Parameters
mouseEvent Mouse event
See also
eventFilter(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Definition at line 1001 of file qwt_picker.cpp.
Handle a mouse release event for the observed widget.
Parameters
mouseEvent Mouse event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Reimplemented in QwtPlotZoomer.
Definition at line 1069 of file qwt_picker.cpp.
Handle a wheel event for the observed widget.
Move the last point of the selection in case of isActive() == true
Parameters
wheelEvent Wheel event
See also
eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
Definition at line 1100 of file qwt_picker.cpp.
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