Qwt User's Guide
6.0.2
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#include <qwt_picker.h>
Public Types | |
enum | DisplayMode { AlwaysOff, AlwaysOn, ActiveOnly } |
enum | ResizeMode { Stretch, KeepSize } |
enum | RubberBand { NoRubberBand = 0, HLineRubberBand, VLineRubberBand, CrossRubberBand, RectRubberBand, EllipseRubberBand, PolygonRubberBand, UserRubberBand = 100 } |
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enum | KeyPatternCode { KeySelect1, KeySelect2, KeyAbort, KeyLeft, KeyRight, KeyUp, KeyDown, KeyRedo, KeyUndo, KeyHome, KeyPatternCount } |
enum | MousePatternCode { MouseSelect1, MouseSelect2, MouseSelect3, MouseSelect4, MouseSelect5, MouseSelect6, MousePatternCount } |
Public Slots | |
void | setEnabled (bool) |
Signals | |
void | activated (bool on) |
void | appended (const QPoint &pos) |
void | changed (const QPolygon &selection) |
void | moved (const QPoint &pos) |
void | removed (const QPoint &pos) |
void | selected (const QPolygon &polygon) |
Public Member Functions | |
QwtPicker (QWidget *parent) | |
QwtPicker (RubberBand rubberBand, DisplayMode trackerMode, QWidget *) | |
virtual | ~QwtPicker () |
virtual void | drawRubberBand (QPainter *) const |
virtual void | drawTracker (QPainter *) const |
virtual bool | eventFilter (QObject *, QEvent *) |
bool | isActive () const |
bool | isEnabled () const |
QWidget * | parentWidget () |
const QWidget * | parentWidget () const |
virtual QRect | pickRect () const |
ResizeMode | resizeMode () const |
RubberBand | rubberBand () const |
QPen | rubberBandPen () const |
QPolygon | selection () const |
void | setResizeMode (ResizeMode) |
void | setRubberBand (RubberBand) |
void | setRubberBandPen (const QPen &) |
void | setStateMachine (QwtPickerMachine *) |
void | setTrackerFont (const QFont &) |
void | setTrackerMode (DisplayMode) |
void | setTrackerPen (const QPen &) |
const QwtPickerMachine * | stateMachine () const |
QwtPickerMachine * | stateMachine () |
QFont | trackerFont () const |
DisplayMode | trackerMode () const |
QPen | trackerPen () const |
QPoint | trackerPosition () const |
virtual QRect | trackerRect (const QFont &) const |
virtual QwtText | trackerText (const QPoint &pos) const |
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QwtEventPattern () | |
virtual | ~QwtEventPattern () |
void | initKeyPattern () |
void | initMousePattern (int numButtons) |
bool | keyMatch (uint pattern, const QKeyEvent *) const |
const QVector< KeyPattern > & | keyPattern () const |
QVector< KeyPattern > & | keyPattern () |
bool | mouseMatch (uint pattern, const QMouseEvent *) const |
const QVector< MousePattern > & | mousePattern () const |
QVector< MousePattern > & | mousePattern () |
void | setKeyPattern (uint pattern, int key, int state=Qt::NoButton) |
void | setKeyPattern (const QVector< KeyPattern > &) |
void | setMousePattern (uint pattern, int button, int state=Qt::NoButton) |
void | setMousePattern (const QVector< MousePattern > &) |
Protected Member Functions | |
virtual bool | accept (QPolygon &) const |
virtual QPolygon | adjustedPoints (const QPolygon &) const |
virtual void | append (const QPoint &) |
virtual void | begin () |
virtual bool | end (bool ok=true) |
virtual void | move (const QPoint &) |
const QPolygon & | pickedPoints () const |
virtual void | remove () |
virtual void | reset () |
const QWidget * | rubberBandWidget () const |
virtual void | stretchSelection (const QSize &oldSize, const QSize &newSize) |
const QWidget * | trackerWidget () const |
virtual void | transition (const QEvent *) |
virtual void | updateDisplay () |
virtual void | widgetEnterEvent (QEvent *) |
virtual void | widgetKeyPressEvent (QKeyEvent *) |
virtual void | widgetKeyReleaseEvent (QKeyEvent *) |
virtual void | widgetLeaveEvent (QEvent *) |
virtual void | widgetMouseDoubleClickEvent (QMouseEvent *) |
virtual void | widgetMouseMoveEvent (QMouseEvent *) |
virtual void | widgetMousePressEvent (QMouseEvent *) |
virtual void | widgetMouseReleaseEvent (QMouseEvent *) |
virtual void | widgetWheelEvent (QWheelEvent *) |
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virtual bool | keyMatch (const KeyPattern &, const QKeyEvent *) const |
virtual bool | mouseMatch (const MousePattern &, const QMouseEvent *) 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 QwtPicker::Stretch.
Rubberband style
The default value is QwtPicker::NoRubberBand.
NoRubberBand |
No rubberband. |
HLineRubberBand |
A horizontal line ( only for QwtPicker::PointSelection ) |
VLineRubberBand |
A vertical line ( only for QwtPicker::PointSelection ) |
CrossRubberBand |
A crosshair ( only for QwtPicker::PointSelection ) |
RectRubberBand |
A rectangle ( only for QwtPicker::RectSelection ) |
EllipseRubberBand |
An ellipse ( only for QwtPicker::RectSelection ) |
PolygonRubberBand |
A polygon ( only for QwtPicker::&PolygonSelection ) |
UserRubberBand |
Values >= UserRubberBand can be used to define additional rubber bands. |
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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 |
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explicit |
Constructor
rubberBand | Rubberband style |
trackerMode | Tracker mode |
parent | Parent widget, that will be observed |
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protectedvirtual |
Validate and fixup the selection.
Accepts all selections unmodified
selection | Selection to validate and fixup |
Reimplemented in QwtPlotZoomer.
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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 |
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protectedvirtual |
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; }
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protectedvirtual |
Append a point to the selection and update rubberband and tracker. The appended() signal is emitted.
pos | Additional point |
Reimplemented in QwtPlotPicker.
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signal |
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protectedvirtual |
Open a selection setting the state to active
Reimplemented in QwtPlotZoomer.
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signal |
A signal emitted when the active selection has been changed. This might happen when the observed widget is resized.
selection | Changed selection |
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virtual |
Draw a rubberband, depending on rubberBand()
painter | Painter, initialized with clip rect |
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virtual |
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protectedvirtual |
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.
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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.
object | Object to be filtered |
event | Event |
bool QwtPicker::isActive | ( | ) | const |
bool QwtPicker::isEnabled | ( | ) | const |
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protectedvirtual |
Move the last point of the selection The moved() signal is emitted.
pos | New position |
Reimplemented in QwtPlotPicker.
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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. |
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protected |
Return the points, that have been collected so far. The selection() is calculated from the pickedPoints() in adjustedPoints().
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virtual |
Find the area of the observed widget, where selection might happen.
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protectedvirtual |
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signal |
A signal emitted whenever the last appended point of the selection has been removed.
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protectedvirtual |
Reset the state machine and terminate (end(false)) the selection
QwtPicker::ResizeMode QwtPicker::resizeMode | ( | ) | const |
QwtPicker::RubberBand QwtPicker::rubberBand | ( | ) | const |
QPen QwtPicker::rubberBandPen | ( | ) | const |
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protected |
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signal |
A signal emitting the selected points, at the end of a selection.
polygon | Selected points |
QPolygon QwtPicker::selection | ( | ) | const |
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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 |
const QwtPickerMachine * QwtPicker::stateMachine | ( | ) | const |
QwtPickerMachine * QwtPicker::stateMachine | ( | ) |
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protectedvirtual |
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 |
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virtual |
Calculate the bounding rectangle for the tracker text from the current position of the tracker
font | Font of the tracker text |
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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.
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protected |
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protectedvirtual |
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()).
event | Event |
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protectedvirtual |
Handle a enter event for the observed widget.
event | Qt event |
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protectedvirtual |
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.
keyEvent | Key event |
Reimplemented in QwtPlotZoomer.
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protectedvirtual |
Handle a key release event for the observed widget.
Passes the event to the state machine.
keyEvent | Key event |
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protectedvirtual |
Handle a leave event for the observed widget.
event | Qt event |
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protectedvirtual |
Handle mouse double click event for the observed widget.
mouseEvent | Mouse event |
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protectedvirtual |
Handle a mouse move event for the observed widget.
mouseEvent | Mouse event |
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protectedvirtual |
Handle a mouse press event for the observed widget.
mouseEvent | Mouse event |
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protectedvirtual |
Handle a mouse relase event for the observed widget.
mouseEvent | Mouse event |
Reimplemented in QwtPlotZoomer.
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protectedvirtual |
Handle a wheel event for the observed widget.
Move the last point of the selection in case of isActive() == true
wheelEvent | Wheel event |