QwtPlotAxisZoomer provides stacked zooming for a plot widget. More...

#include <qwt_plot_axis_zoomer.h>

Inheritance diagram for QwtPlotAxisZoomer:

Classes
class	PrivateData

Public Slots
void	moveBy (double dx, double dy)
	Moves the current zoom rectangle by an offset.

virtual void	moveTo (const QPointF &)
	Moves the current zoom rectangle.

virtual void	zoom (const QRectF &)
	Zooms in to a rectangle.

virtual void	zoom (int offset)
	Zooms in or out by an offset.

Public Slots inherited from QwtPicker
void	setEnabled (bool)
	Enable or disable the picker.

Signals
void	zoomed (const QRectF &rect)

Signals inherited from QwtPlotPicker
void	selected (const QPointF &pos)
	Signal emitted in case of QwtPickerMachine::PointSelection.

void	selected (const QRectF &rect)
	Signal emitted in case of QwtPickerMachine::RectSelection.

void	selected (const QVector< QPointF > &pa)
	Signal emitting the selected points at the end of a selection.

void	appended (const QPointF &pos)
	Signal emitted when a point has been appended to the selection.

void	moved (const QPointF &pos)
	Signal emitted whenever the last appended point of the selection has been moved.

Signals inherited from QwtPicker
void	activated (bool on)
	Signal indicating when the picker has been activated.

void	selected (const QPolygon &polygon)
	Signal emitting the selected points at the end of a selection.

void	appended (const QPoint &pos)
	Signal emitted when a point has been appended to the selection.

void	moved (const QPoint &pos)
	Signal emitted whenever the last appended point of the selection has been moved.

void	removed (const QPoint &pos)
	Signal emitted whenever the last appended point of the selection has been removed.

void	changed (const QPolygon &selection)
	Signal emitted when the active selection has been changed.

Public Member Functions
	QwtPlotAxisZoomer (QWidget *, bool doReplot=true)
	Creates a zoomer for a plot canvas.

	QwtPlotAxisZoomer (QwtAxisId xAxis, QwtAxisId yAxis, QWidget *, bool doReplot=true)
	Creates a zoomer for a plot canvas with specified axes.

virtual void	setZoomBase (bool doReplot=true)
	Reinitializes the zoom stack with scaleRect() as base.

virtual void	setZoomBase (const QRectF &)
	Sets the initial size of the zoomer.

QRectF	zoomBase () const
	Returns the initial rectangle of the zoomer.

QRectF	zoomRect () const
	Returns the rectangle at the current position on the zoom stack.

virtual void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis) override
	Reinitializes the axes, and sets the zoom base to their scales.

void	setMaxStackDepth (int)
	Limits the number of recursive zoom operations to depth.

int	maxStackDepth () const
	Returns the maximal depth of the zoom stack.

const QStack< QRectF > &	zoomStack () const
	Returns the zoom stack.

void	setZoomStack (const QStack< QRectF > &, int zoomRectIndex=-1)
	Assigns a zoom stack.

uint	zoomRectIndex () const
	Returns the index of current position of zoom stack.

Public Member Functions inherited from QwtPlotPicker
	QwtPlotPicker (QWidget *canvas)
	Constructor.

	~QwtPlotPicker () override
	Destructor.

	QwtPlotPicker (QwtAxisId xAxisId, QwtAxisId yAxisId, QWidget *)
	Constructor with axes.

	QwtPlotPicker (QwtAxisId xAxisId, QwtAxisId yAxisId, RubberBand rubberBand, DisplayMode trackerMode, QWidget *)
	Constructor with axes, rubber band and tracker mode.

QwtAxisId	xAxis () const
	Get the x axis.

QwtAxisId	yAxis () const
	Get the y axis.

QwtPlot *	plot ()
	Get the plot widget.

const QwtPlot *	plot () const
	Get the plot widget (const version)

QWidget *	canvas ()
	Get the canvas widget.

const QWidget *	canvas () const
	Get the canvas widget (const version)

Public Member Functions inherited from QwtPicker
	QwtPicker (QWidget *parent)
	Constructor.

	QwtPicker (RubberBand rubberBand, DisplayMode trackerMode, QWidget *)

void	setStateMachine (QwtPickerMachine *)
	Set a state machine and delete the previous one.

const QwtPickerMachine *	stateMachine () const
	Return the assigned state machine (const)

QwtPickerMachine *	stateMachine ()
	Return the assigned state machine.

void	setRubberBand (RubberBand)
	Set the rubber band style.

RubberBand	rubberBand () const
	Return the rubber band style.

void	setTrackerMode (DisplayMode)
	Set the display mode of the tracker.

DisplayMode	trackerMode () const
	Return the tracker display mode.

void	setResizeMode (ResizeMode)
	Set the resize mode.

ResizeMode	resizeMode () const
	Return the resize mode.

void	setRubberBandPen (const QPen &)
	Set the pen for the rubber band.

QPen	rubberBandPen () const
	Return the rubber band pen.

void	setTrackerPen (const QPen &)
	Set the pen for the tracker.

QPen	trackerPen () const
	Return the tracker pen.

void	setTrackerFont (const QFont &)
	Set the font for the tracker.

QFont	trackerFont () const
	Return the tracker font.

bool	isEnabled () const
	Return true when enabled, false otherwise.

bool	isActive () const
	A picker is active between begin() and end()

virtual bool	eventFilter (QObject , QEvent ) override
	Event filter for handling events.

QWidget *	parentWidget ()
	Return the parent widget, where the selection happens.

const QWidget *	parentWidget () const
	Return the parent widget, where the selection happens (const)

virtual QPainterPath	pickArea () const
	Find the area of the observed widget, where selection might happen.

virtual void	drawRubberBand (QPainter *) const
	Draw a rubber band, depending on rubberBand()

virtual void	drawTracker (QPainter *) const
	Draw the tracker.

virtual QRegion	trackerMask () const
	Calculate the mask for the tracker overlay.

virtual QRegion	rubberBandMask () const
	Calculate the mask for the rubber band overlay.

virtual QRect	trackerRect (const QFont &) const
	Calculate the bounding rectangle for the tracker text from the current position of the tracker.

virtual void	setTrackerPosition (const QPoint &pos)
	Set the tracker position manually.

QPoint	trackerPosition () const
	Return the current position of the tracker.

QPolygon	selection () const
	Return the selected points.

void	update ()

void	setActive (bool on)

Public Member Functions inherited from QwtEventPattern
	QwtEventPattern ()
	Constructor.

virtual	~QwtEventPattern ()
	Destructor.

void	initMousePattern (int numButtons)
	Set default mouse patterns depending on the number of mouse buttons.

void	initKeyPattern ()
	Set default key patterns.

void	setMousePattern (MousePatternCode, Qt::MouseButton button, Qt::KeyboardModifiers=Qt::NoModifier)
	Change one mouse pattern.

void	setKeyPattern (KeyPatternCode, int key, Qt::KeyboardModifiers modifiers=Qt::NoModifier)
	Change one key pattern.

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
	Return the mouse pattern vector.

const QVector< KeyPattern > &	keyPattern () const
	Return the key pattern vector.

QVector< MousePattern > &	mousePattern ()
	Return the mouse pattern vector.

QVector< KeyPattern > &	keyPattern ()
	Return the key pattern vector.

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.

Protected Member Functions
virtual void	rescale ()
	Rescale the plot.

virtual QSizeF	minZoomSize () const
	Get minimum zoom size.

virtual void	widgetMouseReleaseEvent (QMouseEvent *) override
	Handle mouse release event.

virtual void	widgetKeyPressEvent (QKeyEvent *) override
	Handle key press event.

virtual void	begin () override
	Begin selection.

virtual bool	end (bool ok=true) override
	End selection.

virtual bool	accept (QPolygon &) const override
	Accept selection.

Protected Member Functions inherited from QwtPlotPicker
QRectF	scaleRect () const
	Get the scale rectangle.

QRectF	invTransform (const QRect &) const
	Inverse transform a rectangle.

QRect	transform (const QRectF &) const
	Transform a rectangle.

QPointF	invTransform (const QPoint &) const
	Inverse transform a point.

QPoint	transform (const QPointF &) const
	Transform a point.

virtual QwtText	trackerText (const QPoint &) const override
	Get the tracker text for a point.

virtual QwtText	trackerTextF (const QPointF &) const
	Get the tracker text for a point (floating point)

virtual void	move (const QPoint &) override
	Move the selection.

virtual void	append (const QPoint &) override
	Append a point to the selection.

Protected Member Functions inherited from QwtPicker
virtual QPolygon	adjustedPoints (const QPolygon &) const
	Map the pickedPoints() into a selection()

virtual void	transition (const QEvent *)
	Passes an event to the state machine and executes the resulting commands.

virtual void	remove ()
	Remove the last point of the selection The removed() signal is emitted.

virtual void	reset ()
	Reset the state machine and terminate ( end(false) ) the selection.

virtual void	widgetMousePressEvent (QMouseEvent *)
	Handle a mouse press event for the observed widget.

virtual void	widgetMouseDoubleClickEvent (QMouseEvent *)
	Handle mouse double click event for the observed widget.

virtual void	widgetMouseMoveEvent (QMouseEvent *)
	Handle a mouse move event for the observed widget.

virtual void	widgetWheelEvent (QWheelEvent *)
	Handle a wheel event for the observed widget.

virtual void	widgetKeyReleaseEvent (QKeyEvent *)
	Handle a key release event for the observed widget.

virtual void	widgetEnterEvent (QEvent *)
	Handle a enter event for the observed widget.

virtual void	widgetLeaveEvent (QEvent *)
	Handle a leave event for the observed widget.

virtual void	stretchSelection (const QSize &oldSize, const QSize &newSize)
	Scale the selection by the ratios of oldSize and newSize The changed() signal is emitted.

virtual void	updateDisplay ()
	Update the state of rubber band and tracker label.

const QwtWidgetOverlay *	rubberBandOverlay () const
	Return the overlay displaying the rubber band.

const QwtWidgetOverlay *	trackerOverlay () const
	Return the overlay displaying the tracker text.

const QPolygon &	pickedPoints () const
	Return the points that have been collected so far.

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.

Additional Inherited Members
Public Types inherited from QwtPicker
enum	RubberBand { NoRubberBand = 0 , HLineRubberBand , VLineRubberBand , CrossRubberBand , RectRubberBand , EllipseRubberBand , PolygonRubberBand , UserRubberBand = 100 }
	Rubber band style. More...

enum	DisplayMode { AlwaysOff , AlwaysOn , ActiveOnly }
	Display mode. More...

enum	ResizeMode { Stretch , KeepSize }
	Controls what to do with the selected points when the observed widget is resized. More...

Public Types inherited from QwtEventPattern
enum	MousePatternCode { MouseSelect1 , MouseSelect2 , MouseSelect3 , MouseSelect4 , MouseSelect5 , MouseSelect6 , MousePatternCount }
	Symbolic mouse input codes. More...

enum	KeyPatternCode { KeySelect1 , KeySelect2 , KeyAbort , KeyLeft , KeyRight , KeyUp , KeyDown , KeyRedo , KeyUndo , KeyHome , KeyPatternCount }
	Symbolic keyboard input codes. More...

Properties inherited from QwtPicker
bool	isEnabled

ResizeMode	resizeMode

DisplayMode	trackerMode

QPen	trackerPen

QFont	trackerFont

RubberBand	rubberBand

QPen	rubberBandPen

Detailed Description

QwtPlotAxisZoomer provides stacked zooming for a plot widget.

QwtPlotAxisZoomer selects rectangles from user inputs ( mouse or keyboard ) translates them into plot coordinates and adjusts the axes to them. The selection is supported by a rubber band and optionally by displaying the coordinates of the current mouse position.

Zooming can be repeated as often as possible, limited only by maxStackDepth() or minZoomSize(). Each rectangle is pushed on a stack.

The default setting how to select rectangles is a QwtPickerDragRectMachine with the following bindings:

QwtEventPattern::MouseSelect1 The first point of the zoom rectangle is selected by a mouse press, the second point from the position, where the mouse is released.
QwtEventPattern::KeySelect1 The first key press selects the first, the second key press selects the second point.
QwtEventPattern::KeyAbort Discard the selection in the state, where the first point is selected.

To traverse the zoom stack the following bindings are used:

QwtEventPattern::MouseSelect3, QwtEventPattern::KeyUndo Zoom out one position on the zoom stack
QwtEventPattern::MouseSelect6, QwtEventPattern::KeyRedo Zoom in one position on the zoom stack
QwtEventPattern::MouseSelect2, QwtEventPattern::KeyHome Zoom to the zoom base

The setKeyPattern() and setMousePattern() functions can be used to configure the zoomer actions. The following example shows, how to configure the 'I' and 'O' keys for zooming in and out one position on the zoom stack. The "Home" key is used to "unzoom" the plot.

zoomer = new QwtPlotAxisZoomer( plot );
zoomer->setKeyPattern( QwtEventPattern::KeyRedo, Qt::Key_I, Qt::ShiftModifier );
zoomer->setKeyPattern( QwtEventPattern::KeyUndo, Qt::Key_O, Qt::ShiftModifier );
zoomer->setKeyPattern( QwtEventPattern::KeyHome, Qt::Key_Home );

QwtPlotAxisZoomer is tailored for plots with one x and y axis, but it is allowed to attach a second QwtPlotAxisZoomer ( without rubber band and tracker ) for the other axes.

Note: The realtime example includes an derived zoomer class that adds scrollbars to the plot canvas.

See also: QwtPlotPanner, QwtPlotMagnifier

Constructor & Destructor Documentation

◆ QwtPlotAxisZoomer() [1/2]

QwtPlotAxisZoomer::QwtPlotAxisZoomer	(	QWidget *	canvas,
		bool	doReplot = `true`
	)

explicit

Creates a zoomer for a plot canvas.

The zoomer is set to those x- and y-axis of the parent plot of the canvas that are enabled. If both or no x-axis are enabled, the picker is set to QwtAxis::XBottom. If both or no y-axis are enabled, it is set to QwtAxis::YLeft.

The zoomer is initialized with a QwtPickerDragRectMachine, the tracker mode is set to QwtPicker::ActiveOnly and the rubber band is set to QwtPicker::RectRubberBand.

Parameters

[in]	canvas	Plot canvas to observe, also the parent object.
[in]	doReplot	Call QwtPlot::replot() for the attached plot before initializing the zoomer with its scales. This might be necessary, when the plot is in a state with pending scale changes.

See also: QwtPlot::autoReplot(), QwtPlot::replot(), setZoomBase()

◆ QwtPlotAxisZoomer() [2/2]

QwtPlotAxisZoomer::QwtPlotAxisZoomer	(	QwtAxisId	xAxisId,
		QwtAxisId	yAxisId,
		QWidget *	canvas,
		bool	doReplot = `true`
	)

explicit

Creates a zoomer for a plot canvas with specified axes.

The zoomer is initialized with a QwtPickerDragRectMachine, the tracker mode is set to QwtPicker::ActiveOnly and the rubber band is set to QwtPicker::RectRubberBand.

Parameters

[in]	xAxisId	X axis of the zoomer.
[in]	yAxisId	Y axis of the zoomer.
[in]	canvas	Plot canvas to observe, also the parent object.
[in]	doReplot	Call QwtPlot::replot() for the attached plot before initializing the zoomer with its scales. This might be necessary, when the plot is in a state with pending scale changes.

See also: QwtPlot::autoReplot(), QwtPlot::replot(), setZoomBase()

Member Function Documentation

◆ accept()

bool QwtPlotAxisZoomer::accept ( QPolygon & pa ) const

overrideprotectedvirtual

Accept selection.

Check and correct a selected rectangle.

Reject rectangles with a height or width < 2, otherwise expand the selected rectangle to a minimum size of 11x11 and accept it.

Returns: true If the rectangle is accepted, or has been changed to an accepted one.

Reimplemented from QwtPicker.

◆ begin()

void QwtPlotAxisZoomer::begin ( )

overrideprotectedvirtual

Begin selection.

Rejects selections, when the stack depth is too deep, or the zoomed rectangle is minZoomSize().

See also: minZoomSize(), maxStackDepth()

Reimplemented from QwtPicker.

◆ end()

bool QwtPlotAxisZoomer::end ( bool ok = true )

overrideprotectedvirtual

End selection.

Expand the selected rectangle to minZoomSize() and zoom in if accepted.

Parameters

ok	If true, complete the selection and emit selected signals otherwise discard the selection.

See also: accept(), minZoomSize()

Returns: True if the selection has been accepted, false otherwise

Reimplemented from QwtPlotPicker.

◆ maxStackDepth()

int QwtPlotAxisZoomer::maxStackDepth ( ) const

Returns the maximal depth of the zoom stack.

Returns: Maximal depth of the zoom stack.

See also: setMaxStackDepth()

◆ minZoomSize()

QSizeF QwtPlotAxisZoomer::minZoomSize ( ) const

protectedvirtual

Get minimum zoom size.

Limit zooming by a minimum rectangle.

Returns: zoomBase().width() / 10e4, zoomBase().height() / 10e4

◆ moveBy

void QwtPlotAxisZoomer::moveBy	(	double	dx,
		double	dy
	)

slot

Moves the current zoom rectangle by an offset.

Parameters

[in]	dx	X offset.
[in]	dy	Y offset.

Note: The changed rectangle is limited by the zoom base.

◆ moveTo

void QwtPlotAxisZoomer::moveTo ( const QPointF & pos )

virtualslot

Moves the current zoom rectangle.

Parameters

[in] pos New position.

See also: QRectF::moveTo()

Note: The changed rectangle is limited by the zoom base.

◆ rescale()

void QwtPlotAxisZoomer::rescale ( )

protectedvirtual

Rescale the plot.

Adjust the observed plot to zoomRect()

Note: Initiates QwtPlot::replot()

◆ setAxes()

void QwtPlotAxisZoomer::setAxes	(	QwtAxisId	xAxisId,
		QwtAxisId	yAxisId
	)

overridevirtual

Reinitializes the axes, and sets the zoom base to their scales.

Parameters

[in]	xAxisId	X axis.
[in]	yAxisId	Y axis.

Reimplemented from QwtPlotPicker.

◆ setMaxStackDepth()

void QwtPlotAxisZoomer::setMaxStackDepth ( int depth )

Limits the number of recursive zoom operations to depth.

A value of -1 sets the depth to unlimited, 0 disables zooming. If the current zoom rectangle is below depth, the plot is unzoomed.

Parameters

[in] depth Maximum for the stack depth.

See also: maxStackDepth()

Note: depth doesn't include the zoom base, so zoomStack().count() might be maxStackDepth() + 1.

◆ setZoomBase() [1/2]

void QwtPlotAxisZoomer::setZoomBase ( bool doReplot = true )

virtual

Reinitializes the zoom stack with scaleRect() as base.

Parameters

[in] doReplot Call QwtPlot::replot() for the attached plot before initializing the zoomer with its scales. This might be necessary, when the plot is in a state with pending scale changes.

See also: zoomBase(), scaleRect(), QwtPlot::autoReplot(), QwtPlot::replot()

◆ setZoomBase() [2/2]

void QwtPlotAxisZoomer::setZoomBase ( const QRectF & base )

virtual

Sets the initial size of the zoomer.

base is united with the current scaleRect() and the zoom stack is reinitialized with it as zoom base. plot is zoomed to scaleRect().

Parameters

[in] base Zoom base rectangle.

See also: zoomBase(), scaleRect()

◆ setZoomStack()

void QwtPlotAxisZoomer::setZoomStack	(	const QStack< QRectF > &	zoomStack,
		int	zoomRectIndex = `-1`
	)

Assigns a zoom stack.

In combination with other types of navigation it might be useful to modify to manipulate the complete zoom stack.

Parameters

[in]	zoomStack	New zoom stack.
[in]	zoomRectIndex	Index of the current position of zoom stack. In case of -1 the current position is at the top of the stack.

Note: The zoomed signal might be emitted.

See also: zoomStack(), zoomRectIndex()

◆ widgetKeyPressEvent()

void QwtPlotAxisZoomer::widgetKeyPressEvent ( QKeyEvent * ke )

overrideprotectedvirtual

Handle key press event.

Qt::Key_Plus zooms in, Qt::Key_Minus zooms out one position on the zoom stack, Qt::Key_Escape zooms out to the zoom base.

Changes the current position on the stack, but doesn't pop any rectangle.

Note: The keys codes can be changed, using QwtEventPattern::setKeyPattern: 3, 4, 5

Reimplemented from QwtPicker.

◆ widgetMouseReleaseEvent()

void QwtPlotAxisZoomer::widgetMouseReleaseEvent ( QMouseEvent * me )

overrideprotectedvirtual

Handle mouse release event.

Qt::MidButton zooms out one position on the zoom stack, Qt::RightButton to the zoom base.

Changes the current position on the stack, but doesn't pop any rectangle.

Note: The mouse events can be changed, using QwtEventPattern::setMousePattern: 2, 1

Reimplemented from QwtPicker.

◆ zoom [1/2]

void QwtPlotAxisZoomer::zoom ( const QRectF & rect )

virtualslot

Zooms in to a rectangle.

Clears all rectangles above the current position of the zoom stack and pushes the normalized rectangle on it.

Parameters

[in] rect Rectangle to zoom to.

Note: If the maximal stack depth is reached, zoom is ignored.; The zoomed signal is emitted.

◆ zoom [2/2]

void QwtPlotAxisZoomer::zoom ( int offset )

virtualslot

Zooms in or out by an offset.

Activates a rectangle on the zoom stack with an offset relative to the current position. Negative values of offset will zoom out, positive zoom in. A value of 0 zooms out to the zoom base.

Parameters

[in] offset Offset relative to the current position of the zoom stack.

Note: The zoomed signal is emitted.

See also: zoomRectIndex()

◆ zoomBase()

QRectF QwtPlotAxisZoomer::zoomBase ( ) const

Returns the initial rectangle of the zoomer.

Returns: Initial rectangle of the zoomer.

See also: setZoomBase(), zoomRect()

◆ zoomed

void QwtPlotAxisZoomer::zoomed ( const QRectF & rect )

signal

A signal emitting the zoomRect(), when the plot has been zoomed in or out.

Parameters

rect	Current zoom rectangle.

◆ zoomRect()

QRectF QwtPlotAxisZoomer::zoomRect ( ) const

Returns the rectangle at the current position on the zoom stack.

Returns: Rectangle at the current position on the zoom stack.

See also: zoomRectIndex(), scaleRect()

◆ zoomRectIndex()

uint QwtPlotAxisZoomer::zoomRectIndex ( ) const

Returns the index of current position of zoom stack.

Returns: Index of current position of zoom stack.

◆ zoomStack()

const QStack< QRectF > & QwtPlotAxisZoomer::zoomStack ( ) const

Returns the zoom stack.

Returns: The zoom stack. zoomStack()[0] is the zoom base, zoomStack()[1] the first zoomed rectangle.

See also: setZoomStack(), zoomRectIndex()

The documentation for this class was generated from the following files:

/home/runner/work/QWT/QWT/src/plot/qwt_plot_axis_zoomer.h
/home/runner/work/QWT/QWT/src/plot/qwt_plot_axis_zoomer.cpp

Classes

Public Slots

Signals

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QwtPlotAxisZoomer() [1/2]

◆ QwtPlotAxisZoomer() [2/2]

Member Function Documentation

◆ accept()

◆ begin()

◆ end()

◆ maxStackDepth()

◆ minZoomSize()

◆ moveBy

◆ moveTo

◆ rescale()

◆ setAxes()

◆ setMaxStackDepth()

◆ setZoomBase() [1/2]

◆ setZoomBase() [2/2]

◆ setZoomStack()

◆ widgetKeyPressEvent()

◆ widgetMouseReleaseEvent()

◆ zoom [1/2]

◆ zoom [2/2]

◆ zoomBase()

◆ zoomed

◆ zoomRect()

◆ zoomRectIndex()

◆ zoomStack()