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

#include <qwt_plot_zoomer.h>

Inheritance diagram for QwtPlotZoomer:

Public Slots
void	moveBy (double dx, double dy)

virtual void	moveTo (const QPointF &)

virtual void	zoom (const QRectF &)
	Zoom in.

virtual void	zoom (int offset)
	Zoom in or out.

Public Slots inherited from QwtPicker
void	setEnabled (bool)
	En/disable the picker.

Signals
void	zoomed (const QRectF &rect)

Signals inherited from QwtPlotPicker
void	selected (const QPointF &pos)

void	selected (const QRectF &rect)

void	selected (const QVector< QPointF > &pa)

void	appended (const QPointF &pos)

void	moved (const QPointF &pos)

Signals inherited from QwtPicker
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)

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

	QwtPlotZoomer (QwtAxisId xAxis, QwtAxisId yAxis, QWidget *, bool doReplot=true)
	Create a zoomer for a plot canvas.

virtual void	setZoomBase (bool doReplot=true)

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

QRectF	zoomBase () const

QRectF	zoomRect () const

virtual void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis) override

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

int	maxStackDepth () const

const QStack< QRectF > &	zoomStack () const

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

uint	zoomRectIndex () const

Public Member Functions inherited from QwtPlotPicker
	QwtPlotPicker (QWidget *canvas)
	Create a plot picker.

virtual	~QwtPlotPicker ()
	Destructor.

	QwtPlotPicker (QwtAxisId xAxisId, QwtAxisId yAxisId, QWidget *)

	QwtPlotPicker (QwtAxisId xAxisId, QwtAxisId yAxisId, RubberBand rubberBand, DisplayMode trackerMode, QWidget *)

QwtAxisId	xAxis () const
	Return x axis.

QwtAxisId	yAxis () const
	Return y axis.

QwtPlot *	plot ()

const QwtPlot *	plot () const

QWidget *	canvas ()

const QWidget *	canvas () const

Public Member Functions inherited from QwtPicker
	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

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.

Protected Member Functions
virtual void	rescale ()

virtual QSizeF	minZoomSize () const
	Limit zooming by a minimum rectangle.

virtual void	widgetMouseReleaseEvent (QMouseEvent *) override

virtual void	widgetKeyPressEvent (QKeyEvent *) override

virtual void	begin () override

virtual bool	end (bool ok=true) override

virtual bool	accept (QPolygon &) const override
	Check and correct a selected rectangle.

Protected Member Functions inherited from QwtPlotPicker
QRectF	scaleRect () const

QRectF	invTransform (const QRect &) const

QRect	transform (const QRectF &) const

QPointF	invTransform (const QPoint &) const

QPoint	transform (const QPointF &) const

virtual QwtText	trackerText (const QPoint &) const override

virtual QwtText	trackerTextF (const QPointF &) const
	Translate a position into a position string.

virtual void	move (const QPoint &) override

virtual void	append (const QPoint &) override

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

virtual void	transition (const QEvent *)

virtual void	remove ()

virtual void	reset ()

virtual void	widgetMousePressEvent (QMouseEvent *)

virtual void	widgetMouseDoubleClickEvent (QMouseEvent *)

virtual void	widgetMouseMoveEvent (QMouseEvent *)

virtual void	widgetWheelEvent (QWheelEvent *)

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.

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

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

enum	ResizeMode { Stretch , KeepSize }

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...

Detailed Description

QwtPlotZoomer provides stacked zooming for a plot widget.

QwtPlotZoomer 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 QwtPlotZoomer( 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 );

QwtPlotZoomer is tailored for plots with one x and y axis, but it is allowed to attach a second QwtPlotZoomer ( 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

Definition at line 79 of file qwt_plot_zoomer.h.

Constructor & Destructor Documentation

◆ QwtPlotZoomer() [1/2]

QwtPlotZoomer::QwtPlotZoomer	(	QWidget *	canvas,
		bool	doReplot = true )

explicit

Create 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

canvas	Plot canvas to observe, also the parent object
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()

Definition at line 109 of file qwt_plot_zoomer.cpp.

◆ QwtPlotZoomer() [2/2]

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

explicit

Create a zoomer for a plot canvas.

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

xAxisId	X axis of the zoomer
yAxisId	Y axis of the zoomer
canvas	Plot canvas to observe, also the parent object
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()

Definition at line 133 of file qwt_plot_zoomer.cpp.

◆ ~QwtPlotZoomer()

QwtPlotZoomer::~QwtPlotZoomer ( )

virtual

Definition at line 158 of file qwt_plot_zoomer.cpp.

Member Function Documentation

◆ accept()

bool QwtPlotZoomer::accept ( QPolygon & pa ) const

overrideprotectedvirtual

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.

Definition at line 567 of file qwt_plot_zoomer.cpp.

◆ begin()

void QwtPlotZoomer::begin ( )

overrideprotectedvirtual

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

See also: minZoomSize(), maxStackDepth()

Reimplemented from QwtPicker.

Definition at line 609 of file qwt_plot_zoomer.cpp.

◆ end()

bool QwtPlotZoomer::end ( bool ok = true )

overrideprotectedvirtual

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.

Definition at line 643 of file qwt_plot_zoomer.cpp.

◆ maxStackDepth()

int QwtPlotZoomer::maxStackDepth ( ) const

Returns: Maximal depth of the zoom stack.

See also: setMaxStackDepth()

Definition at line 201 of file qwt_plot_zoomer.cpp.

◆ minZoomSize()

QSizeF QwtPlotZoomer::minZoomSize ( ) const

protectedvirtual

Limit zooming by a minimum rectangle.

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

Definition at line 597 of file qwt_plot_zoomer.cpp.

◆ moveBy

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

slot

Move the current zoom rectangle.

Parameters

dx	X offset
dy	Y offset

Note: The changed rectangle is limited by the zoom base

Definition at line 520 of file qwt_plot_zoomer.cpp.

◆ moveTo

void QwtPlotZoomer::moveTo ( const QPointF & pos )

virtualslot

Move the the current zoom rectangle.

Parameters

pos	New position

See also: QRectF::moveTo()

Note: The changed rectangle is limited by the zoom base

Definition at line 534 of file qwt_plot_zoomer.cpp.

◆ rescale()

void QwtPlotZoomer::rescale ( )

protectedvirtual

Adjust the observed plot to zoomRect()

Note: Initiates QwtPlot::replot()

Definition at line 416 of file qwt_plot_zoomer.cpp.

◆ setAxes()

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

overridevirtual

Reinitialize the axes, and set the zoom base to their scales.

Parameters

xAxisId	X axis
yAxisId	Y axis

Reimplemented from QwtPlotPicker.

Definition at line 455 of file qwt_plot_zoomer.cpp.

◆ setMaxStackDepth()

void QwtPlotZoomer::setMaxStackDepth ( int depth )

Limit the number of recursive zoom operations to depth.

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

Parameters

depth Maximum for the stack depth

See also: maxStackDepth()

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

Definition at line 174 of file qwt_plot_zoomer.cpp.

◆ setZoomBase() [1/2]

void QwtPlotZoomer::setZoomBase ( bool doReplot = true )

virtual

Reinitialized the zoom stack with scaleRect() as base.

Parameters

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().

Definition at line 235 of file qwt_plot_zoomer.cpp.

◆ setZoomBase() [2/2]

void QwtPlotZoomer::setZoomBase ( const QRectF & base )

virtual

Set 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

base Zoom base

See also: zoomBase(), scaleRect()

Definition at line 261 of file qwt_plot_zoomer.cpp.

◆ setZoomStack()

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

Assign a zoom stack.

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

Parameters

zoomStack	New zoom stack
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()

Definition at line 383 of file qwt_plot_zoomer.cpp.

◆ widgetKeyPressEvent()

void QwtPlotZoomer::widgetKeyPressEvent ( QKeyEvent * ke )

overrideprotectedvirtual

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.

Definition at line 497 of file qwt_plot_zoomer.cpp.

◆ widgetMouseReleaseEvent()

void QwtPlotZoomer::widgetMouseReleaseEvent ( QMouseEvent * me )

overrideprotectedvirtual

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.

Definition at line 474 of file qwt_plot_zoomer.cpp.

◆ zoom [1/2]

void QwtPlotZoomer::zoom ( const QRectF & rect )

virtualslot

Zoom in.

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

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

Definition at line 310 of file qwt_plot_zoomer.cpp.

◆ zoom [2/2]

void QwtPlotZoomer::zoom ( int offset )

virtualslot

Zoom in or out.

Activate 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

offset Offset relative to the current position of the zoom stack.

Note: The zoomed signal is emitted.

See also: zoomRectIndex()

Definition at line 347 of file qwt_plot_zoomer.cpp.

◆ zoomBase()

QRectF QwtPlotZoomer::zoomBase ( ) const

Returns: Initial rectangle of the zoomer

See also: setZoomBase(), zoomRect()

Definition at line 221 of file qwt_plot_zoomer.cpp.

◆ zoomed

void QwtPlotZoomer::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 QwtPlotZoomer::zoomRect ( ) const

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

See also: zoomRectIndex(), scaleRect().

Definition at line 287 of file qwt_plot_zoomer.cpp.

◆ zoomRectIndex()

uint QwtPlotZoomer::zoomRectIndex ( ) const

Returns: Index of current position of zoom stack.

Definition at line 295 of file qwt_plot_zoomer.cpp.

◆ zoomStack()

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

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

See also: setZoomStack(), zoomRectIndex()

Definition at line 212 of file qwt_plot_zoomer.cpp.

Public Slots

Signals

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QwtPlotZoomer() [1/2]

◆ QwtPlotZoomer() [2/2]

◆ ~QwtPlotZoomer()

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()