#include <qwt_plot_zoomer.h>

Inheritance diagram for QwtPlotZoomer:

Public Slots
virtual void	move (double x, double y)
void	moveBy (double x, double y)
virtual void	zoom (const QwtDoubleRect &)
virtual void	zoom (int up)

Signals
void	zoomed (const QwtDoubleRect &rect)
Signals inherited from QwtPlotPicker
void	appended (const QwtDoublePoint &pos)
void	moved (const QwtDoublePoint &pos)
void	selected (const QwtDoublePoint &pos)
void	selected (const QwtDoubleRect &rect)
void	selected (const QwtArray< QwtDoublePoint > &pa)
Signals inherited from QwtPicker
void	appended (const QPoint &pos)
void	changed (const QwtPolygon &pa)
void	moved (const QPoint &pos)
void	selected (const QwtPolygon &pa)

Public Member Functions
	QwtPlotZoomer (QwtPlotCanvas *, bool doReplot=true)
	QwtPlotZoomer (int xAxis, int yAxis, QwtPlotCanvas *, bool doReplot=true)
	QwtPlotZoomer (int xAxis, int yAxis, int selectionFlags, DisplayMode trackerMode, QwtPlotCanvas *, bool doReplot=true)
int	maxStackDepth () const
virtual void	setAxis (int xAxis, int yAxis)
void	setMaxStackDepth (int)
virtual void	setSelectionFlags (int)
virtual void	setZoomBase (bool doReplot=true)
virtual void	setZoomBase (const QwtDoubleRect &)
void	setZoomStack (const QStack< QwtDoubleRect > &, int zoomRectIndex=-1)
QwtDoubleRect	zoomBase () const
QwtDoubleRect	zoomRect () const
uint	zoomRectIndex () const
const QStack< QwtDoubleRect > &	zoomStack () const
Public Member Functions inherited from QwtPlotPicker
	QwtPlotPicker (QwtPlotCanvas *)
	QwtPlotPicker (int xAxis, int yAxis, QwtPlotCanvas *)
	QwtPlotPicker (int xAxis, int yAxis, int selectionFlags, RubberBand rubberBand, DisplayMode trackerMode, QwtPlotCanvas *)
virtual	~QwtPlotPicker ()
QwtPlotCanvas *	canvas ()
const QwtPlotCanvas *	canvas () const
QwtPlot *	plot ()
const QwtPlot *	plot () const
int	xAxis () const
int	yAxis () const
Public Member Functions inherited from QwtPicker
	QwtPicker (QWidget *parent)
	QwtPicker (int selectionFlags, 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
const QwtPolygon &	selection () const
int	selectionFlags () const
virtual void	setEnabled (bool)
virtual void	setResizeMode (ResizeMode)
virtual void	setRubberBand (RubberBand)
virtual void	setRubberBandPen (const QPen &)
virtual void	setTrackerFont (const QFont &)
virtual void	setTrackerMode (DisplayMode)
virtual void	setTrackerPen (const QPen &)
QFont	trackerFont () const
DisplayMode	trackerMode () const
QPen	trackerPen () const
QPoint	trackerPosition () const
QRect	trackerRect (const QFont &) const
Public Member Functions inherited from QwtEventPattern
	QwtEventPattern ()
virtual	~QwtEventPattern ()
void	initKeyPattern ()
void	initMousePattern (int numButtons)
bool	keyMatch (uint pattern, const QKeyEvent *) const
const QwtArray< KeyPattern > &	keyPattern () const
QwtArray< KeyPattern > &	keyPattern ()
bool	mouseMatch (uint pattern, const QMouseEvent *) const
const QwtArray< MousePattern > &	mousePattern () const
QwtArray< MousePattern > &	mousePattern ()
void	setKeyPattern (uint pattern, int key, int state=Qt::NoButton)
void	setKeyPattern (const QwtArray< KeyPattern > &)
void	setMousePattern (uint pattern, int button, int state=Qt::NoButton)
void	setMousePattern (const QwtArray< MousePattern > &)

Protected Member Functions
virtual bool	accept (QwtPolygon &) const
virtual void	begin ()
virtual bool	end (bool ok=true)
virtual QwtDoubleSize	minZoomSize () const
virtual void	rescale ()
virtual void	widgetKeyPressEvent (QKeyEvent *)
virtual void	widgetMouseReleaseEvent (QMouseEvent *)
Protected Member Functions inherited from QwtPlotPicker
virtual void	append (const QPoint &)
QwtDoubleRect	invTransform (const QRect &) const
QwtDoublePoint	invTransform (const QPoint &) const
virtual void	move (const QPoint &)
QwtDoubleRect	scaleRect () const
virtual QwtText	trackerText (const QPoint &) const
virtual QwtText	trackerText (const QwtDoublePoint &) const
QRect	transform (const QwtDoubleRect &) const
QPoint	transform (const QwtDoublePoint &) const
Protected Member Functions inherited from QwtPicker
virtual void	reset ()
const QWidget *	rubberBandWidget () const
virtual QwtPickerMachine *	stateMachine (int) const
virtual void	stretchSelection (const QSize &oldSize, const QSize &newSize)
const QWidget *	trackerWidget () const
virtual void	transition (const QEvent *)
virtual void	updateDisplay ()
virtual void	widgetKeyReleaseEvent (QKeyEvent *)
virtual void	widgetLeaveEvent (QEvent *)
virtual void	widgetMouseDoubleClickEvent (QMouseEvent *)
virtual void	widgetMouseMoveEvent (QMouseEvent *)
virtual void	widgetMousePressEvent (QMouseEvent *)
virtual void	widgetWheelEvent (QWheelEvent *)
Protected Member Functions inherited from QwtEventPattern
virtual bool	keyMatch (const KeyPattern &, const QKeyEvent *) const
virtual bool	mouseMatch (const MousePattern &, const QMouseEvent *) const

Detailed Description

QwtPlotZoomer provides stacked zooming for a plot widget.

QwtPlotZoomer offers rubberband selections on the plot canvas, translating the selected rectangles into plot coordinates and adjusting the axes to them. Zooming can repeated as often as possible, limited only by maxStackDepth() or minZoomSize(). Each rectangle is pushed on a stack.

Zoom rectangles can be selected depending on selectionFlags() using the mouse or keyboard (QwtEventPattern, QwtPickerMachine). QwtEventPattern::MouseSelect3/QwtEventPattern::KeyUndo, or QwtEventPattern::MouseSelect6/QwtEventPattern::KeyRedo walk up and down the zoom stack. QwtEventPattern::MouseSelect2 or QwtEventPattern::KeyHome unzoom to the initial size.

QwtPlotZoomer is tailored for plots with one x and y axis, but it is allowed to attach a second QwtPlotZoomer for the other axes.

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

Constructor & Destructor Documentation

QwtPlotZoomer::QwtPlotZoomer	(	QwtPlotCanvas *	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 QwtPlot::xBottom. If both or no y-axis are enabled, it is set to QwtPlot::yLeft.

The selectionFlags() are set to QwtPicker::RectSelection | QwtPicker::ClickSelection, the tracker mode to QwtPicker::ActiveOnly.

Parameters:

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

QwtPlotZoomer::QwtPlotZoomer	(	int	xAxis,
		int	yAxis,
		QwtPlotCanvas *	canvas,
		bool	doReplot = `true`
	)

explicit

Create a zoomer for a plot canvas.

The selectionFlags() are set to QwtPicker::RectSelection | QwtPicker::ClickSelection, the tracker mode to QwtPicker::ActiveOnly.

Parameters:

xAxis	X axis of the zoomer
yAxis	Y axis of the zoomer
canvas	Plot canvas to observe, also the parent object
doReplot	Call 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()

QwtPlotZoomer::QwtPlotZoomer	(	int	xAxis,
		int	yAxis,
		int	selectionFlags,
		DisplayMode	trackerMode,
		QwtPlotCanvas *	canvas,
		bool	doReplot = `true`
	)

explicit

Create a zoomer for a plot canvas.

Parameters:

xAxis	X axis of the zoomer
yAxis	Y axis of the zoomer
selectionFlags	Or'd value of QwtPicker::RectSelectionType and QwtPicker::SelectionMode. QwtPicker::RectSelection will be auto added.
trackerMode	Tracker mode
canvas	Plot canvas to observe, also the parent object
doReplot	Call 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:: QwtPicker, QwtPicker::setSelectionFlags(), QwtPicker::setRubberBand(), QwtPicker::setTrackerMode(); QwtPlot::autoReplot(), QwtPlot::replot(), setZoomBase()

Member Function Documentation

bool QwtPlotZoomer::accept ( QwtPolygon & pa ) const

protectedvirtual

Check and correct a selected rectangle.

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

Returns:: true If rect is accepted, or has been changed to a accepted rectangle.

Reimplemented from QwtPicker.

void QwtPlotZoomer::begin ( )

protectedvirtual

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

See also:: minZoomSize(), maxStackDepth()

Reimplemented from QwtPicker.

bool QwtPlotZoomer::end ( bool ok = true )

protectedvirtual

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

See also:: accept(), minZoomSize()

Reimplemented from QwtPlotPicker.

int QwtPlotZoomer::maxStackDepth ( ) const

Returns:: Maximal depth of the zoom stack.

See also:: setMaxStackDepth()

QwtDoubleSize QwtPlotZoomer::minZoomSize ( ) const

protectedvirtual

Limit zooming by a minimum rectangle.

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

void QwtPlotZoomer::move	(	double	x,
		double	y
	)

virtualslot

Move the the current zoom rectangle.

Parameters:

x	X value
y	Y value

See also:: QwtDoubleRect::move()

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

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

void QwtPlotZoomer::rescale ( )

protectedvirtual

Adjust the observed plot to zoomRect()

Note:: Initiates QwtPlot::replot

void QwtPlotZoomer::setAxis	(	int	xAxis,
		int	yAxis
	)

virtual

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

Parameters:

xAxis	X axis
yAxis	Y axis

Reimplemented from QwtPlotPicker.

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.

void QwtPlotZoomer::setSelectionFlags ( int flags )

virtual

Set the selection flags

Parameters:

flags Or'd value of QwtPicker::RectSelectionType and QwtPicker::SelectionMode. The default value is QwtPicker::RectSelection & QwtPicker::ClickSelection.

See also:: selectionFlags(), SelectionType, RectSelectionType, SelectionMode

Note:: QwtPicker::RectSelection will be auto added.

Reimplemented from QwtPicker.

void QwtPlotZoomer::setZoomBase ( bool doReplot = true )

virtual

Reinitialized the zoom stack with scaleRect() as base.

Parameters:

doReplot Call 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().

void QwtPlotZoomer::setZoomBase ( const QwtDoubleRect & base )

virtual

Set the initial size of the zoomer.

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

Parameters:

base Zoom base

See also:: zoomBase(), scaleRect()

void QwtPlotZoomer::setZoomStack	(	const QStack< QwtDoubleRect > &	,
		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()

void QwtPlotZoomer::widgetKeyPressEvent ( QKeyEvent * ke )

protectedvirtual

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.

void QwtPlotZoomer::widgetMouseReleaseEvent ( QMouseEvent * me )

protectedvirtual

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.

void QwtPlotZoomer::zoom ( const QwtDoubleRect & rect )

virtualslot

Zoom in.

Clears all rectangles above the current position of the zoom stack and pushs the intersection of zoomRect() and the normalized rect on it.

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

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 offest 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.