QwtPlotCanvasZoomer provides zooming for all axes of a plot canvas. More...

#include <qwt_plot_canvas_zoomer.h>

Inheritance diagram for QwtPlotCanvasZoomer:

Classes
class	PrivateData

Public Slots
virtual void	zoom (int offset)
	Navigate in the zoom stack by the specified offset.

virtual void	appendZoom (const QList< QwtPlotCanvasZoomState > &rect)
	Append a new zoom state to the zoom stack.

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

Signals
void	zoomed (const QList< QwtPlotCanvasZoomState > &state)
	Signal emitted when the plot has been zoomed in or out.

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
	QwtPlotCanvasZoomer (QWidget *canvas, bool doReplot=true)
	Constructor creating a zoomer for a plot canvas.

virtual void	setZoomBase (bool doReplot=true)
	Set the zoom base to the current axis ranges.

void	setAutoReplot (bool on=true)
	Enable or disable automatic replot after zoom operations.

bool	isAutoReplot () const
	Check if automatic replot is enabled.

QList< QwtPlotCanvasZoomState >	zoomBase () const
	Get the base zoom state (initial unzoomed state)

QList< QwtPlotCanvasZoomState >	zoomState () const
	Get the current zoom state.

void	setMaxStackDepth (int)
	Set the maximum depth of the zoom stack.

int	maxStackDepth () const
	Get the maximum depth of the zoom stack.

const QStack< QList< QwtPlotCanvasZoomState > > &	zoomStack () const
	Get the zoom stack containing all zoom states.

uint	zoomStateIndex () const

Public Member Functions inherited from QwtCanvasPicker
	QwtCanvasPicker (QWidget *canvas)
	Constructor with canvas widget.

	~QwtCanvasPicker () override
	Destructor.

QwtPlot *	plot ()
	Get the associated plot.

const QwtPlot *	plot () const
	Get the associated plot (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 QwtText	trackerText (const QPoint &pos) const
	Return the label for a position.

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 ()

virtual void	widgetMouseReleaseEvent (QMouseEvent *) override
	Handle a mouse release event for the observed widget.

virtual void	widgetKeyPressEvent (QKeyEvent *) override
	Handle a key press event for the observed widget.

virtual void	begin () override
	Open a selection setting the state to active.

virtual bool	end (bool ok=true) override
	Close a selection setting the state to inactive.

virtual bool	accept (QPolygon &) const override
	Validate and fix up 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	append (const QPoint &)
	Append a point to the selection and update rubber band and tracker.

virtual void	move (const QPoint &)
	Move the last point of the selection The moved() signal is emitted.

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

QwtPlotCanvasZoomer provides zooming for all axes of a plot canvas.

QwtPlotCanvasZoomer selects rectangles from user inputs (mouse or keyboard) and adjusts ALL axes of the plot simultaneously. Unlike QwtPlotZoomer which only works on two axes, this zoomer works on the entire canvas and maintains separate ranges for all four axes.

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 zoom state is pushed on a stack.

Mouse shortcuts:

MouseSelect2: Reset to base
MouseSelect3: Zoom out (back)
MouseSelect6: Zoom in (forward)

Keyboard shortcuts:

KeyUndo: Zoom out (back)
KeyRedo: Zoom in (forward)
KeyHome: Reset to base

See also: QwtPlotPanner, QwtPlotMagnifier

Constructor & Destructor Documentation

◆ QwtPlotCanvasZoomer()

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

explicit

Constructor creating a zoomer for a plot canvas.

Parameters

[in]	canvas	Plot canvas to observe, also the parent object
[in]	doReplot	If true, call QwtPlot::replot() before initializing

The zoomer will zoom all axes of the plot simultaneously. It uses a drag rectangle picker machine for selecting zoom regions. The tracker mode is set to ActiveOnly and the rubber band is set to RectRubberBand.

Destructor

Member Function Documentation

◆ accept()

bool QwtPlotCanvasZoomer::accept ( QPolygon & selection ) const

overrideprotectedvirtual

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 from QwtPicker.

◆ appendZoom

void QwtPlotCanvasZoomer::appendZoom ( const QList< QwtPlotCanvasZoomState > & rect )

virtualslot

Append a new zoom state to the zoom stack.

Parameters

[in] rect List of zoom states for all plots

This method adds a new zoom state to the stack and makes it the current state. The zoomed() signal is emitted after the zoom is applied.

◆ begin()

void QwtPlotCanvasZoomer::begin ( )

overrideprotectedvirtual

Open a selection setting the state to active.

See also: isActive(), end(), append(), move()

Reimplemented from QwtPicker.

◆ end()

bool QwtPlotCanvasZoomer::end ( bool ok = true )

overrideprotectedvirtual

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 from QwtPicker.

◆ isAutoReplot()

bool QwtPlotCanvasZoomer::isAutoReplot ( ) const

Check if automatic replot is enabled.

Returns: true if automatic replot is enabled

◆ maxStackDepth()

int QwtPlotCanvasZoomer::maxStackDepth ( ) const

Get the maximum depth of the zoom stack.

Returns: Maximum number of zoom levels, -1 means unlimited

◆ setAutoReplot()

void QwtPlotCanvasZoomer::setAutoReplot ( bool on = true )

Enable or disable automatic replot after zoom operations.

Parameters

[in] on If true, the plot will be automatically replotted after zoom

When enabled, the plot will automatically replot after each zoom operation. This is enabled by default.

◆ setMaxStackDepth()

void QwtPlotCanvasZoomer::setMaxStackDepth ( int depth )

Set the maximum depth of the zoom stack.

Parameters

[in] depth Maximum number of zoom levels, -1 for unlimited

When the stack exceeds this depth, older zoom states are removed. If the current zoom level is beyond the new limit, it will be adjusted.

◆ setZoomBase()

void QwtPlotCanvasZoomer::setZoomBase ( bool doReplot = true )

virtual

Set the zoom base to the current axis ranges.

Parameters

[in] doReplot If true, call QwtPlot::replotAll() before capturing state

This method clears the zoom stack and sets the current view as the base state. It captures the axis ranges of the main plot and all parasite plots.

◆ widgetKeyPressEvent()

void QwtPlotCanvasZoomer::widgetKeyPressEvent ( QKeyEvent * keyEvent )

overrideprotectedvirtual

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 from QwtPicker.

◆ widgetMouseReleaseEvent()

void QwtPlotCanvasZoomer::widgetMouseReleaseEvent ( QMouseEvent * mouseEvent )

overrideprotectedvirtual

Handle a mouse release event for the observed widget.

Parameters

mouseEvent Mouse event

See also: eventFilter(), widgetMousePressEvent(), widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(), widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()

Reimplemented from QwtPicker.

◆ zoom

void QwtPlotCanvasZoomer::zoom ( int offset )

virtualslot

Navigate in the zoom stack by the specified offset.

Parameters

[in] offset Number of positions to move (negative = zoom out, positive = zoom in)

Moving by 0 resets to the base zoom level. The zoomed() signal is emitted if the zoom state changes.

◆ zoomBase()

QList< QwtPlotCanvasZoomState > QwtPlotCanvasZoomer::zoomBase ( ) const

Get the base zoom state (initial unzoomed state)

Returns: List of zoom states for all plots at the base level

Returns an empty list if the zoom stack is empty.

◆ zoomed

void QwtPlotCanvasZoomer::zoomed ( const QList< QwtPlotCanvasZoomState > & state )

signal

Signal emitted when the plot has been zoomed in or out.

Parameters

state Current zoom state containing all axis ranges

◆ zoomStack()

const QStack< QList< QwtPlotCanvasZoomState > > & QwtPlotCanvasZoomer::zoomStack ( ) const

Get the zoom stack containing all zoom states.

Returns: Const reference to the internal zoom stack

The stack contains the complete history of zoom operations, with index 0 being the base (unzoomed) state.

◆ zoomState()

QList< QwtPlotCanvasZoomState > QwtPlotCanvasZoomer::zoomState ( ) const

Get the current zoom state.

Returns: List of zoom states for all plots at the current zoom level

Returns an empty list if the zoom stack is empty.

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

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

Classes

Public Slots

Signals

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QwtPlotCanvasZoomer()

Member Function Documentation

◆ accept()

◆ appendZoom

◆ begin()

◆ end()

◆ isAutoReplot()

◆ maxStackDepth()

◆ setAutoReplot()

◆ setMaxStackDepth()

◆ setZoomBase()

◆ widgetKeyPressEvent()

◆ widgetMouseReleaseEvent()

◆ zoom

◆ zoomBase()

◆ zoomed

◆ zoomStack()

◆ zoomState()