GraphicsView Class Reference

QGraphicsView subclass with built-in mouse pan and wheel zoom support. More...

#include <graphicsview.h>

Inheritance diagram for GraphicsView:

Collaboration diagram for GraphicsView:

Signals
void	scaleChanged (double scale)
	Emitted when the view scale changes.
void	resized (const Size &newSize, const Size &oldSize)
	Emitted when the viewport is resized.

Public Member Functions
	GraphicsView (QWidget *parent=nullptr)
	Construct with an optional parent widget.
bool	panEnabled () const
	Return whether mouse-drag panning is enabled.
void	setPanEnabled (bool value)
	Enable or disable mouse-drag panning.
bool	isZoomEnabled () const
	Return whether mouse-wheel zooming is enabled.
void	setZoomEnabled (bool value)
	Enable or disable mouse-wheel zooming.
void	setScaleFactor (double factor)
	Set the view scale to an absolute factor.
double	currentScale () const
	Return the current horizontal scale of the view transform.

Protected Member Functions
virtual void	resizeEvent (QResizeEvent *event) override
	Emit resized() with old and new viewport sizes.

Detailed Description

QGraphicsView subclass with built-in mouse pan and wheel zoom support.

GraphicsView installs itself as an event filter and handles wheel events for zooming and mouse button press/move/release events for panning. Both features can be enabled or disabled at runtime. scaleChanged() is emitted whenever the view transform changes, and resized() is emitted on resize events.

Definition at line 20 of file graphicsview.h.

Constructor & Destructor Documentation

GraphicsView()

GraphicsView::GraphicsView ( QWidget *  parent = nullptr )

explicit

Construct with an optional parent widget.

Parameters

parent

Optional QWidget parent

Member Function Documentation

currentScale()

double GraphicsView::currentScale

(

)

const

Return the current horizontal scale of the view transform.

Returns

Current scale factor

isZoomEnabled()

bool GraphicsView::isZoomEnabled ( ) const

inline

Return whether mouse-wheel zooming is enabled.

Returns

true if zoom is enabled

Definition at line 47 of file graphicsview.h.

panEnabled()

bool GraphicsView::panEnabled ( ) const

inline

Return whether mouse-drag panning is enabled.

Returns

true if pan is enabled

Definition at line 35 of file graphicsview.h.

resized

void GraphicsView::resized ( const Size &  newSize, const Size &  oldSize  )

signal

Emitted when the viewport is resized.

Parameters

newSize	New viewport size
oldSize	Previous viewport size

scaleChanged

void GraphicsView::scaleChanged ( double  scale )

signal

Emitted when the view scale changes.

Parameters

scale

New scale factor

setPanEnabled()

void GraphicsView::setPanEnabled ( bool  value )

inline

Enable or disable mouse-drag panning.

Parameters

value

true to enable pan

Definition at line 41 of file graphicsview.h.

setScaleFactor()

void GraphicsView::setScaleFactor

(

double

factor

)

Set the view scale to an absolute factor.

Parameters

factor

Scale factor (1.0 = no zoom)

setZoomEnabled()

void GraphicsView::setZoomEnabled ( bool  value )

inline

Enable or disable mouse-wheel zooming.

Parameters

value

true to enable zoom

Definition at line 53 of file graphicsview.h.

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

• include/Kanoop/gui/graphics/graphicsview.h