CanvasView Class Reference

Custom QGraphicsView for a canvas application. More...

#include <canvas_view.h>

Inheritance diagram for CanvasView:

Public Member Functions
	CanvasView (QWidget *parent=nullptr)
	Constructs a new CanvasView object.
QPointF	getCenter () const
	Gets the current center point of the view.
qreal	getScale () const
	Gets the current scale factor of the view.
void	setScale (qreal scale)
	Sets the scale factor of the view.
void	zoom (float scaleFactor)
	Zooms in by a given scale factor.
void	centerOn (const QPointF &pos)
	Centers the view on a specific position.
void	centerOn (const QGraphicsItem *item)
	Centers the view on a specific QGraphicsItem.
void	onSettingsChanged (const AppearanceSettings &settings)
	Handles settings changes, specifically for appearance settings.

Protected Member Functions
void	keyPressEvent (QKeyEvent *) override
	Overrides the key press event to handle zoom and pan controls.
void	keyReleaseEvent (QKeyEvent *) override
	Overrides the key release event to handle zoom and pan controls.
void	mouseMoveEvent (QMouseEvent *) override
	Overrides the mouse move event to handle panning.
void	mousePressEvent (QMouseEvent *) override
	Overrides the mouse press event to start panning or zooming.
void	mouseReleaseEvent (QMouseEvent *) override
	Overrides the mouse release event to stop panning.
void	wheelEvent (QWheelEvent *) override
	Overrides the wheel event to handle zooming.
void	drawBackground (QPainter *painter, const QRectF &rect) override
	Draws the background of the view, including a grid if enabled.

Private Member Functions
void	zoomIn ()
	Zooms in by applying a zoom factor of 1 + mZoomDelta.
void	zoomOut ()
	Zooms out by applying a zoom factor of 1 - mZoomDelta.
void	resetZoom ()
	Resets the view to its default scale.
qreal	quantisedScale (qreal proposedScale) const
	Quantises the proposed scale to ensure it is within valid limits and aligned with grid size.
void	setMaxSize ()
	Sets the maximum size of the view's scene rectangle.

Private Attributes
bool	mDoMousePanning
	Flags to determine if zooming or panning should be done.
bool	mDoKeyZoom
	Flag to determine if key-based zooming is active.
bool	mShowGrid
	Flag to show the grid on the canvas.
QPoint	mLastMousePos
	Last mouse position for panning.
qreal	mZoomDelta
	Delta value for zooming.
qreal	mZoomKey
	Key used for zooming.
qreal	mMinZoom
	Minimum allowed zoom level.
qreal	mMaxZoom
	Maximum allowed zoom level.
Qt::MouseButton	mPanButton
	Mouse button used for panning.

Detailed Description

Custom QGraphicsView for a canvas application.

Constructor & Destructor Documentation

CanvasView()

CanvasView::CanvasView

(

QWidget *

parent = nullptr

)

Constructs a new CanvasView object.

Parameters

parent

Pointer to the parent widget.

Member Function Documentation

centerOn() [1/2]

void CanvasView::centerOn

(

const QGraphicsItem *

item

)

Centers the view on a specific QGraphicsItem.

Parameters

item	The QGraphicsItem to center on.

centerOn() [2/2]

void CanvasView::centerOn

(

const QPointF &

pos

)

Centers the view on a specific position.

Parameters

pos	The position to center on.

drawBackground()

void CanvasView::drawBackground ( QPainter * painter, const QRectF & rect )

overrideprotected

Draws the background of the view, including a grid if enabled.

Parameters

painter	Pointer to the QPainter object.
rect	The rectangle to draw the background in.

getCenter()

QPointF CanvasView::getCenter

(

)

const

Gets the current center point of the view.

Returns

QPointF The center point.

getScale()

qreal CanvasView::getScale

(

)

const

Gets the current scale factor of the view.

Returns

qreal The scale factor.

keyPressEvent()

void CanvasView::keyPressEvent ( QKeyEvent * event )

overrideprotected

Overrides the key press event to handle zoom and pan controls.

Parameters

event

Pointer to the QKeyEvent object.

keyReleaseEvent()

void CanvasView::keyReleaseEvent ( QKeyEvent * event )

overrideprotected

Overrides the key release event to handle zoom and pan controls.

Parameters

event

Pointer to the QKeyEvent object.

mouseMoveEvent()

void CanvasView::mouseMoveEvent ( QMouseEvent * event )

overrideprotected

Overrides the mouse move event to handle panning.

Parameters

event

Pointer to the QMouseEvent object.

mousePressEvent()

void CanvasView::mousePressEvent ( QMouseEvent * event )

overrideprotected

Overrides the mouse press event to start panning or zooming.

Parameters

event

Pointer to the QMouseEvent object.

mouseReleaseEvent()

void CanvasView::mouseReleaseEvent ( QMouseEvent * event )

overrideprotected

Overrides the mouse release event to stop panning.

Parameters

event

Pointer to the QMouseEvent object.

onSettingsChanged()

void CanvasView::onSettingsChanged

(

const AppearanceSettings &

settings

)

Handles settings changes, specifically for appearance settings.

Parameters

settings

The new appearance settings.

quantisedScale()

qreal CanvasView::quantisedScale ( qreal proposedScale ) const

private

Quantises the proposed scale to ensure it is within valid limits and aligned with grid size.

Parameters

proposedScale

The proposed scale factor.

Returns

qreal The quantised scale factor.

setScale()

void CanvasView::setScale

(

qreal

scale

)

Sets the scale factor of the view.

Parameters

scale

The new scale factor.

wheelEvent()

void CanvasView::wheelEvent ( QWheelEvent * event )

overrideprotected

Overrides the wheel event to handle zooming.

Parameters

event

Pointer to the QWheelEvent object.

zoom()

void CanvasView::zoom

(

float

scaleFactor

)

Zooms in by a given scale factor.

Parameters

scaleFactor

The zoom scale factor.

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

• /__w/maki/maki/app/system/canvas_view.h
• /__w/maki/maki/app/system/canvas_view.cpp