QgsMapCanvasItem Class Reference

An abstract class for items that can be placed on the map canvas. More...

#include <qgsmapcanvasitem.h>

Inheritance diagram for QgsMapCanvasItem:

Public Member Functions
QRectF	boundingRect () const override
QgsRectangle	rect () const
	returns canvas item rectangle in map units
void	setRect (const QgsRectangle &r, bool resetRotation=true)
	sets canvas item rectangle in map units
QPointF	toCanvasCoordinates (const QgsPointXY &point) const
	transformation from map coordinates to screen coordinates
QgsPointXY	toMapCoordinates (QPoint point) const
	transformation from screen coordinates to map coordinates
virtual void	updatePosition ()
	called on changed extent or resize event to update position of the item

Protected Member Functions
	QgsMapCanvasItem (QgsMapCanvas *mapCanvas)
	protected constructor: cannot be constructed directly
	~QgsMapCanvasItem () override
virtual void	paint (QPainter *painter)=0
	function to be implemented by derived classes
void	paint (QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget=nullptr) override
bool	setRenderContextVariables (QPainter *p, QgsRenderContext &context) const
	Sets render context parameters.
void	updateCanvas ()
	schedules map canvas for repaint

Protected Attributes
QSizeF	mItemSize
	cached size of the item (to return in boundingRect())
QgsMapCanvas *	mMapCanvas = nullptr
	pointer to map canvas
QgsRectangle	mRect
	cached canvas item rectangle in map coordinates encodes position (xmin,ymax) and size (width/height) used to re-position and re-size the item on zoom/pan while waiting for the renderer to complete.
double	mRectRotation

Detailed Description

An abstract class for items that can be placed on the map canvas.

Definition at line 33 of file qgsmapcanvasitem.h.

Constructor & Destructor Documentation

QgsMapCanvasItem()

QgsMapCanvasItem::QgsMapCanvasItem ( QgsMapCanvas *  mapCanvas )

protected

protected constructor: cannot be constructed directly

Definition at line 28 of file qgsmapcanvasitem.cpp.

~QgsMapCanvasItem()

QgsMapCanvasItem::~QgsMapCanvasItem ( )

overrideprotected

Definition at line 37 of file qgsmapcanvasitem.cpp.

Member Function Documentation

boundingRect()

QRectF QgsMapCanvasItem::boundingRect ( ) const

override

Definition at line 104 of file qgsmapcanvasitem.cpp.

paint() [1/2]

virtual void QgsMapCanvasItem::paint ( QPainter *  painter )

protectedpure virtual

function to be implemented by derived classes

Implemented in QgsHighlight, QgsRubberBand, QgsVertexMarker, QgsAdvancedDigitizingCanvasItem, QgsGeometryRubberBand, QgsMapCanvasAnnotationItem, and QgsSnapToGridCanvasItem.

paint() [2/2]

void QgsMapCanvasItem::paint ( QPainter *  painter, const QStyleOptionGraphicsItem *  option, QWidget *  widget = nullptr  )

overrideprotected

Definition at line 42 of file qgsmapcanvasitem.cpp.

rect()

QgsRectangle QgsMapCanvasItem::rect

(

)

const

returns canvas item rectangle in map units

Definition at line 66 of file qgsmapcanvasitem.cpp.

setRect()

void QgsMapCanvasItem::setRect	(	const QgsRectangle &	r,
		bool	resetRotation = true
	)

sets canvas item rectangle in map units

Definition at line 72 of file qgsmapcanvasitem.cpp.

setRenderContextVariables()

bool QgsMapCanvasItem::setRenderContextVariables ( QPainter *  p, QgsRenderContext &  context  ) const

protected

Sets render context parameters.

Parameters

p	painter for rendering
context	out: configured context

Returns

true in case of success

Definition at line 117 of file qgsmapcanvasitem.cpp.

toCanvasCoordinates()

QPointF QgsMapCanvasItem::toCanvasCoordinates

(

const QgsPointXY &

point

)

const

transformation from map coordinates to screen coordinates

Definition at line 59 of file qgsmapcanvasitem.cpp.

toMapCoordinates()

QgsPointXY QgsMapCanvasItem::toMapCoordinates

(

QPoint

point

)

const

transformation from screen coordinates to map coordinates

Definition at line 53 of file qgsmapcanvasitem.cpp.

updateCanvas()

void QgsMapCanvasItem::updateCanvas ( )

protected

schedules map canvas for repaint

Definition at line 110 of file qgsmapcanvasitem.cpp.

updatePosition()

void QgsMapCanvasItem::updatePosition ( )

virtual

called on changed extent or resize event to update position of the item

Reimplemented in QgsAdvancedDigitizingCanvasItem, QgsGeometryRubberBand, QgsHighlight, QgsMapCanvasAnnotationItem, QgsRubberBand, and QgsVertexMarker.

Definition at line 133 of file qgsmapcanvasitem.cpp.

Member Data Documentation

mItemSize

QSizeF QgsMapCanvasItem::mItemSize

protected

cached size of the item (to return in boundingRect())

Definition at line 94 of file qgsmapcanvasitem.h.

mMapCanvas

QgsMapCanvas* QgsMapCanvasItem::mMapCanvas = nullptr

protected

pointer to map canvas

Definition at line 77 of file qgsmapcanvasitem.h.

mRect

QgsRectangle QgsMapCanvasItem::mRect

protected

cached canvas item rectangle in map coordinates encodes position (xmin,ymax) and size (width/height) used to re-position and re-size the item on zoom/pan while waiting for the renderer to complete.

NOTE: does not include rotation information, so cannot be used to correctly present pre-rendered map on rotation change

Definition at line 89 of file qgsmapcanvasitem.h.

mRectRotation

double QgsMapCanvasItem::mRectRotation

protected

Definition at line 91 of file qgsmapcanvasitem.h.

---

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

• /build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/gui/qgsmapcanvasitem.h
• /build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/gui/qgsmapcanvasitem.cpp