Map canvas is a class for displaying all GIS data types on a canvas. More...

#include <qgsmapcanvas.h>

Classes
class	CanvasProperties

Public Types
enum	WheelAction { WheelZoom, WheelZoomAndRecenter, WheelZoomToMouseCursor, WheelNothing }

Public Slots
static void	enableRotation (bool enabled)
	change canvas rotation support
void	getDatumTransformInfo (const QgsMapLayer *ml, const QString &srcAuthId, const QString &destAuthId)
	ask user about datum transformation
bool	hasCrsTransformEnabled ()
	A simple helper method to find out if on the fly projections are enabled or not.
void	layerCrsChange ()
	This slot is connected to the layer's CRS change.
void	layerStateChange ()
	This slot is connected to the visibility change of one or more layers.
void	readProject (const QDomDocument &)
	called to read map canvas settings from project
void	refresh ()
	Repaints the canvas map.
bool	renderFlag ()
	State of render suppression flag.
static bool	rotationEnabled ()
	return if canvas rotation is enabled
void	saveAsImage (QString theFileName, QPixmap *QPixmap=0, QString="PNG")
	Save the convtents of the map canvas to disk as an image.
void	selectionChangedSlot ()
	Receives signal about selection change, and pass it on with layer info.
void	setRenderFlag (bool theFlag)
	Whether to suppress rendering or not.
Q_DECL_DEPRECATED void	showError (QgsMapLayer *mapLayer)
void	stopRendering ()
	stop rendering (if there is any right now)
Q_DECL_DEPRECATED void	updateMap ()
void	writeProject (QDomDocument &)
	called to write map canvas settings to project

Signals
void	currentLayerChanged (QgsMapLayer *layer)
	Emitted when the current layer is changed.
void	destinationCrsChanged ()
	Emitted when map CRS has changed.
void	extentsChanged ()
	Emitted when the extents of the map change.
void	hasCrsTransformEnabledChanged (bool flag)
	Emitted when on-the-fly projection has been turned on/off.
void	keyPressed (QKeyEvent *e)
	Emit key press event.
void	keyReleased (QKeyEvent *e)
	Emit key release event.
void	layersChanged ()
	Emitted when a new set of layers has been received.
void	mapCanvasRefreshed ()
	Emitted when canvas finished a refresh request.
void	mapToolSet (QgsMapTool *tool)
	Emit map tool changed event.
void	mapToolSet (QgsMapTool newTool, QgsMapTool oldTool)
	Emit map tool changed with the old tool.
void	mapUnitsChanged ()
	Emmitted when map units are changed.
void	renderComplete (QPainter *)
	Emitted when the canvas has rendered.
void	renderStarting ()
	Emitted when the canvas is about to be rendered.
void	rotationChanged (double)
	Emitted when the rotation of the map changes.
void	scaleChanged (double)
	Emitted when the scale of the map changes.
void	selectionChanged (QgsMapLayer *layer)
	Emitted when selection in any layer gets changed.
Q_DECL_DEPRECATED void	setProgress (int, int)
	Let the owner know how far we are with render operations.
void	xyCoordinates (const QgsPoint &p)
	emits current mouse position
void	zoomLastStatusChanged (bool)
	Emitted when zoom last status changed.
void	zoomNextStatusChanged (bool)
	Emitted when zoom next status changed.

Public Member Functions
	QgsMapCanvas (QWidget parent=0, const char name=0)
	Constructor.
	~QgsMapCanvas ()
	Destructor.
bool	antiAliasingEnabled () const
	true if antialising is enabled
virtual QColor	canvasColor () const
	Read property of QColor bgColor.
Q_DECL_DEPRECATED QPaintDevice &	canvasPaintDevice ()
	Accessor for the canvas paint device.
QgsPoint	center () const
	Get map center, in geographical coordinates.
Q_DECL_DEPRECATED void	clear ()
	Clear the map canvas.
void	clearCache ()
	Make sure to remove any rendered images from cache (does nothing if cache is not enabled)
void	clearExtentHistory ()
QgsMapLayer *	currentLayer ()
	returns current layer (set by legend widget)
void	enableAntiAliasing (bool theFlag)
	used to determine if anti-aliasing is enabled or not
void	enableOverviewMode (QgsMapOverviewCanvas *overview)
QgsRectangle	extent () const
	Returns the current zoom exent of the map canvas.
void	freeze (bool frz=true)
QgsRectangle	fullExtent () const
	Returns the combined exent for all layers on the map canvas.
const QgsMapToPixel *	getCoordinateTransform ()
	Get the current coordinate transform.
bool	isCachingEnabled () const
	Check whether images of rendered layers are curerently being cached.
Q_DECL_DEPRECATED bool	isDirty () const
	Return the state of the canvas (dirty or not)
bool	isDrawing ()
	Find out whether rendering is in progress.
bool	isFrozen ()
bool	isParallelRenderingEnabled () const
	Check whether the layers are rendered in parallel or sequentially.
const QgsLabelingResults *	labelingResults () const
	Get access to the labeling results (may be null)
QgsMapLayer *	layer (int index)
	return the map layer at position index in the layer stack
int	layerCount () const
	return number of layers on the map
QList< QgsMapLayer * >	layers () const
	return list of layers within map canvas.
QgsMapCanvasMap *	map ()
Q_DECL_DEPRECATED QgsMapRenderer *	mapRenderer ()
const QgsMapSettings &	mapSettings () const
	Get access to properties used for map rendering.
QgsMapTool *	mapTool ()
	Returns the currently active tool.
QGis::UnitType	mapUnits () const
	Get the current canvas map units.
double	mapUnitsPerPixel () const
	Returns the mapUnitsPerPixel (map units per pixel) for the canvas.
int	mapUpdateInterval () const
	Find out how often map preview should be updated while it is being rendered (in milliseconds)
QPoint	mouseLastXY ()
	returns last position of mouse cursor
void	panAction (QMouseEvent *event)
	Called when mouse is moving and pan is activated.
void	panActionEnd (QPoint releasePoint)
	Ends pan action and redraws the canvas.
void	panToSelected (QgsVectorLayer *layer=NULL)
	Pan to the selected features of current (vector) layer keeping same extent.
QgsPreviewEffect::PreviewMode	previewMode () const
	Returns the current preview mode for the map canvas.
bool	previewModeEnabled () const
	Returns whether a preview mode is enabled for the map canvas.
double	rotation () const
	Get the current map canvas rotation in clockwise degrees.
double	scale ()
	Get the last reported scale of the canvas.
void	setCachingEnabled (bool enabled)
	Set whether to cache images of rendered layers.
virtual void	setCanvasColor (const QColor &_newVal)
	Write property of QColor bgColor.
void	setCenter (const QgsPoint &center)
	Set the center of the map canvas, in geographical coordinates.
void	setCrsTransformEnabled (bool enabled)
	sets whether to use projections for this layer set
void	setCurrentLayer (QgsMapLayer *layer)
void	setDestinationCrs (const QgsCoordinateReferenceSystem &crs)
	sets destination coordinate reference system
Q_DECL_DEPRECATED void	setDirty (bool _dirty)
	Flag the canvas as dirty and needed a refresh.
void	setExtent (const QgsRectangle &r)
	Set the extent of the map canvas.
void	setLayerSet (QList< QgsMapCanvasLayer > &layers)
void	setMapTool (QgsMapTool *mapTool)
	Sets the map tool currently being used on the canvas.
void	setMapUnits (QGis::UnitType mapUnits)
	Set map units (needed by project properties dialog)
void	setMapUpdateInterval (int timeMiliseconds)
	Set how often map preview should be updated while it is being rendered (in milliseconds)
void	setParallelRenderingEnabled (bool enabled)
	Set whether the layers are rendered in parallel or sequentially.
void	setPreviewMode (QgsPreviewEffect::PreviewMode mode)
	Sets a preview mode for the map canvas.
void	setPreviewModeEnabled (bool previewEnabled)
	Enables a preview mode for the map canvas.
void	setRotation (double degrees)
	Set the rotation of the map canvas in clockwise degrees.
void	setSelectionColor (const QColor &color)
	Set color of selected vector features.
void	setSnappingUtils (QgsSnappingUtils *utils)
	Assign an instance of snapping utils to the map canvas.
void	setWheelAction (WheelAction action, double factor=2)
	set wheel action and zoom factor (should be greater than 1)
QgsSnappingUtils *	snappingUtils () const
	Return snapping utility class that is associated with map canvas.
void	unsetMapTool (QgsMapTool *mapTool)
	Unset the current map tool or last non zoom tool.
Q_DECL_DEPRECATED void	updateFullExtent ()
	Updates the full extent.
void	updateOverview ()
void	updateScale ()
	Emits signal scaleChanged to update scale in main window.
Q_DECL_DEPRECATED void	useImageToRender (bool theFlag)
	Select which Qt class to render with.
void	zoomByFactor (double scaleFactor, const QgsPoint *center=0)
	Zoom with the factor supplied.
void	zoomIn ()
	Zoom in with fixed factor.
void	zoomOut ()
	Zoom out with fixed factor.
void	zoomScale (double scale)
	Zoom to a specific scale.
void	zoomToFullExtent ()
	Zoom to the full extent of all layers.
void	zoomToNextExtent ()
	Zoom to the next extent (view)
void	zoomToPreviousExtent ()
	Zoom to the previous extent (view)
void	zoomToSelected (QgsVectorLayer *layer=NULL)
	Zoom to the extent of the selected features of current (vector) layer.
void	zoomWithCenter (int x, int y, bool zoomIn)
	Zooms in/out with a given center.

Protected Member Functions
void	dragEnterEvent (QDragEnterEvent *e) override
	Overridden drag enter event.
void	keyPressEvent (QKeyEvent *e) override
	Overridden key press event.
void	keyReleaseEvent (QKeyEvent *e) override
	Overridden key release event.
void	mouseDoubleClickEvent (QMouseEvent *e) override
	Overridden mouse double click event.
void	mouseMoveEvent (QMouseEvent *e) override
	Overridden mouse move event.
void	mousePressEvent (QMouseEvent *e) override
	Overridden mouse press event.
void	mouseReleaseEvent (QMouseEvent *e) override
	Overridden mouse release event.
void	moveCanvasContents (bool reset=false)
	called when panning is in action, reset indicates end of panning
void	paintEvent (QPaintEvent *e) override
	Overridden paint event.
void	resizeEvent (QResizeEvent *e) override
	Overridden resize event.
void	updateCanvasItemPositions ()
	called on resize or changed extent to notify canvas items to change their rectangle
void	updateDatumTransformEntries ()
	Make sure the datum transform store is properly populated.
void	wheelEvent (QWheelEvent *e) override
	Overridden mouse wheel event.

Protected Attributes
QScopedPointer< CanvasProperties >	mCanvasProperties
	Handle pattern for implementation object.

Detailed Description

Map canvas is a class for displaying all GIS data types on a canvas.

Definition at line 105 of file qgsmapcanvas.h.

Member Enumeration Documentation

enum QgsMapCanvas::WheelAction

Enumerator:

WheelZoom
WheelZoomAndRecenter
WheelZoomToMouseCursor
WheelNothing

Definition at line 111 of file qgsmapcanvas.h.

Constructor & Destructor Documentation

QgsMapCanvas::QgsMapCanvas	(	QWidget *	parent = `0`,
		const char *	name = `0`
	)

Constructor.

Definition at line 184 of file qgsmapcanvas.cpp.

QgsMapCanvas::~QgsMapCanvas ( )

Destructor.

Definition at line 269 of file qgsmapcanvas.cpp.

Member Function Documentation

bool QgsMapCanvas::antiAliasingEnabled ( ) const

inline

true if antialising is enabled

Definition at line 335 of file qgsmapcanvas.h.

QColor QgsMapCanvas::canvasColor ( ) const

virtual

Read property of QColor bgColor.

Definition at line 1547 of file qgsmapcanvas.cpp.

QPaintDevice & QgsMapCanvas::canvasPaintDevice ( )

Accessor for the canvas paint device.

Deprecated:: since 2.4

Definition at line 1606 of file qgsmapcanvas.cpp.

QgsPoint QgsMapCanvas::center ( ) const

Get map center, in geographical coordinates.

Note: added in 2.8

Definition at line 913 of file qgsmapcanvas.cpp.

void QgsMapCanvas::clear ( )

Clear the map canvas.

Deprecated:: since 2.4 - use refresh() - clear does the same thing

Definition at line 951 of file qgsmapcanvas.cpp.

void QgsMapCanvas::clearCache ( )

Make sure to remove any rendered images from cache (does nothing if cache is not enabled)

Note: added in 2.4

Definition at line 574 of file qgsmapcanvas.cpp.

void QgsMapCanvas::clearExtentHistory ( )

Definition at line 1009 of file qgsmapcanvas.cpp.

QgsMapLayer * QgsMapCanvas::currentLayer ( )

returns current layer (set by legend widget)

Definition at line 611 of file qgsmapcanvas.cpp.

void QgsMapCanvas::currentLayerChanged ( QgsMapLayer * layer )

signal

Emitted when the current layer is changed.

Note: added in 2.8

void QgsMapCanvas::destinationCrsChanged ( )

signal

Emitted when map CRS has changed.

Note: added in 2.4

void QgsMapCanvas::dragEnterEvent ( QDragEnterEvent * e )

overrideprotected

Overridden drag enter event.

Definition at line 1920 of file qgsmapcanvas.cpp.

void QgsMapCanvas::enableAntiAliasing ( bool theFlag )

used to determine if anti-aliasing is enabled or not

Definition at line 308 of file qgsmapcanvas.cpp.

void QgsMapCanvas::enableOverviewMode ( QgsMapOverviewCanvas * overview )

Definition at line 467 of file qgsmapcanvas.cpp.

void QgsMapCanvas::enableRotation ( bool enabled )

staticslot

change canvas rotation support

Note: added in 2.8

Definition at line 1960 of file qgsmapcanvas.cpp.

QgsRectangle QgsMapCanvas::extent ( ) const

Returns the current zoom exent of the map canvas.

Definition at line 835 of file qgsmapcanvas.cpp.

void QgsMapCanvas::extentsChanged ( )

signal

Emitted when the extents of the map change.

void QgsMapCanvas::freeze ( bool frz = true )

Freeze/thaw the map canvas. This is used to prevent the canvas from responding to events while layers are being added/removed etc.

Parameters

frz	Boolean specifying if the canvas should be frozen (true) or thawed (false). Default is true.

Definition at line 1595 of file qgsmapcanvas.cpp.

QgsRectangle QgsMapCanvas::fullExtent ( ) const

Returns the combined exent for all layers on the map canvas.

Definition at line 840 of file qgsmapcanvas.cpp.

const QgsMapToPixel * QgsMapCanvas::getCoordinateTransform ( )

Get the current coordinate transform.

Definition at line 374 of file qgsmapcanvas.cpp.

void QgsMapCanvas::getDatumTransformInfo	(	const QgsMapLayer *	ml,
		const QString &	srcAuthId,
		const QString &	destAuthId
	)

slot

ask user about datum transformation

Ask user which datum transform to use.

Definition at line 1836 of file qgsmapcanvas.cpp.

bool QgsMapCanvas::hasCrsTransformEnabled ( )

slot

A simple helper method to find out if on the fly projections are enabled or not.

Definition at line 1020 of file qgsmapcanvas.cpp.

void QgsMapCanvas::hasCrsTransformEnabledChanged ( bool flag )

signal

Emitted when on-the-fly projection has been turned on/off.

Note: added in 2.4

bool QgsMapCanvas::isCachingEnabled ( ) const

Check whether images of rendered layers are curerently being cached.

Note: added in 2.4

Definition at line 569 of file qgsmapcanvas.cpp.

bool QgsMapCanvas::isDirty ( ) const

Return the state of the canvas (dirty or not)

Deprecated:: since 2.4 - dirty flag is not kept anymore - always returns false

Definition at line 359 of file qgsmapcanvas.cpp.

bool QgsMapCanvas::isDrawing ( )

Find out whether rendering is in progress.

Definition at line 366 of file qgsmapcanvas.cpp.

bool QgsMapCanvas::isFrozen ( )

Accessor for frozen status of canvas

Definition at line 1600 of file qgsmapcanvas.cpp.

bool QgsMapCanvas::isParallelRenderingEnabled ( ) const

Check whether the layers are rendered in parallel or sequentially.

Note: added in 2.4

Definition at line 585 of file qgsmapcanvas.cpp.

void QgsMapCanvas::keyPressed ( QKeyEvent * e )

signal

Emit key press event.

void QgsMapCanvas::keyPressEvent ( QKeyEvent * e )

overrideprotected

Overridden key press event.

Definition at line 1090 of file qgsmapcanvas.cpp.

void QgsMapCanvas::keyReleased ( QKeyEvent * e )

signal

Emit key release event.

void QgsMapCanvas::keyReleaseEvent ( QKeyEvent * e )

overrideprotected

Overridden key release event.

Definition at line 1199 of file qgsmapcanvas.cpp.

const QgsLabelingResults * QgsMapCanvas::labelingResults ( ) const

Get access to the labeling results (may be null)

Note: added in 2.4

Definition at line 548 of file qgsmapcanvas.cpp.

QgsMapLayer * QgsMapCanvas::layer ( int index )

return the map layer at position index in the layer stack

Definition at line 332 of file qgsmapcanvas.cpp.

int QgsMapCanvas::layerCount ( ) const

return number of layers on the map

Definition at line 1557 of file qgsmapcanvas.cpp.

void QgsMapCanvas::layerCrsChange ( )

slot

This slot is connected to the layer's CRS change.

Definition at line 1584 of file qgsmapcanvas.cpp.

QList< QgsMapLayer * > QgsMapCanvas::layers ( ) const

return list of layers within map canvas.

Definition at line 1563 of file qgsmapcanvas.cpp.

void QgsMapCanvas::layersChanged ( )

signal

Emitted when a new set of layers has been received.

void QgsMapCanvas::layerStateChange ( )

slot

This slot is connected to the visibility change of one or more layers.

Definition at line 1576 of file qgsmapcanvas.cpp.

QgsMapCanvasMap * QgsMapCanvas::map ( )

Deprecated:: since 2.4 - there could be more than just one "map" items

Definition at line 321 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mapCanvasRefreshed ( )

signal

Emitted when canvas finished a refresh request.

QgsMapRenderer * QgsMapCanvas::mapRenderer ( )

Deprecated:: since 2.4 - use mapSettings() for anything related to current renderer settings / SIP: removed /Transfer/ because it crashes after few calls to iface.mapCanvas().mapRenderer().hasCrsTransformEnabled() / and in fact there is no transfer of ownership from c++ to python! / Actually the problem comes from the fact that "hasCrsTransformEnabled" is both a signal and a normal method / /KeepReference/ is necessary because otherwise mapRenderer().hasCrsTransformEnabled() was crashing

Definition at line 326 of file qgsmapcanvas.cpp.

const QgsMapSettings & QgsMapCanvas::mapSettings ( ) const

Get access to properties used for map rendering.

Note: added in 2.4

Definition at line 492 of file qgsmapcanvas.cpp.

QgsMapTool * QgsMapCanvas::mapTool ( )

Returns the currently active tool.

Definition at line 1685 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mapToolSet ( QgsMapTool * tool )

signal

Emit map tool changed event.

void QgsMapCanvas::mapToolSet	(	QgsMapTool *	newTool,
		QgsMapTool *	oldTool
	)

signal

Emit map tool changed with the old tool.

Note: added in 2.3

QGis::UnitType QgsMapCanvas::mapUnits ( ) const

Get the current canvas map units.

Definition at line 1635 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mapUnitsChanged ( )

signal

Emmitted when map units are changed.

Note: added in 2.4

double QgsMapCanvas::mapUnitsPerPixel ( ) const

Returns the mapUnitsPerPixel (map units per pixel) for the canvas.

Definition at line 1613 of file qgsmapcanvas.cpp.

int QgsMapCanvas::mapUpdateInterval ( ) const

Find out how often map preview should be updated while it is being rendered (in milliseconds)

Note: added in 2.4

Definition at line 595 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mouseDoubleClickEvent ( QMouseEvent * e )

overrideprotected

Overridden mouse double click event.

Definition at line 1231 of file qgsmapcanvas.cpp.

QPoint QgsMapCanvas::mouseLastXY ( )

returns last position of mouse cursor

Definition at line 1731 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mouseMoveEvent ( QMouseEvent * e )

overrideprotected

Overridden mouse move event.

Definition at line 1448 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mousePressEvent ( QMouseEvent * e )

overrideprotected

Overridden mouse press event.

Definition at line 1241 of file qgsmapcanvas.cpp.

void QgsMapCanvas::mouseReleaseEvent ( QMouseEvent * e )

overrideprotected

Overridden mouse release event.

Definition at line 1270 of file qgsmapcanvas.cpp.

void QgsMapCanvas::moveCanvasContents ( bool reset = false )

protected

called when panning is in action, reset indicates end of panning

Definition at line 1717 of file qgsmapcanvas.cpp.

void QgsMapCanvas::paintEvent ( QPaintEvent * e )

overrideprotected

Overridden paint event.

Definition at line 1337 of file qgsmapcanvas.cpp.

void QgsMapCanvas::panAction ( QMouseEvent * event )

Called when mouse is moving and pan is activated.

Definition at line 1709 of file qgsmapcanvas.cpp.

void QgsMapCanvas::panActionEnd ( QPoint releasePoint )

Ends pan action and redraws the canvas.

Definition at line 1690 of file qgsmapcanvas.cpp.

void QgsMapCanvas::panToSelected ( QgsVectorLayer * layer = NULL )

Pan to the selected features of current (vector) layer keeping same extent.

Definition at line 1067 of file qgsmapcanvas.cpp.

QgsPreviewEffect::PreviewMode QgsMapCanvas::previewMode ( ) const

Returns the current preview mode for the map canvas.

This setting only has an effect if previewModeEnabled is true.

Returns: preview mode for map canvas

See Also: setPreviewMode; previewModeEnabled

Note: added in 2.3

Definition at line 1766 of file qgsmapcanvas.cpp.

bool QgsMapCanvas::previewModeEnabled ( ) const

Returns whether a preview mode is enabled for the map canvas.

Returns: true if a preview mode is currently enabled

See Also: setPreviewModeEnabled; previewMode

Note: added in 2.3

Definition at line 1746 of file qgsmapcanvas.cpp.

void QgsMapCanvas::readProject ( const QDomDocument & doc )

slot

called to read map canvas settings from project

Definition at line 1792 of file qgsmapcanvas.cpp.

void QgsMapCanvas::refresh ( )

slot

Repaints the canvas map.

Definition at line 617 of file qgsmapcanvas.cpp.

void QgsMapCanvas::renderComplete ( QPainter * )

signal

Emitted when the canvas has rendered.

Passes a pointer to the painter on which the map was drawn. This is useful for plugins that wish to draw on the map after it has been rendered. Passing the painter allows plugins to work when the map is being rendered onto a pixmap other than the mapCanvas own pixmap member.TODO: deprecate when decorations are reimplemented as map canvas items

anything related to rendering progress is not visible outside of map canvas
additional drawing shall be done directly within the renderer job or independently as a map canvas item

bool QgsMapCanvas::renderFlag ( )

inlineslot

State of render suppression flag.

Definition at line 419 of file qgsmapcanvas.h.

void QgsMapCanvas::renderStarting ( )

signal

Emitted when the canvas is about to be rendered.

void QgsMapCanvas::resizeEvent ( QResizeEvent * e )

overrideprotected

Overridden resize event.

Definition at line 1313 of file qgsmapcanvas.cpp.

double QgsMapCanvas::rotation ( ) const

Get the current map canvas rotation in clockwise degrees.

Note: added in 2.8

Definition at line 920 of file qgsmapcanvas.cpp.

void QgsMapCanvas::rotationChanged ( double )

signal

Emitted when the rotation of the map changes.

Note: added in 2.8

bool QgsMapCanvas::rotationEnabled ( )

staticslot

return if canvas rotation is enabled

Note: added in 2.8

Definition at line 1955 of file qgsmapcanvas.cpp.

void QgsMapCanvas::saveAsImage	(	QString	theFileName,
		QPixmap *	QPixmap = `0`,
		QString	theFormat = `"PNG"`
	)

slot

Save the convtents of the map canvas to disk as an image.

Definition at line 782 of file qgsmapcanvas.cpp.

double QgsMapCanvas::scale ( )

Get the last reported scale of the canvas.

Definition at line 348 of file qgsmapcanvas.cpp.

void QgsMapCanvas::scaleChanged ( double )

signal

Emitted when the scale of the map changes.

void QgsMapCanvas::selectionChanged ( QgsMapLayer * layer )

signal

Emitted when selection in any layer gets changed.

void QgsMapCanvas::selectionChangedSlot ( )

slot

Receives signal about selection change, and pass it on with layer info.

Definition at line 1912 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setCachingEnabled ( bool enabled )

Set whether to cache images of rendered layers.

Note: added in 2.4

Definition at line 553 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setCanvasColor ( const QColor & theColor )

virtual

Write property of QColor bgColor.

Definition at line 1529 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setCenter ( const QgsPoint & center )

Set the center of the map canvas, in geographical coordinates.

Note: added in 2.8

Definition at line 900 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setCrsTransformEnabled ( bool enabled )

sets whether to use projections for this layer set

Note: added in 2.4

Definition at line 497 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setCurrentLayer ( QgsMapLayer * layer )

Definition at line 342 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setDestinationCrs ( const QgsCoordinateReferenceSystem & crs )

sets destination coordinate reference system

Note: added in 2.4

Definition at line 511 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setDirty ( bool _dirty )

Flag the canvas as dirty and needed a refresh.

Deprecated:: since 2.4 - use refresh() to trigger a refresh (clients should not decide explicitly whether canvas is dirty or not)

Definition at line 353 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setExtent ( const QgsRectangle & r )

Set the extent of the map canvas.

Definition at line 846 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setLayerSet ( QList< QgsMapCanvasLayer > & layers )

Definition at line 379 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setMapTool ( QgsMapTool * mapTool )

Sets the map tool currently being used on the canvas.

Definition at line 1474 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setMapUnits ( QGis::UnitType mapUnits )

Set map units (needed by project properties dialog)

Definition at line 1619 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setMapUpdateInterval ( int timeMiliseconds )

Set how often map preview should be updated while it is being rendered (in milliseconds)

Note: added in 2.4

Definition at line 590 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setParallelRenderingEnabled ( bool enabled )

Set whether the layers are rendered in parallel or sequentially.

Note: added in 2.4

Definition at line 580 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setPreviewMode ( QgsPreviewEffect::PreviewMode mode )

Sets a preview mode for the map canvas.

This setting only has an effect if previewModeEnabled is true.

Parameters

mode	preview mode for the canvas

See Also: previewMode; setPreviewModeEnabled; previewModeEnabled

Note: added in 2.3

Definition at line 1756 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setPreviewModeEnabled ( bool previewEnabled )

Enables a preview mode for the map canvas.

Parameters

previewEnabled set to true to enable a preview mode

See Also: setPreviewMode

Note: added in 2.3

Definition at line 1736 of file qgsmapcanvas.cpp.

Q_DECL_DEPRECATED void QgsMapCanvas::setProgress	(	int	,
		int
	)

signal

Let the owner know how far we are with render operations.

Deprecated:: since 2.4 - already unused in 2.0 anyway

void QgsMapCanvas::setRenderFlag ( bool theFlag )

slot

Whether to suppress rendering or not.

Definition at line 1641 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setRotation ( double degrees )

Set the rotation of the map canvas in clockwise degrees.

Note: added in 2.8

Definition at line 925 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setSelectionColor ( const QColor & color )

Set color of selected vector features.

Note: added in 2.4

Definition at line 1552 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setSnappingUtils ( QgsSnappingUtils * utils )

Assign an instance of snapping utils to the map canvas.

The instance is not owned by the canvas, so it is possible to use one instance in multiple canvases.

For main canvas in QGIS, do not associate a different instance from the existing one (it is updated from the project's snapping configuration).

Note: added in 2.8

Definition at line 1787 of file qgsmapcanvas.cpp.

void QgsMapCanvas::setWheelAction	(	WheelAction	action,
		double	factor = `2`
	)

set wheel action and zoom factor (should be greater than 1)

Definition at line 1415 of file qgsmapcanvas.cpp.

void QgsMapCanvas::showError ( QgsMapLayer * mapLayer )

slot

Deprecated:: since 2.4 - does nothing - errors are reported by different means

Definition at line 1726 of file qgsmapcanvas.cpp.

QgsSnappingUtils * QgsMapCanvas::snappingUtils ( ) const

Return snapping utility class that is associated with map canvas.

If no snapping utils instance has been associated previously, an internal will be created for convenience (so map tools do not need to test for existence of the instance).

Main canvas in QGIS returns an instance which is always up-to-date with the project's snapping configuration.

Note: added in 2.8

Definition at line 1776 of file qgsmapcanvas.cpp.

void QgsMapCanvas::stopRendering ( )

slot

stop rendering (if there is any right now)

Note: added in 2.4

Definition at line 766 of file qgsmapcanvas.cpp.

void QgsMapCanvas::unsetMapTool ( QgsMapTool * mapTool )

Unset the current map tool or last non zoom tool.

This is called from destructor of map tools to make sure that this map tool won't be used any more. You don't have to call it manualy, QgsMapTool takes care of it.

Definition at line 1511 of file qgsmapcanvas.cpp.

void QgsMapCanvas::updateCanvasItemPositions ( )

protected

called on resize or changed extent to notify canvas items to change their rectangle

Definition at line 1344 of file qgsmapcanvas.cpp.

void QgsMapCanvas::updateDatumTransformEntries ( )

protected

Make sure the datum transform store is properly populated.

Definition at line 1661 of file qgsmapcanvas.cpp.

Q_DECL_DEPRECATED void QgsMapCanvas::updateFullExtent ( )

inline

Updates the full extent.

Deprecated:: since v2.4 - does nothing

Definition at line 268 of file qgsmapcanvas.h.

void QgsMapCanvas::updateMap ( )

slot

Deprecated:: in 2.4 - does nothing - kept for API compatibility

Definition at line 777 of file qgsmapcanvas.cpp.

void QgsMapCanvas::updateOverview ( )

Definition at line 601 of file qgsmapcanvas.cpp.

void QgsMapCanvas::updateScale ( )

Emits signal scaleChanged to update scale in main window.

Definition at line 945 of file qgsmapcanvas.cpp.

void QgsMapCanvas::useImageToRender ( bool theFlag )

Select which Qt class to render with.

Deprecated:: since 2.4 - does nothing because now we always render to QImage

Definition at line 316 of file qgsmapcanvas.cpp.

void QgsMapCanvas::wheelEvent ( QWheelEvent * e )

overrideprotected

Overridden mouse wheel event.

Definition at line 1362 of file qgsmapcanvas.cpp.

void QgsMapCanvas::writeProject ( QDomDocument & doc )

slot

called to write map canvas settings to project

Definition at line 1816 of file qgsmapcanvas.cpp.

void QgsMapCanvas::xyCoordinates ( const QgsPoint & p )

signal

emits current mouse position

Note: changed in 1.3

void QgsMapCanvas::zoomByFactor	(	double	scaleFactor,
		const QgsPoint *	center = `0`
	)

Zoom with the factor supplied.

Factor > 1 zooms out, interval (0,1) zooms in If point is given, re-center on it

Definition at line 1904 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomIn ( )

Zoom in with fixed factor.

Definition at line 1421 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomLastStatusChanged ( bool )

signal

Emitted when zoom last status changed.

void QgsMapCanvas::zoomNextStatusChanged ( bool )

signal

Emitted when zoom next status changed.

void QgsMapCanvas::zoomOut ( )

Zoom out with fixed factor.

Definition at line 1426 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomScale ( double scale )

Zoom to a specific scale.

Definition at line 1431 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomToFullExtent ( )

Zoom to the full extent of all layers.

Definition at line 958 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomToNextExtent ( )

Zoom to the next extent (view)

Definition at line 992 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomToPreviousExtent ( )

Zoom to the previous extent (view)

Definition at line 974 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomToSelected ( QgsVectorLayer * layer = NULL )

Zoom to the extent of the selected features of current (vector) layer.

Parameters

layer optionally specify different than current layer

Definition at line 1025 of file qgsmapcanvas.cpp.

void QgsMapCanvas::zoomWithCenter	(	int	x,
		int	y,
		bool	zoomIn
	)

Zooms in/out with a given center.

Definition at line 1436 of file qgsmapcanvas.cpp.

Member Data Documentation

QScopedPointer<CanvasProperties> QgsMapCanvas::mCanvasProperties

protected

Handle pattern for implementation object.

Definition at line 588 of file qgsmapcanvas.h.

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

/tmp/buildd/qgis-2.8.2+12wheezy/src/gui/qgsmapcanvas.h
/tmp/buildd/qgis-2.8.2+12wheezy/src/gui/qgsmapcanvas.cpp

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