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

#include <qgsmapcanvas.h>

Collaboration diagram for QgsMapCanvas:

Classes
class	CanvasProperties

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

Public Slots
void	refresh ()
	Repaints the canvas map.
void	selectionChangedSlot ()
	Receives signal about selection change, and pass it on with layer info.
void	saveAsImage (QString theFileName, QPixmap *QPixmap=0, QString="PNG")
	Save the convtents of the map canvas to disk as an image.
void	layerStateChange ()
	This slot is connected to the visibility change of one or more layers.
void	setRenderFlag (bool theFlag)
	Whether to suppress rendering or not.
bool	renderFlag ()
	State of render suppression flag.
bool	hasCrsTransformEnabled ()
	A simple helper method to find out if on the fly projections are enabled or not.
void	mapUnitsChanged ()
	The map units may have changed, so cope with that.
void	updateMap ()
	updates pixmap on render progress
void	showError (QgsMapLayer *mapLayer)
	show whatever error is exposed by the QgsMapLayer.
void	readProject (const QDomDocument &)
	called to read map canvas settings from project
void	writeProject (QDomDocument &)
	called to write map canvas settings to project
void	getDatumTransformInfo (const QgsMapLayer *ml, const QString &srcAuthId, const QString &destAuthId)
	ask user about datum transformation

Signals
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	scaleChanged (double)
	Emitted when the scale of the map changes.
void	extentsChanged ()
	Emitted when the extents of the map change.
void	renderComplete (QPainter *)
	Emitted when the canvas has rendered.
void	mapCanvasRefreshed ()
	Emitted when canvas finished a refresh request.
void	renderStarting ()
	Emitted when the canvas is about to be rendered.
void	layersChanged ()
	Emitted when a new set of layers has been received.
void	keyPressed (QKeyEvent *e)
	Emit key press event.
void	keyReleased (QKeyEvent *e)
	Emit key release event.
void	mapToolSet (QgsMapTool *tool)
	Emit map tool changed event.
void	selectionChanged (QgsMapLayer *layer)
	Emitted when selection in any layer gets changed.
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.
void	setLayerSet (QList< QgsMapCanvasLayer > &layers)
void	setCurrentLayer (QgsMapLayer *layer)
void	updateOverview ()
void	enableOverviewMode (QgsMapOverviewCanvas *overview)
QgsMapCanvasMap *	map ()
QgsMapRenderer *	mapRenderer ()
QPaintDevice &	canvasPaintDevice ()
	Accessor for the canvas paint device.
double	scale ()
	Get the last reported scale of the canvas.
void	clear ()
	Clear the map canvas.
double	mapUnitsPerPixel () const
	Returns the mapUnitsPerPixel (map units per pixel) for the canvas.
QgsRectangle	extent () const
	Returns the current zoom exent of the map canvas.
QgsRectangle	fullExtent () const
	Returns the combined exent for all layers on the map canvas.
void	setExtent (const QgsRectangle &r)
	Set the extent of the map canvas.
void	zoomToFullExtent ()
	Zoom to the full extent of all layers.
void	zoomToPreviousExtent ()
	Zoom to the previous extent (view)
void	zoomToNextExtent ()
	Zoom to the next extent (view)
void	clearExtentHistory ()
void	zoomToSelected (QgsVectorLayer *layer=NULL)
	Zoom to the extent of the selected features of current (vector) layer.
void	panToSelected (QgsVectorLayer *layer=NULL)
	Pan to the selected features of current (vector) layer keeping same extent.
void	setMapTool (QgsMapTool *mapTool)
	Sets the map tool currently being used on the canvas.
void	unsetMapTool (QgsMapTool *mapTool)
	Unset the current map tool or last non zoom tool.
QgsMapTool *	mapTool ()
	Returns the currently active tool.
virtual void	setCanvasColor (const QColor &_newVal)
	Write property of QColor bgColor.
virtual QColor	canvasColor () const
	Read property of QColor bgColor.
void	updateScale ()
	Emits signal scaleChanged to update scale in main window.
void	updateFullExtent ()
	Updates the full extent.
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. Added in v1.5
void	freeze (bool frz=true)
bool	isFrozen ()
void	setDirty (bool _dirty)
	Flag the canvas as dirty and needed a refresh.
bool	isDirty () const
	Return the state of the canvas (dirty or not)
void	setMapUnits (QGis::UnitType mapUnits)
	Set map units (needed by project properties dialog)
QGis::UnitType	mapUnits () const
	Get the current canvas map units.
const QgsMapToPixel *	getCoordinateTransform ()
	Get the current coordinate transform.
bool	isDrawing ()
	true if canvas currently drawing
QgsMapLayer *	currentLayer ()
	returns current layer (set by legend widget)
void	setWheelAction (WheelAction action, double factor=2)
	set wheel action and zoom factor (should be greater than 1)
void	zoomIn ()
	Zoom in with fixed factor.
void	zoomOut ()
	Zoom out with fixed factor.
void	zoomScale (double scale)
	Zoom to a specific scale.
void	zoomByFactor (double scaleFactor)
	Zoom with the factor supplied. Factor > 1 zooms out, interval (0,1) zooms in.
void	zoomWithCenter (int x, int y, bool zoomIn)
	Zooms in/out with a given center.
void	enableAntiAliasing (bool theFlag)
	used to determine if anti-aliasing is enabled or not
bool	antiAliasingEnabled () const
	true if antialising is enabled
void	useImageToRender (bool theFlag)
	Select which Qt class to render with.
void	panActionEnd (QPoint releasePoint)
	Ends pan action and redraws the canvas.
void	panAction (QMouseEvent *event)
	Called when mouse is moving and pan is activated.
QPoint	mouseLastXY ()
	returns last position of mouse cursor

Protected Member Functions
void	keyPressEvent (QKeyEvent *e)
	Overridden key press event.
void	keyReleaseEvent (QKeyEvent *e)
	Overridden key release event.
void	mouseDoubleClickEvent (QMouseEvent *e)
	Overridden mouse double click event.
void	mouseMoveEvent (QMouseEvent *e)
	Overridden mouse move event.
void	mousePressEvent (QMouseEvent *e)
	Overridden mouse press event.
void	mouseReleaseEvent (QMouseEvent *e)
	Overridden mouse release event.
void	wheelEvent (QWheelEvent *e)
	Overridden mouse wheel event.
void	resizeEvent (QResizeEvent *e)
	Overridden resize event.
void	paintEvent (QPaintEvent *e)
	Overridden paint event.
void	dragEnterEvent (QDragEnterEvent *e)
	Overridden drag enter event.
void	moveCanvasContents (bool reset=false)
	called when panning is in action, reset indicates end of panning
void	updateCanvasItemPositions ()
	called on resize or changed extent to notify canvas items to change their rectangle
void	connectNotify (const char *signal)
	debugging member invoked when a connect() is made to this object

Protected Attributes
std::auto_ptr< CanvasProperties >	mCanvasProperties
	Handle pattern for implementation object.

Private Slots
void	mapToolDestroyed ()
	called when current maptool is destroyed
void	crsTransformEnabled (bool)

Private Member Functions
	QgsMapCanvas (QgsMapCanvas const &)
	this class is non-copyable

Private Attributes
QgsMapRenderer *	mMapRenderer
	all map rendering is done in this class
QgsMapCanvasMap *	mMap
	owns pixmap with rendered map and controls rendering
QgsMapOverviewCanvas *	mMapOverview
	map overview widget - it's controlled by QgsMapCanvas
bool	mBackbufferEnabled
	If backbuffering is currently enabled.
bool	mDrawing
	Flag indicating a map refresh is in progress.
bool	mFrozen
	Flag indicating if the map canvas is frozen.
bool	mDirty
	Flag to track the state of the Map canvas.
bool	mRenderFlag
	determines whether user has requested to suppress rendering
QList< QPair< int, int > >	mResizeQueue
	Resize events that have been ignored because the canvas is busy with rendering may put their sizes into this list.
QgsMapLayer *	mCurrentLayer
	current layer in legend
QGraphicsScene *	mScene
	graphics scene manages canvas items
QgsMapTool *	mMapTool
	pointer to current map tool
QgsMapTool *	mLastNonZoomMapTool
	previous tool if current is for zooming/panning
QList< QgsRectangle >	mLastExtent
	recently used extent
int	mLastExtentIndex
double	mWheelZoomFactor
	Scale factor multiple for default zoom in/out.
WheelAction	mWheelAction
	Mouse wheel action.
QSize	mNewSize
	resize canvas size
bool	mPainting
	currently in paint event
bool	mAntiAliasing
	indicates whether antialiasing will be used for rendering
QTimer *	mResizeTimer

Detailed Description

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

Definition at line 99 of file qgsmapcanvas.h.

Member Enumeration Documentation

enum QgsMapCanvas::WheelAction

Enumerator:

WheelZoom
WheelZoomAndRecenter
WheelZoomToMouseCursor
WheelNothing

Definition at line 105 of file qgsmapcanvas.h.

Constructor & Destructor Documentation

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

Constructor.

Definition at line 84 of file qgsmapcanvas.cpp.

References crsTransformEnabled(), getDatumTransformInfo(), hasCrsTransformEnabled(), QgsProject::instance(), mBackbufferEnabled, mCurrentLayer, mDirty, mDrawing, mFrozen, mLastExtentIndex, mLastNonZoomMapTool, mMap, mMapOverview, mMapRenderer, mMapTool, moveCanvasContents(), mRenderFlag, mResizeTimer, mScene, readProject(), refresh(), QgsMapCanvasMap::resize(), setWheelAction(), showError(), size, WheelZoom, and writeProject().

QgsMapCanvas::~QgsMapCanvas ( )

Destructor.

Definition at line 150 of file qgsmapcanvas.cpp.

References QgsMapTool::deactivate(), mLastNonZoomMapTool, mMapRenderer, mMapTool, and mScene.

QgsMapCanvas::QgsMapCanvas ( QgsMapCanvas const & )

private

this class is non-copyable

Note

Otherwise std::auto_ptr would pass the object responsiblity on to the copy like a hot potato leaving the copyer in a weird state.

Member Function Documentation

bool QgsMapCanvas::antiAliasingEnabled ( ) const

inline

true if antialising is enabled

Definition at line 253 of file qgsmapcanvas.h.

Referenced by QgsMapCanvasItem::paint().

QColor QgsMapCanvas::canvasColor ( ) const

virtual

Read property of QColor bgColor.

Definition at line 1306 of file qgsmapcanvas.cpp.

References mScene.

QPaintDevice & QgsMapCanvas::canvasPaintDevice ( )

Accessor for the canvas paint device.

Definition at line 1351 of file qgsmapcanvas.cpp.

References mMap, and QgsMapCanvasMap::paintDevice().

void QgsMapCanvas::clear ( )

Clear the map canvas.

Definition at line 618 of file qgsmapcanvas.cpp.

References setDirty().

Referenced by refresh().

void QgsMapCanvas::clearExtentHistory ( )

Definition at line 696 of file qgsmapcanvas.cpp.

References extent(), mLastExtent, mLastExtentIndex, zoomLastStatusChanged(), and zoomNextStatusChanged().

Referenced by readProject().

void QgsMapCanvas::connectNotify ( const char * signal )

protected

debugging member invoked when a connect() is made to this object

Definition at line 1393 of file qgsmapcanvas.cpp.

References QgsDebugMsg.

void QgsMapCanvas::crsTransformEnabled ( bool enabled )

privateslot

Definition at line 1655 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, and refresh().

Referenced by QgsMapCanvas().

QgsMapLayer * QgsMapCanvas::currentLayer ( )

returns current layer (set by legend widget)

Definition at line 375 of file qgsmapcanvas.cpp.

References mCurrentLayer.

Referenced by QgsMapToolIdentify::identify(), setLayerSet(), QgsMapCanvasSnapper::snapToBackgroundLayers(), and QgsMapCanvasSnapper::snapToCurrentLayer().

void QgsMapCanvas::dragEnterEvent ( QDragEnterEvent * e )

protected

Overridden drag enter event.

Definition at line 1647 of file qgsmapcanvas.cpp.

void QgsMapCanvas::enableAntiAliasing ( bool theFlag )

used to determine if anti-aliasing is enabled or not

Definition at line 179 of file qgsmapcanvas.cpp.

References QgsMapCanvasMap::enableAntiAliasing(), QgsMapOverviewCanvas::enableAntiAliasing(), mAntiAliasing, mMap, and mMapOverview.

void QgsMapCanvas::enableOverviewMode ( QgsMapOverviewCanvas * overview )

Definition at line 339 of file qgsmapcanvas.cpp.

References hasCrsTransformEnabled(), mMapOverview, and mMapRenderer.

QgsRectangle QgsMapCanvas::extent ( ) const

Returns the current zoom exent of the map canvas.

Definition at line 537 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), and mMapRenderer.

Referenced by QgsMapToolZoom::canvasReleaseEvent(), clearExtentHistory(), QgsMapOverviewCanvas::drawExtentRect(), QgsMapTip::fetchFeature(), QgsAttributeTableFilterModel::generateListOfVisibleFeatures(), QgsMapToolIdentify::identify(), QgsMapToolIdentify::identifyVectorLayer(), QgsMapOverviewCanvas::mouseReleaseEvent(), QgsHighlight::paint(), QgsHighlight::paintPoint(), QgsMapToolTouch::pinchTriggered(), setExtent(), QgsFormAnnotationItem::setFeatureForMapPosition(), QgsHtmlAnnotationItem::setFeatureForMapPosition(), QgsHighlight::updateRect(), wheelEvent(), zoomToFullExtent(), and zoomToSelected().

void QgsMapCanvas::extentsChanged ( )

signal

Emitted when the extents of the map change.

Referenced by paintEvent(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

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 1340 of file qgsmapcanvas.cpp.

References mFrozen.

QgsRectangle QgsMapCanvas::fullExtent ( ) const

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

Definition at line 542 of file qgsmapcanvas.cpp.

References QgsMapRenderer::fullExtent(), and mMapRenderer.

Referenced by zoomToFullExtent().

const QgsMapToPixel * QgsMapCanvas::getCoordinateTransform ( )

Get the current coordinate transform.

Definition at line 244 of file qgsmapcanvas.cpp.

References QgsMapRenderer::coordinateTransform(), and mMapRenderer.

Referenced by QgsMapToolPan::canvasReleaseEvent(), QgsMapToolZoom::canvasReleaseEvent(), QgsMapToolTouch::canvasReleaseEvent(), QgsMapToolIdentify::identify(), mouseMoveEvent(), panActionEnd(), QgsMapToolTouch::pinchTriggered(), QgsRubberBand::setToCanvasRectangle(), QgsMapCanvasItem::toCanvasCoordinates(), QgsMapTool::toCanvasCoordinates(), QgsMapCanvasItem::toMapCoordinates(), QgsMapTool::toMapCoordinates(), wheelEvent(), and zoomWithCenter().

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 1563 of file qgsmapcanvas.cpp.

References QgsMapRenderer::addLayerCoordinateTransform(), QgsCRSCache::crsByAuthId(), QgsCoordinateTransform::datumTransformations(), QgsMapLayer::id(), QgsCRSCache::instance(), mMapRenderer, QgsMapLayer::name(), and QgsDatumTransformDialog::selectedDatumTransform().

Referenced by QgsMapCanvas().

bool QgsMapCanvas::hasCrsTransformEnabled ( )

slot

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

Definition at line 707 of file qgsmapcanvas.cpp.

References QgsMapRenderer::hasCrsTransformEnabled(), and mMapRenderer.

Referenced by enableOverviewMode(), QgsMapToolIdentify::featureDerivedAttributes(), QgsMapToolIdentify::identifyRasterLayer(), and QgsMapCanvas().

bool QgsMapCanvas::isDirty ( ) const

Return the state of the canvas (dirty or not)

Definition at line 229 of file qgsmapcanvas.cpp.

References mDirty.

bool QgsMapCanvas::isDrawing ( )

true if canvas currently drawing

Definition at line 236 of file qgsmapcanvas.cpp.

References mDrawing.

Referenced by QgsMapToolIdentify::identify().

bool QgsMapCanvas::isFrozen ( )

Accessor for frozen status of canvas

Definition at line 1345 of file qgsmapcanvas.cpp.

References mFrozen.

void QgsMapCanvas::keyPressed ( QKeyEvent * e )

signal

Emit key press event.

Referenced by keyPressEvent().

void QgsMapCanvas::keyPressEvent ( QKeyEvent * e )

protected

Overridden key press event.

Definition at line 805 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), keyPressed(), QgsMapTool::keyPressEvent(), mCanvasProperties, mDrawing, mMapRenderer, mMapTool, QgsDebugMsg, refresh(), setExtent(), QgsRectangle::setXMaximum(), QgsRectangle::setXMinimum(), QgsRectangle::setYMaximum(), QgsRectangle::setYMinimum(), QgsRectangle::xMaximum(), QgsRectangle::xMinimum(), QgsRectangle::yMaximum(), QgsRectangle::yMinimum(), zoomIn(), and zoomOut().

void QgsMapCanvas::keyReleased ( QKeyEvent * e )

signal

Emit key release event.

Referenced by keyReleaseEvent().

void QgsMapCanvas::keyReleaseEvent ( QKeyEvent * e )

protected

Overridden key release event.

Definition at line 908 of file qgsmapcanvas.cpp.

References keyReleased(), QgsMapTool::keyReleaseEvent(), mCanvasProperties, mDrawing, mMapTool, panActionEnd(), and QgsDebugMsg.

QgsMapLayer * QgsMapCanvas::layer ( int index )

return the map layer at position index in the layer stack

Definition at line 204 of file qgsmapcanvas.cpp.

References QgsMapLayerRegistry::instance(), layers(), QgsMapRenderer::layerSet(), QgsMapLayerRegistry::mapLayer(), and mMapRenderer.

Referenced by QgsMapToolIdentify::identify(), layers(), selectionChangedSlot(), setCurrentLayer(), and setLayerSet().

int QgsMapCanvas::layerCount ( ) const

return number of layers on the map

Definition at line 1311 of file qgsmapcanvas.cpp.

References QgsMapRenderer::layerSet(), and mMapRenderer.

Referenced by QgsMapToolIdentify::identify(), and setLayerSet().

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

return list of layers within map canvas. Added in v1.5

Definition at line 1317 of file qgsmapcanvas.cpp.

References QgsMapLayerRegistry::instance(), layer(), QgsMapRenderer::layerSet(), QgsMapLayerRegistry::mapLayer(), and mMapRenderer.

Referenced by layer(), QgsFormAnnotationItem::updateVisibility(), and QgsHtmlAnnotationItem::updateVisibility().

void QgsMapCanvas::layersChanged ( )

signal

Emitted when a new set of layers has been received.

Referenced by setLayerSet().

void QgsMapCanvas::layerStateChange ( )

slot

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

Definition at line 1330 of file qgsmapcanvas.cpp.

References refresh().

QgsMapCanvasMap * QgsMapCanvas::map ( )

Definition at line 193 of file qgsmapcanvas.cpp.

References mMap.

void QgsMapCanvas::mapCanvasRefreshed ( )

signal

Emitted when canvas finished a refresh request.

Note: Added in 2.0

Referenced by refresh().

QgsMapRenderer * QgsMapCanvas::mapRenderer ( )

QgsMapTool * QgsMapCanvas::mapTool ( )

Returns the currently active tool.

Definition at line 1401 of file qgsmapcanvas.cpp.

References mMapTool.

void QgsMapCanvas::mapToolDestroyed ( )

privateslot

called when current maptool is destroyed

Definition at line 1667 of file qgsmapcanvas.cpp.

References mMapTool, and QgsDebugMsg.

Referenced by setMapTool().

void QgsMapCanvas::mapToolSet ( QgsMapTool * tool )

signal

Emit map tool changed event.

Referenced by setMapTool(), and unsetMapTool().

QGis::UnitType QgsMapCanvas::mapUnits ( ) const

Get the current canvas map units.

Definition at line 1369 of file qgsmapcanvas.cpp.

References QgsMapRenderer::mapUnits(), and mMapRenderer.

Referenced by QgsMapToolIdentify::convertMeasurement(), and QgsMapToolIdentify::displayUnits().

void QgsMapCanvas::mapUnitsChanged ( )

slot

The map units may have changed, so cope with that.

Definition at line 712 of file qgsmapcanvas.cpp.

References refresh(), and updateScale().

double QgsMapCanvas::mapUnitsPerPixel ( ) const

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

Definition at line 1356 of file qgsmapcanvas.cpp.

References QgsMapRenderer::mapUnitsPerPixel(), and mMapRenderer.

Referenced by QgsMapToolIdentify::identify(), QgsHighlight::paint(), saveAsImage(), and QgsRubberBand::updateRect().

void QgsMapCanvas::mouseDoubleClickEvent ( QMouseEvent * e )

protected

Overridden mouse double click event.

Definition at line 945 of file qgsmapcanvas.cpp.

References QgsMapTool::canvasDoubleClickEvent(), mDrawing, and mMapTool.

QPoint QgsMapCanvas::mouseLastXY ( )

returns last position of mouse cursor

Definition at line 1525 of file qgsmapcanvas.cpp.

References mCanvasProperties.

void QgsMapCanvas::mouseMoveEvent ( QMouseEvent * e )

protected

Overridden mouse move event.

Definition at line 1208 of file qgsmapcanvas.cpp.

References QgsMapTool::canvasMoveEvent(), getCoordinateTransform(), mCanvasProperties, mDrawing, mMapTool, panAction(), QgsMapToPixel::toMapCoordinates(), and xyCoordinates().

void QgsMapCanvas::mousePressEvent ( QMouseEvent * e )

protected

Overridden mouse press event.

Definition at line 958 of file qgsmapcanvas.cpp.

References QgsMapTool::canvasPressEvent(), mCanvasProperties, mDrawing, and mMapTool.

void QgsMapCanvas::mouseReleaseEvent ( QMouseEvent * e )

protected

Overridden mouse release event.

Definition at line 990 of file qgsmapcanvas.cpp.

References QgsMapTool::canvasReleaseEvent(), QgsVectorLayer::isEditable(), QgsMapTool::isEditTool(), QgsMapTool::isTransient(), mCanvasProperties, mCurrentLayer, mDrawing, mLastNonZoomMapTool, mMapTool, panActionEnd(), QgsDebugMsg, and setMapTool().

void QgsMapCanvas::moveCanvasContents ( bool reset = false )

protected

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

Definition at line 1470 of file qgsmapcanvas.cpp.

References mCanvasProperties, mDrawing, mMap, mScene, QgsMapCanvasMap::setPanningOffset(), QgsMapCanvasItem::setPanningOffset(), and updateCanvasItemPositions().

Referenced by panAction(), panActionEnd(), and QgsMapCanvas().

void QgsMapCanvas::paintEvent ( QPaintEvent * e )

protected

Overridden paint event.

Definition at line 1044 of file qgsmapcanvas.cpp.

References extentsChanged(), mDrawing, mMap, mMapRenderer, mNewSize, mPainting, mResizeTimer, mScene, refresh(), QgsMapRenderer::rendererContext(), QgsMapCanvasMap::resize(), QgsRenderContext::setRenderingStopped(), updateCanvasItemPositions(), and updateScale().

void QgsMapCanvas::panAction ( QMouseEvent * event )

Called when mouse is moving and pan is activated.

Definition at line 1454 of file qgsmapcanvas.cpp.

References mDrawing, and moveCanvasContents().

Referenced by QgsMapToolPan::canvasMoveEvent(), QgsMapToolTouch::canvasMoveEvent(), and mouseMoveEvent().

void QgsMapCanvas::panActionEnd ( QPoint releasePoint )

Ends pan action and redraws the canvas.

Definition at line 1406 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), getCoordinateTransform(), mCanvasProperties, mDrawing, mMapRenderer, moveCanvasContents(), refresh(), setExtent(), QgsRectangle::setXMinimum(), QgsMapToPixel::toMapCoordinates(), QgsPoint::x(), and QgsPoint::y().

Referenced by QgsMapToolPan::canvasReleaseEvent(), QgsMapToolTouch::canvasReleaseEvent(), keyReleaseEvent(), and mouseReleaseEvent().

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

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

Note: added in 2.0

Definition at line 777 of file qgsmapcanvas.cpp.

References QgsVectorLayer::boundingBoxOfSelected(), QgsRectangle::center(), QgsMapRenderer::layerExtentToOutputExtent(), mCurrentLayer, mDrawing, mMapRenderer, refresh(), QgsVectorLayer::selectedFeatureCount(), and setExtent().

void QgsMapCanvas::readProject ( const QDomDocument & doc )

slot

called to read map canvas settings from project

Definition at line 1530 of file qgsmapcanvas.cpp.

References clearExtentHistory(), mMapRenderer, QgsDebugMsg, and QgsMapRenderer::readXML().

Referenced by QgsMapCanvas().

void QgsMapCanvas::refresh ( )

slot

Repaints the canvas map.

Definition at line 381 of file qgsmapcanvas.cpp.

References clear(), QgsMessageLog::logMessage(), mapCanvasRefreshed(), mBackbufferEnabled, mDirty, mDrawing, mFrozen, mMap, mMapTool, mRenderFlag, mResizeTimer, QgsMapCanvasMap::paintDevice(), QgsMapCanvasMap::render(), QgsMapTool::renderComplete(), renderComplete(), renderStarting(), QgsExpression::setSpecialColumn(), and tr.

Referenced by QgsMapToolPan::canvasReleaseEvent(), QgsMapToolZoom::canvasReleaseEvent(), QgsMapToolTouch::canvasReleaseEvent(), crsTransformEnabled(), keyPressEvent(), layerStateChange(), mapUnitsChanged(), QgsMapOverviewCanvas::mouseReleaseEvent(), paintEvent(), panActionEnd(), panToSelected(), QgsMapToolTouch::pinchTriggered(), QgsMapCanvas(), selectionChangedSlot(), setLayerSet(), setRenderFlag(), updateFullExtent(), useImageToRender(), wheelEvent(), zoomByFactor(), zoomToFullExtent(), zoomToNextExtent(), zoomToPreviousExtent(), zoomToSelected(), and zoomWithCenter().

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.

Referenced by refresh(), and saveAsImage().

bool QgsMapCanvas::renderFlag ( )

inlineslot

State of render suppression flag.

Definition at line 286 of file qgsmapcanvas.h.

void QgsMapCanvas::renderStarting ( )

signal

Emitted when the canvas is about to be rendered.

Note: Added in 1.5

Referenced by refresh().

void QgsMapCanvas::resizeEvent ( QResizeEvent * e )

protected

Overridden resize event.

Definition at line 1038 of file qgsmapcanvas.cpp.

References mNewSize, and mResizeTimer.

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 482 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), mapUnitsPerPixel(), mMap, mMapRenderer, QgsMapCanvasMap::paintDevice(), qgsDoubleToString(), QgsMapRenderer::render(), renderComplete(), QgsRectangle::xMinimum(), and QgsRectangle::yMaximum().

double QgsMapCanvas::scale ( )

Get the last reported scale of the canvas.

Definition at line 219 of file qgsmapcanvas.cpp.

References mMapRenderer, and QgsMapRenderer::scale().

Referenced by QgsMapCanvasItem::setRenderContextVariables(), updateScale(), and zoomScale().

void QgsMapCanvas::scaleChanged ( double )

signal

Emitted when the scale of the map changes.

Referenced by updateScale().

void QgsMapCanvas::selectionChanged ( QgsMapLayer * layer )

signal

Emitted when selection in any layer gets changed.

Referenced by selectionChangedSlot(), and setLayerSet().

void QgsMapCanvas::selectionChangedSlot ( )

slot

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

Definition at line 1639 of file qgsmapcanvas.cpp.

References layer(), refresh(), and selectionChanged().

Referenced by setLayerSet().

void QgsMapCanvas::setCanvasColor ( const QColor & theColor )

virtual

Write property of QColor bgColor.

Definition at line 1288 of file qgsmapcanvas.cpp.

References mMap, mScene, and QgsMapCanvasMap::setBackgroundColor().

void QgsMapCanvas::setCurrentLayer ( QgsMapLayer * layer )

Definition at line 214 of file qgsmapcanvas.cpp.

References layer(), and mCurrentLayer.

void QgsMapCanvas::setDirty ( bool _dirty )

Flag the canvas as dirty and needed a refresh.

Definition at line 224 of file qgsmapcanvas.cpp.

References mDirty.

Referenced by clear().

void QgsMapCanvas::setExtent ( const QgsRectangle & r )

Set the extent of the map canvas.

Definition at line 557 of file qgsmapcanvas.cpp.

References QgsRectangle::center(), QgsMapOverviewCanvas::drawExtentRect(), extent(), extentsChanged(), QgsRectangle::height(), QgsRectangle::isEmpty(), mDrawing, mLastExtent, mLastExtentIndex, mMapOverview, mMapRenderer, QgsDebugMsg, QgsMapRenderer::setExtent(), updateCanvasItemPositions(), updateScale(), QgsRectangle::width(), QgsPoint::x(), QgsPoint::y(), zoomLastStatusChanged(), and zoomNextStatusChanged().

Referenced by QgsMapToolPan::canvasReleaseEvent(), QgsMapToolZoom::canvasReleaseEvent(), QgsMapToolTouch::canvasReleaseEvent(), keyPressEvent(), QgsMapOverviewCanvas::mouseReleaseEvent(), panActionEnd(), panToSelected(), QgsMapToolTouch::pinchTriggered(), wheelEvent(), zoomByFactor(), zoomToFullExtent(), zoomToSelected(), and zoomWithCenter().

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

void QgsMapCanvas::setMapTool ( QgsMapTool * mapTool )

Sets the map tool currently being used on the canvas.

Definition at line 1237 of file qgsmapcanvas.cpp.

References QgsMapTool::activate(), QgsMapTool::deactivate(), QgsMapTool::isTransient(), mapToolDestroyed(), mapToolSet(), mLastNonZoomMapTool, and mMapTool.

Referenced by mouseReleaseEvent().

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

Set map units (needed by project properties dialog)

Definition at line 1362 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, and QgsMapRenderer::setMapUnits().

void QgsMapCanvas::setProgress	(	int	,
		int
	)

signal

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

void QgsMapCanvas::setRenderFlag ( bool theFlag )

slot

Whether to suppress rendering or not.

Definition at line 1375 of file qgsmapcanvas.cpp.

References mMapRenderer, mRenderFlag, refresh(), QgsMapRenderer::rendererContext(), and QgsRenderContext::setRenderingStopped().

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

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

Definition at line 1170 of file qgsmapcanvas.cpp.

References mWheelAction, and mWheelZoomFactor.

Referenced by QgsMapCanvas().

void QgsMapCanvas::showError ( QgsMapLayer * mapLayer )

slot

show whatever error is exposed by the QgsMapLayer.

Definition at line 1505 of file qgsmapcanvas.cpp.

References QgsMapLayer::lastError(), QgsMapLayer::lastErrorTitle(), QgsMapLayer::name(), QgsMessageViewer::setMessageAsPlainText(), and tr.

Referenced by QgsMapCanvas().

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 1271 of file qgsmapcanvas.cpp.

References QgsMapTool::deactivate(), mapToolSet(), mLastNonZoomMapTool, and mMapTool.

Referenced by QgsMapTool::~QgsMapTool().

void QgsMapCanvas::updateCanvasItemPositions ( )

protected

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

Definition at line 1090 of file qgsmapcanvas.cpp.

References mScene, and QgsMapCanvasItem::updatePosition().

Referenced by moveCanvasContents(), paintEvent(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::updateFullExtent ( )

Updates the full extent.

Definition at line 547 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, refresh(), and QgsMapRenderer::updateFullExtent().

void QgsMapCanvas::updateMap ( )

slot

updates pixmap on render progress

Definition at line 473 of file qgsmapcanvas.cpp.

References mMap, and QgsMapCanvasMap::updateContents().

Referenced by setLayerSet().

void QgsMapCanvas::updateOverview ( )

Definition at line 365 of file qgsmapcanvas.cpp.

References mMapOverview, and QgsMapOverviewCanvas::refresh().

Referenced by setLayerSet().

void QgsMapCanvas::updateScale ( )

Emits signal scaleChanged to update scale in main window.

Definition at line 610 of file qgsmapcanvas.cpp.

References mMapRenderer, scale(), QgsMapRenderer::scale(), and scaleChanged().

Referenced by mapUnitsChanged(), paintEvent(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::useImageToRender ( bool theFlag )

Select which Qt class to render with.

Definition at line 187 of file qgsmapcanvas.cpp.

References mMap, refresh(), and QgsMapCanvasMap::useImageToRender().

void QgsMapCanvas::wheelEvent ( QWheelEvent * e )

protected

Overridden mouse wheel event.

Definition at line 1108 of file qgsmapcanvas.cpp.

References QgsRectangle::center(), extent(), QgsMapRenderer::extent(), getCoordinateTransform(), mDrawing, mMapRenderer, mMapTool, mWheelAction, mWheelZoomFactor, QgsDebugMsg, refresh(), QgsRectangle::scale(), setExtent(), QgsMapTool::wheelEvent(), WheelNothing, WheelZoom, WheelZoomAndRecenter, WheelZoomToMouseCursor, zoomIn(), zoomOut(), and zoomWithCenter().

void QgsMapCanvas::writeProject ( QDomDocument & doc )

slot

called to write map canvas settings to project

Definition at line 1545 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, and QgsMapRenderer::writeXML().

Referenced by QgsMapCanvas().

void QgsMapCanvas::xyCoordinates ( const QgsPoint & p )

signal

emits current mouse position

Note: changed in 1.3

Referenced by mouseMoveEvent().

void QgsMapCanvas::zoomByFactor ( double scaleFactor )

Zoom with the factor supplied. Factor > 1 zooms out, interval (0,1) zooms in.

Definition at line 1626 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), mDrawing, mMapRenderer, refresh(), QgsRectangle::scale(), and setExtent().

Referenced by zoomIn(), zoomOut(), and zoomScale().

void QgsMapCanvas::zoomIn ( )

Zoom in with fixed factor.

Definition at line 1176 of file qgsmapcanvas.cpp.

References mWheelZoomFactor, and zoomByFactor().

Referenced by keyPressEvent(), and wheelEvent().

void QgsMapCanvas::zoomLastStatusChanged ( bool )

signal

Emitted when zoom last status changed.

Note: : this signal was added in version 1.4

Referenced by clearExtentHistory(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::zoomNextStatusChanged ( bool )

signal

Emitted when zoom next status changed.

Note: : this signal was added in version 1.4

Referenced by clearExtentHistory(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::zoomOut ( )

Zoom out with fixed factor.

Definition at line 1181 of file qgsmapcanvas.cpp.

References mWheelZoomFactor, and zoomByFactor().

Referenced by keyPressEvent(), QgsMapToolTouch::pinchTriggered(), and wheelEvent().

void QgsMapCanvas::zoomScale ( double scale )

Zoom to a specific scale.

Definition at line 1186 of file qgsmapcanvas.cpp.

References scale(), and zoomByFactor().

void QgsMapCanvas::zoomToFullExtent ( )

Zoom to the full extent of all layers.

Definition at line 627 of file qgsmapcanvas.cpp.

References extent(), fullExtent(), QgsRectangle::isEmpty(), mDrawing, refresh(), QgsRectangle::scale(), and setExtent().

void QgsMapCanvas::zoomToNextExtent ( )

Zoom to the next extent (view)

Definition at line 673 of file qgsmapcanvas.cpp.

References QgsMapOverviewCanvas::drawExtentRect(), extentsChanged(), mDrawing, mLastExtent, mLastExtentIndex, mMapOverview, mMapRenderer, refresh(), QgsMapRenderer::setExtent(), updateCanvasItemPositions(), updateScale(), zoomLastStatusChanged(), and zoomNextStatusChanged().

void QgsMapCanvas::zoomToPreviousExtent ( )

Zoom to the previous extent (view)

Definition at line 648 of file qgsmapcanvas.cpp.

References QgsMapOverviewCanvas::drawExtentRect(), extentsChanged(), mDrawing, mLastExtent, mLastExtentIndex, mMapOverview, mMapRenderer, refresh(), QgsMapRenderer::setExtent(), updateCanvasItemPositions(), updateScale(), zoomLastStatusChanged(), and zoomNextStatusChanged().

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

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

Added in version 1.2: optionally specify different than current layer

Definition at line 730 of file qgsmapcanvas.cpp.

References QgsVectorLayer::boundingBoxOfSelected(), QgsRectangle::center(), extent(), QgsRectangle::isEmpty(), QgsMapRenderer::layerExtentToOutputExtent(), mCurrentLayer, mDrawing, mMapRenderer, refresh(), QgsRectangle::scale(), QgsVectorLayer::selectedFeatureCount(), and setExtent().

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

Zooms in/out with a given center.

Definition at line 1191 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), getCoordinateTransform(), mDrawing, mMapRenderer, mWheelZoomFactor, refresh(), QgsRectangle::scale(), setExtent(), and QgsMapToPixel::toMapPoint().

Referenced by QgsMapToolTouch::canvasDoubleClickEvent(), QgsMapToolZoom::canvasReleaseEvent(), and wheelEvent().

Member Data Documentation

bool QgsMapCanvas::mAntiAliasing

private

indicates whether antialiasing will be used for rendering

Definition at line 499 of file qgsmapcanvas.h.

Referenced by enableAntiAliasing().

bool QgsMapCanvas::mBackbufferEnabled

private

If backbuffering is currently enabled.

Definition at line 444 of file qgsmapcanvas.h.

Referenced by QgsMapCanvas(), and refresh().

std::auto_ptr<CanvasProperties> QgsMapCanvas::mCanvasProperties

protected

Handle pattern for implementation object.

Definition at line 411 of file qgsmapcanvas.h.

Referenced by keyPressEvent(), keyReleaseEvent(), mouseLastXY(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), moveCanvasContents(), and panActionEnd().

QgsMapLayer* QgsMapCanvas::mCurrentLayer

private

current layer in legend

Definition at line 471 of file qgsmapcanvas.h.

Referenced by currentLayer(), mouseReleaseEvent(), panToSelected(), QgsMapCanvas(), setCurrentLayer(), and zoomToSelected().

bool QgsMapCanvas::mDirty

private

Flag to track the state of the Map canvas.

The canvas is flagged as dirty by any operation that changes the state of the layers or the view extent. If the canvas is not dirty, paint events are handled by bit-blitting the stored canvas bitmap to the canvas. This improves performance by not reading the data source when no real change has occurred

Definition at line 460 of file qgsmapcanvas.h.

Referenced by isDirty(), QgsMapCanvas(), refresh(), and setDirty().

bool QgsMapCanvas::mDrawing

private

Flag indicating a map refresh is in progress.

Definition at line 446 of file qgsmapcanvas.h.

Referenced by isDrawing(), keyPressEvent(), keyReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), moveCanvasContents(), paintEvent(), panAction(), panActionEnd(), panToSelected(), QgsMapCanvas(), refresh(), setExtent(), setLayerSet(), wheelEvent(), zoomByFactor(), zoomToFullExtent(), zoomToNextExtent(), zoomToPreviousExtent(), zoomToSelected(), and zoomWithCenter().