A widget for showing the bounds of a rectangular region on an interactive map. More...

#include <qgscoordinateboundspreviewmapwidget.h>

Inheritance diagram for QgsCoordinateBoundsPreviewMapWidget:

Public Member Functions
	QgsCoordinateBoundsPreviewMapWidget (QWidget *parent=nullptr)
	Constructor for QgsCoordinateBoundsPreviewMapWidget.

	~QgsCoordinateBoundsPreviewMapWidget () override

QgsRectangle	canvasRect () const
	Returns the current canvas bounds rectangle shown in the map.

void	setCanvasRect (const QgsRectangle &rect)
	Sets the canvas bounds rectangle for the bounds overview map.

void	setPreviewRect (const QgsRectangle &rect)
	Sets the "preview" rectangle for the bounds overview map.

Public Member Functions inherited from QgsMapCanvas
	QgsMapCanvas (QWidget *parent=nullptr)
	Constructor.

	~QgsMapCanvas () override

bool	allowInteraction (QgsMapCanvasInteractionBlocker::Interaction interaction) const
	Returns `true` if the specified interaction is currently permitted on the canvas.

QList< QgsMapCanvasAnnotationItem * >	annotationItems () const
	Returns a list of all annotation items in the canvas.

bool	annotationsVisible () const
	Returns `true` if annotations are visible within the map canvas.

bool	antiAliasingEnabled () const
	`true` if antialiasing is enabled

QgsMapRendererCache *	cache ()
	Returns the map renderer cache, if caching is enabled.

void	cancelJobs ()
	Cancel any rendering job, in a blocking way.

QColor	canvasColor () const
	Read property of QColor bgColor.

QgsPointXY	center () const
	Gets map center, in geographical coordinates.

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

void	clearExtentHistory ()
	Clears the list of extents and sets current extent as first item.

QgsExpressionContext	createExpressionContext () const override
	This method needs to be reimplemented in all classes which implement this interface and return an expression context.

QgsMapLayer *	currentLayer ()
	returns current layer (set by legend widget)

QgsExpressionContextScope *	defaultExpressionContextScope () const
	Creates a new scope which contains default variables and functions relating to the map canvas.

void	enableAntiAliasing (bool flag)
	used to determine if anti-aliasing is enabled or not

void	enableMapTileRendering (bool flag)
	sets map tile rendering flag

QgsExpressionContextScope &	expressionContextScope ()
	Returns a reference to the expression context scope for the map canvas.

const QgsExpressionContextScope &	expressionContextScope () const
	Returns a const reference to the expression context scope for the map canvas.

QgsRectangle	extent () const
	Returns the current zoom extent of the map canvas.

void	flashFeatureIds (QgsVectorLayer *layer, const QgsFeatureIds &ids, const QColor &startColor=QColor(255, 0, 0, 255), const QColor &endColor=QColor(255, 0, 0, 0), int flashes=3, int duration=500)
	Causes a set of features with matching ids from a vector layer to flash within the canvas.

void	flashGeometries (const QList< QgsGeometry > &geometries, const QgsCoordinateReferenceSystem &crs=QgsCoordinateReferenceSystem(), const QColor &startColor=QColor(255, 0, 0, 255), const QColor &endColor=QColor(255, 0, 0, 0), int flashes=3, int duration=500)
	Causes a set of geometries to flash within the canvas.

void	freeze (bool frozen=true)
	Freeze/thaw the map canvas.

QgsRectangle	fullExtent () const
	Returns the combined extent for all layers on the map canvas.

const QgsMapToPixel *	getCoordinateTransform ()
	Gets the current coordinate transform.

void	installInteractionBlocker (QgsMapCanvasInteractionBlocker *blocker)
	Installs an interaction blocker onto the canvas, which may prevent certain map canvas interactions from occurring.

bool	isCachingEnabled () const
	Check whether images of rendered layers are curerently being cached.

bool	isDrawing ()
	Find out whether rendering is in progress.

bool	isFrozen () const
	Returns `true` if canvas is frozen.

bool	isParallelRenderingEnabled () const
	Check whether the layers are rendered in parallel or sequentially.

const QgsLabelingEngineSettings &	labelingEngineSettings () const
	Returns global labeling engine settings from the internal map settings.

const QgsLabelingResults *	labelingResults (bool allowOutdatedResults=true) const
	Gets access to the labeling results (may be `nullptr`).

QgsMapLayer *	layer (const QString &id)
	Returns the map layer with the matching ID, or `nullptr` if no layers could be found.

QgsMapLayer *	layer (int index)
	Returns the map layer at position index in the layer stack.

int	layerCount () const
	Returns number of layers on the map.

QList< QgsMapLayer * >	layers (bool expandGroupLayers=false) const
	Returns the list of layers shown within the map canvas.

QMap< QString, QString >	layerStyleOverrides () const
	Returns the stored overrides of styles for layers.

double	magnificationFactor () const
	Returns the magnification factor.

QgsMapSettings &	mapSettings ()
	Returns a reference to the map settings used for map rendering.

const QgsMapSettings &	mapSettings () const
	Gets access to properties used for map rendering.

QgsMapTool *	mapTool ()
	Returns the currently active tool.

Qgis::DistanceUnit	mapUnits () const
	Convenience function for returning 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	panActionStart (QPoint releasePoint)
	Starts a pan action.

void	panToFeatureIds (QgsVectorLayer *layer, const QgsFeatureIds &ids, bool alwaysRecenter=true)
	Centers canvas extent to feature ids.

void	panToSelected (const QList< QgsMapLayer * > &layers)
	Pan to the combined extent of the selected features of all provided (vector) layers.

void	panToSelected (QgsMapLayer *layer=nullptr)
	Pan to the selected features of current ayer keeping same extent.

bool	previewJobsEnabled () const
	Returns `true` if canvas map preview jobs (low priority render jobs which render portions of the view just outside of the canvas extent, to allow preview of these out-of-canvas areas when panning or zooming out the map) are enabled for the canvas.

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.

QgsProject *	project ()
	Returns the project linked to this canvas.

QgsRectangle	projectExtent () const
	Returns the associated project's full extent, in the canvas' CRS.

void	removeInteractionBlocker (QgsMapCanvasInteractionBlocker *blocker)
	Removes an interaction blocker from the canvas.

const QgsRenderedItemResults *	renderedItemResults (bool allowOutdatedResults=true) const
	Gets access to the rendered item results (may be `nullptr`), which includes the results of rendering annotation items in the canvas map.

bool	renderFlag () const
	Returns `true` if canvas render is disabled as a result of user disabling renders via the GUI.

double	rotation () const
	Gets the current map canvas rotation in clockwise degrees.

double	scale () const
	Returns the last reported scale of the canvas.

bool	scaleLocked () const
	Returns whether the scale is locked, so zooming can be performed using magnication.

QColor	selectionColor () const
	Returns color for selected features.

void	setAnnotationsVisible (bool visible)
	Sets whether annotations are visible in the canvas.

void	setCachingEnabled (bool enabled)
	Set whether to cache images of rendered layers.

void	setCanvasColor (const QColor &_newVal)
	Write property of QColor bgColor.

void	setCenter (const QgsPointXY &center)
	Set the center of the map canvas, in geographical coordinates.

void	setCurrentLayer (QgsMapLayer *layer)

void	setCustomDropHandlers (const QVector< QPointer< QgsCustomDropHandler > > &handlers)
	Sets a list of custom drop handlers to use when drop events occur on the canvas.

void	setDestinationCrs (const QgsCoordinateReferenceSystem &crs)
	Sets destination coordinate reference system.

void	setExpressionContextScope (const QgsExpressionContextScope &scope)
	Sets an expression context scope for the map canvas.

void	setExtent (const QgsRectangle &r, bool magnified=false)
	Sets the extent of the map canvas to the specified rectangle.

void	setLabelingEngineSettings (const QgsLabelingEngineSettings &settings)
	Sets global labeling engine settings in the internal map settings.

void	setLayers (const QList< QgsMapLayer * > &layers)
	Sets the list of layers that should be shown in the canvas.

void	setLayerStyleOverrides (const QMap< QString, QString > &overrides)
	Sets the stored overrides of styles for rendering layers.

void	setMapController (QgsAbstract2DMapController *controller)
	Sets the input controller device to use for controlling the canvas.

void	setMapSettingsFlags (Qgis::MapSettingsFlags flags)
	Resets the flags for the canvas' map settings.

void	setMapTool (QgsMapTool *mapTool, bool clean=false)
	Sets the map tool currently being used on the canvas.

void	setMapUpdateInterval (int timeMilliseconds)
	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	setPreviewJobsEnabled (bool enabled)
	Sets whether canvas map preview jobs (low priority render jobs which render portions of the view just outside of the canvas extent, to allow preview of these out-of-canvas areas when panning or zooming out the map) are enabled for the canvas.

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	setProject (QgsProject *project)
	Sets the project linked to this canvas.

bool	setReferencedExtent (const QgsReferencedRectangle &extent)
	Sets the canvas to the specified extent.

void	setRotation (double degrees)
	Set the rotation of the map canvas in clockwise degrees.

void	setSegmentationTolerance (double tolerance)
	Sets the segmentation tolerance applied when rendering curved geometries.

void	setSegmentationToleranceType (QgsAbstractGeometry::SegmentationToleranceType type)
	Sets segmentation tolerance type (maximum angle or maximum difference between curve and approximation)

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	setTemporalController (QgsTemporalController *controller)
	Sets the temporal controller for this canvas.

void	setTemporalRange (const QgsDateTimeRange &range)
	Set datetime range for the map canvas.

void	setTheme (const QString &theme)
	Sets a map theme to show in the canvas.

void	setWheelFactor (double factor)
	Sets wheel zoom factor (should be greater than 1)

QgsSnappingUtils *	snappingUtils () const
	Returns snapping utility class that is associated with map canvas.

const QgsTemporalController *	temporalController () const
	Gets access to the temporal controller that will be used to update the canvas temporal range.

const QgsDateTimeRange &	temporalRange () const
	Returns map canvas datetime range.

QString	theme () const
	Returns the map's theme shown in the canvas, if set.

void	unsetMapTool (QgsMapTool *mapTool)
	Unset the current map tool or last non zoom tool.

void	updateScale ()
	Emits signal scaleChanged to update scale in main window.

void	waitWhileRendering ()
	Blocks until the rendering job has finished.

void	zoomByFactor (double scaleFactor, const QgsPointXY *center=nullptr, bool ignoreScaleLock=false)
	Zoom with the factor supplied.

void	zoomScale (double scale, bool ignoreScaleLock=false)
	Zooms the canvas to a specific scale.

void	zoomToFeatureExtent (QgsRectangle &rect)
	Zooms to feature extent.

void	zoomToFeatureIds (QgsVectorLayer *layer, const QgsFeatureIds &ids)
	Set canvas extent to the bounding box of a set of features.

void	zoomToFullExtent ()
	Zoom to the full extent of all layers currently visible in the canvas.

void	zoomToNextExtent ()
	Zoom to the next extent (view)

void	zoomToPreviousExtent ()
	Zoom to the previous extent (view)

void	zoomToProjectExtent ()
	Zoom to the full extent the project associated with this canvas.

void	zoomWithCenter (int x, int y, bool zoomIn)
	Zooms in/out with a given center.

Public Member Functions inherited from QgsExpressionContextGenerator
virtual	~QgsExpressionContextGenerator ()=default

Additional Inherited Members
Public Slots inherited from QgsMapCanvas
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	redrawAllLayers ()
	Clears all cached images and redraws all layers.

void	refresh ()
	Repaints the canvas map.

void	refreshAllLayers ()
	Reload all layers (including refreshing layer properties from their data sources), clears the cache and refreshes the canvas.

void	saveAsImage (const QString &fileName, QPixmap *QPixmap=nullptr, const QString &="PNG")
	Save the contents of the map canvas to disk as an image.

void	selectionChangedSlot ()
	Receives signal about selection change, and pass it on with layer info.

void	setMagnificationFactor (double factor, const QgsPointXY *center=nullptr)
	Sets the factor of magnification to apply to the map canvas.

void	setRenderFlag (bool flag)
	Sets whether a user has disabled canvas renders via the GUI.

void	setScaleLocked (bool isLocked)
	Lock the scale, so zooming can be performed using magnication.

void	setZoomResolutions (const QList< double > &resolutions)
	Set a list of resolutions (map units per pixel) to which to "snap to" when zooming the map.

void	setZRange (const QgsDoubleRange &range)
	Sets the range of z-values which will be visible in the map.

void	stopRendering ()
	stop rendering (if there is any right now)

void	writeProject (QDomDocument &)
	called to write map canvas settings to project

void	zoomIn ()
	Zoom in with fixed factor.

double	zoomInFactor () const
	Returns the zoom in factor.

void	zoomOut ()
	Zoom out with fixed factor.

double	zoomOutFactor () const
	Returns the zoom in factor.

const QList< double > &	zoomResolutions () const

void	zoomToSelected (const QList< QgsMapLayer * > &layers)
	Zoom to the combined extent of the selected features of all provided (vector) layers.

void	zoomToSelected (QgsMapLayer *layer=nullptr)
	Zoom to the extent of the selected features of provided map layer.

QgsDoubleRange	zRange () const
	Returns the range of z-values which will be visible in the map.

Signals inherited from QgsMapCanvas
void	canvasColorChanged ()
	Emitted when canvas background color changes.

void	contextMenuAboutToShow (QMenu menu, QgsMapMouseEvent event)
	Emitted before the map canvas context menu will be shown.

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	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	layerStyleOverridesChanged ()
	Emitted when the configuration of overridden layer styles changes.

void	magnificationChanged (double)
	Emitted when the scale of the map changes.

void	mapCanvasRefreshed ()
	Emitted when canvas finished a refresh request.

void	mapRefreshCanceled ()
	Emitted when the pending map refresh has been canceled.

void	mapToolSet (QgsMapTool newTool, QgsMapTool oldTool)
	Emit map tool changed with the old tool.

void	messageEmitted (const QString &title, const QString &message, Qgis::MessageLevel=Qgis::MessageLevel::Info)
	emit a message (usually to be displayed in a message bar)

void	panDistanceBearingChanged (double distance, Qgis::DistanceUnit unit, double bearing)
	Emitted whenever the distance or bearing of an in-progress panning operation is changed.

void	renderComplete (QPainter *)
	Emitted when the canvas has rendered.

void	renderErrorOccurred (const QString &error, QgsMapLayer *layer)
	Emitted whenever an error is encountered during a map render operation.

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	scaleLockChanged (bool locked)
	Emitted when the scale locked state of the map changes.

void	selectionChanged (QgsMapLayer *layer)
	Emitted when selection in any layer gets changed.

void	tapAndHoldGestureOccurred (const QgsPointXY &mapPoint, QTapAndHoldGesture *gesture)
	Emitted whenever a tap and hold gesture occurs at the specified map point.

void	temporalRangeChanged ()
	Emitted when the map canvas temporal range changes.

void	themeChanged (const QString &theme)
	Emitted when the canvas has been assigned a different map theme.

void	transformContextChanged ()
	Emitted when the canvas transform context is changed.

void	xyCoordinates (const QgsPointXY &p)
	Emits current mouse position.

void	zoomLastStatusChanged (bool)
	Emitted when zoom last status changed.

void	zoomNextStatusChanged (bool)
	Emitted when zoom next status changed.

void	zRangeChanged ()
	Emitted when the map canvas z (elevation) range changes.

Protected Slots inherited from QgsMapCanvas
void	updateCanvasItemPositions ()
	called on resize or changed extent to notify canvas items to change their rectangle

Protected Member Functions inherited from QgsMapCanvas
void	dragEnterEvent (QDragEnterEvent *e) override

void	dropEvent (QDropEvent *event) override

void	emitExtentsChanged ()
	Emits the extentsChanged signal when appropriate.

bool	event (QEvent *e) override

void	keyPressEvent (QKeyEvent *e) override

void	keyReleaseEvent (QKeyEvent *e) override

void	mouseDoubleClickEvent (QMouseEvent *e) override

void	mouseMoveEvent (QMouseEvent *e) override

void	mousePressEvent (QMouseEvent *e) override

void	mouseReleaseEvent (QMouseEvent *e) override

void	moveCanvasContents (bool reset=false)
	called when panning is in action, reset indicates end of panning

void	paintEvent (QPaintEvent *e) override

void	resizeEvent (QResizeEvent *e) override

void	showEvent (QShowEvent *event) override

bool	viewportEvent (QEvent *event) override

void	wheelEvent (QWheelEvent *e) override

Protected Attributes inherited from QgsMapCanvas
std::unique_ptr< CanvasProperties >	mCanvasProperties
	Handle pattern for implementation object.

Properties inherited from QgsMapCanvas
bool	previewJobsEnabled

QString	theme