Subgroup: Map

Class: QgsMapCanvas

class qgis.gui.QgsMapCanvas

Bases: PyQt5.QtWidgets.QGraphicsView

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

Methods

acceptDrops
accessibleDescription
accessibleName
actionEvent
actions
activateWindow
addAction
addActions
addScrollBarWidget
adjustSize
alignment
annotationItems	Returns a list of all annotation items in the canvas.
annotationsVisible	Returns true if annotations are visible within the map canvas.
antiAliasingEnabled	true if antialising is enabled
autoFillBackground
backgroundBrush
backgroundRole
baseSize
blockSignals
cacheMode
canvasColor	Read property of QColor bgColor.
center	Get map center, in geographical coordinates
centerOn	centerOn(self, QGraphicsItem)
changeEvent
childAt	childAt(self, int, int) -> QWidget
childEvent
children
childrenRect
childrenRegion
clearCache	Make sure to remove any rendered images from cache (does nothing if cache is not enabled)
clearExtentHistory
clearFocus
clearMask
close
closeEvent
colorCount
connectNotify
contentsMargins
contentsRect
contextMenuEvent
contextMenuPolicy
cornerWidget
create
createWindowContainer
currentLayer	returns current layer (set by legend widget)
cursor
customEvent
deleteLater
depth
destroy
devType
devicePixelRatio
devicePixelRatioF
devicePixelRatioFScale
disconnect
disconnectNotify
dragEnterEvent	Overridden drag enter event
dragLeaveEvent
dragMode
dragMoveEvent
drawBackground
drawForeground
drawFrame
dropEvent
dumpObjectInfo
dumpObjectTree
dynamicPropertyNames
effectiveWinId
enableAntiAliasing	used to determine if anti-aliasing is enabled or not
enableMapTileRendering	sets map tile rendering flag
ensurePolished
ensureVisible	ensureVisible(self, QGraphicsItem, xMargin: int = 50, yMargin: int = 50)
enterEvent
event	Overridden standard event to be gestures aware
eventFilter
expressionContextScope	Returns a reference to the expression context scope for the map canvas.
extent	Returns the current zoom extent of the map canvas
find
findChild	findChild(self, Tuple, name: str = ‘’, options: Union[Qt.FindChildOptions, Qt.FindChildOption] = Qt.FindChildrenRecursively) -> QObject
findChildren	findChildren(self, Tuple, name: str = ‘’, options: Union[Qt.FindChildOptions, Qt.FindChildOption] = Qt.FindChildrenRecursively) -> List[QObject]
fitInView	fitInView(self, QGraphicsItem, mode: Qt.AspectRatioMode = Qt.IgnoreAspectRatio)
flashFeatureIds	Causes a set of features with matching ids from a vector layer to flash within the canvas.
flashGeometries	Causes a set of geometries to flash within the canvas.
focusInEvent
focusNextChild
focusNextPrevChild
focusOutEvent
focusPolicy
focusPreviousChild
focusProxy
focusWidget
font
fontInfo
fontMetrics
foregroundBrush
foregroundRole
frameGeometry
frameRect
frameShadow
frameShape
frameSize
frameStyle
frameWidth
freeze	Freeze/thaw the map canvas.
fullExtent	Returns the combined extent for all layers on the map canvas
geometry
getContentsMargins
getCoordinateTransform	Get the current coordinate transform
grab
grabGesture
grabKeyboard
grabMouse	grabMouse(self, Union[QCursor, Qt.CursorShape])
grabShortcut
graphicsEffect
graphicsProxyWidget
hasFocus
hasHeightForWidth
hasMouseTracking
hasTabletTracking
height
heightForWidth
heightMM
hide
hideEvent
horizontalScrollBar
horizontalScrollBarPolicy
inherits
initPainter
initStyleOption
inputMethodEvent
inputMethodHints
inputMethodQuery
insertAction
insertActions
installEventFilter
invalidateScene
isActiveWindow
isAncestorOf
isCachingEnabled	Check whether images of rendered layers are curerently being cached
isDrawing	Find out whether rendering is in progress
isEnabled
isEnabledTo
isFrozen	Returns true if canvas is frozen.
isFullScreen
isHidden
isInteractive
isLeftToRight
isMaximized
isMinimized
isModal
isParallelRenderingEnabled	Check whether the layers are rendered in parallel or sequentially
isRightToLeft
isSignalConnected
isTransformed
isVisible
isVisibleTo
isWidgetType
isWindow
isWindowModified
isWindowType
itemAt	itemAt(self, int, int) -> QGraphicsItem
items	items(self, QPoint) -> List[QGraphicsItem]
keyPressEvent	Overridden key press event
keyReleaseEvent	Overridden key release event
keyboardGrabber
killTimer
labelingEngineSettings	Returns global labeling engine settings from the internal map settings
labelingResults	Get access to the labeling results (may be null)
layer	return the map layer at position index in the layer stack
layerCount	return number of layers on the map
layerStateChange	This slot is connected to the visibility change of one or more layers
layerStyleOverrides	Returns the stored overrides of styles for layers.
layers	Return the list of layers shown within the map canvas.
layout
layoutDirection
leaveEvent
lineWidth
locale
logicalDpiX
logicalDpiY
lower
magnificationFactor	Returns the magnification factor
mapFrom
mapFromGlobal
mapFromParent
mapFromScene	mapFromScene(self, QRectF) -> QPolygon
mapSettings	Get access to properties used for map rendering
mapTo
mapToGlobal
mapToParent
mapToScene	mapToScene(self, QRect) -> QPolygonF
mapTool	Returns the currently active tool
mapUnits	Convience function for returning the current canvas map units.
mapUnitsPerPixel	Returns the mapUnitsPerPixel (map units per pixel) for the canvas
mapUpdateInterval	Find out how often map preview should be updated while it is being rendered (in milliseconds)
mask
maximumHeight
maximumSize
maximumViewportSize
maximumWidth
metaObject
metric
midLineWidth
minimumHeight
minimumSize
minimumSizeHint
minimumWidth
mouseDoubleClickEvent	Overridden mouse double-click event
mouseGrabber
mouseLastXY	returns last position of mouse cursor
mouseMoveEvent	Overridden mouse move event
mousePressEvent	Overridden mouse press event
mouseReleaseEvent	Overridden mouse release event
move	move(self, int, int)
moveCanvasContents	called when panning is in action, reset indicates end of panning
moveEvent
moveToThread
nativeEvent
nativeParentWidget
nextInFocusChain
normalGeometry
objectName
optimizationFlags
overrideWindowFlags
overrideWindowState
paintEngine
paintEvent	Overridden paint event
paintingActive
palette
panAction	Called when mouse is moving and pan is activated
panActionEnd	Ends pan action and redraws the canvas.
panToFeatureIds	Centers canvas extent to feature ids
panToSelected	Pan to the selected features of current (vector) layer keeping same extent.
parent
parentWidget
physicalDpiX
physicalDpiY
pos
previewJobsEnabled	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.
previewMode	Returns the current preview mode for the map canvas.
previewModeEnabled	Returns whether a preview mode is enabled for the map canvas
previousInFocusChain
property
pyqtConfigure	Each keyword argument is either the name of a Qt property or a Qt signal.
raise_
readProject	called to read map canvas settings from project
receivers
rect
refresh	Repaints the canvas map
refreshAllLayers	Reload all layers, clear the cache and refresh the canvas
releaseKeyboard
releaseMouse
releaseShortcut
removeAction
removeEventFilter
render
renderFlag	Returns true if canvas render is disabled as a result of user disabling renders via the GUI.
renderHints
repaint	repaint(self, int, int, int, int)
resetCachedContent
resetTransform
resize	resize(self, int, int)
resizeAnchor
resizeEvent	Overridden resize event
restoreGeometry
rotate
rotation	Get the current map canvas rotation in clockwise degrees
rubberBandRect
rubberBandSelectionMode
saveAsImage	Save the convtents of the map canvas to disk as an image
saveGeometry
scale	Returns the last reported scale of the canvas.
scaleLocked	Returns whether the scale is locked, so zooming can be performed using magnication.
scene
sceneRect
scroll	scroll(self, int, int, QRect)
scrollBarWidgets
scrollContentsBy
selectionChangedSlot	Receives signal about selection change, and pass it on with layer info
selectionColor	Returns color for selected features
sender
senderSignalIndex
setAcceptDrops
setAccessibleDescription
setAccessibleName
setAlignment
setAnnotationsVisible	Sets whether annotations are visible in the canvas.
setAttribute
setAutoFillBackground
setBackgroundBrush
setBackgroundRole
setBaseSize	setBaseSize(self, QSize)
setCacheMode
setCachingEnabled	Set whether to cache images of rendered layers
setCanvasColor	Write property of QColor bgColor.
setCenter	Set the center of the map canvas, in geographical coordinates
setContentsMargins	setContentsMargins(self, QMargins)
setContextMenuPolicy
setCornerWidget
setCurrentLayer
setCursor
setDestinationCrs	sets destination coordinate reference system
setDisabled
setDragMode
setEnabled
setExpressionContextScope	Sets an expression context scope for the map canvas.
setExtent	Set the extent of the map canvas
setFixedHeight
setFixedSize	setFixedSize(self, int, int)
setFixedWidth
setFocus	setFocus(self, Qt.FocusReason)
setFocusPolicy
setFocusProxy
setFont
setForegroundBrush
setForegroundRole
setFrameRect
setFrameShadow
setFrameShape
setFrameStyle
setGeometry	setGeometry(self, int, int, int, int)
setGraphicsEffect
setHidden
setHorizontalScrollBar
setHorizontalScrollBarPolicy
setInputMethodHints
setInteractive
setLabelingEngineSettings	Sets global labeling engine settings in the internal map settings
setLayerStyleOverrides	Sets the stored overrides of styles for rendering layers.
setLayers	Sets the list of layers that should be shown in the canvas.
setLayout
setLayoutDirection
setLineWidth
setLocale
setMagnificationFactor	Sets the factor of magnification to apply to the map canvas.
setMapSettingsFlags	Resets the flags for the canvas’ map settings.
setMapTool	Sets the map tool currently being used on the canvas
setMapUpdateInterval	Set how often map preview should be updated while it is being rendered (in milliseconds)
setMask	setMask(self, QRegion)
setMaximumHeight
setMaximumSize	setMaximumSize(self, QSize)
setMaximumWidth
setMidLineWidth
setMinimumHeight
setMinimumSize	setMinimumSize(self, QSize)
setMinimumWidth
setMouseTracking
setObjectName
setOptimizationFlag
setOptimizationFlags
setPalette
setParallelRenderingEnabled	Set whether the layers are rendered in parallel or sequentially
setParent	setParent(self, QWidget, Union[Qt.WindowFlags, Qt.WindowType])
setPreviewJobsEnabled	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.
setPreviewMode	Sets a preview mode for the map canvas.
setPreviewModeEnabled	Enables a preview mode for the map canvas
setProperty
setRenderFlag	Sets whether a user has disabled canvas renders via the GUI.
setRenderHint
setRenderHints
setResizeAnchor
setRotation	Set the rotation of the map canvas in clockwise degrees
setRubberBandSelectionMode
setScaleLocked	Lock the scale, so zooming can be performed using magnication
setScene
setSceneRect	setSceneRect(self, float, float, float, float)
setSegmentationTolerance	Sets the segmentation tolerance applied when rendering curved geometries
setSegmentationToleranceType	Sets segmentation tolerance type (maximum angle or maximum difference between curve and approximation)
setSelectionColor	Set color of selected vector features
setShortcutAutoRepeat
setShortcutEnabled
setSizeAdjustPolicy
setSizeIncrement	setSizeIncrement(self, QSize)
setSizePolicy	setSizePolicy(self, QSizePolicy.Policy, QSizePolicy.Policy)
setSnappingUtils	Assign an instance of snapping utils to the map canvas.
setStatusTip
setStyle
setStyleSheet
setTabOrder
setTabletTracking
setTheme	Sets a map theme to show in the canvas.
setToolTip
setToolTipDuration
setTransform
setTransformationAnchor
setUpdatesEnabled
setVerticalScrollBar
setVerticalScrollBarPolicy
setViewport
setViewportMargins
setViewportUpdateMode
setVisible
setWhatsThis
setWheelFactor	set wheel zoom factor (should be greater than 1)
setWindowFilePath
setWindowFlag
setWindowFlags
setWindowIcon
setWindowIconText
setWindowModality
setWindowModified
setWindowOpacity
setWindowRole
setWindowState
setWindowTitle
setupViewport
sharedPainter
shear
show
showEvent
showFullScreen
showMaximized
showMinimized
showNormal
signalsBlocked
size
sizeAdjustPolicy
sizeHint
sizeIncrement
sizePolicy
snappingUtils	Return snapping utility class that is associated with map canvas.
stackUnder
startTimer
statusTip
stopRendering	stop rendering (if there is any right now)
style
styleSheet
tabletEvent
testAttribute
theme	Returns the map’s theme shown in the canvas, if set.
thread
timerEvent
toolTip
toolTipDuration
tr
transform
transformationAnchor
translate
underMouse
ungrabGesture
unsetCursor
unsetLayoutDirection
unsetLocale
unsetMapTool	Unset the current map tool or last non zoom tool
update	update(self, QRect)
updateCanvasItemPositions	called on resize or changed extent to notify canvas items to change their rectangle
updateGeometry
updateMicroFocus
updateScale	Emits signal scaleChanged to update scale in main window
updateScene
updateSceneRect
updatesEnabled
verticalScrollBar
verticalScrollBarPolicy
viewport
viewportEvent
viewportMargins
viewportSizeHint
viewportTransform
viewportUpdateMode
visibleRegion
waitWhileRendering	Blocks until the rendering job has finished.
whatsThis
wheelEvent	Overridden mouse wheel event
width
widthMM
winId
window
windowFilePath
windowFlags
windowHandle
windowIcon
windowIconText
windowModality
windowOpacity
windowRole
windowState
windowTitle
windowType
writeProject	called to write map canvas settings to project
x
y
zoomByFactor	Zoom with the factor supplied.
zoomIn	Zoom in with fixed factor
zoomOut	Zoom out with fixed factor
zoomScale	Zooms the canvas to a specific scale.
zoomToFeatureExtent	Zooms to feature extent.
zoomToFeatureIds	Set canvas extent to the bounding box of a set of features
zoomToFullExtent	Zoom to the full extent of all layers
zoomToNextExtent	Zoom to the next extent (view)
zoomToPreviousExtent	Zoom to the previous extent (view)
zoomToSelected	Zoom to the extent of the selected features of current (vector) layer.
zoomWithCenter	Zooms in/out with a given center

Attributes

AdjustIgnored
AdjustToContents
AdjustToContentsOnFirstShow
AnchorUnderMouse
AnchorViewCenter
BoundingRectViewportUpdate
Box
CacheBackground
CacheNone
DontAdjustForAntialiasing
DontClipPainter
DontSavePainterState
DrawChildren
DrawWindowBackground
FullViewportUpdate
HLine
IgnoreMask
MinimalViewportUpdate
NoAnchor
NoDrag
NoFrame
NoViewportUpdate
Panel
PdmDepth
PdmDevicePixelRatio
PdmDevicePixelRatioScaled
PdmDpiX
PdmDpiY
PdmHeight
PdmHeightMM
PdmNumColors
PdmPhysicalDpiX
PdmPhysicalDpiY
PdmWidth
PdmWidthMM
Plain
Raised
RubberBandDrag
ScrollHandDrag
Shadow_Mask
Shape_Mask
SmartViewportUpdate
StyledPanel
Sunken
VLine
WinPanel
canvasColorChanged	Emitted when canvas background color changes
currentLayerChanged	Emitted when the current layer is changed
customContextMenuRequested	customContextMenuRequested(self, QPoint) [signal]
destinationCrsChanged	Emitted when map CRS has changed
destroyed	destroyed(self, QObject = None) [signal]
extentsChanged	Emitted when the extents of the map change [signal]
keyPressed	Emit key press event [signal]
keyReleased	Emit key release event [signal]
layerStyleOverridesChanged	Emitted when the configuration of overridden layer styles changes
layersChanged	Emitted when a new set of layers has been received [signal]
magnificationChanged	Emitted when the scale of the map changes
mapCanvasRefreshed	Emitted when canvas finished a refresh request.
mapToolSet	Emit map tool changed with the old tool
messageEmitted	emit a message (usually to be displayed in a message bar) [signal]
objectNameChanged	objectNameChanged(self, str) [signal]
renderComplete	TODO: deprecate when decorations are reimplemented as map canvas items
renderStarting	Emitted when the canvas is about to be rendered.
rotationChanged	Emitted when the rotation of the map changes
rubberBandChanged	rubberBandChanged(self, QRect, Union[QPointF, QPoint], Union[QPointF, QPoint]) [signal]
scaleChanged	Emitted when the scale of the map changes [signal]
selectionChanged	Emitted when selection in any layer gets changed [signal]
staticMetaObject
themeChanged	Emitted when the canvas has been assigned a different map theme.
transformContextChanged	Emitted when the canvas transform context is changed.
windowIconChanged	windowIconChanged(self, QIcon) [signal]
windowIconTextChanged	windowIconTextChanged(self, str) [signal]
windowTitleChanged	windowTitleChanged(self, str) [signal]
xyCoordinates	Emits current mouse position
zoomLastStatusChanged	Emitted when zoom last status changed [signal]
zoomNextStatusChanged	Emitted when zoom next status changed [signal]

actionEvent()

annotationItems(self) → object

Returns a list of all annotation items in the canvas.

New in version 3.0.

annotationsVisible(self) → bool

Returns true if annotations are visible within the map canvas.

New in version 3.0.

See also

setAnnotationsVisible()

antiAliasingEnabled(self) → bool

true if antialising is enabled

canvasColor(self) → QColor

Read property of QColor bgColor.

canvasColorChanged

Emitted when canvas background color changes

New in version 3.0: [signal]

center(self) → QgsPointXY

Get map center, in geographical coordinates

New in version 2.8.

changeEvent()

childEvent()

clearCache(self)

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

New in version 2.4.

clearExtentHistory(self)

closeEvent()

connectNotify()

contextMenuEvent()

create()

currentLayer(self) → QgsMapLayer

returns current layer (set by legend widget)

currentLayerChanged

Emitted when the current layer is changed

New in version 2.8: [signal]

customEvent()

destinationCrsChanged

Emitted when map CRS has changed

New in version 2.4: [signal]

destroy()

disconnectNotify()

dragEnterEvent(self, e: QDragEnterEvent)

Overridden drag enter event

dragLeaveEvent()

dragMoveEvent()

drawBackground()

drawForeground()

drawFrame()

dropEvent()

enableAntiAliasing(self, flag: bool)

used to determine if anti-aliasing is enabled or not

enableMapTileRendering(self, flag: bool)

sets map tile rendering flag

enterEvent()

event(self, e: QEvent) → bool

Overridden standard event to be gestures aware

eventFilter()

expressionContextScope(self) → QgsExpressionContextScope

Returns a reference to the expression context scope for the map canvas. This scope is injected into the expression context used for rendering the map, and can be used to apply specific variable overrides for expression evaluation for the map canvas render.

New in version 2.12.

See also

setExpressionContextScope()

extent(self) → QgsRectangle

Returns the current zoom extent of the map canvas

extentsChanged

Emitted when the extents of the map change [signal]

flashFeatureIds(self, layer: QgsVectorLayer, ids: object, startColor: Union[QColor, Qt.GlobalColor, QGradient] = QColor(255, 0, 0, 255), endColor: Union[QColor, Qt.GlobalColor, QGradient] = QColor(255, 0, 0, 0), flashes: int = 3, duration: int = 500)

Causes a set of features with matching ids from a vector layer to flash within the canvas.

The startColor and endColor can be specified, along with the number of flashes and duration of each flash (in milliseconds).

Note

If the features or geometries are already available, flashGeometries() is much more efficient.

New in version 3.0.

See also

flashGeometries()

flashGeometries(self, geometries: object, crs: QgsCoordinateReferenceSystem = QgsCoordinateReferenceSystem(), startColor: Union[QColor, Qt.GlobalColor, QGradient] = QColor(255, 0, 0, 255), endColor: Union[QColor, Qt.GlobalColor, QGradient] = QColor(255, 0, 0, 0), flashes: int = 3, duration: int = 500)

Causes a set of geometries to flash within the canvas.

If crs is a valid coordinate reference system, the geometries will be automatically transformed from this CRS to the canvas CRS.

The startColor and endColor can be specified, along with the number of flashes and duration of each flash (in milliseconds).

New in version 3.0.

See also

flashFeatureIds()

focusInEvent()

focusNextChild()

focusNextPrevChild()

focusOutEvent()

focusPreviousChild()

freeze(self, frozen: bool = 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:frozen – Boolean specifying if the canvas should be frozen (true) or

thawed (false). Default is true.

See also

isFrozen()

See also

setRenderFlag()

while setRenderFlag() should only be used when users disable rendering via GUI.

fullExtent(self) → QgsRectangle

Returns the combined extent for all layers on the map canvas

getCoordinateTransform(self) → QgsMapToPixel

Get the current coordinate transform

hideEvent()

initPainter()

initStyleOption()

inputMethodEvent()

isCachingEnabled(self) → bool

Check whether images of rendered layers are curerently being cached

New in version 2.4.

isDrawing(self) → bool

Find out whether rendering is in progress

isFrozen(self) → bool

Returns true if canvas is frozen.

See also

renderFlag()

have been halted programmatically, while renderFlag() should be used to determine whether a user has disabled rendering via GUI.

See also

freeze()

isParallelRenderingEnabled(self) → bool

Check whether the layers are rendered in parallel or sequentially

New in version 2.4.

isSignalConnected()

keyPressEvent(self, e: QKeyEvent)

Overridden key press event

keyPressed

Emit key press event [signal]

keyReleaseEvent(self, e: QKeyEvent)

Overridden key release event

keyReleased

Emit key release event [signal]

labelingEngineSettings(self) → QgsLabelingEngineSettings

Returns global labeling engine settings from the internal map settings

New in version 3.0.

labelingResults(self) → QgsLabelingResults

Get access to the labeling results (may be null)

New in version 2.4.

layer(self, index: int) → QgsMapLayer

return the map layer at position index in the layer stack

layerCount(self) → int

return number of layers on the map

layerStateChange(self)

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

layerStyleOverrides(self) → Dict[str, str]

Returns the stored overrides of styles for layers.

New in version 2.12.

See also

setLayerStyleOverrides()

layerStyleOverridesChanged

Emitted when the configuration of overridden layer styles changes

New in version 2.12: [signal]

layers(self) → List[QgsMapLayer]

Return the list of layers shown within the map canvas.

See also

setLayers()

layersChanged

Emitted when a new set of layers has been received [signal]

leaveEvent()

magnificationChanged

Emitted when the scale of the map changes

New in version 2.16: [signal]

magnificationFactor(self) → float

Returns the magnification factor

New in version 2.16.

mapCanvasRefreshed

Emitted when canvas finished a refresh request. [signal]

mapSettings(self) → QgsMapSettings

Get access to properties used for map rendering

New in version 2.4.

mapTool(self) → QgsMapTool

Returns the currently active tool

mapToolSet

Emit map tool changed with the old tool

New in version 2.3: [signal]

mapUnits(self) → QgsUnitTypes.DistanceUnit

Convience function for returning the current canvas map units. The map units are dictated by the canvas’ destinationCrs() map units.

mapUnitsPerPixel(self) → float

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

mapUpdateInterval(self) → int

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

New in version 2.4.

messageEmitted

emit a message (usually to be displayed in a message bar) [signal]

metric()

mouseDoubleClickEvent(self, e: QMouseEvent)

Overridden mouse double-click event

mouseLastXY(self) → QPoint

returns last position of mouse cursor

mouseMoveEvent(self, e: QMouseEvent)

Overridden mouse move event

mousePressEvent(self, e: QMouseEvent)

Overridden mouse press event

mouseReleaseEvent(self, e: QMouseEvent)

Overridden mouse release event

moveCanvasContents(self, reset: bool = False)

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

moveEvent()

nativeEvent()

paintEvent(self, e: QPaintEvent)

Overridden paint event

panAction(self, event: QMouseEvent)

Called when mouse is moving and pan is activated

panActionEnd(self, releasePoint: QPoint)

Ends pan action and redraws the canvas.

panToFeatureIds(self, layer: QgsVectorLayer, ids: object)

Centers canvas extent to feature ids

Parameters:

• layer – the vector layer
• ids – the feature ids*

panToSelected(self, layer: QgsVectorLayer = None)

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

previewJobsEnabled(self) → bool

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.

See also

setPreviewJobsEnabled()

New in version 3.0.

previewMode(self) → QgsPreviewEffect.PreviewMode

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()

See also

previewModeEnabled()

New in version 2.3.

previewModeEnabled(self) → bool

Returns whether a preview mode is enabled for the map canvas

Returns:true if a preview mode is currently enabled

See also

setPreviewModeEnabled()

See also

previewMode()

New in version 2.3.

readProject(self, QDomDocument)

called to read map canvas settings from project

receivers()

refresh(self)

Repaints the canvas map

refreshAllLayers(self)

Reload all layers, clear the cache and refresh the canvas

New in version 2.9.

renderComplete

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 [signal]

renderFlag(self) → bool

Returns true if canvas render is disabled as a result of user disabling renders via the GUI.

See also

setRenderFlag()

See also

isFrozen()

have been halted programmatically, while renderFlag() should be used to determine whether a user has disabled rendering via GUI.

renderStarting

Emitted when the canvas is about to be rendered. [signal]

resizeEvent(self, e: QResizeEvent)

Overridden resize event

rotation(self) → float

Get the current map canvas rotation in clockwise degrees

New in version 2.8.

rotationChanged

Emitted when the rotation of the map changes

New in version 2.8: [signal]

saveAsImage(self, fileName: str, QPixmap: QPixmap = None, a2: str = '')

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

scale(self) → float

Returns the last reported scale of the canvas. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.

scaleChanged

Emitted when the scale of the map changes [signal]

scaleLocked(self) → bool

Returns whether the scale is locked, so zooming can be performed using magnication.

New in version 2.16.

See also

setScaleLocked()

scrollContentsBy()

selectionChanged

Emitted when selection in any layer gets changed [signal]

selectionChangedSlot(self)

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

selectionColor(self) → QColor

Returns color for selected features

New in version 3.0.

sender()

senderSignalIndex()

setAnnotationsVisible(self, visible: bool)

Sets whether annotations are visible in the canvas.

New in version 3.0.

See also

annotationsVisible()

setCachingEnabled(self, enabled: bool)

Set whether to cache images of rendered layers

New in version 2.4.

setCanvasColor(self, _newVal: Union[QColor, Qt.GlobalColor, QGradient])

Write property of QColor bgColor.

setCenter(self, center: QgsPointXY)

Set the center of the map canvas, in geographical coordinates

New in version 2.8.

setCurrentLayer(self, layer: QgsMapLayer)

setDestinationCrs(self, crs: QgsCoordinateReferenceSystem)

sets destination coordinate reference system

New in version 2.4.

setExpressionContextScope(self, scope: QgsExpressionContextScope)

Sets an expression context scope for the map canvas. This scope is injected into the expression context used for rendering the map, and can be used to apply specific variable overrides for expression evaluation for the map canvas render. This method will overwrite the existing expression context scope for the canvas.

Parameters:scope – new expression context scope

New in version 2.12.

See also

expressionContextScope()

setExtent(self, r: QgsRectangle, magnified: bool = False)

Set the extent of the map canvas

setLabelingEngineSettings(self, settings: QgsLabelingEngineSettings)

Sets global labeling engine settings in the internal map settings

New in version 3.0.

setLayerStyleOverrides(self, overrides: Dict[str, str])

Sets the stored overrides of styles for rendering layers.

If the map canvas has been associated with a map theme via a call to setTheme(), then any calls to setLayerStyleOverrides() are ignored. It is necessary to first clear the theme association by calling setTheme() with an empty string before setLayerStyleOverrides() calls can be made.

New in version 2.12.

See also

layerStyleOverrides()

setLayers(self, layers: Iterable[QgsMapLayer])

Sets the list of layers that should be shown in the canvas.

If the map canvas has been associated with a map theme via a call to setTheme(), then any calls to setLayers() are ignored. It is necessary to first clear the theme association by calling setTheme() with an empty string before setLayers() calls can be made.

New in version 3.0.

See also

layers()

setMagnificationFactor(self, factor: float)

Sets the factor of magnification to apply to the map canvas. Indeed, we increase/decrease the DPI of the map settings according to this factor in order to render marker point, labels, … bigger.

New in version 2.16.

setMapSettingsFlags(self, flags: Union[QgsMapSettings.Flags, QgsMapSettings.Flag])

Resets the flags for the canvas’ map settings.

New in version 3.0.

setMapTool(self, mapTool: QgsMapTool, clean: bool = False)

Sets the map tool currently being used on the canvas

setMapUpdateInterval(self, timeMilliseconds: int)

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

New in version 2.4.

setParallelRenderingEnabled(self, enabled: bool)

Set whether the layers are rendered in parallel or sequentially

New in version 2.4.

setPreviewJobsEnabled(self, enabled: bool)

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.

See also

previewJobsEnabled()

New in version 3.0.

setPreviewMode(self, mode: QgsPreviewEffect.PreviewMode)

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()

See also

setPreviewModeEnabled()

See also

previewModeEnabled()

New in version 2.3.

setPreviewModeEnabled(self, previewEnabled: bool)

Enables a preview mode for the map canvas

Parameters:previewEnabled – set to true to enable a preview mode

See also

setPreviewMode()

New in version 2.3.

setRenderFlag(self, flag: bool)

Sets whether a user has disabled canvas renders via the GUI.

Parameters:flag – set to false to indicate that user has disabled renders

See also

renderFlag()

See also

freeze()

while setRenderFlag() should only be used when users disable rendering via GUI.

setRotation(self, degrees: float)

Set the rotation of the map canvas in clockwise degrees

New in version 2.8.

setScaleLocked(self, isLocked: bool)

Lock the scale, so zooming can be performed using magnication

New in version 2.16.

See also

scaleLocked()

setSegmentationTolerance(self, tolerance: float)

Sets the segmentation tolerance applied when rendering curved geometries

Parameters:tolerance – the segmentation tolerance*

setSegmentationToleranceType(self, type: QgsAbstractGeometry.SegmentationToleranceType)

Sets segmentation tolerance type (maximum angle or maximum difference between curve and approximation)

Parameters:type – the segmentation tolerance typename*

setSelectionColor(self, color: Union[QColor, Qt.GlobalColor, QGradient])

Set color of selected vector features

New in version 2.4.

setSnappingUtils(self, utils: QgsSnappingUtils)

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).

New in version 2.8.

setTheme(self, theme: str)

Sets a map theme to show in the canvas. The theme name must match a theme present in the associated project’s QgsMapThemeCollection.

When the canvas is associated to a map theme, it will automatically follow the layer selection and layer styles from that theme. Calls to setLayers() or setLayerStyleOverrides() will have no effect, and canvases associated with a QgsLayerTreeMapCanvasBridge will no longer synchronize their state with the layer tree. In these cases it is necessary to call setTheme() with an empty string to clear the theme association and allow map updates with setLayers(), setLayerStyleOverrides(), or via QgsLayerTreeMapCanvasBridge.

If an empty string is passed then the current theme association will be cleared.

New in version 3.0.

See also

theme()

setViewportMargins()

setWheelFactor(self, factor: float)

set wheel zoom factor (should be greater than 1)

setupViewport()

sharedPainter()

showEvent()

snappingUtils(self) → QgsSnappingUtils

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.

New in version 2.8.

stopRendering(self)

stop rendering (if there is any right now)

New in version 2.4.

tabletEvent()

theme(self) → str

Returns the map’s theme shown in the canvas, if set.

New in version 3.0.

See also

setTheme()

themeChanged

Emitted when the canvas has been assigned a different map theme.

See also

setTheme()

New in version 3.0: [signal]

timerEvent()

transformContextChanged

Emitted when the canvas transform context is changed.

New in version 3.0: [signal]

unsetMapTool(self, mapTool: QgsMapTool)

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 manually, QgsMapTool takes care of it.

updateCanvasItemPositions(self)

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

updateMicroFocus()

updateScale(self)

Emits signal scaleChanged to update scale in main window

viewportEvent()

viewportMargins()

viewportSizeHint()

waitWhileRendering(self)

Blocks until the rendering job has finished.

In almost all cases you do NOT want to call this, as it will hang the UI until the rendering job is complete. It’s included in API solely for unit testing and standalone Python scripts.

New in version 3.0.

wheelEvent(self, e: QWheelEvent)

Overridden mouse wheel event

writeProject(self, QDomDocument)

called to write map canvas settings to project

xyCoordinates

Emits current mouse position

Note

changed in 1.3 * [signal]

zoomByFactor(self, scaleFactor: float, center: QgsPointXY = None)

Zoom with the factor supplied. Factor > 1 zooms out, interval (0,1) zooms in If point is given, re-center on it

zoomIn(self)

Zoom in with fixed factor

zoomLastStatusChanged

Emitted when zoom last status changed [signal]

zoomNextStatusChanged

Emitted when zoom next status changed [signal]

zoomOut(self)

Zoom out with fixed factor

zoomScale(self, scale: float)

Zooms the canvas to a specific scale. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.

zoomToFeatureExtent(self, rect: QgsRectangle)

Zooms to feature extent. Adds a small margin around the extent and does a pan if rect is empty (point extent)

zoomToFeatureIds(self, layer: QgsVectorLayer, ids: object)

Set canvas extent to the bounding box of a set of features

Parameters:

• layer – the vector layer
• ids – the feature ids*

zoomToFullExtent(self)

Zoom to the full extent of all layers

zoomToNextExtent(self)

Zoom to the next extent (view)

zoomToPreviousExtent(self)

Zoom to the previous extent (view)

zoomToSelected(self, layer: QgsVectorLayer = None)

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

Parameters:layer – optionally specify different than current layer

zoomWithCenter(self, x: int, y: int, zoomIn: bool)

Zooms in/out with a given center