Class: QgsPlotCanvas

Plot canvas is a class for displaying interactive 2d charts and plots.

Added in version 3.26.

Class Hierarchy

Base classes

QGraphicsView
QAbstractScrollArea
QFrame
QWidget
QObject
QPaintDevice

Subclasses

QgsElevationProfileCanvas

A canvas for elevation profiles.

class qgis.gui.QgsPlotCanvas

Bases: QGraphicsView

__init__(parent: QWidget | None = None)

Constructor for QgsPlotCanvas, with the specified parent widget.

Parameters:

parent (Optional[QWidget] = None)

virtual centerPlotOn(self, x: float, y: float)

Centers the plot on the plot point corresponding to x, y in canvas units.

The default implementation does nothing.

Parameters:

• x (float)

• y (float)

signal contextMenuAboutToShow

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

virtual crs(self) → QgsCoordinateReferenceSystem

Returns the coordinate reference system (CRS) for map coordinates used by the canvas.

May return an invalid CRS if no CRS is associated with the canvas.

Return type:

QgsCoordinateReferenceSystem

virtual panContentsBy(self, dx: float, dy: float)

Pans the plot contents by dx, dy in canvas units.

The default implementation does nothing.

Parameters:

• dx (float)

• dy (float)

signal plotAreaChanged

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

virtual refresh(self)

Updates and redraws the plot.

virtual scalePlot(self, factor: float)

Scales the plot by a specified scale factor.

The default implementation does nothing.

Parameters:

factor (float)

setTool(self, tool: QgsPlotTool | None)

Sets the interactive tool currently being used on the canvas.

Parameters:

tool (Optional[QgsPlotTool])

virtual snapToPlot(self, point: QPoint) → QgsPointXY

Snap a canvas point to the plot

Returns an empty point if snapping was not possible.

Parameters:

point (QPoint) – point in canvas coordinates

Return type:

QgsPointXY

virtual toCanvasCoordinates(self, point: QgsPoint) → QgsPointXY

Converts a point in map coordinates to the associated canvas point.

May return an empty point if the map point cannot be converted to a canvas point.

Parameters:

point (QgsPoint)

Return type:

QgsPointXY

virtual toMapCoordinates(self, point: QgsPointXY) → QgsPoint

Converts a point on the canvas to the associated map coordinate.

May return an empty point if the canvas point cannot be converted to a map point.

Parameters:

point (QgsPointXY)

Return type:

QgsPoint

tool(self) → QgsPlotTool | None

Returns the currently active tool.

Return type:

Optional[QgsPlotTool]

signal toolChanged

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

unsetTool(self, tool: QgsPlotTool | None)

Unset the current tool.

This is called from destructor of plot tools to make sure that this map tool won’t be used any more.

You don’t have to call it manually, QgsPlotTool takes care of it.

Parameters:

tool (Optional[QgsPlotTool])

virtual wheelZoom(self, event: QWheelEvent | None)

Zoom plot from a mouse wheel event.

The default implementation does nothing.

Parameters:

event (Optional[QWheelEvent])

signal willBeDeleted

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

virtual zoomToRect(self, rect: QRectF)

Zooms the plot to the specified rect in canvas units.

The default implementation does nothing.

Parameters:

rect (QRectF)