QgsDiagram class

Base class for all diagram types.

Constructors, destructors, conversion operators

auto clone() const -> QgsDiagram* pure virtual: Returns an instance that is equivalent to this one.
auto diagramName() const -> QString pure virtual: Gets a descriptive name for this diagram type.
auto diagramSize(const QgsAttributes& attributes, const QgsRenderContext& c, const QgsDiagramSettings& s) -> QSizeF pure virtual: Returns the size in map units the diagram will use to render.
auto diagramSize(const QgsFeature& feature, const QgsRenderContext& c, const QgsDiagramSettings& s, const QgsDiagramInterpolationSettings& is) -> QSizeF pure virtual: Returns the size in map units the diagram will use to render. Interpolate size.
auto getExpression(const QString& expression, const QgsExpressionContext& context) -> QgsExpression*: Returns a prepared expression for the specified context.
auto legendSize(double value, const QgsDiagramSettings& s, const QgsDiagramInterpolationSettings& is) const -> double pure virtual: Returns the size of the legend item for the diagram corresponding to a specified value.
void renderDiagram(const QgsFeature& feature, QgsRenderContext& c, const QgsDiagramSettings& s, QPointF position) pure virtual: Draws the diagram at the given position (in pixel coordinates)

auto scaledFont(const QgsDiagramSettings& s, const QgsRenderContext& c) -> QFont: Calculates a size to match the current settings and rendering context.
void setPenWidth(QPen& pen, const QgsDiagramSettings& s, const QgsRenderContext& c): Changes the pen width to match the current settings and rendering context.
auto sizeForValue(double value, const QgsDiagramSettings& s, const QgsDiagramInterpolationSettings& is) const -> QSizeF: Returns the scaled size of a diagram for a value, respecting the specified diagram interpolation settings.
auto sizePainterUnits(QSizeF size, const QgsDiagramSettings& s, const QgsRenderContext& c) -> QSizeF: Calculates a size to match the current settings and rendering context.
auto sizePainterUnits(double l, const QgsDiagramSettings& s, const QgsRenderContext& c) -> double: Calculates a length to match the current settings and rendering context.

Returns an instance that is equivalent to this one.

Returns a prepared expression for the specified context.

Parameters
expression	expression string
context	expression context

Returns the size of the legend item for the diagram corresponding to a specified value.

Parameters
value	value to return legend item size for
s	diagram settings
is	interpolation settings

Calculates a size to match the current settings and rendering context.

Parameters
s	The settings that contain the font size and size type
c	The rendering specifying the proper scale units for pixel conversion
Returns	The properly scaled font for rendering

Changes the pen width to match the current settings and rendering context.

Parameters
pen	The pen to modify
s	The settings that specify the pen width
c	The rendering specifying the proper scale units for pixel conversion

Returns the scaled size of a diagram for a value, respecting the specified diagram interpolation settings.

Parameters
value	value to calculate corresponding circular size for
s	diagram settings
is	interpolation settings

Calculates a size to match the current settings and rendering context.

Parameters
size	The size to convert
s	The settings that specify the size type
c	The rendering specifying the proper scale units for pixel conversion
Returns	The converted size for rendering

Calculates a length to match the current settings and rendering context.

Parameters
l	The length to convert
s	Unused
c	The rendering specifying the proper scale units for pixel conversion
Returns	The converted length for rendering