QgsLayoutItemRenderContext class

Contains settings and helpers relating to a render of a QgsLayoutItem.

Reference
- Constructors, destructors, conversion operators
- Public functions

Constructors, destructors, conversion operators

QgsLayoutItemRenderContext(QgsRenderContext& context, double viewScaleFactor = 1.0): Constructor for QgsLayoutItemRenderContext.
QgsLayoutItemRenderContext(const QgsLayoutItemRenderContext& other) deleted: QgsLayoutItemRenderContext cannot be copied.

Public functions

auto operator=(const QgsLayoutItemRenderContext& other) -> QgsLayoutItemRenderContext& deleted: QgsLayoutItemRenderContext cannot be copied.
auto renderContext() -> QgsRenderContext&: Returns a reference to the context's render context.
auto renderContext() const -> const QgsRenderContext&: Returns a reference to the context's render context.
auto viewScaleFactor() const -> double: Returns the current view zoom (scale factor).

Function documentation

QgsLayoutItemRenderContext::QgsLayoutItemRenderContext(QgsRenderContext& context, double viewScaleFactor = 1.0)

Constructor for QgsLayoutItemRenderContext.

The renderContext parameter specifies a QgsRenderContext for use within the QgsLayoutItemRenderContext.

The viewScaleFactor gives the current view zoom (scale factor). It can be used to scale render graphics so that they always appear a constant size, regardless of the current view zoom.

QgsRenderContext& QgsLayoutItemRenderContext::renderContext()

Returns a reference to the context's render context.

Note that the context's painter has been scaled so that painter units are pixels. Use the QgsRenderContext methods to convert from millimeters or other units to the painter's units.

const QgsRenderContext& QgsLayoutItemRenderContext::renderContext() const

Returns a reference to the context's render context.

Note that the context's painter has been scaled so that painter units are pixels. Use the QgsRenderContext methods to convert from millimeters or other units to the painter's units.

double QgsLayoutItemRenderContext::viewScaleFactor() const

Returns the current view zoom (scale factor).

It can be used to scale render graphics so that they always appear a constant size, regardless of the current view zoom.

E.g. a value of 0.5 indicates that the view is zoomed out to 50% size, so rendered items must be scaled by 200% in order to have a constant visible size. A value of 2.0 indicates that the view is zoomed in 200%, so rendered items must be scaled by 50% in order to have a constant visible size.