This class provides map rendering functionality for vector tile layers. More...

#include <qgsvectortilelayerrenderer.h>

Inheritance diagram for QgsVectorTileLayerRenderer:

Public Member Functions
	QgsVectorTileLayerRenderer (QgsVectorTileLayer *layer, QgsRenderContext &context)
	Creates the renderer. Always called from main thread, should copy whatever necessary from the layer.

	~QgsVectorTileLayerRenderer () override

virtual QgsFeedback *	feedback () const override
	Access to feedback object of the layer renderer (may be `nullptr`)

bool	forceRasterRender () const override
	Returns `true` if the renderer must be rendered to a raster paint device (e.g.

virtual bool	render () override
	Do the rendering (based on data stored in the class).

Public Member Functions inherited from QgsMapLayerRenderer
	QgsMapLayerRenderer (const QString &layerID, QgsRenderContext *context=nullptr)
	Constructor for QgsMapLayerRenderer, with the associated layerID and render context.

virtual	~QgsMapLayerRenderer ()

QStringList	errors () const
	Returns list of errors (problems) that happened during the rendering.

virtual Qgis::MapLayerRendererFlags	flags () const
	Returns flags which control how the map layer rendering behaves.

bool	isReadyToCompose () const
	Returns whether the renderer has already drawn (at least partially) some data.

QString	layerId () const
	Gets access to the ID of the layer rendered by this class.

QgsRenderContext *	renderContext ()
	Returns the render context associated with the renderer.

const QgsRenderContext *	renderContext () const
	Returns the render context associated with the renderer.

virtual void	setLayerRenderingTimeHint (int time)
	Sets approximate render time (in ms) for the layer to render.

QList< QgsRenderedItemDetails * >	takeRenderedItemDetails ()
	Takes the list of rendered item details from the renderer.

Additional Inherited Members
Protected Member Functions inherited from QgsMapLayerRenderer
void	appendRenderedItemDetails (QgsRenderedItemDetails *details)
	Appends the details of a rendered item to the renderer.

Protected Attributes inherited from QgsMapLayerRenderer
QStringList	mErrors

QString	mLayerID

bool	mReadyToCompose = true
	The flag must be set to false in renderer's constructor if wants to use the smarter map redraws functionality https://github.com/qgis/QGIS-Enhancement-Proposals/issues/181.

Static Protected Attributes inherited from QgsMapLayerRenderer
static constexpr int	MAX_TIME_TO_USE_CACHED_PREVIEW_IMAGE = 3000
	Maximum time (in ms) to allow display of a previously cached preview image while rendering layers, before switching to a progressive rendering display.

Detailed Description

This class provides map rendering functionality for vector tile layers.

In render() function (assumed to be run in a worker thread) it will:

fetch vector tiles using QgsVectorTileLoader
decode raw tiles into QgsFeature objects using QgsVectorTileDecoder
render tiles using a class derived from QgsVectorTileRenderer

Since: QGIS 3.14

Definition at line 43 of file qgsvectortilelayerrenderer.h.

Constructor & Destructor Documentation

◆ QgsVectorTileLayerRenderer()

QgsVectorTileLayerRenderer::QgsVectorTileLayerRenderer	(	QgsVectorTileLayer *	layer,
		QgsRenderContext &	context
	)

Creates the renderer. Always called from main thread, should copy whatever necessary from the layer.

Definition at line 36 of file qgsvectortilelayerrenderer.cpp.

◆ ~QgsVectorTileLayerRenderer()

QgsVectorTileLayerRenderer::~QgsVectorTileLayerRenderer ( )

overridedefault

Member Function Documentation

◆ feedback()

virtual QgsFeedback * QgsVectorTileLayerRenderer::feedback ( ) const

inlineoverridevirtual

Access to feedback object of the layer renderer (may be nullptr)

Reimplemented from QgsMapLayerRenderer.

Definition at line 51 of file qgsvectortilelayerrenderer.h.

◆ forceRasterRender()

bool QgsVectorTileLayerRenderer::forceRasterRender ( ) const

overridevirtual

Returns true if the renderer must be rendered to a raster paint device (e.g.

QImage).

Some layer settings require layers to be effectively "flattened" while rendering maps, which is achieved by first rendering the layer onto a raster paint device and then compositing the resultant image onto the final map render.

E.g. if a layer contains features with transparency or alternative blending modes, and the effects of these opacity or blending modes should be restricted to only affect other features within the SAME layer, then a flattened raster based render is required.

Subclasses should return true whenever their corresponding layer settings require the layer to always be rendered using a raster paint device.

Since: QGIS 3.18

Reimplemented from QgsMapLayerRenderer.

Definition at line 239 of file qgsvectortilelayerrenderer.cpp.

◆ render()

bool QgsVectorTileLayerRenderer::render ( )

overridevirtual

Do the rendering (based on data stored in the class).

Returns true if the layer was completely rendered successfully (i.e. the render was not canceled early).

Implements QgsMapLayerRenderer.

Definition at line 74 of file qgsvectortilelayerrenderer.cpp.

The documentation for this class was generated from the following files:

/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/vectortile/qgsvectortilelayerrenderer.h
/build/qgis-3.41.0+git20241119+45a0abf3bec+99sid/src/core/vectortile/qgsvectortilelayerrenderer.cpp

Public Member Functions

Additional Inherited Members