Implementation of threaded rendering for vector layers. More...
#include <qgsvectorlayerrenderer.h>
Public Member Functions | |
| QgsVectorLayerRenderer (QgsVectorLayer *layer, QgsRenderContext &context) | |
| ~QgsVectorLayerRenderer () override | |
| QgsFeatureRenderer * | featureRenderer () |
| Returns the feature renderer. More... | |
| QgsFeedback * | feedback () const override |
Access to feedback object of the layer renderer (may be nullptr) More... | |
| bool | forceRasterRender () const override |
Returns true if the renderer must be rendered to a raster paint device (e.g. More... | |
| bool | render () override |
| Do the rendering (based on data stored in the class). More... | |
| void | setLayerRenderingTimeHint (int time) override |
| Sets approximate render time (in ms) for the layer to render. More... | |
 Public Member Functions inherited from QgsMapLayerRenderer | |
| QgsMapLayerRenderer (const QString &layerID, QgsRenderContext *context=nullptr) | |
| Constructor for QgsMapLayerRenderer, with the associated layerID and render context. More... | |
| virtual | ~QgsMapLayerRenderer () |
| QStringList | errors () const |
| Returns list of errors (problems) that happened during the rendering. More... | |
| virtual QgsFeedback * | feedback () const |
Access to feedback object of the layer renderer (may be nullptr) More... | |
| virtual bool | forceRasterRender () const |
Returns true if the renderer must be rendered to a raster paint device (e.g. More... | |
| bool | isReadyToCompose () const |
| Returns whether the renderer has already drawn (at least partially) some data. More... | |
| QString | layerId () const |
| Gets access to the ID of the layer rendered by this class. More... | |
| virtual bool | render ()=0 |
| Do the rendering (based on data stored in the class). More... | |
| QgsRenderContext * | renderContext () |
| Returns the render context associated with the renderer. More... | |
| const QgsRenderContext * | renderContext () const |
| Returns the render context associated with the renderer. More... | |
| virtual void | setLayerRenderingTimeHint (int time) |
| Sets approximate render time (in ms) for the layer to render. More... | |
| QList< QgsRenderedItemDetails * > | takeRenderedItemDetails () |
| Takes the list of rendered item details from the renderer. More... | |
Additional Inherited Members | |
| Protected Member Functions inherited from QgsMapLayerRenderer | |
| void | appendRenderedItemDetails (QgsRenderedItemDetails *details) |
| Appends the details of a rendered item to the renderer. More... | |
| 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. More... | |
| 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. More... | |
Detailed Description
Implementation of threaded rendering for vector layers.
- Note
- not available in Python bindings
- Since
- QGIS 2.4
Definition at line 58 of file qgsvectorlayerrenderer.h.
Constructor & Destructor Documentation
◆ QgsVectorLayerRenderer()
| QgsVectorLayerRenderer::QgsVectorLayerRenderer | ( | QgsVectorLayer * | layer, |
| QgsRenderContext & | context | ||
| ) |
Definition at line 47 of file qgsvectorlayerrenderer.cpp.
◆ ~QgsVectorLayerRenderer()
|
overridedefault |
Member Function Documentation
◆ featureRenderer()
|
inline |
Returns the feature renderer.
This may be used for tweaking it before the actual rendering of the layer.
- Since
- QGIS 3.12
Definition at line 71 of file qgsvectorlayerrenderer.h.
◆ feedback()
|
overridevirtual |
Access to feedback object of the layer renderer (may be nullptr)
- Since
- QGIS 3.0
Reimplemented from QgsMapLayerRenderer.
Definition at line 187 of file qgsvectorlayerrenderer.cpp.
◆ forceRasterRender()
|
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 192 of file qgsvectorlayerrenderer.cpp.
◆ 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 197 of file qgsvectorlayerrenderer.cpp.
◆ setLayerRenderingTimeHint()
|
overridevirtual |
Sets approximate render time (in ms) for the layer to render.
This can be used to specifies a hint at the expected render times for the layer, so that the individual layer renderer subclasses can apply heuristics and determine appropriate update intervals during the render operation.
- Note
- Not available in Python bindings.
- Since
- QGIS 3.18
Reimplemented from QgsMapLayerRenderer.
Definition at line 182 of file qgsvectorlayerrenderer.cpp.
The documentation for this class was generated from the following files:
- /build/qgis-3.30.0+99sid/src/core/vector/qgsvectorlayerrenderer.h
- /build/qgis-3.30.0+99sid/src/core/vector/qgsvectorlayerrenderer.cpp
