QGIS API Documentation
2.4.0-Chugiak
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Base class for utility classes that encapsulate information necessary for rendering of map layers. More...
#include <qgsmaplayerrenderer.h>
Public Member Functions | |
QgsMapLayerRenderer (const QString &layerID) | |
virtual | ~QgsMapLayerRenderer () |
virtual bool | render ()=0 |
Do the rendering (based on data stored in the class) More... | |
QStringList | errors () const |
Return list of errors (problems) that happened during the rendering. More... | |
QString | layerID () const |
Get access to the ID of the layer rendered by this class. More... | |
Protected Attributes | |
QStringList | mErrors |
QString | mLayerID |
Base class for utility classes that encapsulate information necessary for rendering of map layers.
The rendering is typically done in a background thread, so it is necessary to keep all structures required for rendering away from the original map layer because it may change any time.
Because the data needs to be copied (to avoid the need for locking), is is highly desirable to use copy-on-write where possible. This way, the overhead of copying (both memory and CPU) will be kept low. Qt containers and various Qt classes use implicit sharing.
The scenario will be:
Definition at line 43 of file qgsmaplayerrenderer.h.
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inline |
Definition at line 46 of file qgsmaplayerrenderer.h.
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inlinevirtual |
Definition at line 47 of file qgsmaplayerrenderer.h.
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inline |
Return list of errors (problems) that happened during the rendering.
Definition at line 53 of file qgsmaplayerrenderer.h.
Referenced by QgsMapRendererJob::cleanupJobs().
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inline |
Get access to the ID of the layer rendered by this class.
Definition at line 56 of file qgsmaplayerrenderer.h.
Referenced by QgsMapRendererJob::cleanupJobs(), and QgsVectorLayerRenderer::drawRendererV2().
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pure virtual |
Do the rendering (based on data stored in the class)
Implemented in QgsVectorLayerRenderer, QgsPluginLayerRenderer, and QgsRasterLayerRenderer.
Referenced by QgsMapRendererCustomPainterJob::doRender().
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protected |
Definition at line 59 of file qgsmaplayerrenderer.h.
Referenced by QgsVectorLayerRenderer::render().
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protected |
Definition at line 60 of file qgsmaplayerrenderer.h.
Referenced by QgsVectorLayerRenderer::drawRendererV2(), QgsVectorLayerRenderer::drawRendererV2Levels(), and QgsVectorLayerRenderer::prepareLabeling().