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	Make associated QgsRenderContext a base class member, since all renderer subclasses require this
		
			
				
	
	
		
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			90 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| /************************************************************************
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|  * This file has been generated automatically from                      *
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|  *                                                                      *
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|  * src/core/qgsmaplayerrenderer.h                                       *
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|  *                                                                      *
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|  * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
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|  ************************************************************************/
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| 
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| 
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| 
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| 
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| 
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| class QgsMapLayerRenderer
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| {
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| %Docstring
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| Base class for utility classes that encapsulate information necessary
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| for rendering of map layers. The rendering is typically done in a background
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| thread, so it is necessary to keep all structures required for rendering away
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| from the original map layer because it may change any time.
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| 
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| Because the data needs to be copied (to avoid the need for locking),
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| it is highly desirable to use copy-on-write where possible. This way,
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| the overhead of copying (both memory and CPU) will be kept low.
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| Qt containers and various Qt classes use implicit sharing.
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| 
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| The scenario will be:
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| 1. renderer job (doing preparation in the GUI thread) calls
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| QgsMapLayer.createMapRenderer() and gets instance of this class.
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| The instance is initialized at that point and should not need
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| additional calls to QgsVectorLayer.
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| 2. renderer job (still in GUI thread) stores the renderer for later use.
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| 3. renderer job (in worker thread) calls :py:func:`QgsMapLayerRenderer.render()`
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| 4. renderer job (again in GUI thread) will check errors() and report them
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| 
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| .. versionadded:: 2.4
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| %End
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| 
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| %TypeHeaderCode
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| #include "qgsmaplayerrenderer.h"
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| %End
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|   public:
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| 
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|     QgsMapLayerRenderer( const QString &layerID, QgsRenderContext *context = 0 );
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| %Docstring
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| Constructor for QgsMapLayerRenderer, with the associated ``layerID`` and render ``context``.
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| %End
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| 
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|     virtual ~QgsMapLayerRenderer();
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| 
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|     virtual bool render() = 0;
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| %Docstring
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| Do the rendering (based on data stored in the class)
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| %End
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| 
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|     virtual QgsFeedback *feedback() const;
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| %Docstring
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| Access to feedback object of the layer renderer (may be ``None``)
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| 
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| .. versionadded:: 3.0
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| %End
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| 
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|     QStringList errors() const;
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| %Docstring
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| Returns list of errors (problems) that happened during the rendering
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| %End
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| 
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|     QString layerId() const;
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| %Docstring
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| Gets access to the ID of the layer rendered by this class
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| %End
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| 
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|     QgsRenderContext *renderContext();
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| %Docstring
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| Returns the render context associated with the renderer.
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| 
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| .. versionadded:: 3.10
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| %End
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| 
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|   protected:
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| 
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| };
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| 
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| /************************************************************************
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|  * This file has been generated automatically from                      *
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|  *                                                                      *
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|  * src/core/qgsmaplayerrenderer.h                                       *
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|  *                                                                      *
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|  * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
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|  ************************************************************************/
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