mirror of
				https://github.com/qgis/QGIS.git
				synced 2025-11-04 00:04:25 -05:00 
			
		
		
		
	
		
			
				
	
	
		
			148 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			148 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
/************************************************************************
 | 
						|
 * This file has been generated automatically from                      *
 | 
						|
 *                                                                      *
 | 
						|
 * src/core/qgsmaplayerrenderer.h                                       *
 | 
						|
 *                                                                      *
 | 
						|
 * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
 | 
						|
 ************************************************************************/
 | 
						|
 | 
						|
 | 
						|
 | 
						|
 | 
						|
 | 
						|
class QgsMapLayerRenderer
 | 
						|
{
 | 
						|
%Docstring(signature="appended")
 | 
						|
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),
 | 
						|
it 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:
 | 
						|
 | 
						|
1. renderer job (doing preparation in the GUI thread) calls :py:func:`QgsMapLayer.createMapRenderer()` and gets instance of this class. The instance is initialized at that point and should not need additional calls to :py:class:`QgsVectorLayer`.
 | 
						|
2. renderer job (still in GUI thread) stores the renderer for later use.
 | 
						|
3. renderer job (in worker thread) calls :py:func:`QgsMapLayerRenderer.render()`
 | 
						|
4. renderer job (again in GUI thread) will check :py:func:`~errors` and report them
 | 
						|
 | 
						|
.. versionadded:: 2.4
 | 
						|
%End
 | 
						|
 | 
						|
%TypeHeaderCode
 | 
						|
#include "qgsmaplayerrenderer.h"
 | 
						|
%End
 | 
						|
  public:
 | 
						|
 | 
						|
    QgsMapLayerRenderer( const QString &layerID, QgsRenderContext *context = 0 );
 | 
						|
%Docstring
 | 
						|
Constructor for QgsMapLayerRenderer, with the associated ``layerID`` and render ``context``.
 | 
						|
%End
 | 
						|
 | 
						|
    virtual ~QgsMapLayerRenderer();
 | 
						|
 | 
						|
    virtual bool render() = 0;
 | 
						|
%Docstring
 | 
						|
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).
 | 
						|
%End
 | 
						|
 | 
						|
    virtual bool forceRasterRender() const;
 | 
						|
%Docstring
 | 
						|
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.
 | 
						|
 | 
						|
.. versionadded:: 3.18
 | 
						|
%End
 | 
						|
 | 
						|
    virtual QgsFeedback *feedback() const;
 | 
						|
%Docstring
 | 
						|
Access to feedback object of the layer renderer (may be ``None``)
 | 
						|
 | 
						|
.. versionadded:: 3.0
 | 
						|
%End
 | 
						|
 | 
						|
    QStringList errors() const;
 | 
						|
%Docstring
 | 
						|
Returns list of errors (problems) that happened during the rendering
 | 
						|
%End
 | 
						|
 | 
						|
    QString layerId() const;
 | 
						|
%Docstring
 | 
						|
Gets access to the ID of the layer rendered by this class
 | 
						|
%End
 | 
						|
 | 
						|
    QgsRenderContext *renderContext();
 | 
						|
%Docstring
 | 
						|
Returns the render context associated with the renderer.
 | 
						|
 | 
						|
.. versionadded:: 3.10
 | 
						|
%End
 | 
						|
 | 
						|
 | 
						|
    bool isReadyToCompose() const;
 | 
						|
%Docstring
 | 
						|
Returns whether the renderer has already drawn (at
 | 
						|
least partially) some data
 | 
						|
 | 
						|
.. versionadded:: 3.18
 | 
						|
%End
 | 
						|
 | 
						|
 | 
						|
    QList< QgsRenderedItemDetails * > takeRenderedItemDetails() /TransferBack/;
 | 
						|
%Docstring
 | 
						|
Takes the list of rendered item details from the renderer.
 | 
						|
 | 
						|
Ownership of items is transferred to the caller.
 | 
						|
 | 
						|
.. seealso:: :py:func:`appendRenderedItemDetails`
 | 
						|
 | 
						|
.. versionadded:: 3.22
 | 
						|
%End
 | 
						|
 | 
						|
  protected:
 | 
						|
 | 
						|
 | 
						|
 | 
						|
 | 
						|
    void appendRenderedItemDetails( QgsRenderedItemDetails *details /Transfer/ );
 | 
						|
%Docstring
 | 
						|
Appends the ``details`` of a rendered item to the renderer.
 | 
						|
 | 
						|
Rendered item details can be retrieved by calling :py:func:`~QgsMapLayerRenderer.takeRenderedItemDetails`.
 | 
						|
 | 
						|
Ownership of ``details`` is transferred to the renderer.
 | 
						|
 | 
						|
.. seealso:: :py:func:`takeRenderedItemDetails`
 | 
						|
 | 
						|
.. versionadded:: 3.22
 | 
						|
%End
 | 
						|
 | 
						|
};
 | 
						|
 | 
						|
/************************************************************************
 | 
						|
 * This file has been generated automatically from                      *
 | 
						|
 *                                                                      *
 | 
						|
 * src/core/qgsmaplayerrenderer.h                                       *
 | 
						|
 *                                                                      *
 | 
						|
 * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
 | 
						|
 ************************************************************************/
 |