Also add signal for when layer rendering starts

qgis · Dec 31, 2021 · dbff1e1 · dbff1e1
1 parent 79d5065
commit dbff1e1
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Showing 5 changed files with 26 additions and 0 deletions.
diff --git a/python/core/auto_generated/maprenderer/qgsmaprendererjob.sip.in b/python/core/auto_generated/maprenderer/qgsmaprendererjob.sip.in
@@ -191,6 +191,18 @@ Rendering labels is not yet done. If the fully rendered layer including labels i
 .. versionadded:: 3.0
 %End
 
+
+    void layerRenderingStarted( const QString &layerId );
+%Docstring
+Emitted just before rendering starts for a particular layer.
+
+.. note::
+
+   the :py:class:`QgsMapRendererParallelJob` subclass does not emit this signal.
+
+.. versionadded:: 3.24
+%End
+
     void layerRendered( const QString &layerId );
 %Docstring
 Emitted when a layer has completed rendering.

diff --git a/src/core/maprenderer/qgsmaprenderercustompainterjob.cpp b/src/core/maprenderer/qgsmaprenderercustompainterjob.cpp
@@ -295,6 +295,8 @@ void QgsMapRendererCustomPainterJob::doRender()
     if ( job.context()->renderingStopped() )
       break;
 
+    emit layerRenderingStarted( job.layerId );
+
     if ( ! hasSecondPass && job.context()->useAdvancedEffects() )
     {
       // Set the QPainter composition mode so that this layer is rendered using

diff --git a/src/core/maprenderer/qgsmaprendererjob.h b/src/core/maprenderer/qgsmaprendererjob.h
@@ -431,6 +431,16 @@ class CORE_EXPORT QgsMapRendererJob : public QObject SIP_ABSTRACT
      */
     void renderingLayersFinished();
 
+
+    /**
+     * Emitted just before rendering starts for a particular layer.
+     *
+     * \note the QgsMapRendererParallelJob subclass does not emit this signal.
+     *
+     * \since QGIS 3.24
+     */
+    void layerRenderingStarted( const QString &layerId );
+
     /**
      * Emitted when a layer has completed rendering.
      *

diff --git a/src/core/maprenderer/qgsmaprenderersequentialjob.cpp b/src/core/maprenderer/qgsmaprenderersequentialjob.cpp
@@ -71,6 +71,7 @@ void QgsMapRendererSequentialJob::startPrivate()
 
   connect( mInternalJob, &QgsMapRendererJob::finished, this, &QgsMapRendererSequentialJob::internalFinished );
   connect( mInternalJob, &QgsMapRendererJob::layerRendered, this, &QgsMapRendererSequentialJob::layerRendered );
+  connect( mInternalJob, &QgsMapRendererJob::layerRenderingStarted, this, &QgsMapRendererSequentialJob::layerRenderingStarted );
 
   mInternalJob->start();
 }

diff --git a/src/core/maprenderer/qgsmaprendererstagedrenderjob.cpp b/src/core/maprenderer/qgsmaprendererstagedrenderjob.cpp
@@ -103,6 +103,7 @@ bool QgsMapRendererStagedRenderJob::renderCurrentPart( QPainter *painter )
   if ( mJobIt != mLayerJobs.end() )
   {
     LayerRenderJob &job = *mJobIt;
+    emit layerRenderingStarted( job.layerId );
     job.renderer->renderContext()->setPainter( painter );
 
     if ( job.context()->useAdvancedEffects() )