feat: Enhance the ability to customize icons for QgsPluginLayer

python/PyQt6/core/auto_generated/qgspluginlayer.sip.in

@@ -58,6 +58,13 @@ Set source string. This is used for example in layer tree to show tooltip.
     virtual QgsDataProvider *dataProvider();
 
 
+    virtual QIcon icon() const;
+%Docstring
+Returns an icon for the layer.
+
+.. versionadded:: 3.42
+%End
+
   protected:
 };
 

python/core/auto_generated/qgspluginlayer.sip.in

@@ -58,6 +58,13 @@ Set source string. This is used for example in layer tree to show tooltip.
     virtual QgsDataProvider *dataProvider();
 
 
+    virtual QIcon icon() const;
+%Docstring
+Returns an icon for the layer.
+
+.. versionadded:: 3.42
+%End
+
   protected:
 };
 

src/core/qgsiconutils.cpp

@@ -19,6 +19,7 @@
 #include "qgsapplication.h"
 #include "qgsmaplayer.h"
 #include "qgsvectorlayer.h"
+#include "qgspluginlayer.h"
 
 #include <QIcon>
 
@@ -111,14 +112,23 @@ QIcon QgsIconUtils::iconForLayer( const QgsMapLayer *layer )
       case Qgis::LayerType::Mesh:
       case Qgis::LayerType::VectorTile:
       case Qgis::LayerType::PointCloud:
-      case Qgis::LayerType::Plugin:
       case Qgis::LayerType::Annotation:
       case Qgis::LayerType::Group:
       case Qgis::LayerType::TiledScene:
       {
         return QgsIconUtils::iconForLayerType( layer->type() );
       }
-
+      case Qgis::LayerType::Plugin:
+      {
+        if ( const QgsPluginLayer *pl = qobject_cast<const QgsPluginLayer *>( layer ) )
+        {
+          const QIcon icon = pl->icon();
+          if ( !icon.isNull() )
+            return icon;
+        }
+        // fallback to default icon if layer did not provide a specific icon
+        return QgsIconUtils::iconForLayerType( layer->type() );
+      }
       case Qgis::LayerType::Vector:
       {
         const QgsVectorLayer *vl = qobject_cast<const QgsVectorLayer *>( layer );

src/core/qgspluginlayer.cpp

@@ -14,6 +14,7 @@
  ***************************************************************************/
 #include "qgspluginlayer.h"
 #include "moc_qgspluginlayer.cpp"
+#include "qgsiconutils.h"
 
 QgsPluginLayer::QgsPluginLayer( const QString &layerType, const QString &layerName )
   : QgsMapLayer( Qgis::LayerType::Plugin, layerName )
@@ -56,6 +57,11 @@ const QgsDataProvider *QgsPluginLayer::dataProvider() const
   return mDataProvider;
 }
 
+QIcon QgsPluginLayer::icon() const
+{
+  return QgsIconUtils::iconForLayerType( Qgis::LayerType::Plugin );
+}
+
 //
 // QgsPluginLayerDataProvider
 //

src/core/qgspluginlayer.h

@@ -64,6 +64,12 @@ class CORE_EXPORT QgsPluginLayer : public QgsMapLayer
     QgsDataProvider *dataProvider() override;
     const QgsDataProvider *dataProvider() const override SIP_SKIP;
 
+    /**
+     * Returns an icon for the layer.
+     * \since QGIS 3.42
+     */
+    virtual QIcon icon() const;
+
   protected:
     QString mPluginLayerType;
     QgsDataProvider *mDataProvider;