[annotations] Add linked layer option for annotation layers

Adds a new "Linked layer" setting to the render page for annotation
layers, which allows users to optionally set a linked visibility
layer for the annotation layer. If set, then the annotations will
only be drawn when the linked layer is visible in the map.

This is designed to mimic the similar linked layer option for
the older annotation framework, in order to close the feature
gap between old vs new annotations

Refs qgis/QGIS-Enhancement-Proposals#269

python/PyQt6/core/auto_generated/annotations/qgsannotationlayer.sip.in

@@ -12,7 +12,6 @@
 
 
 
-
 class QgsAnnotationLayer : QgsMapLayer
 {
 %Docstring(signature="appended")
@@ -170,6 +169,8 @@ Returns ``True`` if the operation was successfully applied.
 
     virtual QString htmlMetadata() const;
 
+    virtual void resolveReferences( QgsProject *project );
+
 
     QgsPaintEffect *paintEffect() const;
 %Docstring
@@ -189,6 +190,26 @@ Ownership is transferred to the renderer.
 .. seealso:: :py:func:`paintEffect`
 
 .. versionadded:: 3.22
+%End
+
+    QgsMapLayer *linkedVisibilityLayer();
+%Docstring
+Returns a linked layer, where the items in this annotation layer
+will only be visible when the linked layer is also visible.
+
+.. seealso:: :py:func:`setLinkedVisibilityLayer`
+
+.. versionadded:: 3.40
+%End
+
+    void setLinkedVisibilityLayer( QgsMapLayer *layer );
+%Docstring
+Sets a linked ``layer``, where the items in this annotation layer
+will only be visible when the linked layer is also visible.
+
+.. seealso:: :py:func:`linkedVisibilityLayer`
+
+.. versionadded:: 3.40
 %End
 
 };

python/core/auto_generated/annotations/qgsannotationlayer.sip.in

@@ -12,7 +12,6 @@
 
 
 
-
 class QgsAnnotationLayer : QgsMapLayer
 {
 %Docstring(signature="appended")
@@ -170,6 +169,8 @@ Returns ``True`` if the operation was successfully applied.
 
     virtual QString htmlMetadata() const;
 
+    virtual void resolveReferences( QgsProject *project );
+
 
     QgsPaintEffect *paintEffect() const;
 %Docstring
@@ -189,6 +190,26 @@ Ownership is transferred to the renderer.
 .. seealso:: :py:func:`paintEffect`
 
 .. versionadded:: 3.22
+%End
+
+    QgsMapLayer *linkedVisibilityLayer();
+%Docstring
+Returns a linked layer, where the items in this annotation layer
+will only be visible when the linked layer is also visible.
+
+.. seealso:: :py:func:`setLinkedVisibilityLayer`
+
+.. versionadded:: 3.40
+%End
+
+    void setLinkedVisibilityLayer( QgsMapLayer *layer );
+%Docstring
+Sets a linked ``layer``, where the items in this annotation layer
+will only be visible when the linked layer is also visible.
+
+.. seealso:: :py:func:`linkedVisibilityLayer`
+
+.. versionadded:: 3.40
 %End
 
 };

src/app/annotations/qgsannotationlayerproperties.cpp

@@ -36,6 +36,8 @@ QgsAnnotationLayerProperties::QgsAnnotationLayerProperties( QgsAnnotationLayer *
 {
   setupUi( this );
 
+  mLayerComboBox->setAllowEmptyLayer( true );
+
   connect( this, &QDialog::accepted, this, &QgsAnnotationLayerProperties::apply );
   connect( this, &QDialog::rejected, this, &QgsAnnotationLayerProperties::rollback );
   connect( buttonBox->button( QDialogButtonBox::Apply ), &QAbstractButton::clicked, this, &QgsAnnotationLayerProperties::apply );
@@ -98,6 +100,8 @@ void QgsAnnotationLayerProperties::apply()
   if ( mPaintEffect )
     mLayer->setPaintEffect( mPaintEffect->clone() );
 
+  mLayer->setLinkedVisibilityLayer( mLayerComboBox->currentLayer() );
+
   for ( QgsMapLayerConfigWidget *w : std::as_const( mConfigWidgets ) )
     w->apply();
 
@@ -145,6 +149,8 @@ void QgsAnnotationLayerProperties::syncToLayer()
     mEffectWidget->setPaintEffect( mPaintEffect.get() );
   }
 
+  mLayerComboBox->setLayer( mLayer->linkedVisibilityLayer() );
+
   for ( QgsMapLayerConfigWidget *w : std::as_const( mConfigWidgets ) )
     w->syncToLayer( mLayer );
 }

src/core/annotations/qgsannotationlayer.cpp

@@ -334,6 +334,8 @@ QgsAnnotationLayer *QgsAnnotationLayer::clone() const
   if ( mPaintEffect )
     layer->setPaintEffect( mPaintEffect->clone() );
 
+  layer->mLinkedLayer = mLinkedLayer;
+
   return layer.release();
 }
 
@@ -387,6 +389,14 @@ bool QgsAnnotationLayer::readXml( const QDomNode &layerNode, QgsReadWriteContext
   readItems( layerNode, errorMsg, context );
   readSymbology( layerNode, errorMsg, context );
 
+  {
+    const QString layerId = layerNode.toElement().attribute( QStringLiteral( "linkedLayer" ) );
+    const QString layerName = layerNode.toElement().attribute( QStringLiteral( "linkedLayerName" ) );
+    const QString layerSource = layerNode.toElement().attribute( QStringLiteral( "linkedLayerSource" ) );
+    const QString layerProvider = layerNode.toElement().attribute( QStringLiteral( "linkedLayerProvider" ) );
+    mLinkedLayer = QgsMapLayerRef( layerId, layerName, layerSource, layerProvider );
+  }
+
   triggerRepaint();
 
   return mValid;
@@ -407,6 +417,14 @@ bool QgsAnnotationLayer::writeXml( QDomNode &layer_node, QDomDocument &doc, cons
 
   mapLayerNode.setAttribute( QStringLiteral( "type" ), QgsMapLayerFactory::typeToString( Qgis::LayerType::Annotation ) );
 
+  if ( mLinkedLayer )
+  {
+    mapLayerNode.setAttribute( QStringLiteral( "linkedLayer" ), mLinkedLayer.layerId );
+    mapLayerNode.setAttribute( QStringLiteral( "linkedLayerName" ), mLinkedLayer.name );
+    mapLayerNode.setAttribute( QStringLiteral( "linkedLayerSource" ), mLinkedLayer.source );
+    mapLayerNode.setAttribute( QStringLiteral( "linkedLayerProvider" ), mLinkedLayer.provider );
+  }
+
   QString errorMsg;
   writeItems( layer_node, doc, errorMsg, context );
 
@@ -642,6 +660,11 @@ QString QgsAnnotationLayer::htmlMetadata() const
   return metadata;
 }
 
+void QgsAnnotationLayer::resolveReferences( QgsProject *project )
+{
+  mLinkedLayer.resolve( project );
+}
+
 QgsPaintEffect *QgsAnnotationLayer::paintEffect() const
 {
   QGIS_PROTECT_QOBJECT_THREAD_ACCESS
@@ -656,6 +679,21 @@ void QgsAnnotationLayer::setPaintEffect( QgsPaintEffect *effect )
   mPaintEffect.reset( effect );
 }
 
+QgsMapLayer *QgsAnnotationLayer::linkedVisibilityLayer()
+{
+  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
+
+  return mLinkedLayer.get();
+}
+
+void QgsAnnotationLayer::setLinkedVisibilityLayer( QgsMapLayer *layer )
+{
+  QGIS_PROTECT_QOBJECT_THREAD_ACCESS
+
+  mLinkedLayer.setLayer( layer );
+  triggerRepaint();
+}
+
 
 //
 // QgsAnnotationLayerDataProvider

src/core/annotations/qgsannotationlayer.h

@@ -21,7 +21,7 @@
 #include "qgis_sip.h"
 #include "qgsmaplayer.h"
 #include "qgsmaplayerrenderer.h"
-
+#include "qgsmaplayerref.h"
 
 class QgsAnnotationItem;
 class QgsAbstractAnnotationItemEditOperation;
@@ -185,6 +185,7 @@ class CORE_EXPORT QgsAnnotationLayer : public QgsMapLayer
     QgsDataProvider *dataProvider() override;
     const QgsDataProvider *dataProvider() const override SIP_SKIP;
     QString htmlMetadata() const override;
+    void resolveReferences( QgsProject *project ) override;
 
     /**
      * Returns the current paint effect for the layer.
@@ -203,6 +204,24 @@ class CORE_EXPORT QgsAnnotationLayer : public QgsMapLayer
      */
     void setPaintEffect( QgsPaintEffect *effect SIP_TRANSFER );
 
+    /**
+     * Returns a linked layer, where the items in this annotation layer
+     * will only be visible when the linked layer is also visible.
+     *
+     * \see setLinkedVisibilityLayer()
+     * \since QGIS 3.40
+     */
+    QgsMapLayer *linkedVisibilityLayer();
+
+    /**
+     * Sets a linked \a layer, where the items in this annotation layer
+     * will only be visible when the linked layer is also visible.
+     *
+     * \see linkedVisibilityLayer()
+     * \since QGIS 3.40
+     */
+    void setLinkedVisibilityLayer( QgsMapLayer *layer );
+
   private:
 
     QStringList queryIndex( const QgsRectangle &bounds, QgsFeedback *feedback = nullptr ) const;
@@ -219,6 +238,8 @@ class CORE_EXPORT QgsAnnotationLayer : public QgsMapLayer
 
     std::unique_ptr< QgsPaintEffect > mPaintEffect;
 
+    QgsMapLayerRef mLinkedLayer;
+
     friend class QgsAnnotationLayerRenderer;
 
 };

src/core/annotations/qgsannotationlayerrenderer.cpp

@@ -27,6 +27,15 @@ QgsAnnotationLayerRenderer::QgsAnnotationLayerRenderer( QgsAnnotationLayer *laye
   , mFeedback( std::make_unique< QgsFeedback >() )
   , mLayerOpacity( layer->opacity() )
 {
+  if ( QgsMapLayer *linkedLayer = layer->linkedVisibilityLayer() )
+  {
+    if ( !context.customProperties().value( QStringLiteral( "visible_layer_ids" ) ).toList().contains( linkedLayer->id() ) )
+    {
+      mReadyToCompose = true;
+      return;
+    }
+  }
+
   // Clone items from layer which fall inside the rendered extent
   // Because some items have scale dependent bounds, we have to accept some limitations here.
   // first, we can use the layer's spatial index to very quickly retrieve items we know will fall within the visible

src/core/project/qgsproject.cpp

@@ -2375,6 +2375,7 @@ bool QgsProject::readProjectFile( const QString &filename, Qgis::ProjectReadFlag
   {
     it.value()->resolveReferences( this );
   }
+  mMainAnnotationLayer->resolveReferences( this );
 
   mLayerTreeRegistryBridge->setEnabled( true );
 

src/gui/qgsmapcanvas.cpp

@@ -410,14 +410,13 @@ void QgsMapCanvas::setLayers( const QList<QgsMapLayer *> &layers )
 
 void QgsMapCanvas::setLayersPrivate( const QList<QgsMapLayer *> &layers )
 {
-  QList<QgsMapLayer *> oldLayers = mSettings.layers();
+  const QList<QgsMapLayer *> oldLayers = mSettings.layers();
 
   // update only if needed
   if ( layers == oldLayers )
     return;
 
-  const auto constOldLayers = oldLayers;
-  for ( QgsMapLayer *layer : constOldLayers )
+  for ( QgsMapLayer *layer : oldLayers )
   {
     disconnect( layer, &QgsMapLayer::repaintRequested, this, &QgsMapCanvas::layerRepaintRequested );
     disconnect( layer, &QgsMapLayer::autoRefreshIntervalChanged, this, &QgsMapCanvas::updateAutoRefreshTimer );
@@ -451,8 +450,7 @@ void QgsMapCanvas::setLayersPrivate( const QList<QgsMapLayer *> &layers )
 
   mSettings.setLayers( layers );
 
-  const auto constLayers = layers;
-  for ( QgsMapLayer *layer : constLayers )
+  for ( QgsMapLayer *layer : std::as_const( layers ) )
   {
     if ( !layer )
       continue;
@@ -754,6 +752,24 @@ void QgsMapCanvas::refresh()
   mRenderedItemResultsOutdated = true;
 }
 
+QList< QgsMapLayer * > filterLayersForRender( const QList< QgsMapLayer * > &layers )
+{
+  QList<QgsMapLayer *> filteredLayers;
+  for ( QgsMapLayer *layer : layers )
+  {
+    if ( QgsAnnotationLayer *annotationLayer = qobject_cast< QgsAnnotationLayer * >( layer ) )
+    {
+      if ( QgsMapLayer *linkedLayer = annotationLayer->linkedVisibilityLayer() )
+      {
+        if ( !layers.contains( linkedLayer ) )
+          continue;
+      }
+    }
+    filteredLayers.append( layer );
+  }
+  return filteredLayers;
+}
+
 void QgsMapCanvas::refreshMap()
 {
   Q_ASSERT( mRefreshScheduled );
@@ -810,7 +826,8 @@ void QgsMapCanvas::refreshMap()
   QgsMapSettings renderSettings = mSettings;
   QList<QgsMapLayer *> allLayers = renderSettings.layers();
   allLayers.insert( 0, QgsProject::instance()->mainAnnotationLayer() );
-  renderSettings.setLayers( allLayers );
+
+  renderSettings.setLayers( filterLayersForRender( allLayers ) );
 
   // create the renderer job
 
@@ -3577,7 +3594,7 @@ void QgsMapCanvas::startPreviewJob( int number )
   {
     previewLayers.insert( 0, QgsProject::instance()->mainAnnotationLayer() );
   }
-  jobSettings.setLayers( previewLayers );
+  jobSettings.setLayers( filterLayersForRender( previewLayers ) );
 
   QgsMapRendererQImageJob *job = new QgsMapRendererSequentialJob( jobSettings );
   job->setProperty( "number", number );