[vectortiles] Fix labels disappear randomly between map redraws

Fixes #37450
qgis · Sep 1, 2020 · 9f83b41 · 9f83b41
1 parent 5a2bc75
commit 9f83b41
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Showing 5 changed files with 89 additions and 20 deletions.
diff --git a/python/core/auto_generated/labeling/qgspallabeling.sip.in b/python/core/auto_generated/labeling/qgspallabeling.sip.in
@@ -782,9 +782,9 @@ class QgsPalLabeling
 %End
   public:
 
-    static bool staticWillUseLayer( QgsVectorLayer *layer );
+    static bool staticWillUseLayer( const QgsMapLayer *layer );
 %Docstring
-called to find out whether the layer is used for labeling
+Called to find out whether a specified ``layer`` is used for labeling.
 
 .. versionadded:: 2.4
 %End

diff --git a/src/core/labeling/qgspallabeling.cpp b/src/core/labeling/qgspallabeling.cpp
@@ -67,6 +67,8 @@
 #include "qgsgeometrycollection.h"
 #include "callouts/qgscallout.h"
 #include "callouts/qgscalloutsregistry.h"
+#include "qgsvectortilelayer.h"
+#include "qgsvectortilebasiclabeling.h"
 #include <QMessageBox>
 
 using namespace pal;
@@ -3533,9 +3535,35 @@ void QgsPalLayerSettings::parseDropShadow( QgsRenderContext &context )
 // -------------
 
 
-bool QgsPalLabeling::staticWillUseLayer( QgsVectorLayer *layer )
+bool QgsPalLabeling::staticWillUseLayer( const QgsMapLayer *layer )
 {
-  return layer->labelsEnabled() || layer->diagramsEnabled();
+  switch ( layer->type() )
+  {
+    case QgsMapLayerType::VectorLayer:
+    {
+      const QgsVectorLayer *vl = qobject_cast< const QgsVectorLayer * >( layer );
+      return vl->labelsEnabled() || vl->diagramsEnabled();
+    }
+
+    case QgsMapLayerType::VectorTileLayer:
+    {
+      const QgsVectorTileLayer *vl = qobject_cast< const QgsVectorTileLayer * >( layer );
+      if ( !vl->labeling() )
+        return false;
+
+      if ( const QgsVectorTileBasicLabeling *labeling = dynamic_cast< const QgsVectorTileBasicLabeling *>( vl->labeling() ) )
+        return !labeling->styles().empty();
+
+      return false;
+    }
+
+    case QgsMapLayerType::RasterLayer:
+    case QgsMapLayerType::PluginLayer:
+    case QgsMapLayerType::MeshLayer:
+    case QgsMapLayerType::AnnotationLayer:
+      return false;
+  }
+  return false;
 }
 
 

diff --git a/src/core/labeling/qgspallabeling.h b/src/core/labeling/qgspallabeling.h
@@ -1263,10 +1263,10 @@ class CORE_EXPORT QgsPalLabeling
   public:
 
     /**
-     * called to find out whether the layer is used for labeling
+     * Called to find out whether a specified \a layer is used for labeling.
      * \since QGIS 2.4
      */
-    static bool staticWillUseLayer( QgsVectorLayer *layer );
+    static bool staticWillUseLayer( const QgsMapLayer *layer );
 
     //! \note not available in Python bindings
     static void drawLabelCandidateRect( pal::LabelPosition *lp, QPainter *painter, const QgsMapToPixel *xform, QList<QgsLabelCandidate> *candidates = nullptr ) SIP_SKIP;

diff --git a/src/core/qgsmaprendererjob.cpp b/src/core/qgsmaprendererjob.cpp
@@ -31,6 +31,7 @@
 #include "qgspallabeling.h"
 #include "qgsvectorlayerrenderer.h"
 #include "qgsvectorlayer.h"
+#include "qgsvectortilelayer.h"
 #include "qgsexception.h"
 #include "qgslabelingengine.h"
 #include "qgsmaplayerlistutils.h"
@@ -95,16 +96,39 @@ bool QgsMapRendererJob::prepareLabelCache() const
   // calculate which layers will be labeled
   QSet< QgsMapLayer * > labeledLayers;
   const QList<QgsMapLayer *> layers = mSettings.layers();
-  for ( const QgsMapLayer *ml : layers )
+  for ( QgsMapLayer *ml : layers )
   {
-    QgsVectorLayer *vl = const_cast< QgsVectorLayer * >( qobject_cast<const QgsVectorLayer *>( ml ) );
-    if ( vl && QgsPalLabeling::staticWillUseLayer( vl ) )
-      labeledLayers << vl;
-    if ( vl && vl->labelsEnabled() && vl->labeling()->requiresAdvancedEffects() )
+    if ( QgsPalLabeling::staticWillUseLayer( ml ) )
+      labeledLayers << ml;
+
+    switch ( ml->type() )
     {
-      canCache = false;
-      break;
+      case QgsMapLayerType::VectorLayer:
+      {
+        QgsVectorLayer *vl = qobject_cast< QgsVectorLayer *>( ml );
+        if ( vl->labelsEnabled() && vl->labeling()->requiresAdvancedEffects() )
+        {
+          canCache = false;
+        }
+        break;
+      }
+
+      case QgsMapLayerType::VectorTileLayer:
+      {
+        // TODO -- add detection of advanced labeling effects for vector tile layers
+        break;
+      }
+
+      case QgsMapLayerType::RasterLayer:
+      case QgsMapLayerType::AnnotationLayer:
+      case QgsMapLayerType::PluginLayer:
+      case QgsMapLayerType::MeshLayer:
+        break;
     }
+
+    if ( !canCache )
+      break;
+
   }
 
   if ( mCache && mCache->hasCacheImage( LABEL_CACHE_ID ) )
@@ -331,11 +355,10 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter *painter, QgsLabelingEn
 
     // Force render of layers that are being edited
     // or if there's a labeling engine that needs the layer to register features
-    if ( mCache && vl )
+    if ( mCache )
     {
-      bool requiresLabeling = false;
-      requiresLabeling = ( labelingEngine2 && QgsPalLabeling::staticWillUseLayer( vl ) ) && requiresLabelRedraw;
-      if ( vl->isEditable() || requiresLabeling )
+      const bool requiresLabeling = ( labelingEngine2 && QgsPalLabeling::staticWillUseLayer( ml ) ) && requiresLabelRedraw;
+      if ( ( vl && vl->isEditable() ) || requiresLabeling )
       {
         mCache->clearCacheImage( ml->id() );
       }

diff --git a/tests/src/python/test_qgspallabeling_base.py b/tests/src/python/test_qgspallabeling_base.py
@@ -43,7 +43,11 @@
     QgsVectorLayer,
     QgsVectorLayerSimpleLabeling,
     QgsMultiRenderChecker,
-    QgsUnitTypes
+    QgsUnitTypes,
+    QgsVectorTileLayer,
+    QgsVectorTileBasicLabelingStyle,
+    QgsWkbTypes,
+    QgsVectorTileBasicLabeling
 )
 
 from qgis.testing import start_app, unittest
@@ -277,8 +281,8 @@ def controlImagePath(self, grpprefix=''):
     def saveControlImage(self, tmpimg=''):
         # don't save control images for RenderVsOtherOutput (Vs) tests, since
         # those control images belong to a different test result
-        if ('PAL_CONTROL_IMAGE' not in os.environ or
-                'Vs' in self._TestGroup):
+        if ('PAL_CONTROL_IMAGE' not in os.environ
+                or 'Vs' in self._TestGroup):
             return
         imgpath = self.controlImagePath()
         testdir = os.path.dirname(imgpath)
@@ -399,6 +403,20 @@ def test_layer_pal_activated(self):
         msg = '\nLayer labeling not activated, as reported by labelingEngine'
         self.assertTrue(QgsPalLabeling.staticWillUseLayer(self.layer), msg)
 
+        # also test for vector tile layer
+        tile_layer = QgsVectorTileLayer('x', 'y')
+        self.assertFalse(QgsPalLabeling.staticWillUseLayer(tile_layer))
+
+        st = QgsVectorTileBasicLabelingStyle()
+        st.setStyleName("st1")
+        st.setLayerName("place")
+        st.setFilterExpression("rank = 1 AND class = 'country'")
+        st.setGeometryType(QgsWkbTypes.PointGeometry)
+        labeling = QgsVectorTileBasicLabeling()
+        labeling.setStyles([st])
+        tile_layer.setLabeling(labeling)
+        self.assertTrue(QgsPalLabeling.staticWillUseLayer(tile_layer))
+
     def test_write_read_settings(self):
         # Verify written PAL settings are same when read from layer
         # load and write default test settings