fix(QgsVectorLayer-dependencies): don't emit too many dataChanged sig…

…nals
qgis · Nov 5, 2024 · 37e70f3 · 37e70f3
1 parent cc8cd21
commit 37e70f3
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Showing 2 changed files with 32 additions and 12 deletions.
diff --git a/src/core/vector/qgsvectorlayer.cpp b/src/core/vector/qgsvectorlayer.cpp
@@ -6109,6 +6109,20 @@ void QgsVectorLayer::emitDataChanged()
   if ( mDataChangedFired )
     return;
 
+  // If a dependent layer has mCommitChangesActive, don't fire dataChanged
+  // more than necessary. It will be fired by afterCommitChanges.
+  if ( QgsProject *p = project() )
+  {
+    for ( const QgsMapLayerDependency &dep : dependencies() )
+    {
+      QgsVectorLayer *lyr = static_cast<QgsVectorLayer *>( p->mapLayer( dep.layerId() ) );
+      if ( !lyr )
+        continue;
+      if ( lyr->mCommitChangesActive )
+        return;
+    }
+  }
+
   updateExtents(); // reset cached extent to reflect data changes
 
   mDataChangedFired = true;

diff --git a/tests/src/python/test_layer_dependencies.py b/tests/src/python/test_layer_dependencies.py
@@ -192,11 +192,19 @@ def test_circular_dependencies_with_2_layers(self):
         self.assertEqual(len(spy_points_data_changed), 3)
         self.assertEqual(len(spy_lines_data_changed), 2)
 
-        # added feature is deleted and added with its new defined id
-        # (it was -1 before) so it fires 3 more signal dataChanged on
-        # depending line (on featureAdded and on featureDeleted and on afterCommitChanges)
-        # and so 2 more signal on points because it depends on line
-        self.pointsLayer.commitChanges()
+        # commit changes fires dataChanged because external changes could happen (provider side)
+        self.pointsLayer.commitChanges(False)
+        self.assertEqual(len(spy_points_data_changed), 4)
+        self.assertEqual(len(spy_lines_data_changed), 3)
+
+        # points fire dataChanged on geometryChanged
+        # line depends on point, so fire dataChanged
+        self.pointsLayer.changeGeometry(f.id(), QgsGeometry.fromWkt("POINT(0 2)"))
+        self.assertEqual(len(spy_points_data_changed), 5)
+        self.assertEqual(len(spy_lines_data_changed), 4)
+
+        # commit changes fires dataChanged because external changes could happen (provider side)
+        self.assertTrue(self.pointsLayer.commitChanges())
         self.assertEqual(len(spy_points_data_changed), 6)
         self.assertEqual(len(spy_lines_data_changed), 5)
 
@@ -228,23 +236,21 @@ def test_circular_dependencies_with_1_layer(self):
         self.linesLayer.addFeatures([f])
         self.assertEqual(len(spy_lines_data_changed), 2)
 
-        # added feature is deleted and added with its new defined id
-        # (it was -1 before) so it fires 3 more signal dataChanged on
-        # depending line (on featureAdded and on featureDeleted and on afterCommitChanges)
+        # line fire dataChanged on commitChanges
         self.linesLayer.commitChanges(False)
-        self.assertEqual(len(spy_lines_data_changed), 5)
+        self.assertEqual(len(spy_lines_data_changed), 3)
 
         # repaintRequested is called only once on commit changes on line
         # (ideally only one repaintRequested signal is fired, but it's harmless to fire multiple ones)
         self.assertGreaterEqual(len(spy_lines_repaint_requested), 2)
 
         # line fire dataChanged on geometryChanged
         self.linesLayer.changeGeometry(f.id(), QgsGeometry.fromWkt("LINESTRING(0 0, 2 2)"))
-        self.assertEqual(len(spy_lines_data_changed), 6)
+        self.assertEqual(len(spy_lines_data_changed), 4)
 
-        # line fire dataChanged on commitChanges
+        # commit changes fires dataChanged because external changes could happen (provider side)
         self.linesLayer.commitChanges()
-        self.assertEqual(len(spy_lines_data_changed), 7)
+        self.assertEqual(len(spy_lines_data_changed), 5)
 
     def test_layerDefinitionRewriteId(self):
         tmpfile = os.path.join(tempfile.tempdir, "test.qlr")