Layer and layer node items have access to map layer expression contex…

…t scope
qgis · Jan 18, 2019 · 349946c · 349946c
1 parent 7ba5998
commit 349946c
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Showing 3 changed files with 24 additions and 2 deletions.
diff --git a/src/core/qgslegendrenderer.cpp b/src/core/qgslegendrenderer.cpp
@@ -537,13 +537,25 @@ QgsLegendRenderer::Nucleon QgsLegendRenderer::drawSymbolItemInternal( QgsLayerTr
 {
   QgsLayerTreeModelLegendNode::ItemContext ctx;
   ctx.context = context;
+
+  // add a layer expression context scope
+  QgsExpressionContextScope *layerScope = nullptr;
+  if ( context && symbolItem->layerNode()->layer() )
+  {
+    layerScope = QgsExpressionContextUtils::layerScope( symbolItem->layerNode()->layer() );
+    context->expressionContext().appendScope( layerScope );
+  }
+
   ctx.painter = context ? context->painter() : painter;
   ctx.point = point;
   ctx.labelXOffset = labelXOffset;
 
   QgsLayerTreeModelLegendNode::ItemMetrics im = symbolItem->draw( mSettings, context ? &ctx
       : ( painter ? &ctx : nullptr ) );
 
+  if ( layerScope )
+    delete context->expressionContext().popScope();
+
   Nucleon nucleon;
   nucleon.item = symbolItem;
   nucleon.symbolSize = im.symbolSize;
@@ -578,6 +590,13 @@ QSizeF QgsLegendRenderer::drawLayerTitleInternal( QgsLayerTreeLayer *nodeLayer,
 
   QFont layerFont = mSettings.style( nodeLegendStyle( nodeLayer ) ).font();
 
+  QgsExpressionContextScope *layerScope = nullptr;
+  if ( context && nodeLayer->layer() )
+  {
+    layerScope = QgsExpressionContextUtils::layerScope( nodeLayer->layer() );
+    context->expressionContext().appendScope( layerScope );
+  }
+
   QgsExpressionContext tempContext;
 
   const QStringList lines = mSettings.evaluateItemText( mLegendModel->data( idx, Qt::DisplayRole ).toString(),
@@ -599,6 +618,9 @@ QSizeF QgsLegendRenderer::drawLayerTitleInternal( QgsLayerTreeLayer *nodeLayer,
   size.rheight() = y - point.y();
   size.rheight() += mSettings.style( nodeLegendStyle( nodeLayer ) ).margin( QgsLegendStyle::Side::Bottom );
 
+  if ( layerScope )
+    delete context->expressionContext().popScope();
+
   return size;
 }
 

diff --git a/tests/src/python/test_qgslayoutlegend.py b/tests/src/python/test_qgslayoutlegend.py
@@ -348,10 +348,10 @@ def testExpressionInText(self):
 
         group = legend.model().rootGroup().addGroup("Group [% 1 + 5 %] [% @layout_name %]")
         layer_tree_layer = group.addLayer(point_layer)
-        layer_tree_layer.setCustomProperty("legend/title-label", 'bbbb [% 1+2 %] xx [% @layout_name %]')
+        layer_tree_layer.setCustomProperty("legend/title-label", 'bbbb [% 1+2 %] xx [% @layout_name %] [% @layer_name %]')
         QgsMapLayerLegendUtils.setLegendNodeUserLabel(layer_tree_layer, 0, 'xxxx')
         legend.model().refreshLayerLegend(layer_tree_layer)
-        legend.model().layerLegendNodes(layer_tree_layer)[0].setUserLabel('bbbb [% 1+2 %] xx [% @layout_name %]')
+        legend.model().layerLegendNodes(layer_tree_layer)[0].setUserLabel('bbbb [% 1+2 %] xx [% @layout_name %] [% @layer_name %]')
 
         layout.addLayoutItem(legend)
         legend.setLinkedMap(map)

diff --git a/...d/expected_composer_legend_expressions/expected_composer_legend_expressions.png b/...d/expected_composer_legend_expressions/expected_composer_legend_expressions.png