[composer] Fix polylines would be removed if they had < 3 points

when deleting nodes (2 node lines should be allowed)

python/core/composer/qgscomposernodesitem.sip

@@ -87,6 +87,9 @@ class QgsComposerNodesItem: QgsComposerItem
     /** Method called in addNode. */
     virtual bool _addNode( const int nodeIndex, const QPointF &newPoint, const double radius ) = 0;
 
+    /** Method called in removeNode. */
+    virtual bool _removeNode( const int nodeIndex ) = 0;
+
     /** Method called in paint. */
     virtual void _draw( QPainter *painter ) = 0;
 

python/core/composer/qgscomposerpolygon.sip

@@ -23,10 +23,10 @@ class QgsComposerPolygon: QgsComposerNodesItem
 
   protected:
 
-    /** Add the point newPoint at the given position according to some
-     * criteres. */
     bool _addNode( const int indexPoint, const QPointF &newPoint, const double radius );
 
+    bool _removeNode( const int indexPoint );
+
     /** Draw points for the current shape. */
     void _draw( QPainter *painter );
 

python/core/composer/qgscomposerpolyline.sip

@@ -23,10 +23,10 @@ class QgsComposerPolyline: QgsComposerNodesItem
 
   protected:
 
-    /** Add the point newPoint at the given position according to some
-     * criteres. */
     bool _addNode( const int indexPoint, const QPointF &newPoint, const double radius );
 
+    bool _removeNode( const int indexPoint );
+
     /** Draw points for the current shape. */
     void _draw( QPainter *painter );
 

src/core/composer/qgscomposernodesitem.cpp

@@ -255,27 +255,9 @@ bool QgsComposerNodesItem::nodePosition( const int index, QPointF &position )
 
 bool QgsComposerNodesItem::removeNode( const int index )
 {
-  bool rc( false );
-
-  if ( index >= 0 && index < mPolygon.size() )
-  {
-    mPolygon.remove( index );
-
-    if ( mPolygon.size() < 3 )
-      mPolygon.clear();
-    else
-    {
-      int newSelectNode = index;
-      if ( index == mPolygon.size() )
-        newSelectNode = 0;
-      setSelectedNode( newSelectNode );
-    }
-
+  bool rc = _removeNode( index );
+  if ( rc )
     updateSceneRect();
-
-    rc = true;
-  }
-
   return rc;
 }
 

src/core/composer/qgscomposernodesitem.h

@@ -128,6 +128,9 @@ class CORE_EXPORT QgsComposerNodesItem: public QgsComposerItem
     /** Method called in addNode. */
     virtual bool _addNode( const int nodeIndex, const QPointF &newNode, const double radius ) = 0;
 
+    /** Method called in removeNode. */
+    virtual bool _removeNode( const int nodeIndex ) = 0;
+
     /** Method called in paint. */
     virtual void _draw( QPainter *painter ) = 0;
 

src/core/composer/qgscomposerpolygon.cpp

@@ -120,3 +120,23 @@ void QgsComposerPolygon::_writeXMLStyle( QDomDocument &doc, QDomElement &elmt )
                          doc );
   elmt.appendChild( pe );
 }
+
+bool QgsComposerPolygon::_removeNode( const int index )
+{
+  if ( index < 0 || index >= mPolygon.size() )
+    return false;
+
+  mPolygon.remove( index );
+
+  if ( mPolygon.size() < 3 )
+    mPolygon.clear();
+  else
+  {
+    int newSelectNode = index;
+    if ( index == mPolygon.size() )
+      newSelectNode = 0;
+    setSelectedNode( newSelectNode );
+  }
+
+  return true;
+}

src/core/composer/qgscomposerpolygon.h

@@ -69,6 +69,8 @@ class CORE_EXPORT QgsComposerPolygon: public QgsComposerNodesItem
      * criteres. */
     bool _addNode( const int indexPoint, const QPointF &newPoint, const double radius ) override;
 
+    bool _removeNode( const int nodeIndex ) override;
+
     /** Draw nodes for the current shape. */
     void _draw( QPainter *painter ) override;
 

src/core/composer/qgscomposerpolyline.cpp

@@ -59,6 +59,26 @@ bool QgsComposerPolyline::_addNode( const int indexPoint,
   return true;
 }
 
+bool QgsComposerPolyline::_removeNode( const int index )
+{
+  if ( index < 0 || index >= mPolygon.size() )
+    return false;
+
+  mPolygon.remove( index );
+
+  if ( mPolygon.size() < 2 )
+    mPolygon.clear();
+  else
+  {
+    int newSelectNode = index;
+    if ( index >= mPolygon.size() )
+      newSelectNode = mPolygon.size() - 1;
+    setSelectedNode( newSelectNode );
+  }
+
+  return true;
+}
+
 void QgsComposerPolyline::createDefaultPolylineStyleSymbol()
 {
   QgsStringMap properties;

src/core/composer/qgscomposerpolyline.h

@@ -68,6 +68,8 @@ class CORE_EXPORT QgsComposerPolyline: public QgsComposerNodesItem
      * criteres. */
     bool _addNode( const int indexPoint, const QPointF &newPoint, const double radius ) override;
 
+    bool _removeNode( const int nodeIndex ) override;
+
     /** Draw nodes for the current shape. */
     void _draw( QPainter *painter ) override;
 

src/gui/qgscomposerview.cpp

@@ -1577,27 +1577,24 @@ void QgsComposerView::deleteSelectedItems()
     if ( mNodesItemIndex != -1 )
     {
       composition()->beginCommand( mNodesItem, tr( "Remove item node" ) );
-      bool rc = mNodesItem->removeNode( mNodesItemIndex );
-      composition()->endCommand();
-
-      bool nodeDeleted = true;
-      if ( rc )
+      if ( mNodesItem->removeNode( mNodesItemIndex ) )
       {
-        mNodesItemIndex = mNodesItem->selectedNode();
-
-        if ( mNodesItemIndex != -1 )
+        composition()->endCommand();
+        if ( mNodesItem->nodesSize() > 0 )
         {
-          nodeDeleted = false;
-          setSelectedNode( mNodesItem, mNodesItemIndex );
+          mNodesItemIndex = mNodesItem->selectedNode();
+          // setSelectedNode( mNodesItem, mNodesItemIndex );
+        }
+        else
+        {
+          mNodesItemIndex = -1;
+          mNodesItem = nullptr;
         }
-      }
-
-      if ( nodeDeleted )
-      {
         scene()->update();
-
-        mNodesItemIndex = -1;
-        mNodesItem = nullptr;
+      }
+      else
+      {
+        composition()->cancelCommand();
       }
     }
   }

tests/src/python/test_qgscomposerpolygon.py

@@ -139,15 +139,6 @@ class TestQgsComposerPolygon(unittest.TestCase):
         assert myTestResult, myMessage
 
         self.assertEqual(self.mComposerPolygon.nodesSize(), 4)
-        rc = self.mComposerPolygon.removeNode(3)
-        self.assertEqual(rc, True)
-        self.assertEqual(self.mComposerPolygon.nodesSize(), 3)
-
-        checker = QgsCompositionChecker(
-            'composerpolygon_removednode', self.mComposition)
-        checker.setControlPathPrefix("composer_polygon")
-        myTestResult, myMessage = checker.testComposition()
-        assert myTestResult, myMessage
 
     def testAddNode(self):
         """Test addNode method"""