Fix broken manual rotation anchor point setting via ctrl+click in rot…

…ate features tool

Ctrl+clicking to set the manual rotation point had no effect, and the selected
rotation point was always reset as soon as the rotation action started.

Apparently this has been broken for some time (confirmed broken since 3.4 at least!).

Also add tests.

src/app/qgsmaptoolrotatefeature.cpp

@@ -202,7 +202,8 @@ void QgsMapToolRotateFeature::canvasReleaseEvent( QgsMapMouseEvent *e )
   {
     if ( !mAnchorPoint )
     {
-      return;
+      mAnchorPoint = qgis::make_unique<QgsVertexMarker>( mCanvas );
+      mAnchorPoint->setIconType( QgsVertexMarker::ICON_CROSS );
     }
     mAnchorPoint->setCenter( toMapCoordinates( e->pos() ) );
     mStartPointMapCoords = toMapCoordinates( e->pos() );
@@ -233,10 +234,12 @@ void QgsMapToolRotateFeature::canvasReleaseEvent( QgsMapMouseEvent *e )
     QgsRectangle selectRect( layerCoords.x() - searchRadius, layerCoords.y() - searchRadius,
                              layerCoords.x() + searchRadius, layerCoords.y() + searchRadius );
 
+    bool autoCalculateAnchorPoint = false;
     if ( !mAnchorPoint )
     {
       mAnchorPoint = qgis::make_unique<QgsVertexMarker>( mCanvas );
       mAnchorPoint->setIconType( QgsVertexMarker::ICON_CROSS );
+      autoCalculateAnchorPoint = true;
     }
 
     if ( vlayer->selectedFeatureCount() == 0 )
@@ -274,8 +277,15 @@ void QgsMapToolRotateFeature::canvasReleaseEvent( QgsMapMouseEvent *e )
       }
 
       QgsRectangle bound = cf.geometry().boundingBox();
-      mStartPointMapCoords = toMapCoordinates( vlayer, bound.center() );
-      mAnchorPoint->setCenter( mStartPointMapCoords );
+      if ( autoCalculateAnchorPoint )
+      {
+        mStartPointMapCoords = toMapCoordinates( vlayer, bound.center() );
+        mAnchorPoint->setCenter( mStartPointMapCoords );
+      }
+      else
+      {
+        mStartPointMapCoords = mAnchorPoint->center();
+      }
 
       mStPoint = toCanvasCoordinates( mStartPointMapCoords );
 
@@ -407,14 +417,8 @@ void QgsMapToolRotateFeature::applyRotation( double rotation )
       i = i + 1;
       vertex = geom.vertexAt( i );
     }
-
   }
 
-  double anchorX = a * anchorPoint.x() + b * anchorPoint.y() + c;
-  double anchorY = d * anchorPoint.x() + ee * anchorPoint.y() + f;
-
-  mAnchorPoint->setCenter( QgsPointXY( anchorX, anchorY ) );
-
   deleteRotationWidget();
   deleteRubberband();
 

tests/src/app/testqgsmaptoolrotatefeature.cpp

@@ -44,6 +44,9 @@ class TestQgsMapToolRotateFeature: public QObject
     void cleanupTestCase();// will be called after the last testfunction was executed.
 
     void testRotateFeature();
+    void testRotateFeatureManualAnchor();
+    void testCancelManualAnchor();
+    void testRotateFeatureManualAnchorAfterStartRotate();
 
   private:
     QgisApp *mQgisApp = nullptr;
@@ -140,6 +143,68 @@ void TestQgsMapToolRotateFeature::testRotateFeature()
   mLayerBase->undoStack()->undo();
 }
 
+void TestQgsMapToolRotateFeature::testRotateFeatureManualAnchor()
+{
+  // test rotating around a fixed anchor point
+  TestQgsMapToolUtils utils( mRotateTool );
+
+  // set anchor point
+  utils.mouseClick( 0, 5, Qt::LeftButton, Qt::ControlModifier, true );
+
+  utils.mouseClick( 1, 1, Qt::LeftButton, Qt::KeyboardModifiers(), true );
+  utils.mouseMove( 2, 1 );
+  utils.mouseClick( 2, 1, Qt::LeftButton, Qt::KeyboardModifiers(), true );
+
+  QCOMPARE( mLayerBase->getFeature( 1 ).geometry().asWkt( 2 ), QStringLiteral( "Polygon ((2.06 0.34, 0.87 1.1, 1.84 1.31, 2.06 0.34))" ) );
+  QCOMPARE( mLayerBase->getFeature( 2 ).geometry().asWkt( 2 ), QStringLiteral( "Polygon ((1.1 0, 1.1 5, 2.1 5, 2.1 0))" ) );
+
+  mLayerBase->undoStack()->undo();
+}
+
+void TestQgsMapToolRotateFeature::testCancelManualAnchor()
+{
+  // test canceling rotation around a fixed anchor point
+  TestQgsMapToolUtils utils( mRotateTool );
+
+  // set anchor point
+  utils.mouseClick( 0, 5, Qt::LeftButton, Qt::ControlModifier, true );
+
+  // right click = remove anchor point
+  utils.mouseClick( 10, 15, Qt::RightButton, Qt::KeyboardModifiers(), true );
+
+  // now rotate -- should be around feature center, not anchor point
+  utils.mouseClick( 1, 1, Qt::LeftButton, Qt::KeyboardModifiers(), true );
+  utils.mouseMove( 2, 1 );
+  utils.mouseClick( 2, 1, Qt::LeftButton, Qt::KeyboardModifiers(), true );
+
+  QCOMPARE( mLayerBase->getFeature( 1 ).geometry().asWkt( 2 ), QStringLiteral( "Polygon ((0.72 -0.17, 0.28 1.17, 1.17 0.72, 0.72 -0.17))" ) );
+  QCOMPARE( mLayerBase->getFeature( 2 ).geometry().asWkt( 2 ), QStringLiteral( "Polygon ((1.1 0, 1.1 5, 2.1 5, 2.1 0))" ) );
+
+  mLayerBase->undoStack()->undo();
+}
+
+void TestQgsMapToolRotateFeature::testRotateFeatureManualAnchorAfterStartRotate()
+{
+  // test rotating around a fixed anchor point, where the fixed anchor point is placed after rotation begins
+  TestQgsMapToolUtils utils( mRotateTool );
+
+  // start rotation
+  utils.mouseClick( 1, 1, Qt::LeftButton, Qt::KeyboardModifiers(), true );
+
+  // set anchor point
+  utils.mouseMove( 0, 5 );
+  utils.mouseClick( 0, 5, Qt::LeftButton, Qt::ControlModifier, true );
+
+  // complete rotation
+  utils.mouseMove( 2, 1 );
+  utils.mouseClick( 2, 1, Qt::LeftButton, Qt::KeyboardModifiers(), true );
+
+  QCOMPARE( mLayerBase->getFeature( 1 ).geometry().asWkt( 2 ), QStringLiteral( "Polygon ((-5.06 5.63, -3.79 6.26, -4.11 5.32, -5.06 5.63))" ) );
+  QCOMPARE( mLayerBase->getFeature( 2 ).geometry().asWkt( 2 ), QStringLiteral( "Polygon ((1.1 0, 1.1 5, 2.1 5, 2.1 0))" ) );
+
+  mLayerBase->undoStack()->undo();
+}
+
 
 QGSTEST_MAIN( TestQgsMapToolRotateFeature )
 #include "testqgsmaptoolrotatefeature.moc"