Fix resizing items with non-top-left reference point using mouse handles

python/core/layout/qgslayoutitem.sip

@@ -235,13 +235,20 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem, QgsLayoutUndoObjectInt
 .. seealso:: sizeWithUnits()
 %End
 
-    virtual void attemptMove( const QgsLayoutPoint &point );
+    virtual void attemptMove( const QgsLayoutPoint &point, bool useReferencePoint = true );
 %Docstring
- Attempts to move the item to a specified ``point``. This method respects the item's
+ Attempts to move the item to a specified ``point``.
+
+ If ``useReferencePoint`` is true, this method will respect the item's
  reference point, in that the item will be moved so that its current reference
  point is placed at the specified target point.
+
+ If ``useReferencePoint`` is false, the item will be moved so that ``point``
+ falls at the top-left corner of the item.
+
  Note that the final position of the item may not match the specified target position,
  as data defined item position may override the specified value.
+
 .. seealso:: attemptResize()
 .. seealso:: referencePoint()
 .. seealso:: positionWithUnits()
@@ -575,7 +582,7 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem, QgsLayoutUndoObjectInt
     QPointF adjustPointForReferencePosition( const QPointF &point, const QSizeF &size, const ReferencePoint &reference ) const;
 %Docstring
  Adjusts the specified ``point`` at which a ``reference`` position of the item
- sits and returns the top left corner of the item, if reference point where placed at the specified position.
+ sits and returns the top left corner of the item, if reference point were placed at the specified position.
  :rtype: QPointF
 %End
 
@@ -585,6 +592,13 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem, QgsLayoutUndoObjectInt
  :rtype: QPointF
 %End
 
+    QgsLayoutPoint topLeftToReferencePoint( const QgsLayoutPoint &point ) const;
+%Docstring
+ Returns the position for the reference point of the item, if the top-left of the item
+ was placed at the specified ``point``.
+ :rtype: QgsLayoutPoint
+%End
+
     virtual bool writePropertiesToElement( QDomElement &element, QDomDocument &document, const QgsReadWriteContext &context ) const;
 %Docstring
  Stores item state within an XML DOM element.

python/core/layout/qgslayoutitemgroup.sip

@@ -62,7 +62,7 @@ class QgsLayoutItemGroup: QgsLayoutItem
     virtual void setVisibility( const bool visible );
 
 
-    virtual void attemptMove( const QgsLayoutPoint &point );
+    virtual void attemptMove( const QgsLayoutPoint &point, bool useReferencePoint = true );
 
     virtual void attemptResize( const QgsLayoutSize &size );
 

src/core/layout/qgslayoutitem.cpp

@@ -351,7 +351,7 @@ void QgsLayoutItem::attemptResize( const QgsLayoutSize &size )
   emit sizePositionChanged();
 }
 
-void QgsLayoutItem::attemptMove( const QgsLayoutPoint &point )
+void QgsLayoutItem::attemptMove( const QgsLayoutPoint &point, bool useReferencePoint )
 {
   if ( !mLayout )
   {
@@ -360,7 +360,13 @@ void QgsLayoutItem::attemptMove( const QgsLayoutPoint &point )
     return;
   }
 
-  QgsLayoutPoint evaluatedPoint = applyDataDefinedPosition( point );
+  QgsLayoutPoint evaluatedPoint = point;
+  if ( !useReferencePoint )
+  {
+    evaluatedPoint = topLeftToReferencePoint( point );
+  }
+
+  evaluatedPoint = applyDataDefinedPosition( evaluatedPoint );
   QPointF evaluatedPointLayoutUnits = mLayout->convertToLayoutUnits( evaluatedPoint );
   QPointF topLeftPointLayoutUnits = adjustPointForReferencePosition( evaluatedPointLayoutUnits, rect().size(), mReferencePoint );
   if ( topLeftPointLayoutUnits == scenePos() && point.units() == mItemPosition.units() )
@@ -737,6 +743,13 @@ QPointF QgsLayoutItem::positionAtReferencePoint( const QgsLayoutItem::ReferenceP
   return mapToScene( pointWithinItem );
 }
 
+QgsLayoutPoint QgsLayoutItem::topLeftToReferencePoint( const QgsLayoutPoint &point ) const
+{
+  QPointF topLeft = mLayout->convertToLayoutUnits( point );
+  QPointF refPoint = topLeft + itemPositionAtReferencePoint( mReferencePoint, rect().size() );
+  return mLayout->convertFromLayoutUnits( refPoint, point.units() );
+}
+
 bool QgsLayoutItem::writePropertiesToElement( QDomElement &element, QDomDocument &document, const QgsReadWriteContext &context ) const
 {
   element.setAttribute( QStringLiteral( "uuid" ), mUuid );

src/core/layout/qgslayoutitem.h

@@ -250,16 +250,23 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
     virtual void attemptResize( const QgsLayoutSize &size );
 
     /**
-     * Attempts to move the item to a specified \a point. This method respects the item's
+     * Attempts to move the item to a specified \a point.
+     *
+     * If \a useReferencePoint is true, this method will respect the item's
      * reference point, in that the item will be moved so that its current reference
      * point is placed at the specified target point.
+     *
+     * If \a useReferencePoint is false, the item will be moved so that \a point
+     * falls at the top-left corner of the item.
+     *
      * Note that the final position of the item may not match the specified target position,
      * as data defined item position may override the specified value.
+     *
      * \see attemptResize()
      * \see referencePoint()
      * \see positionWithUnits()
     */
-    virtual void attemptMove( const QgsLayoutPoint &point );
+    virtual void attemptMove( const QgsLayoutPoint &point, bool useReferencePoint = true );
 
     /**
      * Returns the item's current position, including units. The position returned
@@ -572,7 +579,7 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
 
     /**
      * Adjusts the specified \a point at which a \a reference position of the item
-     * sits and returns the top left corner of the item, if reference point where placed at the specified position.
+     * sits and returns the top left corner of the item, if reference point were placed at the specified position.
      */
     QPointF adjustPointForReferencePosition( const QPointF &point, const QSizeF &size, const ReferencePoint &reference ) const;
 
@@ -581,6 +588,12 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
     */
     QPointF positionAtReferencePoint( const ReferencePoint &reference ) const;
 
+    /**
+     * Returns the position for the reference point of the item, if the top-left of the item
+     * was placed at the specified \a point.
+    */
+    QgsLayoutPoint topLeftToReferencePoint( const QgsLayoutPoint &point ) const;
+
     /**
      * Stores item state within an XML DOM element.
      * \param element is the DOM element to store the item's properties in

src/core/layout/qgslayoutitemgroup.cpp

@@ -127,7 +127,7 @@ void QgsLayoutItemGroup::setVisibility( const bool visible )
     mLayout->undoStack()->endMacro();
 }
 
-void QgsLayoutItemGroup::attemptMove( const QgsLayoutPoint &point )
+void QgsLayoutItemGroup::attemptMove( const QgsLayoutPoint &point, bool useReferencePoint )
 {
   if ( !mLayout )
     return;

src/core/layout/qgslayoutitemgroup.h

@@ -69,7 +69,7 @@ class CORE_EXPORT QgsLayoutItemGroup: public QgsLayoutItem
     void setVisibility( const bool visible ) override;
 
     //overridden to move child items
-    void attemptMove( const QgsLayoutPoint &point ) override;
+    void attemptMove( const QgsLayoutPoint &point, bool useReferencePoint = true ) override;
     void attemptResize( const QgsLayoutSize &size ) override;
 
     bool writeXml( QDomElement &parentElement, QDomDocument &document, const QgsReadWriteContext &context ) const override;

src/gui/layout/qgslayoutmousehandles.cpp

@@ -657,13 +657,13 @@ void QgsLayoutMouseHandles::mouseReleaseEvent( QGraphicsSceneMouseEvent *event )
       itemRect = itemRect.normalized();
       QPointF newPos = mapToScene( itemRect.topLeft() );
 
-      // translate new position to current item units
-      QgsLayoutPoint itemPos = mLayout->convertFromLayoutUnits( newPos, item->positionWithUnits().units() );
-      item->attemptMove( itemPos );
-
       QgsLayoutSize itemSize = mLayout->convertFromLayoutUnits( itemRect.size(), item->sizeWithUnits().units() );
       item->attemptResize( itemSize );
 
+      // translate new position to current item units
+      QgsLayoutPoint itemPos = mLayout->convertFromLayoutUnits( newPos, item->positionWithUnits().units() );
+      item->attemptMove( itemPos, false );
+
       command->saveAfterState();
       mLayout->undoStack()->stack()->push( command.release() );
     }

tests/src/core/testqgslayoutitem.cpp

@@ -1139,7 +1139,24 @@ void TestQgsLayoutItem::move()
 
   l.setUnits( QgsUnitTypes::LayoutMillimeters );
 
-  //TODO - reference points
+  //reference points
+  item->attemptMove( QgsLayoutPoint( 5, 9 ) );
+  item->attemptResize( QgsLayoutSize( 4, 6 ) );
+  item->setReferencePoint( QgsLayoutItem::LowerRight );
+  QCOMPARE( item->positionWithUnits().x(), 9.0 );
+  QCOMPARE( item->positionWithUnits().y(), 15.0 );
+
+  item->attemptMove( QgsLayoutPoint( 11, 13 ) );
+  QCOMPARE( item->positionWithUnits().x(), 11.0 );
+  QCOMPARE( item->positionWithUnits().y(), 13.0 );
+  QCOMPARE( item->scenePos().x(), 7.0 );
+  QCOMPARE( item->scenePos().y(), 7.0 );
+
+  item->attemptMove( QgsLayoutPoint( 10, 12 ), false );
+  QCOMPARE( item->positionWithUnits().x(), 14.0 );
+  QCOMPARE( item->positionWithUnits().y(), 18.0 );
+  QCOMPARE( item->scenePos().x(), 10.0 );
+  QCOMPARE( item->scenePos().y(), 12.0 );
 }
 
 void TestQgsLayoutItem::rotation()