Port data defined item position and size

python/core/layout/qgslayoutitem.sip

@@ -91,6 +91,7 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem
 .. seealso:: minimumSize()
 .. seealso:: fixedSize()
 .. seealso:: attemptMove()
+.. seealso:: sizeWithUnits()
 %End
 
     virtual void attemptMove( const QgsLayoutPoint &point );
@@ -102,6 +103,7 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem
  as data defined item position may override the specified value.
 .. seealso:: attemptResize()
 .. seealso:: referencePoint()
+.. seealso:: positionWithUnits()
 %End
 
     QgsLayoutPoint positionWithUnits() const;
@@ -111,9 +113,18 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem
  left corner of the item.
 .. seealso:: attemptMove()
 .. seealso:: referencePoint()
+.. seealso:: sizeWithUnits()
  :rtype: QgsLayoutPoint
 %End
 
+    QgsLayoutSize sizeWithUnits() const;
+%Docstring
+ Returns the item's current size, including units.
+.. seealso:: attemptResize()
+.. seealso:: positionWithUnits()
+ :rtype: QgsLayoutSize
+%End
+
   public slots:
 
     virtual void refresh();
@@ -123,6 +134,14 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem
  recalculation of its position and size.
 %End
 
+    virtual void refreshDataDefinedProperty( const QgsLayoutObject::DataDefinedProperty property = QgsLayoutObject::AllProperties );
+%Docstring
+ Refreshes a data defined ``property`` for the item by reevaluating the property's value
+ and redrawing the item with this new value. If ``property`` is set to
+ QgsLayoutObject.AllProperties then all data defined properties for the item will be
+ refreshed.
+%End
+
   protected:
 
     virtual void drawDebugRect( QPainter *painter );

src/core/layout/qgslayoutitem.cpp

@@ -67,6 +67,7 @@ void QgsLayoutItem::setReferencePoint( const QgsLayoutItem::ReferencePoint &poin
   //also need to adjust stored position
   QPointF positionReferencePointLayoutUnits = adjustPointForReferencePosition( pos(), QSizeF( -rect().width(), -rect().height() ) );
   mItemPosition = mLayout->convertFromLayoutUnits( positionReferencePointLayoutUnits, mItemPosition.units() );
+  refreshItemPosition();
 }
 
 void QgsLayoutItem::attemptResize( const QgsLayoutSize &size )
@@ -78,7 +79,8 @@ void QgsLayoutItem::attemptResize( const QgsLayoutSize &size )
     return;
   }
 
-  QSizeF targetSizeLayoutUnits = mLayout->convertToLayoutUnits( size );
+  QgsLayoutSize evaluatedSize = applyDataDefinedSize( size );
+  QSizeF targetSizeLayoutUnits = mLayout->convertToLayoutUnits( evaluatedSize );
   QSizeF actualSizeLayoutUnits = applyMinimumSize( targetSizeLayoutUnits );
   actualSizeLayoutUnits = applyFixedSize( actualSizeLayoutUnits );
 
@@ -103,27 +105,71 @@ void QgsLayoutItem::attemptMove( const QgsLayoutPoint &point )
     return;
   }
 
-  QPointF targetPointLayoutUnits = mLayout->convertToLayoutUnits( point );
-  //TODO - apply data defined position here
-  targetPointLayoutUnits = adjustPointForReferencePosition( targetPointLayoutUnits, rect().size() );
-  QPointF actualPointLayoutUnits = targetPointLayoutUnits;
-
-  if ( actualPointLayoutUnits == pos() )
+  QgsLayoutPoint evaluatedPoint = applyDataDefinedPosition( point );
+  QPointF evaluatedPointLayoutUnits = mLayout->convertToLayoutUnits( evaluatedPoint );
+  QPointF topLeftPointLayoutUnits = adjustPointForReferencePosition( evaluatedPointLayoutUnits, rect().size() );
+  if ( topLeftPointLayoutUnits == pos() && point.units() == mItemPosition.units() )
   {
+    //TODO - add test for second condition
     return;
   }
 
-  QgsLayoutPoint actualPointTargetUnits = mLayout->convertFromLayoutUnits( actualPointLayoutUnits, point.units() );
-  mItemPosition = actualPointTargetUnits;
+  QgsLayoutPoint referencePointTargetUnits = mLayout->convertFromLayoutUnits( evaluatedPointLayoutUnits, point.units() );
+  mItemPosition = referencePointTargetUnits;
+
+  setPos( topLeftPointLayoutUnits );
+}
+
+QgsLayoutPoint QgsLayoutItem::applyDataDefinedPosition( const QgsLayoutPoint &position )
+{
+  if ( !mLayout )
+  {
+    return position;
+  }
 
-  setPos( targetPointLayoutUnits );
+  QgsExpressionContext context = createExpressionContext();
+  double evaluatedX = mDataDefinedProperties.valueAsDouble( QgsLayoutObject::PositionX, context, position.x() );
+  double evaluatedY = mDataDefinedProperties.valueAsDouble( QgsLayoutObject::PositionY, context, position.y() );
+  return QgsLayoutPoint( evaluatedX, evaluatedY, position.units() );
 }
 
+QgsLayoutSize QgsLayoutItem::applyDataDefinedSize( const QgsLayoutSize &size )
+{
+  if ( !mLayout )
+  {
+    return size;
+  }
+
+  QgsExpressionContext context = createExpressionContext();
+  double evaluatedWidth = mDataDefinedProperties.valueAsDouble( QgsLayoutObject::ItemWidth, context, size.width() );
+  double evaluatedHeight = mDataDefinedProperties.valueAsDouble( QgsLayoutObject::ItemHeight, context, size.height() );
+  return QgsLayoutSize( evaluatedWidth, evaluatedHeight, size.units() );
+}
+
+void QgsLayoutItem::refreshDataDefinedProperty( const QgsLayoutObject::DataDefinedProperty property )
+{
+  //update data defined properties and update item to match
+
+  //evaluate width and height first, since they may affect position if non-top-left reference point set
+  if ( property == QgsLayoutObject::ItemWidth || property == QgsLayoutObject::ItemHeight ||
+       property == QgsLayoutObject::AllProperties )
+  {
+    refreshItemSize();
+  }
+  if ( property == QgsLayoutObject::PositionX || property == QgsLayoutObject::PositionY ||
+       property == QgsLayoutObject::AllProperties )
+  {
+    refreshItemPosition();
+  }
+}
+
+
 void QgsLayoutItem::refresh()
 {
   QgsLayoutObject::refresh();
   refreshItemSize();
-  refreshItemPosition();
+
+  refreshDataDefinedProperty();
 }
 
 void QgsLayoutItem::drawDebugRect( QPainter *painter )

src/core/layout/qgslayoutitem.h

@@ -105,6 +105,7 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
      * \see minimumSize()
      * \see fixedSize()
      * \see attemptMove()
+     * \see sizeWithUnits()
     */
     virtual void attemptResize( const QgsLayoutSize &size );
 
@@ -116,6 +117,7 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
      * as data defined item position may override the specified value.
      * \see attemptResize()
      * \see referencePoint()
+     * \see positionWithUnits()
     */
     virtual void attemptMove( const QgsLayoutPoint &point );
 
@@ -125,9 +127,17 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
      * left corner of the item.
      * \see attemptMove()
      * \see referencePoint()
+     * \see sizeWithUnits()
     */
     QgsLayoutPoint positionWithUnits() const { return mItemPosition; }
 
+    /**
+     * Returns the item's current size, including units.
+     * \see attemptResize()
+     * \see positionWithUnits()
+     */
+    QgsLayoutSize sizeWithUnits() const { return mItemSize; }
+
   public slots:
 
     /**
@@ -136,6 +146,14 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
      */
     void refresh() override;
 
+    /**
+     * Refreshes a data defined \a property for the item by reevaluating the property's value
+     * and redrawing the item with this new value. If \a property is set to
+     * QgsLayoutObject::AllProperties then all data defined properties for the item will be
+     * refreshed.
+    */
+    virtual void refreshDataDefinedProperty( const QgsLayoutObject::DataDefinedProperty property = QgsLayoutObject::AllProperties );
+
   protected:
 
     /** Draws a debugging rectangle of the item's current bounds within the specified
@@ -205,6 +223,8 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
 
     QSizeF applyMinimumSize( const QSizeF &targetSize );
     QSizeF applyFixedSize( const QSizeF &targetSize );
+    QgsLayoutPoint applyDataDefinedPosition( const QgsLayoutPoint &position );
+    QgsLayoutSize applyDataDefinedSize( const QgsLayoutSize &size );
 
     friend class TestQgsLayoutItem;
 };