[composer] Respect reference point when resizing scalebar and legend

Previously, the reference point (and data defined position/size) were
ignored when scalebars or legends resized themselves.

Fix #11321, #11380

Author: nyalldawson

python/core/composer/qgscomposeritem.sip

@@ -761,8 +761,17 @@ class QgsComposerItem : QgsComposerObject, QGraphicsRectItem
     void deleteVAlignSnapItem();
     void deleteAlignItems();
 
-    /**Update an item rect to consider data defined position and size of item*/
-    QRectF evalItemRect( const QRectF &newRect );
+    /**Evaluates an item's bounding rect to consider data defined position and size of item
+     * and reference point
+     * @param newRect target bouding rect for item
+     * @param resizeOnly set to true if the item is only being resized. If true then
+     * the position of the returned rect will be adjusted to account for the item's
+     * position mode
+     * @returns bounding box rectangle for item after data defined size and position have been
+     * set and position mode has been accounted for
+     * @note added in QGIS 2.5
+    */
+    QRectF evalItemRect( const QRectF &newRect, const bool resizeOnly = false );
 
     /**Returns whether the item should be drawn in the current context
      * @returns true if item should be drawn

src/core/composer/qgscomposeritem.cpp

@@ -708,7 +708,7 @@ void QgsComposerItem::setSceneRect( const QRectF& rectangle )
   emit sizeChanged();
 }
 
-QRectF QgsComposerItem::evalItemRect( const QRectF &newRect )
+QRectF QgsComposerItem::evalItemRect( const QRectF &newRect, const bool resizeOnly )
 {
   QRectF result = newRect;
 
@@ -737,14 +737,29 @@ QRectF QgsComposerItem::evalItemRect( const QRectF &newRect )
   }
 
   double x = result.left();
-  //initially adjust for position mode to get top-left coordinate
-  if ( mLastUsedPositionMode == UpperMiddle || mLastUsedPositionMode == Middle || mLastUsedPositionMode == LowerMiddle )
+  //initially adjust for position mode to get x coordinate
+  if ( !resizeOnly )
   {
-    x += newRect.width() / 2.0;
+    //adjust x-coordinate if placement is not done to a left point
+    if ( mLastUsedPositionMode == UpperMiddle || mLastUsedPositionMode == Middle || mLastUsedPositionMode == LowerMiddle )
+    {
+      x += newRect.width() / 2.0;
+    }
+    else if ( mLastUsedPositionMode == UpperRight || mLastUsedPositionMode == MiddleRight || mLastUsedPositionMode == LowerRight )
+    {
+      x += newRect.width();
+    }
   }
-  else if ( mLastUsedPositionMode == UpperRight || mLastUsedPositionMode == MiddleRight || mLastUsedPositionMode == LowerRight )
+  else
   {
-    x += newRect.width();
+    if ( mLastUsedPositionMode == UpperMiddle || mLastUsedPositionMode == Middle || mLastUsedPositionMode == LowerMiddle )
+    {
+      x += rect().width() / 2.0;
+    }
+    else if ( mLastUsedPositionMode == UpperRight || mLastUsedPositionMode == MiddleRight || mLastUsedPositionMode == LowerRight )
+    {
+      x += rect().width();
+    }
   }
   if ( dataDefinedEvaluate( QgsComposerObject::PositionX, exprVal ) )
   {
@@ -758,16 +773,30 @@ QRectF QgsComposerItem::evalItemRect( const QRectF &newRect )
   }
 
   double y = result.top();
-  //adjust y-coordinate if placement is not done to an upper point
-  if ( mLastUsedPositionMode == MiddleLeft || mLastUsedPositionMode == Middle || mLastUsedPositionMode == MiddleRight )
+  //initially adjust for position mode to get y coordinate
+  if ( !resizeOnly )
   {
-    y += newRect.height() / 2.0;
+    //adjust y-coordinate if placement is not done to an upper point
+    if ( mLastUsedPositionMode == MiddleLeft || mLastUsedPositionMode == Middle || mLastUsedPositionMode == MiddleRight )
+    {
+      y += newRect.height() / 2.0;
+    }
+    else if ( mLastUsedPositionMode == LowerLeft || mLastUsedPositionMode == LowerMiddle || mLastUsedPositionMode == LowerRight )
+    {
+      y += newRect.height();
+    }
   }
-  else if ( mLastUsedPositionMode == LowerLeft || mLastUsedPositionMode == LowerMiddle || mLastUsedPositionMode == LowerRight )
+  else
   {
-    y += newRect.height();
+    if ( mLastUsedPositionMode == MiddleLeft || mLastUsedPositionMode == Middle || mLastUsedPositionMode == MiddleRight )
+    {
+      y += rect().height() / 2.0;
+    }
+    else if ( mLastUsedPositionMode == LowerLeft || mLastUsedPositionMode == LowerMiddle || mLastUsedPositionMode == LowerRight )
+    {
+      y += rect().height();
+    }
   }
-
   if ( dataDefinedEvaluate( QgsComposerObject::PositionY, exprVal ) )
   {
     bool ok;

src/core/composer/qgscomposeritem.h

@@ -774,8 +774,17 @@ class CORE_EXPORT QgsComposerItem: public QgsComposerObject, public QGraphicsRec
     void deleteVAlignSnapItem();
     void deleteAlignItems();
 
-    /**Update an item rect to consider data defined position and size of item*/
-    QRectF evalItemRect( const QRectF &newRect );
+    /**Evaluates an item's bounding rect to consider data defined position and size of item
+     * and reference point
+     * @param newRect target bouding rect for item
+     * @param resizeOnly set to true if the item is only being resized. If true then
+     * the position of the returned rect will be adjusted to account for the item's
+     * position mode
+     * @returns bounding box rectangle for item after data defined size and position have been
+     * set and position mode has been accounted for
+     * @note added in QGIS 2.5
+    */
+    QRectF evalItemRect( const QRectF &newRect, const bool resizeOnly = false );
 
     /**Returns whether the item should be drawn in the current context
      * @returns true if item should be drawn

src/core/composer/qgscomposerlegend.cpp

@@ -103,10 +103,18 @@ void QgsComposerLegend::paint( QPainter* painter, const QStyleOptionGraphicsItem
 
   //adjust box if width or height is too small
   QSizeF size = legendRenderer.minimumSize();
-  if ( size.height() > rect().height() )
-    setSceneRect( QRectF( pos().x(), pos().y(), rect().width(), size.height() ) );
-  if ( size.width() > rect().width() )
-    setSceneRect( QRectF( pos().x(), pos().y(), size.width(), rect().height() ) );
+  if ( size.height() > rect().height() || size.width() > rect().width() )
+  {
+    //need to resize box
+    QRectF targetRect = QRectF( pos().x(), pos().y(), rect().width(), rect().height() );
+    if ( size.height() > targetRect.height() )
+      targetRect.setHeight( size.height() );
+    if ( size.width() > rect().width() )
+      targetRect.setWidth( size.width() );
+
+    //set new rect, respecting position mode and data defined size/position
+    setSceneRect( evalItemRect( targetRect, true ) );
+  }
 
   legendRenderer.drawLegend( painter );
 
@@ -137,7 +145,9 @@ void QgsComposerLegend::adjustBoxSize()
   QgsDebugMsg( QString( "width = %1 height = %2" ).arg( size.width() ).arg( size.height() ) );
   if ( size.isValid() )
   {
-    setSceneRect( QRectF( pos().x(), pos().y(), size.width(), size.height() ) );
+    QRectF targetRect = QRectF( pos().x(), pos().y(), size.width(), size.height() );
+    //set new rect, respecting position mode and data defined size/position
+    setSceneRect( evalItemRect( targetRect, true ) );
   }
 }
 

src/core/composer/qgscomposerscalebar.cpp

@@ -389,7 +389,7 @@ void QgsComposerScaleBar::adjustBoxSize()
   QRectF box = mStyle->calculateBoxSize();
 
   //update rect for data defined size and position
-  QRectF newRect = evalItemRect( box );
+  QRectF newRect = evalItemRect( box, true );
 
   //scale bars have a minimum size, respect that regardless of data defined settings
   if ( newRect.width() < box.width() )