Fix and update to Freeze/Thaw, Move, and Rotate Label tools

Updates
- Move tool now preserves calculated x, y offset for upside-down labels, when initially moved and data-defined fields have no previous data.
- Move tool now stores the label's PAL solution for rotation on initial move, if rotation is data-defined with no previous data.
- Freeze/Thaw and Move tools now support all variations of previously data-defined halign and valign options on initial freeze.
- Freeze/Thaw tool has updated key modifiers that should work across major platforms.
- Tests for whether layer labels support data-defined rotation moved to base QgsMapToolLabel class.
Fixes
- Fix bug where labels defined in map units causing font to show as pointsize of same integer at small map scales.
- Half of a fix for rotation point of labels with data-defined size of map units actually being based off of point size.
  (still references the layer-defined font size somewhere in the rotation point calculation)
- Valign settings of Base and Half now more accurately key off of inverse of font ascent (instead of descent). No discernible shift occurs now on initial freeze.

src/app/qgsmaptoolfreezelabels.cpp

@@ -257,8 +257,8 @@ void QgsMapToolFreezeLabels::freezeThawLabels( const QgsRectangle& ext, QMouseEv
 {
 
   bool doThaw = e->modifiers() & Qt::ShiftModifier ? true : false;
-  bool toggleThawOrFreeze = e->modifiers() & Qt::AltModifier ? true : false;
-  bool doHide = e->modifiers() & Qt::ControlModifier ? true : false;
+  bool toggleThawOrFreeze = e->modifiers() & Qt::ControlModifier ? true : false;
+  bool doHide = ( doThaw && toggleThawOrFreeze );
 
   // get list of all drawn labels from all layers within, or touching, chosen extent
   bool labelChanged = false;
@@ -432,16 +432,23 @@ bool QgsMapToolFreezeLabels::freezeThawLabel( QgsVectorLayer* vlayer,
   if ( freeze )
   {
 
-    QgsPoint labelpoint = labelpos.cornerPoints.at( 0 );
+//     QgsPoint labelpoint = labelpos.cornerPoints.at( 0 );
 
-    double labelX = labelpoint.x();
-    double labelY = labelpoint.y();
+    QgsPoint referencePoint;
+    if ( !rotationPoint( referencePoint, true ) )
+    {
+      referencePoint.setX( mCurrentLabelPos.labelRect.xMinimum() );
+      referencePoint.setY( mCurrentLabelPos.labelRect.yMinimum() );
+    }
+
+    double labelX = referencePoint.x();
+    double labelY = referencePoint.y();
     double labelR = labelpos.rotation * 180 / M_PI;
 
     // transform back to layer crs, if on-fly on
     if ( mRender->hasCrsTransformEnabled() )
     {
-      QgsPoint transformedPoint = mRender->mapToLayerCoordinates( vlayer, labelpoint );
+      QgsPoint transformedPoint = mRender->mapToLayerCoordinates( vlayer, referencePoint );
       labelX = transformedPoint.x();
       labelY = transformedPoint.y();
     }

src/app/qgsmaptoollabel.cpp

@@ -230,7 +230,14 @@ QFont QgsMapToolLabel::labelFontCurrentFeature()
       QMap< QgsPalLayerSettings::DataDefinedProperties, int >::const_iterator sizeIt = ddProperties.find( QgsPalLayerSettings::Size );
       if ( sizeIt != ddProperties.constEnd() )
       {
-        font.setPointSizeF( attributes[*sizeIt].toDouble() );
+        if ( layerSettings.fontSizeInMapUnits )
+        {
+          font.setPixelSize( layerSettings.sizeToPixel( attributes[*sizeIt].toDouble(), QgsRenderContext() ) );
+        }
+        else
+        {
+          font.setPointSizeF( attributes[*sizeIt].toDouble() );
+        }
       }
 
       //family
@@ -273,15 +280,15 @@ QFont QgsMapToolLabel::labelFontCurrentFeature()
   return font;
 }
 
-bool QgsMapToolLabel::rotationPoint( QgsPoint& pos )
+bool QgsMapToolLabel::rotationPoint( QgsPoint& pos, bool ignoreUpsideDown )
 {
   QVector<QgsPoint> cornerPoints = mCurrentLabelPos.cornerPoints;
   if ( cornerPoints.size() < 4 )
   {
     return false;
   }
 
-  if ( mCurrentLabelPos.upsideDown )
+  if ( mCurrentLabelPos.upsideDown && !ignoreUpsideDown )
   {
     pos = mCurrentLabelPos.cornerPoints.at( 2 );
   }
@@ -336,7 +343,7 @@ bool QgsMapToolLabel::rotationPoint( QgsPoint& pos )
   }
   else
   {
-    double descentRatio = labelFontMetrics.descent() / labelFontMetrics.height();
+    double descentRatio = 1 / labelFontMetrics.ascent() / labelFontMetrics.height();
     if ( valiString.compare( "Base", Qt::CaseInsensitive ) == 0 )
     {
       ydiff = labelSizeY * descentRatio;
@@ -351,7 +358,7 @@ bool QgsMapToolLabel::rotationPoint( QgsPoint& pos )
   double angle = mCurrentLabelPos.rotation;
   double xd = xdiff * cos( angle ) - ydiff * sin( angle );
   double yd = xdiff * sin( angle ) + ydiff * cos( angle );
-  if ( mCurrentLabelPos.upsideDown )
+  if ( mCurrentLabelPos.upsideDown && !ignoreUpsideDown )
   {
     pos.setX( pos.x() - xd );
     pos.setY( pos.y() - yd );
@@ -399,7 +406,65 @@ bool QgsMapToolLabel::dataDefinedPosition( QgsVectorLayer* vlayer, int featureId
   return true;
 }
 
-bool QgsMapToolLabel:: diagramMoveable( const QgsMapLayer* ml, int& xCol, int& yCol ) const
+bool QgsMapToolLabel::layerIsRotatable( const QgsMapLayer* layer, int& rotationCol ) const
+{
+  const QgsVectorLayer* vlayer = dynamic_cast<const QgsVectorLayer*>( layer );
+  if ( !vlayer || !vlayer->isEditable() )
+  {
+    return false;
+  }
+
+  QVariant rotation = layer->customProperty( "labeling/dataDefinedProperty14" );
+  if ( !rotation.isValid() )
+  {
+    return false;
+  }
+
+  bool rotationOk;
+  rotationCol = rotation.toInt( &rotationOk );
+  if ( !rotationOk )
+  {
+    return false;
+  }
+  return true;
+}
+
+bool QgsMapToolLabel::dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess )
+{
+  rotationSuccess = false;
+  if ( !vlayer )
+  {
+    return false;
+  }
+
+  int rotationCol;
+  if ( !layerIsRotatable( vlayer, rotationCol ) )
+  {
+    return false;
+  }
+
+  QgsFeature f;
+  if ( !vlayer->featureAtId( featureId, f, false, true ) )
+  {
+    return false;
+  }
+
+  QgsAttributeMap attributes = f.attributeMap();
+
+  //test, if data defined x- and y- values are not null. Otherwise, the position is determined by PAL and the rotation cannot be fixed
+  int xCol, yCol;
+  double x, y;
+  bool xSuccess, ySuccess;
+  if ( !dataDefinedPosition( vlayer, featureId, x, xSuccess, y, ySuccess, xCol, yCol ) || !xSuccess || !ySuccess )
+  {
+    return false;
+  }
+
+  rotation = attributes[rotationCol].toDouble( &rotationSuccess );
+  return true;
+}
+
+bool QgsMapToolLabel::diagramMoveable( const QgsMapLayer* ml, int& xCol, int& yCol ) const
 {
   const QgsVectorLayer* vlayer = dynamic_cast<const QgsVectorLayer*>( ml );
   if ( vlayer && vlayer->diagramRenderer() )

src/app/qgsmaptoollabel.h

@@ -46,6 +46,9 @@ class QgsMapToolLabel: public QgsMapTool
         @param yCol out: index of the attribute for data defined y coordinate
         @return true if layer fields set up and exist*/
     bool layerCanFreeze( const QgsMapLayer* ml, int& xCol, int& yCol ) const;
+    /**Checks if labels in a layer can be rotated
+      @param rotationCol out: attribute column for data defined label rotation*/
+    bool layerIsRotatable( const QgsMapLayer* layer, int& rotationCol ) const;
 
   protected:
     QgsRubberBand* mLabelRubberBand;
@@ -63,8 +66,9 @@ class QgsMapToolLabel: public QgsMapTool
     bool labelAtPosition( QMouseEvent* e, QgsLabelPosition& p );
 
     /**Finds out rotation point of current label position
+      @param ignoreUpsideDown treat label as right-side-up
       @return true in case of success*/
-    bool rotationPoint( QgsPoint& pos );
+    bool rotationPoint( QgsPoint& pos, bool ignoreUpsideDown = false );
 
     /**Creates label / feature / fixpoint rubber bands for the current label position*/
     void createRubberBands();
@@ -90,7 +94,8 @@ class QgsMapToolLabel: public QgsMapTool
     QFont labelFontCurrentFeature();
 
     /**Get data defined position of a feature
-      @param layerId layer identification string
+      @param vlayer vector layer
+      @param featureId feature identification integer
       @param x out: data defined x-coordinate
       @param xSuccess out: false if attribute value is NULL
       @param y out: data defined y-coordinate
@@ -100,6 +105,15 @@ class QgsMapToolLabel: public QgsMapTool
       @return false if layer does not have data defined label position enabled*/
     bool dataDefinedPosition( QgsVectorLayer* vlayer, int featureId, double& x, bool& xSuccess, double& y, bool& ySuccess, int& xCol, int& yCol ) const;
 
+    /**Returns data defined rotation of a feature.
+      @param vlayer vector layer
+      @param featureId feature identification integer
+      @param rotation out: rotation value
+      @param rotationSuccess out: false if rotation value is NULL
+      @return true if data defined rotation is enabled on the layer
+      */
+    bool dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess );
+
   private:
     QgsPalLayerSettings mInvalidLabelSettings;
 };

src/app/qgsmaptoolmovelabel.cpp

@@ -50,7 +50,7 @@ void QgsMapToolMoveLabel::canvasPressEvent( QMouseEvent * e )
   {
     mStartPointMapCoords = toMapCoordinates( e->pos() );
     QgsPoint referencePoint;
-    if ( !rotationPoint( referencePoint ) )
+    if ( !rotationPoint( referencePoint, true ) )
     {
       referencePoint.setX( mCurrentLabelPos.labelRect.xMinimum() );
       referencePoint.setY( mCurrentLabelPos.labelRect.yMinimum() );
@@ -152,6 +152,26 @@ void QgsMapToolMoveLabel::canvasReleaseEvent( QMouseEvent * e )
   vlayer->beginEditCommand( tr( "Label moved" ) );
   vlayer->changeAttributeValue( mCurrentLabelPos.featureId, xCol, xPosNew, false );
   vlayer->changeAttributeValue( mCurrentLabelPos.featureId, yCol, yPosNew, false );
+
+  // set rotation to that of label, if data-defined and no rotation set yet
+  // handle case of initially set rotation column fields of 0 instead of NULL
+  // must come after setting x and y positions
+  int rCol;
+  if ( !mCurrentLabelPos.isDiagram && !mCurrentLabelPos.isFrozen
+       && layerIsRotatable( vlayer, rCol ) )
+  {
+    double labelRot = 0;
+    double defRot;
+    bool rSuccess;
+    if ( dataDefinedRotation( vlayer, mCurrentLabelPos.featureId, defRot, rSuccess ) )
+    {
+      labelRot = mCurrentLabelPos.rotation * 180 / M_PI;
+      if ( !rSuccess || ( rSuccess && defRot != labelRot ) )
+      {
+        vlayer->changeAttributeValue( mCurrentLabelPos.featureId, rCol, labelRot, false );
+      }
+    }
+  }
   vlayer->endEditCommand();
 
   mCanvas->refresh();

src/app/qgsmaptoolrotatelabel.cpp

@@ -166,64 +166,6 @@ void QgsMapToolRotateLabel::canvasReleaseEvent( QMouseEvent *e )
   mCanvas->refresh();
 }
 
-bool QgsMapToolRotateLabel::layerIsRotatable( const QgsMapLayer* layer, int& rotationCol ) const
-{
-  const QgsVectorLayer* vlayer = dynamic_cast<const QgsVectorLayer*>( layer );
-  if ( !vlayer || !vlayer->isEditable() )
-  {
-    return false;
-  }
-
-  QVariant rotation = layer->customProperty( "labeling/dataDefinedProperty14" );
-  if ( !rotation.isValid() )
-  {
-    return false;
-  }
-
-  bool rotationOk;
-  rotationCol = rotation.toInt( &rotationOk );
-  if ( !rotationOk )
-  {
-    return false;
-  }
-  return true;
-}
-
-bool QgsMapToolRotateLabel::dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess )
-{
-  rotationSuccess = false;
-  if ( !vlayer )
-  {
-    return false;
-  }
-
-  int rotationCol;
-  if ( !layerIsRotatable( vlayer, rotationCol ) )
-  {
-    return false;
-  }
-
-  QgsFeature f;
-  if ( !vlayer->featureAtId( featureId, f, false, true ) )
-  {
-    return false;
-  }
-
-  QgsAttributeMap attributes = f.attributeMap();
-
-  //test, if data defined x- and y- values are not null. Otherwise, the position is determined by PAL and the rotation cannot be fixed
-  int xCol, yCol;
-  double x, y;
-  bool xSuccess, ySuccess;
-  if ( !dataDefinedPosition( vlayer, featureId, x, xSuccess, y, ySuccess, xCol, yCol ) || !xSuccess || !ySuccess )
-  {
-    return false;
-  }
-
-  rotation = attributes[rotationCol].toDouble( &rotationSuccess );
-  return true;
-}
-
 int QgsMapToolRotateLabel::roundTo15Degrees( double n )
 {
   int m = ( int )( n / 15.0 + 0.5 );

src/app/qgsmaptoolrotatelabel.h

@@ -33,17 +33,7 @@ class QgsMapToolRotateLabel: public QgsMapToolLabel
     virtual void canvasMoveEvent( QMouseEvent * e );
     virtual void canvasReleaseEvent( QMouseEvent * e );
 
-    /**Checks if labels in a layer can be rotated
-      @param rotationCol out: attribute column for data defined label rotation*/
-    bool layerIsRotatable( const QgsMapLayer* layer, int& rotationCol ) const;
-
   protected:
-    /**Returns data defined rotation of a feature.
-      @param rotation out: rotation value
-      @param rotationSuccess out: false if rotation value is NULL
-      @return true if data defined rotation is enabled on the layer
-      */
-    bool dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess );
 
     static int roundTo15Degrees( double n );
     /**Converts azimuth value to counterclockwise 0 - 360*/

src/core/qgspallabeling.cpp

@@ -513,7 +513,7 @@ void QgsPalLayerSettings::registerFeature( QgsVectorLayer* layer,  QgsFeature& f
     if ( size.isValid() )
     {
       double sizeDouble = size.toDouble();
-      if ( sizeDouble <= 0 )
+      if ( sizeDouble <= 0 || sizeToPixel( sizeDouble, context ) < 1 )
       {
         return;
       }
@@ -859,8 +859,18 @@ int QgsPalLabeling::prepareLayer( QgsVectorLayer* layer, QSet<int>& attrIndices,
   // set whether adjacent lines should be merged
   l->setMergeConnectedLines( lyr.mergeLines );
 
-  lyr.textFont.setPixelSize( lyr.sizeToPixel( lyr.textFont.pointSizeF(), ctx ) );
+  // fix for font size in map units causing font to show pointsize at small map scales
+  int pixelFontSize = lyr.sizeToPixel( lyr.textFont.pointSizeF(), ctx );
 
+  if ( pixelFontSize < 1 )
+  {
+    lyr.textFont.setPixelSize( 1 );
+    lyr.textFont.setPointSize( 1 );
+  }
+  else
+  {
+    lyr.textFont.setPixelSize( pixelFontSize );
+  }
   //raster and vector scale factors
   lyr.vectorScaleFactor = ctx.scaleFactor();
   lyr.rasterCompressFactor = ctx.rasterScaleFactor();

src/ui/qgisapp.ui

@@ -1720,7 +1720,7 @@
    </property>
    <property name="toolTip">
     <string>Freeze or Thaw Labels
-Shift thaws, Alt toggles, Ctl (Cmd) hides</string>
+Shift thaws, Ctl (Cmd) toggles, Shift+Ctl (Cmd) hides</string>
    </property>
   </action>
   <action name="mActionShowFrozenLabels">