Option to preserve existing rotation values during freeze/thaw label operations

- PAL layer setting for preserving existing rotation values
- Clean up field-mapping checks

Author: dakcarto

src/app/qgslabelinggui.cpp

@@ -140,6 +140,7 @@ QgsLabelingGui::QgsLabelingGui( QgsPalLabeling* lbl, QgsVectorLayer* layer, QgsM
   mMinSizeSpinBox->setValue( lyr.minFeatureSize );
   chkAddDirectionSymbol->setChecked( lyr.addDirectionSymbol );
   wrapCharacterEdit->setText( lyr.wrapChar );
+  chkPreserveRotation->setChecked( lyr.preserveRotation );
 
   bool scaleBased = ( lyr.scaleMin != 0 && lyr.scaleMax != 0 );
   chkScaleBasedVisibility->setChecked( scaleBased );
@@ -323,6 +324,14 @@ QgsPalLayerSettings QgsLabelingGui::layerSettings()
   lyr.minFeatureSize = mMinSizeSpinBox->value();
   lyr.fontSizeInMapUnits = ( mFontSizeUnitComboBox->currentIndex() == 1 );
   lyr.wrapChar = wrapCharacterEdit->text();
+  if ( chkPreserveRotation->isChecked() )
+  {
+    lyr.preserveRotation = true;
+  }
+  else
+  {
+    lyr.preserveRotation = false;
+  }
 
   //data defined labeling
   setDataDefinedProperty( mSizeAttributeComboBox, QgsPalLayerSettings::Size, lyr );
@@ -600,11 +609,13 @@ void QgsLabelingGui::disableDataDefinedAlignment()
   mVerticalAlignmentComboBox->setEnabled( false );
   mRotationComboBox->setCurrentIndex( mRotationComboBox->findText( "" ) );
   mRotationComboBox->setEnabled( false );
+  chkPreserveRotation->setEnabled( false );
 }
 
 void QgsLabelingGui::enableDataDefinedAlignment()
 {
   mHorizontalAlignmentComboBox->setEnabled( true );
   mVerticalAlignmentComboBox->setEnabled( true );
   mRotationComboBox->setEnabled( true );
+  chkPreserveRotation->setEnabled( true );
 }

src/app/qgsmaptoolfreezelabels.cpp

@@ -379,50 +379,28 @@ bool QgsMapToolFreezeLabels::freezeThawLabel( QgsVectorLayer* vlayer,
     QgsDebugMsg( QString( "Label is diagram, skipping" ) );
     return false;
   }
-  // verify attribute table has proper fields setup
-  bool xColOk, yColOk, rColOk;
-  int xCol, yCol, rCol;
 
-  QVariant xColumn = vlayer->customProperty( "labeling/dataDefinedProperty9" );
-  if ( !xColumn.isValid() )
-  {
-    QgsDebugMsg( QString( "X column not set" ) );
-    return false;
-  }
-  xCol = xColumn.toInt( &xColOk );
-  if ( !xColOk )
-  {
-    QgsDebugMsg( QString( "X column not convertible to integer" ) );
-    return false;
-  }
+  // verify attribute table has x, y fields mapped
+  int xCol, yCol;
+  double xPosOrig, yPosOrig;
+  bool xSuccess, ySuccess;
 
-  QVariant yColumn = vlayer->customProperty( "labeling/dataDefinedProperty10" );
-  if ( !yColumn.isValid() )
-  {
-    QgsDebugMsg( QString( "Y column not set" ) );
-    return false;
-  }
-  yCol = yColumn.toInt( &yColOk );
-  if ( !yColOk )
+  if ( !dataDefinedPosition( vlayer, mCurrentLabelPos.featureId, xPosOrig, xSuccess, yPosOrig, ySuccess, xCol, yCol ) )
   {
-    QgsDebugMsg( QString( "Y column not convertible to integer" ) );
+    QgsDebugMsg( QString( "Label X or Y column not mapped, skipping" ) );
     return false;
   }
 
-  // rotation field is optional, but will be used if available
-  bool hasRCol = true;
-  QVariant rColumn = vlayer->customProperty( "labeling/dataDefinedProperty14" );
-  if ( !rColumn.isValid() )
-  {
-    QgsDebugMsg( QString( "Rotation column not set" ) );
-    hasRCol = false;
-  }
-  rCol = rColumn.toInt( &rColOk );
-  if ( !rColOk )
-  {
-    QgsDebugMsg( QString( "Rotation column not convertible to integer" ) );
-    hasRCol = false;
-  }
+  // rotation field is optional, but will be used if available, unless data exists
+  int rCol;
+  bool rSuccess = false;
+  double defRot;
+
+  bool hasRCol = ( layerIsRotatable( vlayer, rCol )
+                   && dataDefinedRotation( vlayer, mCurrentLabelPos.featureId, defRot, rSuccess, true ) );
+
+  // get whether to preserve predefined rotation data during label freeze/thaw operations
+  bool preserveRot = preserveRotation();
 
   // edit attribute table
   int fid = labelpos.featureId;
@@ -464,7 +442,7 @@ bool QgsMapToolFreezeLabels::freezeThawLabel( QgsVectorLayer* vlayer,
       QgsDebugMsg( failedWrite );
       return false;
     }
-    if ( hasRCol )
+    if ( hasRCol && !preserveRot )
     {
       if ( !vlayer->changeAttributeValue( fid, rCol, labelR, false ) )
       {
@@ -487,7 +465,7 @@ bool QgsMapToolFreezeLabels::freezeThawLabel( QgsVectorLayer* vlayer,
       QgsDebugMsg( failedWrite );
       return false;
     }
-    if ( hasRCol )
+    if ( hasRCol && !preserveRot )
     {
       if ( !vlayer->changeAttributeValue( fid, rCol, QVariant(), false ) )
       {

src/app/qgsmaptoollabel.cpp

@@ -280,6 +280,19 @@ QFont QgsMapToolLabel::labelFontCurrentFeature()
   return font;
 }
 
+bool QgsMapToolLabel::preserveRotation()
+{
+  bool labelSettingsOk;
+  QgsPalLayerSettings& layerSettings = currentLabelSettings( &labelSettingsOk );
+
+  if ( labelSettingsOk )
+  {
+    return layerSettings.preserveRotation;
+  }
+
+  return true; // default, so there is no accidental data loss
+}
+
 bool QgsMapToolLabel::rotationPoint( QgsPoint& pos, bool ignoreUpsideDown )
 {
   QVector<QgsPoint> cornerPoints = mCurrentLabelPos.cornerPoints;
@@ -429,7 +442,7 @@ bool QgsMapToolLabel::layerIsRotatable( const QgsMapLayer* layer, int& rotationC
   return true;
 }
 
-bool QgsMapToolLabel::dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess )
+bool QgsMapToolLabel::dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess, bool ignoreXY )
 {
   rotationSuccess = false;
   if ( !vlayer )
@@ -452,12 +465,15 @@ bool QgsMapToolLabel::dataDefinedRotation( QgsVectorLayer* vlayer, int featureId
   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 )
+  if ( !ignoreXY )
   {
-    return false;
+    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 );

src/app/qgsmaptoollabel.h

@@ -93,6 +93,9 @@ class QgsMapToolLabel: public QgsMapTool
     /**Returns the font for the current feature (considering default font and data defined properties*/
     QFont labelFontCurrentFeature();
 
+    /**Returns whether to preserve predefined rotation data during label freeze/thaw operations*/
+    bool preserveRotation();
+
     /**Get data defined position of a feature
       @param vlayer vector layer
       @param featureId feature identification integer
@@ -110,9 +113,10 @@ class QgsMapToolLabel: public QgsMapTool
       @param featureId feature identification integer
       @param rotation out: rotation value
       @param rotationSuccess out: false if rotation value is NULL
+      @param ignoreXY ignore that x and y are required to be data-defined
       @return true if data defined rotation is enabled on the layer
       */
-    bool dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess );
+    bool dataDefinedRotation( QgsVectorLayer* vlayer, int featureId, double& rotation, bool& rotationSuccess, bool ignoreXY = false );
 
   private:
     QgsPalLayerSettings mInvalidLabelSettings;

src/app/qgsmaptoolmovelabel.cpp

@@ -154,22 +154,20 @@ void QgsMapToolMoveLabel::canvasReleaseEvent( QMouseEvent * e )
   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
+  // honor whether to preserve preexisting data on freeze
   // must come after setting x and y positions
   int rCol;
-  if ( !mCurrentLabelPos.isDiagram && !mCurrentLabelPos.isFrozen
+  if ( !mCurrentLabelPos.isDiagram
+       && !mCurrentLabelPos.isFrozen
+       && !preserveRotation()
        && 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 );
-      }
+      double labelRot = mCurrentLabelPos.rotation * 180 / M_PI;
+      vlayer->changeAttributeValue( mCurrentLabelPos.featureId, rCol, labelRot, false );
     }
   }
   vlayer->endEditCommand();

src/core/qgspallabeling.cpp

@@ -163,6 +163,7 @@ QgsPalLayerSettings::QgsPalLayerSettings()
   fontSizeInMapUnits = false;
   distInMapUnits = false;
   wrapChar = "";
+  preserveRotation = true;
 }
 
 QgsPalLayerSettings::QgsPalLayerSettings( const QgsPalLayerSettings& s )
@@ -194,6 +195,7 @@ QgsPalLayerSettings::QgsPalLayerSettings( const QgsPalLayerSettings& s )
   fontSizeInMapUnits = s.fontSizeInMapUnits;
   distInMapUnits = s.distInMapUnits;
   wrapChar = s.wrapChar;
+  preserveRotation = s.preserveRotation;
 
   dataDefinedProperties = s.dataDefinedProperties;
   fontMetrics = NULL;
@@ -337,6 +339,7 @@ void QgsPalLayerSettings::readFromLayer( QgsVectorLayer* layer )
   fontSizeInMapUnits = layer->customProperty( "labeling/fontSizeInMapUnits" ).toBool();
   distInMapUnits = layer->customProperty( "labeling/distInMapUnits" ).toBool();
   wrapChar = layer->customProperty( "labeling/wrapChar" ).toString();
+  preserveRotation = layer->customProperty( "labeling/preserveRotation", QVariant( true ) ).toBool();
   _readDataDefinedPropertyMap( layer, dataDefinedProperties );
 }
 
@@ -376,6 +379,7 @@ void QgsPalLayerSettings::writeToLayer( QgsVectorLayer* layer )
   layer->setCustomProperty( "labeling/fontSizeInMapUnits", fontSizeInMapUnits );
   layer->setCustomProperty( "labeling/distInMapUnits", distInMapUnits );
   layer->setCustomProperty( "labeling/wrapChar", wrapChar );
+  layer->setCustomProperty( "labeling/preserveRotation", preserveRotation );
   _writeDataDefinedPropertyMap( layer, dataDefinedProperties );
 }
 

src/core/qgspallabeling.h

@@ -161,6 +161,8 @@ class CORE_EXPORT QgsPalLayerSettings
     /**Stores field indices for data defined layer properties*/
     QMap< DataDefinedProperties, int > dataDefinedProperties;
 
+    bool preserveRotation; // preserve predefined rotation data during label freeze/thaw operations
+
     /**Calculates pixel size (considering output size should be in pixel or map units, scale factors and oversampling)
      @param size size to convert
      @param c rendercontext

src/ui/qgslabelingguibase.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>703</width>
-    <height>469</height>
+    <height>482</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -463,8 +463,8 @@
            <rect>
             <x>0</x>
             <y>0</y>
-            <width>647</width>
-            <height>435</height>
+            <width>621</width>
+            <height>479</height>
            </rect>
           </property>
           <layout class="QGridLayout" name="gridLayout_13">
@@ -924,9 +924,9 @@
           <property name="geometry">
            <rect>
             <x>0</x>
-            <y>0</y>
-            <width>647</width>
-            <height>507</height>
+            <y>-289</y>
+            <width>618</width>
+            <height>599</height>
            </rect>
           </property>
           <layout class="QGridLayout" name="gridLayout_11">
@@ -1050,6 +1050,26 @@
               <string>Position</string>
              </property>
              <layout class="QGridLayout" name="gridLayout_4">
+              <item row="5" column="1">
+               <widget class="QComboBox" name="mRotationComboBox"/>
+              </item>
+              <item row="5" column="0">
+               <widget class="QLabel" name="mRotationLabel">
+                <property name="text">
+                 <string>Rotation</string>
+                </property>
+               </widget>
+              </item>
+              <item row="0" column="1">
+               <widget class="QComboBox" name="mLabelDistanceComboBox"/>
+              </item>
+              <item row="0" column="0">
+               <widget class="QLabel" name="mLabelDistanceLabel">
+                <property name="text">
+                 <string>Label distance</string>
+                </property>
+               </widget>
+              </item>
               <item row="1" column="0">
                <widget class="QLabel" name="mXCoordinateLabel">
                 <property name="text">
@@ -1090,23 +1110,19 @@
               <item row="4" column="1">
                <widget class="QComboBox" name="mVerticalAlignmentComboBox"/>
               </item>
-              <item row="5" column="1">
-               <widget class="QComboBox" name="mRotationComboBox"/>
-              </item>
-              <item row="5" column="0">
-               <widget class="QLabel" name="mRotationLabel">
-                <property name="text">
-                 <string>Rotation</string>
+              <item row="6" column="0" colspan="2">
+               <widget class="QCheckBox" name="chkPreserveRotation">
+                <property name="toolTip">
+                 <string>Uncheck to write labeling engine derived rotation on freeze and NULL on thaw</string>
+                </property>
+                <property name="styleSheet">
+                 <string notr="true">margin-left: 12px;</string>
                 </property>
-               </widget>
-              </item>
-              <item row="0" column="1">
-               <widget class="QComboBox" name="mLabelDistanceComboBox"/>
-              </item>
-              <item row="0" column="0">
-               <widget class="QLabel" name="mLabelDistanceLabel">
                 <property name="text">
-                 <string>Label distance</string>
+                 <string>Preserve existing rotation values during label freeze/thaw operations</string>
+                </property>
+                <property name="checked">
+                 <bool>true</bool>
                 </property>
                </widget>
               </item>