Remove merge conflict

src/app/qgsoptions.cpp

@@ -77,6 +77,8 @@ QgsOptions::QgsOptions( QWidget *parent, Qt::WFlags fl ) :
 
   connect( chkUseStandardDeviation, SIGNAL( stateChanged( int ) ), this, SLOT( toggleStandardDeviation( int ) ) );
 
+  connect( chkEnableBackbuffer, SIGNAL( stateChanged( int ) ), this, SLOT( toggleEnableBackbuffer( int ) ) );
+
   connect( this, SIGNAL( accepted() ), this, SLOT( saveOptions() ) );
 
   QStringList styles = QStyleFactory::keys();
@@ -227,6 +229,10 @@ QgsOptions::QgsOptions( QWidget *parent, Qt::WFlags fl ) :
   if ( index == -1 ) index = 1;
   cmbScanZipInBrowser->setCurrentIndex( index );
 
+  // Set the enable backbuffer state
+  chkEnableBackbuffer->setChecked( settings.value( "/Map/enableBackbuffer" ).toBool() );
+  toggleEnableBackbuffer( chkEnableBackbuffer->checkState() );
+
   // set the display update threshold
   spinBoxUpdateThreshold->setValue( settings.value( "/Map/updateThreshold" ).toInt() );
   //set the default projection behaviour radio buttongs
@@ -720,6 +726,20 @@ void QgsOptions::toggleStandardDeviation( int state )
   }
 }
 
+void QgsOptions::toggleEnableBackbuffer( int state )
+{
+  if ( Qt::Checked == state )
+  {
+    labelUpdateThreshold->setEnabled( false );
+    spinBoxUpdateThreshold->setEnabled( false );
+  }
+  else
+  {
+    labelUpdateThreshold->setEnabled( true );
+    spinBoxUpdateThreshold->setEnabled( true );
+  }
+}
+
 QString QgsOptions::theme()
 {
   // returns the current theme (as selected in the cmbTheme combo box)
@@ -891,6 +911,7 @@ void QgsOptions::saveOptions()
   settings.setValue( "/Raster/cumulativeCutLower", mRasterCumulativeCutLowerDoubleSpinBox->value() / 100.0 );
   settings.setValue( "/Raster/cumulativeCutUpper", mRasterCumulativeCutUpperDoubleSpinBox->value() / 100.0 );
 
+  settings.setValue( "/Map/enableBackbuffer", chkEnableBackbuffer->isChecked() );
   settings.setValue( "/Map/updateThreshold", spinBoxUpdateThreshold->value() );
   //check behaviour so default projection when new layer is added with no
   //projection defined...

src/app/qgsoptions.h

@@ -74,6 +74,10 @@ class QgsOptions : public QDialog, private Ui::QgsOptionsBase
 
     void toggleStandardDeviation( int );
 
+    //! Slot to change backbuffering. This is handled when the user changes
+    // the value of the checkbox
+    void toggleEnableBackbuffer( int );
+
     /**
      * Return the desired state of newly added layers. If a layer
      * is to be drawn when added to the map, this function returns

src/core/qgsvectorlayer.cpp

@@ -733,21 +733,22 @@ void QgsVectorLayer::drawRendererV2( QgsRenderContext& rendererContext, bool lab
       {
         break;
       }
-#if 0 // MK: disable this totally as it breaks QT painting engine (can result in recursive repaint)
 #ifndef Q_WS_MAC //MH: disable this on Mac for now to avoid problems with resizing
-      if ( mUpdateThreshold > 0 && 0 == featureCount % mUpdateThreshold )
+      if ( !mEnableBackbuffer ) // do not handle events, as we're already inside a paint event
       {
-        emit screenUpdateRequested();
-        // emit drawingProgress( featureCount, totalFeatures );
-        qApp->processEvents();
-      }
-      else if ( featureCount % 1000 == 0 )
-      {
-        // emit drawingProgress( featureCount, totalFeatures );
-        qApp->processEvents();
+        if ( mUpdateThreshold > 0 && 0 == featureCount % mUpdateThreshold )
+        {
+          emit screenUpdateRequested();
+          // emit drawingProgress( featureCount, totalFeatures );
+          qApp->processEvents();
+        }
+        else if ( featureCount % 1000 == 0 )
+        {
+          // emit drawingProgress( featureCount, totalFeatures );
+          qApp->processEvents();
+        }
       }
 #endif //Q_WS_MAC
-#endif
 
       bool sel = mSelectedFeatureIds.contains( fet.id() );
       bool drawMarker = ( mEditable && ( !vertexMarkerOnlyForSelection || sel ) );
@@ -956,6 +957,7 @@ bool QgsVectorLayer::draw( QgsRenderContext& rendererContext )
   //set update threshold before each draw to make sure the current setting is picked up
   QSettings settings;
   mUpdateThreshold = settings.value( "Map/updateThreshold", 0 ).toInt();
+  mEnableBackbuffer = settings.value( "/Map/enableBackbuffer", 1 ).toBool();
 
   if ( mUsingRendererV2 )
   {

src/core/qgsvectorlayer.h

@@ -866,6 +866,12 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      */
     int mUpdateThreshold;
 
+    /** Enables backbuffering for the map window. This improves graphics performance,
+     *  but the possibility to cancel rendering and incremental feature drawing will be lost.
+     *
+     */
+    bool mEnableBackbuffer;
+
     /** Pointer to data provider derived from the abastract base class QgsDataProvider */
     QgsVectorDataProvider *mDataProvider;
 

src/gui/qgsmapcanvas.cpp

@@ -84,15 +84,16 @@ QgsMapCanvas::QgsMapCanvas( QWidget * parent, const char *name )
     , mAntiAliasing( false )
 {
   setObjectName( name );
-
+
+  QSettings settings;
+  bool enableBackbuffer = settings.value( "/Map/enableBackbuffer", 1 ).toBool();
   //disable the update that leads to the resize crash
-  if ( viewport() )
+  if ( viewport() && !enableBackbuffer )
   {
 #ifndef ANDROID
     viewport()->setAttribute( Qt::WA_PaintOnScreen, true );
 #endif //ANDROID
   }
-#endif
 
   mScene = new QGraphicsScene();
   setScene( mScene );

src/ui/qgsoptionsbase.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>800</width>
-    <height>526</height>
+    <width>1107</width>
+    <height>843</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -33,7 +33,7 @@
    <item row="2" column="0">
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
-      <number>0</number>
+      <number>3</number>
      </property>
      <property name="iconSize">
       <size>
@@ -953,46 +953,63 @@
               <string>Rendering behavior</string>
              </property>
              <layout class="QGridLayout">
-              <item row="0" column="0">
+              <item row="1" column="0">
                <widget class="QCheckBox" name="chkAddedVisibility">
                 <property name="text">
                  <string>By default new la&amp;yers added to the map should be displayed</string>
                 </property>
                </widget>
               </item>
-              <item row="2" column="0" colspan="2">
+              <item row="4" column="0" colspan="3">
                <widget class="QLabel" name="textLabel3">
                 <property name="text">
                  <string>&lt;b&gt;Note:&lt;/b&gt; Use zero to prevent display updates until all features have been rendered</string>
                 </property>
                </widget>
               </item>
-              <item row="3" column="0" colspan="2">
+              <item row="5" column="0" colspan="3">
                <widget class="QCheckBox" name="chkUseRenderCaching">
                 <property name="text">
                  <string>Use render caching where possible to speed up redraws</string>
                 </property>
                </widget>
               </item>
-              <item row="1" column="0">
-               <widget class="QLabel" name="textLabel1_6">
+              <item row="2" column="0">
+               <widget class="QCheckBox" name="chkEnableBackbuffer">
                 <property name="text">
-                 <string>Number of features to draw before updating the display</string>
+                 <string>Enable back buffer (Better graphics performance at the cost loosing the possibiliti to cancel rendering and incremental feature drawing)</string>
                 </property>
                </widget>
               </item>
-              <item row="1" column="1">
-               <widget class="QSpinBox" name="spinBoxUpdateThreshold">
-                <property name="toolTip">
-                 <string>Map display will be updated (drawn) after this many features have been read from the data source</string>
-                </property>
-                <property name="maximum">
-                 <number>1000000</number>
-                </property>
-                <property name="value">
-                 <number>1000</number>
-                </property>
-               </widget>
+              <item row="3" column="0">
+               <layout class="QHBoxLayout" name="horizontalLayout_16">
+                <item>
+                 <widget class="QLabel" name="labelUpdateThreshold">
+                  <property name="text">
+                   <string>Number of features to draw before updating the display</string>
+                  </property>
+                 </widget>
+                </item>
+                <item>
+                 <widget class="QSpinBox" name="spinBoxUpdateThreshold">
+                  <property name="maximumSize">
+                   <size>
+                    <width>200</width>
+                    <height>16777215</height>
+                   </size>
+                  </property>
+                  <property name="toolTip">
+                   <string>Map display will be updated (drawn) after this many features have been read from the data source</string>
+                  </property>
+                  <property name="maximum">
+                   <number>1000000</number>
+                  </property>
+                  <property name="value">
+                   <number>1000</number>
+                  </property>
+                 </widget>
+                </item>
+               </layout>
               </item>
              </layout>
             </widget>
@@ -2693,7 +2710,6 @@
   <tabstop>buttonBox</tabstop>
   <tabstop>scrollArea_3</tabstop>
   <tabstop>chkAddedVisibility</tabstop>
-  <tabstop>spinBoxUpdateThreshold</tabstop>
   <tabstop>chkUseRenderCaching</tabstop>
   <tabstop>chkAntiAliasing</tabstop>
   <tabstop>chkUseQPixmap</tabstop>