[effects] Initially populate effects with a default list of effects

Default list shows a number of common effects like drop shadows,
but they are disabled. This allows users to easily enable them
just by checking them in the list. End result is a more user
friendly and familiar effects interface.

Advanced users can still reorder, add/remove effects as before.

Author: nyalldawson

python/core/effects/qgspainteffectregistry.sip

@@ -102,6 +102,13 @@ class QgsPaintEffectRegistry
      */
     QStringList effects() const;
 
+    /** Returns a new effect stack consisting of a sensible selection of default
+     * effects. All effects except the standard draw source effect are disabled,
+     * but are included so that they can be easily drawn just by enabling the effect.
+     * @returns default effects stack
+     */
+    static QgsPaintEffect* defaultStack() /Factory/;
+
   protected:
     QgsPaintEffectRegistry();
     ~QgsPaintEffectRegistry();

src/core/effects/qgspainteffectregistry.cpp

@@ -119,3 +119,22 @@ QStringList QgsPaintEffectRegistry::effects() const
   }
   return lst;
 }
+
+QgsPaintEffect* QgsPaintEffectRegistry::defaultStack()
+{
+  QgsEffectStack* stack = new QgsEffectStack();
+  QgsDropShadowEffect* dropShadow = new QgsDropShadowEffect();
+  dropShadow->setEnabled( false );
+  stack->appendEffect( dropShadow );
+  QgsOuterGlowEffect* outerGlow = new QgsOuterGlowEffect();
+  outerGlow->setEnabled( false );
+  stack->appendEffect( outerGlow );
+  stack->appendEffect( new QgsDrawSourceEffect() );
+  QgsInnerShadowEffect* innerShadow = new QgsInnerShadowEffect();
+  innerShadow->setEnabled( false );
+  stack->appendEffect( innerShadow );
+  QgsInnerGlowEffect* innerGlow = new QgsInnerGlowEffect();
+  innerGlow->setEnabled( false );
+  stack->appendEffect( innerGlow );
+  return stack;
+}

src/core/effects/qgspainteffectregistry.h

@@ -189,6 +189,13 @@ class CORE_EXPORT QgsPaintEffectRegistry
      */
     QStringList effects() const;
 
+    /** Returns a new effect stack consisting of a sensible selection of default
+     * effects. All effects except the standard draw source effect are disabled,
+     * but are included so that they can be easily drawn just by enabling the effect.
+     * @returns default effects stack
+     */
+    static QgsPaintEffect* defaultStack();
+
   protected:
     QgsPaintEffectRegistry();
     ~QgsPaintEffectRegistry();

src/core/symbology-ng/qgsrendererv2.cpp

@@ -210,9 +210,7 @@ QgsFeatureRendererV2::QgsFeatureRendererV2( QString type )
     , mCurrentVertexMarkerSize( 3 )
     , mPaintEffect( 0 )
 {
-  QgsEffectStack* stack = new QgsEffectStack();
-  stack->appendEffect( new QgsDrawSourceEffect() );
-  mPaintEffect = stack;
+  mPaintEffect = QgsPaintEffectRegistry::defaultStack();
   mPaintEffect->setEnabled( false );
 }
 

src/core/symbology-ng/qgssymbollayerv2.cpp

@@ -22,6 +22,7 @@
 #include "qgsgeometrysimplifier.h"
 #include "qgspainteffect.h"
 #include "qgseffectstack.h"
+#include "qgspainteffectregistry.h"
 #include "qgsdatadefined.h"
 
 #include <QSize>
@@ -291,9 +292,7 @@ QgsSymbolLayerV2::QgsSymbolLayerV2( QgsSymbolV2::SymbolType type, bool locked )
     , mRenderingPass( 0 )
     , mPaintEffect( 0 )
 {
-  QgsEffectStack* stack = new QgsEffectStack();
-  stack->appendEffect( new QgsDrawSourceEffect() );
-  mPaintEffect = stack;
+  mPaintEffect = QgsPaintEffectRegistry::defaultStack();
   mPaintEffect->setEnabled( false );
 }