Add ELSE to rule based renderer

Author: NathanW2

src/core/symbology-ng/qgsrulebasedrendererv2.cpp

@@ -29,11 +29,11 @@
 
 
 
-QgsRuleBasedRendererV2::Rule::Rule( QgsSymbolV2* symbol, int scaleMinDenom, int scaleMaxDenom, QString filterExp, QString label, QString description )
+QgsRuleBasedRendererV2::Rule::Rule(QgsSymbolV2* symbol, int scaleMinDenom, int scaleMaxDenom, QString filterExp, QString label, QString description , bool elseRule)
     : mParent( NULL ), mSymbol( symbol ),
     mScaleMinDenom( scaleMinDenom ), mScaleMaxDenom( scaleMaxDenom ),
     mFilterExp( filterExp ), mLabel( label ), mDescription( description ),
-    mFilter( NULL )
+    mFilter( NULL ), mElseRule( elseRule )
 {
   initFilter();
 }
@@ -48,7 +48,12 @@ QgsRuleBasedRendererV2::Rule::~Rule()
 
 void QgsRuleBasedRendererV2::Rule::initFilter()
 {
-  if ( !mFilterExp.isEmpty() )
+  if ( mElseRule || mFilterExp.compare("ELSE", Qt::CaseInsensitive) == 0 )
+  {
+     mElseRule = true;
+     mFilter = NULL;
+  }
+  else if ( !mFilterExp.isEmpty() )
   {
     delete mFilter;
     mFilter = new QgsExpression( mFilterExp );
@@ -132,7 +137,7 @@ QgsLegendSymbolList QgsRuleBasedRendererV2::Rule::legendSymbolItems()
 
 bool QgsRuleBasedRendererV2::Rule::isFilterOK( QgsFeature& f ) const
 {
-  if ( ! mFilter )
+  if ( ! mFilter || mElseRule )
     return true;
 
   QVariant res = mFilter->evaluate( &f );
@@ -373,12 +378,31 @@ bool QgsRuleBasedRendererV2::Rule::renderFeature( QgsRuleBasedRendererV2::Featur
     rendered = true;
   }
 
+  QList<Rule*> elserules;
+  bool willrendersomething = false;
+
   // process children
   for ( QList<Rule*>::iterator it = mActiveChildren.begin(); it != mActiveChildren.end(); ++it )
   {
     Rule* rule = *it;
-    rendered |= rule->renderFeature( featToRender, context, renderQueue );
+    if ( rule->isElse())
+    {
+      elserules << rule;
+      continue;
+    }
+    willrendersomething |= rule->renderFeature( featToRender, context, renderQueue );
+    rendered |= willrendersomething;
   }
+
+  // If none of the rules passed then we jump into the else rules and process them.
+  if ( !willrendersomething )
+  {
+      foreach(Rule* rule, elserules)
+      {
+          rendered |= rule->renderFeature( featToRender, context, renderQueue );
+      }
+  }
+
   return rendered;
 }
 

src/core/symbology-ng/qgsrulebasedrendererv2.h

@@ -86,7 +86,7 @@ class CORE_EXPORT QgsRuleBasedRendererV2 : public QgsFeatureRendererV2
       public:
         //! Constructor takes ownership of the symbol
         Rule( QgsSymbolV2* symbol, int scaleMinDenom = 0, int scaleMaxDenom = 0, QString filterExp = QString(),
-              QString label = QString(), QString description = QString() );
+              QString label = QString(), QString description = QString(), bool elseRule = false );
         //Rule( const Rule& other );
         ~Rule();
         QString dump( int offset = 0 ) const;
@@ -164,6 +164,9 @@ class CORE_EXPORT QgsRuleBasedRendererV2 : public QgsFeatureRendererV2
         //! take child rule out, set parent as null
         Rule* takeChildAt( int i ) { Rule* rule = mChildren.takeAt( i ); rule->mParent = NULL; return rule; }
 
+        void setIsElse( bool iselse ) { mElseRule = iselse; }
+        bool isElse() { return mElseRule; }
+
       protected:
         void initFilter();
 

src/gui/symbology-ng/qgsrulebasedrendererv2widget.cpp

@@ -636,7 +636,15 @@ QVariant QgsRuleBasedRendererV2Model::data( const QModelIndex &index, int role )
     switch ( index.column() )
     {
       case 0: return rule->label();
-      case 1: return rule->filterExpression().isEmpty() ? tr( "(no filter)" ) : rule->filterExpression();
+      case 1:
+        if ( rule->isElse() )
+        {
+            return "ELSE";
+        }
+        else
+        {
+            return rule->filterExpression().isEmpty() ? tr( "(no filter)" ) : rule->filterExpression();
+        }
       case 2: return rule->dependsOnScale() ? _formatScale( rule->scaleMinDenom() ) : QVariant();
       case 3: return rule->dependsOnScale() ? _formatScale( rule->scaleMaxDenom() ) : QVariant();
       case 4:
@@ -683,6 +691,16 @@ QVariant QgsRuleBasedRendererV2Model::data( const QModelIndex &index, int role )
   {
     return ( index.column() == 2 || index.column() == 3 ) ? Qt::AlignRight : Qt::AlignLeft;
   }
+  else if (role == Qt::FontRole && index.column() == 1)
+  {
+      if ( rule->isElse() )
+      {
+          QFont italicFont;
+          italicFont.setItalic(true);
+          return italicFont;
+      }
+      return QVariant();
+  }
   else if ( role == Qt::EditRole )
   {
     switch ( index.column() )