Make sure we have a color ramp when creating categories/ranges.

git-svn-id: http://svn.osgeo.org/qgis/trunk@12160 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/gui/symbology-ng/qgscategorizedsymbolrendererv2widget.cpp

@@ -12,6 +12,7 @@
 #include "qgsvectorlayer.h"
 #include "qgsvectordataprovider.h" // for uniqueValues
 
+#include <QMessageBox>
 #include <QStandardItemModel>
 #include <QStandardItem>
 
@@ -256,6 +257,15 @@ void QgsCategorizedSymbolRendererV2Widget::addCategories()
   else
     ramp = mStyle->colorRamp( rampName );
 
+  if ( ramp == NULL )
+  {
+    if ( cboCategorizedColorRamp->count() == 0 )
+      QMessageBox::critical( this, tr("Error"), tr("There are no available color ramps. You can add them in Style Manager.") );
+    else
+      QMessageBox::critical( this, tr("Error"), tr("The selected color ramp is not available.") );
+    return;
+  }
+
   QgsCategoryList cats;
   _createCategories( cats, unique_vals, mCategorizedSymbol, ramp );
 

src/gui/symbology-ng/qgsgraduatedsymbolrendererv2widget.cpp

@@ -11,6 +11,7 @@
 
 #include "qgssymbolv2selectordialog.h"
 
+#include <QMessageBox>
 #include <QStandardItemModel>
 #include <QStandardItem>
 
@@ -157,6 +158,15 @@ void QgsGraduatedSymbolRendererV2Widget::classifyGraduated()
   else
     ramp = mStyle->colorRamp( rampName );
 
+  if ( ramp == NULL )
+  {
+    if ( cboGraduatedColorRamp->count() == 0 )
+      QMessageBox::critical( this, tr("Error"), tr("There are no available color ramps. You can add them in Style Manager.") );
+    else
+      QMessageBox::critical( this, tr("Error"), tr("The selected color ramp is not available.") );
+    return;
+  }
+
   QgsGraduatedSymbolRendererV2::Mode mode;
   if (cboGraduatedMode->currentIndex() == 0)
     mode = QgsGraduatedSymbolRendererV2::EqualInterval;