fix for legend crash when clicking 'show files' on empty legend

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@5039 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/legend/qgslegend.cpp

@@ -1410,102 +1410,6 @@ void QgsLegend::handleItemChange(QTreeWidgetItem* item, int row)
 	  mStateOfCheckBoxes[item] = item->checkState(0);
 	}
     }
-#if 0
-  QgsLegendGroup* lg = dynamic_cast<QgsLegendGroup*>(item);
-  if(lg)
-    {
-#ifdef QGISDEBUG
-      qWarning("detected legend group in QgsLegend::handleItemChange");
-#endif
-      std::map<QTreeWidgetItem*, Qt::CheckState>::iterator it = mStateOfCheckBoxes.find(item);
-      if(it != mStateOfCheckBoxes.end())
-	{
-	  if(it->second != item->checkState(0)) //the checkState has changed
-	    {
-	      bool checked = (item->checkState(0) == Qt::Checked);
-	      
-	    }
-	}
-      return;
-    }
-
-  QgsLegendLayerFile* llf = dynamic_cast<QgsLegendLayerFile*>(item);
-  if(llf)
-    {
-#ifdef QGISDEBUG
-      qWarning("item is a QgsLegendLayerFile*");
-#endif
-      std::map<QTreeWidgetItem*, Qt::CheckState>::iterator it = mStateOfCheckBoxes.find(item);
-      if(it != mStateOfCheckBoxes.end())
-	{
-	  if(it->second != item->checkState(0)) //the checkState has changed
-	    {
-	      QgsMapLayer* theLayer = llf->layer();
-	      if(theLayer)
-		{
-		  bool checked = (item->checkState(0) == Qt::Checked); 
-		  theLayer->setVisible(checked);
-		  //check, how the checkbox of the legendlayer needs to be updated
-		  QgsLegendLayer* ll = dynamic_cast<QgsLegendLayer*>(item->parent()->parent());
-		  std::list<QgsLegendLayerFile*> llfiles = ll->legendLayerFiles();
-		  std::list<QgsLegendLayerFile*>::iterator iter = llfiles.begin();
-		  Qt::CheckState theState = (*iter)->checkState(0);
-		  for(; iter != llfiles.end(); ++iter)
-		    {
-		      if(theState != (*iter)->checkState(0))
-			{
-			  theState = Qt::PartiallyChecked;
-			  break;
-			}
-		    }
-		  //and update the checkbox of the legendlayer if necessary
-		  if(theState != ll->checkState(0));
-		  {
-		    blockSignals(true);
-		    ll->setCheckState(0, theState);
-		    mStateOfCheckBoxes[ll] = theState;
-		    blockSignals(false);
-		  }
-		}
-	      mStateOfCheckBoxes[item] = item->checkState(0);
-	    }
-	}
-      return;
-    }
-
-  QgsLegendLayer* ll = dynamic_cast<QgsLegendLayer*>(item);
-  if(ll)
-    {
-#ifdef QGISDEBUG
-      qWarning("item is a QgsLegendLayer");
-#endif
-      std::map<QTreeWidgetItem*, Qt::CheckState>::iterator it = mStateOfCheckBoxes.find(item);
-      if(it != mStateOfCheckBoxes.end())
-	{
-	  if(it->second != item->checkState(0)) //the checkState has changed
-	    {
-	      bool checked = (item->checkState(0) == Qt::Checked); 
-	      std::list<QgsLegendLayerFile*> llflist = ll->legendLayerFiles();
-	      mMapCanvas->setRenderFlag(false);
-	      //go through all the legendlayerfiles and set their checkState
-	      for(std::list<QgsLegendLayerFile*>::iterator it = llflist.begin(); it != llflist.end(); ++it)
-		{
-		  if(checked)
-		    {
-		      (*it)->setCheckState(0, Qt::Checked);
-		      mStateOfCheckBoxes[(*it)] = Qt::Checked;
-		    }
-		  else
-		    {
-		      (*it)->setCheckState(0, Qt::Unchecked);
-		      mStateOfCheckBoxes[(*it)] = Qt::Unchecked;
-		    }
-		}
-	      mMapCanvas->setRenderFlag(true);
-	    }
-	}
-    }
-#endif //0
 }
 
 void QgsLegend::openEditor()
@@ -1536,6 +1440,12 @@ void QgsLegend::showLegendLayerFileGroups()
 
   QgsLegendLayerFileGroup* theFileGroup = 0;
   QTreeWidgetItem* theItem = firstItem();
+  
+  if(!theItem)
+    {
+      return;
+    }
+
   do
     {
       theFileGroup = dynamic_cast<QgsLegendLayerFileGroup*>(theItem);