fixed crash on non grass layer

git-svn-id: http://svn.osgeo.org/qgis/trunk@5096 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/plugins/grass/qgsgrassedit.cpp

@@ -135,18 +135,27 @@ QgsGrassEdit::QgsGrassEdit ( QgisApp *qgisApp, QgisIface *iface,
   // At moment QgisIface::activeLayer() does not work
   QgsMapLayer *layer = (QgsMapLayer *) mIface->activeLayer();
 
-  if ( !layer ) {
-    std::cerr << "No layer is selected." << std::endl;
-    QMessageBox::warning( 0, "Warning", "No layer is selected." );
-    return;
-  }
+  if ( !isEditable(layer) ) return;
+
+  //TODO dynamic_cast ?
+  QgsVectorLayer *vector = (QgsVectorLayer*)layer;
+
+  //TODO dynamic_cast ?
+  mProvider = (QgsGrassProvider *) vector->getDataProvider();
+
+  init();
+
+}
+
+bool QgsGrassEdit::isEditable ( QgsMapLayer *layer )
+{
+  if ( !layer ) return false;
 
   std::cerr << "layer name: " << layer->name().toLocal8Bit().data() << std::endl;
 
   if ( layer->type() != QgsMapLayer::VECTOR ) {
     std::cerr << "The selected layer is not vector." << std::endl;
-    QMessageBox::warning( 0, "Warning", "The selected layer is not vector." );
-    return;
+    return false;
   }
 
   //TODO dynamic_cast ?
@@ -155,17 +164,11 @@ QgsGrassEdit::QgsGrassEdit ( QgisApp *qgisApp, QgisIface *iface,
   std::cerr << "Vector layer type: " << vector->providerType().toLocal8Bit().data() << std::endl;
 
   if ( vector->providerType() != "grass" ) {
-    QMessageBox::warning( 0, "Warning", "The selected vector is not in GRASS format." );
-    return;
+    std::cerr << "The selected layer is not GRASS." << std::endl;
+    return false;
   }
-
-  std::cerr << "Vector layer type: " << vector->providerType().toLocal8Bit().data() << std::endl;
-
-  //TODO dynamic_cast ?
-  mProvider = (QgsGrassProvider *) vector->getDataProvider();
-
-  init();
 
+  return true;
 }
 
 QgsGrassEdit::QgsGrassEdit ( QgisApp *qgisApp, QgisIface *iface, 
@@ -897,7 +900,7 @@ QgsGrassEdit::~QgsGrassEdit()
   std::cerr << "QgsGrassEdit::~QgsGrassEdit()" << std::endl;
 #endif
 
-  if (mCanvasEdit) {
+  if ( mValid && mCanvasEdit) {
     eraseDynamic();
     mRubberBandLine->hide();
     mRubberBandIcon->hide();
@@ -965,7 +968,7 @@ void QgsGrassEdit::closeEdit(void)
                                       QgsGrass::getDefaultLocation(),
 				      mapset, map );
   }
-
+  emit finished();
   delete this; 
 }
 

src/plugins/grass/qgsgrassedit.h

@@ -202,6 +202,11 @@ public slots:
     // ! Close event
     void closeEvent(QCloseEvent *e);
 
+    static bool isEditable ( QgsMapLayer *layer );
+
+signals:
+    void finished(); 
+
 private:
     //! Editing is already running
     static bool mRunning;

src/plugins/grass/qgsgrassplugin.cpp

@@ -222,6 +222,9 @@ void QgsGrassPlugin::initGui()
   // Connect display region
   connect( mCanvas, SIGNAL(renderComplete(QPainter *)), this, SLOT(postRender(QPainter *)));
 
+
+  connect ( mCanvas, SIGNAL(layersChanged()), this, SLOT(setEditAction()) );
+
   // Init Region symbology
   mRegionPen.setColor( QColor ( settings.readEntry ("/GRASS/region/color", "#ff0000" ) ) );
   mRegionPen.setWidth( settings.readNumEntry ("/GRASS/region/width", 0 ) );
@@ -436,16 +439,40 @@ void QgsGrassPlugin::edit()
     return;
   }
 
+  mEditAction->setEnabled(false);
   QgsGrassEdit *ed = new QgsGrassEdit( mQgis, qGisInterface, mQgis, Qt::WType_Dialog );
 
   if ( ed->isValid() ) {
     ed->show();
     mCanvas->refresh();
+    connect(ed, SIGNAL(finished()), this, SLOT(setEditAction()));
   } else {
     delete ed;
+    mEditAction->setEnabled(true);
   }
 }
 
+void QgsGrassPlugin::setEditAction()
+{
+#ifdef QGISDEBUG
+    std::cout << "QgsGrassPlugin::setEditAction()" << std::endl;
+#endif
+
+    QgsMapLayer *layer = (QgsMapLayer *) qGisInterface->activeLayer();
+
+    if ( QgsGrassEdit::isEditable(layer) )
+    {
+        mEditAction->setEnabled(true);
+    }
+    else
+    {
+        mEditAction->setEnabled(false);
+    }
+
+    // TODO connect to currentItemChanged()? and disable this:
+    mEditAction->setEnabled(true);
+}
+
 void QgsGrassPlugin::newVector()
 {
 #ifdef QGISDEBUG

src/plugins/grass/qgsgrassplugin.h

@@ -110,7 +110,8 @@ public slots:
   void newProject();
   //! Save mapset to project
   void saveMapset();
-
+  //! Set edit action
+  void setEditAction();
 private:
   //! Name of the plugin
   QString pluginNameQString;