Show provider errors more prominently

Author: m-kuhn

python/core/qgsvectordataprovider.sip

@@ -352,6 +352,10 @@ class QgsVectorDataProvider : QgsDataProvider
      */
     virtual QSet<QString> layerDependencies() const;
 
+  signals:
+    /** Signals an error in this provider */
+    void raiseError( const QString& msg );
+
   protected:
     void clearMinMaxCache();
     void fillMinMaxCache();

python/core/qgsvectorlayer.sip

@@ -1786,6 +1786,10 @@ class QgsVectorLayer : QgsMapLayer
      */
     void writeCustomSymbology( QDomElement& element, QDomDocument& doc, QString& errorMessage ) const;
 
+    /**
+     * Signals an error related to this vector layer.
+     */
+    void raiseError( const QString& msg );
 
   protected:
     /** Set the extent */

src/app/qgisapp.cpp

@@ -9574,6 +9574,8 @@ void QgisApp::layersWereAdded( const QList<QgsMapLayer *>& theLayers )
         }
       }
 
+      connect( vlayer, SIGNAL( raiseError( QString ) ), this, SLOT( onLayerError( QString ) ) );
+
       provider = vProvider;
     }
 
@@ -11225,6 +11227,15 @@ void QgisApp::showStatisticsDockWidget()
   mStatisticalSummaryDockWidget->raise();
 }
 
+void QgisApp::onLayerError( const QString& msg )
+{
+  QgsVectorLayer* layer = qobject_cast<QgsVectorLayer*>( sender() );
+
+  Q_ASSERT( layer );
+
+  mInfoBar->pushCritical( tr( "Layer %1" ).arg( layer->name() ), msg );
+}
+
 
 #ifdef HAVE_TOUCH
 bool QgisApp::gestureEvent( QGestureEvent *event )

src/app/qgisapp.h

@@ -1278,6 +1278,9 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
      */
     void showStatisticsDockWidget();
 
+    /** Pushes a layer error to the message bar */
+    void onLayerError( const QString& msg );
+
   signals:
     /** Emitted when a key is pressed and we want non widget sublasses to be able
       to pick up on this (e.g. maplayer) */

src/core/qgsvectordataprovider.cpp

@@ -559,6 +559,7 @@ void QgsVectorDataProvider::pushError( const QString& msg )
 {
   QgsDebugMsg( msg );
   mErrors << msg;
+  emit raiseError( msg );
 }
 
 QSet<QString> QgsVectorDataProvider::layerDependencies() const

src/core/qgsvectordataprovider.h

@@ -404,6 +404,10 @@ class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider
      */
     virtual QSet<QString> layerDependencies() const;
 
+  signals:
+    /** Signals an error in this provider */
+    void raiseError( const QString& msg );
+
   protected:
     void clearMinMaxCache();
     void fillMinMaxCache();

src/core/qgsvectorlayer.cpp

@@ -1524,6 +1524,7 @@ bool QgsVectorLayer::setDataProvider( QString const & provider )
   //      version big-time with an abnormal termination error
   delete mDataProvider;
   mDataProvider = ( QgsVectorDataProvider* )( QgsProviderRegistry::instance()->provider( provider, mDataSource ) );
+  connect( mDataProvider, SIGNAL( raiseError( QString ) ), this, SIGNAL( raiseError( QString ) ) );
 
   if ( !mDataProvider )
   {

src/core/qgsvectorlayer.h

@@ -1831,6 +1831,10 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      * This can be due to manually adding attributes or due to a join.
      */
     void updatedFields();
+
+    /**
+     * TODO QGIS3: remove in favor of QObject::destroyed
+     */
     void layerDeleted();
 
     void attributeValueChanged( QgsFeatureId fid, int idx, const QVariant & );
@@ -1898,6 +1902,11 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
      */
     void writeCustomSymbology( QDomElement& element, QDomDocument& doc, QString& errorMessage ) const;
 
+    /**
+     * Signals an error related to this vector layer.
+     */
+    void raiseError( const QString& msg );
+
   private slots:
     void onJoinedFieldsChanged();
     void onFeatureDeleted( QgsFeatureId fid );