[GRASS] browser import cancel action

src/providers/grass/qgis.r.in.cpp

@@ -58,6 +58,7 @@ extern "C"
 #define G_set_raster_value_d Rast_set_d_value
 #define G_put_raster_row Rast_put_row
 #define G_raster_size Rast_cell_size
+#define G_unopen_cell Rast_unopen
 #endif
 
 int main( int argc, char **argv )
@@ -127,9 +128,15 @@ int main( int argc, char **argv )
   void *buf = G_allocate_raster_buf( grass_type );
 
   int expectedSize = cols * QgsRasterBlock::typeSize( qgis_type );
+  bool isCanceled;
   QByteArray byteArray;
   for ( int row = 0; row < rows; row++ )
   {
+    stdinStream >> isCanceled;
+    if ( isCanceled )
+    {
+      break;
+    }
     stdinStream >> byteArray;
     if ( byteArray.size() != expectedSize )
     {
@@ -162,11 +169,18 @@ int main( int argc, char **argv )
     G_put_raster_row( cf, buf, grass_type );
   }
 
-  G_close_cell( cf );
-  struct History history;
-  G_short_history( name, "raster", &history );
-  G_command_history( &history );
-  G_write_history( name, &history );
+  if ( isCanceled )
+  {
+    G_unopen_cell( cf );
+  }
+  else
+  {
+    G_close_cell( cf );
+    struct History history;
+    G_short_history( name, "raster", &history );
+    G_command_history( &history );
+    G_write_history( name, &history );
+  }
 
   exit( EXIT_SUCCESS );
 }

src/providers/grass/qgis.v.in.cpp

@@ -66,6 +66,33 @@ void writePolyline( struct Map_info* map, int type, QgsPolyline polyline, struct
   Vect_write_line( map, type, line, cats );
 }
 
+void exitIfCanceled( QDataStream& stdinStream, bool isPolygon,
+                     const QString & tmpName, struct Map_info * tmpMap,
+                     const QString & finalName, struct Map_info * finalMap )
+{
+  bool isCanceled;
+  stdinStream >> isCanceled;
+  if ( !isCanceled )
+  {
+    return;
+  }
+  if ( isPolygon )
+  {
+    Vect_close( tmpMap );
+    Vect_delete( tmpName.toUtf8().data() );
+  }
+  Vect_close( finalMap );
+  Vect_delete( finalName.toUtf8().data() );
+  G_warning( "import canceled -> maps deleted" );
+  exit( EXIT_SUCCESS );
+}
+
+// G_set_percent_routine only works in GRASS >= 7
+//int percent_routine (int)
+//{
+// TODO: use it to interrupt cleaning functions
+//}
+
 int main( int argc, char **argv )
 {
   struct Option *mapOption;
@@ -91,6 +118,7 @@ int main( int argc, char **argv )
   QGis::WkbType wkbFlatType = QGis::flatType( wkbType );
   bool isPolygon = QGis::singleType( wkbFlatType ) == QGis::WKBPolygon;
 
+  QString finalName = QString( mapOption->answer );
   struct Map_info finalMap, tmpMap;
   Vect_open_new( &finalMap, mapOption->answer, 0 );
   struct Map_info * map = &finalMap;
@@ -148,6 +176,7 @@ int main( int argc, char **argv )
   qint32 featureCount = 0;
   while ( true )
   {
+    exitIfCanceled( stdinStream, isPolygon, tmpName, &tmpMap, finalName, &finalMap );
     stdinStream >> feature;
     if ( !feature.isValid() )
     {
@@ -279,6 +308,7 @@ int main( int argc, char **argv )
     // read once more to assign centroids to polygons
     while ( true )
     {
+      exitIfCanceled( stdinStream, isPolygon, tmpName, &tmpMap, finalName, &finalMap );
       stdinStream >> feature;
       if ( !feature.isValid() )
       {

src/providers/grass/qgsgrass.cpp

@@ -1007,10 +1007,13 @@ QStringList GRASS_LIB_EXPORT QgsGrass::vectorLayers( const QString& gisdbase, co
     return list;
   }
 
+  // TODO: Handle errors as exceptions. Do not open QMessageBox here! This method is also used in browser
+  // items which are populated in threads and creating dialog QPixmap is causing crash or even X server freeze.
   if ( level == 1 )
   {
     QgsDebugMsg( "Cannot open vector on level 2" );
-    QMessageBox::warning( 0, QObject::tr( "Warning" ), QObject::tr( "Cannot open vector %1 in mapset %2 on level 2 (topology not available, try to rebuild topology using v.build module)." ).arg( mapName ).arg( mapset ) );
+    // Do not open QMessageBox here!
+    //QMessageBox::warning( 0, QObject::tr( "Warning" ), QObject::tr( "Cannot open vector %1 in mapset %2 on level 2 (topology not available, try to rebuild topology using v.build module)." ).arg( mapName ).arg( mapset ) );
     // Vect_close here is correct, it should work, but it seems to cause
     // crash on win http://trac.osgeo.org/qgis/ticket/2003
     // disabled on win test it
@@ -1023,7 +1026,8 @@ QStringList GRASS_LIB_EXPORT QgsGrass::vectorLayers( const QString& gisdbase, co
   else if ( level < 1 )
   {
     QgsDebugMsg( "Cannot open vector" );
-    QMessageBox::warning( 0, QObject::tr( "Warning" ), QObject::tr( "Cannot open vector %1 in mapset %2" ).arg( mapName ).arg( mapset ) );
+    // Do not open QMessageBox here!
+    //QMessageBox::warning( 0, QObject::tr( "Warning" ), QObject::tr( "Cannot open vector %1 in mapset %2" ).arg( mapName ).arg( mapset ) );
     GRASS_UNLOCK
     return list;
   }

src/providers/grass/qgsgrassimport.cpp

@@ -13,6 +13,8 @@
  *   (at your option) any later version.                                   *
  *                                                                         *
  ***************************************************************************/
+#include <unistd.h>
+
 #include <QByteArray>
 #include <QtConcurrentRun>
 
@@ -37,6 +39,7 @@ extern "C"
 QgsGrassImport::QgsGrassImport( QgsGrassObject grassObject )
     : QObject()
     , mGrassObject( grassObject )
+    , mCanceled( false )
     , mFutureWatcher( 0 )
 {
 }
@@ -220,15 +223,27 @@ bool QgsGrassRasterImport::import()
         char * data = block->bits( row, 0 );
         int size = iterCols * block->dataTypeSize();
         QByteArray byteArray = QByteArray::fromRawData( data, size ); // does not copy data and does not take ownership
+        if ( isCanceled() )
+        {
+          outStream << true; // cancel module
+          break;
+        }
+        outStream << false; // not canceled
         outStream << byteArray;
       }
       delete block;
+      if ( isCanceled() )
+      {
+        outStream << true; // cancel module
+        break;
+      }
     }
 
     // TODO: send something back from module and read it here to close map correctly in module
 
     process->closeWriteChannel();
-    process->waitForFinished( 5000 );
+    // TODO: best timeout?
+    process->waitForFinished( 30000 );
 
     QString stdoutString = process->readAllStandardOutput().data();
     QString stderrString = process->readAllStandardError().data();
@@ -387,9 +402,16 @@ bool QgsGrassVectorImport::import()
       {
         feature.geometry()->transform( coordinateTransform );
       }
+      if ( isCanceled() )
+      {
+        outStream << true; // cancel module
+        break;
+      }
+      outStream << false; // not canceled
       outStream << feature;
     }
     feature = QgsFeature(); // indicate end by invalid feature
+    outStream << false; // not canceled
     outStream << feature;
     QgsDebugMsg( "features sent" );
   }

src/providers/grass/qgsgrassimport.h

@@ -39,9 +39,15 @@ class GRASS_LIB_EXPORT QgsGrassImport : public QObject
     // get error if import failed
     QString error();
     virtual QStringList names() const;
-
+    bool isCanceled() const { return mCanceled; }
   public slots:
     void onFinished();
+    // TODO: this is not completely kosher, because QgsGrassImport exist on the main thread
+    // but import is running in another thread, to do it right, we should have an import object
+    // created on another thread, send cancel signal to that object which regularly processes events
+    // and thus recieves the signal.
+    // Most probably however, it will work correctly, even if read/write the bool wasn't atomic
+    void cancel() { mCanceled = true; }
 
   signals:
     // sent when process finished
@@ -52,6 +58,7 @@ class GRASS_LIB_EXPORT QgsGrassImport : public QObject
     void setError( QString error );
     QgsGrassObject mGrassObject;
     QString mError;
+    bool mCanceled;
     QFutureWatcher<bool>* mFutureWatcher;
 };
 

src/providers/grass/qgsgrassprovidermodule.cpp

@@ -99,7 +99,15 @@ QVector<QgsDataItem*> QgsGrassMapsetItem::createChildren()
 
     QgsGrassObject vectorObject( mGisdbase, mLocation, mName, name, QgsGrassObject::Vector );
     QgsGrassVectorItem *map = 0;
-    if ( layerNames.size() > 1 )
+    if ( layerNames.size() == 0 )
+    {
+      // TODO: differentiate if it is layer with no layers or without topo (throw exception from QgsGrass::vectorLayers)
+      // TODO: refresh (remove) error if topo was build
+      QgsErrorItem * errorItem = new QgsErrorItem( this, name, mapPath );
+      items.append( errorItem );
+      continue;
+    }
+    else if ( layerNames.size() > 1 )
     {
       //map = new QgsDataCollectionItem( this, name, mapPath );
       //map->setCapabilities( QgsDataItem::NoCapabilities ); // disable fertility
@@ -612,11 +620,33 @@ QgsGrassRasterItem::QgsGrassRasterItem( QgsDataItem* parent, QgsGrassObject gras
 QgsGrassImportItem::QgsGrassImportItem( QgsDataItem* parent, const QString& name, const QString& path, QgsGrassImport* import )
     : QgsDataItem( QgsDataItem::Layer, parent, name, path )
     , QgsGrassObjectItemBase( import->grassObject() )
+    , mImport( import )
 {
   setCapabilities( QgsDataItem::NoCapabilities ); // disable fertility
   setState( Populating );
 }
 
+QList<QAction*> QgsGrassImportItem::actions()
+{
+  QList<QAction*> lst;
+
+  QAction* actionRename = new QAction( tr( "Cancel" ), this );
+  connect( actionRename, SIGNAL( triggered() ), this, SLOT( cancel() ) );
+  lst.append( actionRename );
+
+  return lst;
+}
+
+void QgsGrassImportItem::cancel()
+{
+  QgsDebugMsg( "Entered" );
+  if ( !mImport ) // should not happen
+  {
+    return;
+  }
+  mImport->cancel();
+}
+
 //-------------------------------------------------------------------------
 
 QGISEXTERN int dataCapabilities()

src/providers/grass/qgsgrassprovidermodule.h

@@ -148,16 +148,17 @@ class QgsGrassImportItem : public QgsDataItem, public QgsGrassObjectItemBase
     //virtual void setState( State state ) override {
     //  QgsDataItem::setState(state);
     //} // do nothing to keep Populating
-    //virtual QList<QAction*> actions() override;
+    virtual QList<QAction*> actions() override;
 
   public slots:
     virtual void refresh() override {}
-    //void deleteGrassObject();
+    void cancel();
 
   protected:
     // override refresh to keep Populating state
     virtual void refresh( QVector<QgsDataItem*> children ) override { Q_UNUSED( children )};
     //bool mDeleteAction;
+    QgsGrassImport* mImport;
 };
 
 #endif // QGSGRASSPROVIDERMODULE_H