[FEATURE] Background saving of raster layers

Use the task manager framework to handle saving of raster layers in the background
qgis · Apr 6, 2017 · 110828f · 110828f
1 parent 25d9936
commit 110828f
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Showing 13 changed files with 413 additions and 79 deletions.
diff --git a/python/core/core.sip b/python/core/core.sip
@@ -298,6 +298,7 @@
 %Include raster/qgsrasterdataprovider.sip
 %Include raster/qgsrasterdrawer.sip
 %Include raster/qgsrasterfilewriter.sip
+%Include raster/qgsrasterfilewritertask.sip
 %Include raster/qgsrasterhistogram.sip
 %Include raster/qgsrasteridentifyresult.sip
 %Include raster/qgsrasterinterface.sip

diff --git a/python/core/raster/qgsrasterfilewriter.sip b/python/core/raster/qgsrasterfilewriter.sip
@@ -49,7 +49,9 @@ class QgsRasterFileWriter
         @param crs crs to reproject to
         @param p dialog to show progress in */
     WriterError writeRaster( const QgsRasterPipe* pipe, int nCols, int nRows, const QgsRectangle& outputExtent,
-                             const QgsCoordinateReferenceSystem& crs, QProgressDialog* p = 0 );
+                             const QgsCoordinateReferenceSystem& crs, QgsRasterBlockFeedback *feedback = nullptr );
+
+    QString outputUrl() const;
 
     void setOutputFormat( const QString& format );
     QString outputFormat() const;

diff --git a/python/core/raster/qgsrasterfilewritertask.sip b/python/core/raster/qgsrasterfilewritertask.sip
@@ -0,0 +1,68 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/raster/qgsrasterfilewritertask.h                            *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+class QgsRasterFileWriterTask : QgsTask
+{
+%Docstring
+ QgsTask task which performs a QgsRasterFileWriter layer saving operation as a background
+ task. This can be used to save a raster layer out to a file without blocking the
+ QGIS interface.
+ \see QgsVectorFileWriterTask
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsrasterfilewritertask.h"
+%End
+
+  public:
+
+    QgsRasterFileWriterTask( const QgsRasterFileWriter &writer, QgsRasterPipe *pipe /Transfer/,
+                             int columns, int rows,
+                             const QgsRectangle &outputExtent,
+                             const QgsCoordinateReferenceSystem &crs );
+%Docstring
+ Constructor for QgsRasterFileWriterTask. Takes a source writer,
+ columns, rows, outputExtent and destination crs.
+ Ownership of the pipe is transferred to the writer task, and will
+ be deleted when the task completes.
+%End
+
+    virtual void cancel();
+
+  signals:
+
+    void writeComplete( const QString &outputUrl );
+%Docstring
+ Emitted when writing the layer is successfully completed. The outputUrl
+ parameter indicates the file path for the written file(s).
+%End
+
+    void errorOccurred( int error );
+%Docstring
+ Emitted when an error occurs which prevented the file being written (or if
+ the task is canceled). The writing error will be reported.
+%End
+
+  protected:
+
+    virtual bool run();
+    virtual void finished( bool result );
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/raster/qgsrasterfilewritertask.h                            *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -219,6 +219,7 @@
 #include "qgsquerybuilder.h"
 #include "qgsrastercalcdialog.h"
 #include "qgsrasterfilewriter.h"
+#include "qgsrasterfilewritertask.h"
 #include "qgsrasteriterator.h"
 #include "qgsrasterlayer.h"
 #include "qgsrasterlayerproperties.h"
@@ -6453,13 +6454,6 @@ void QgisApp::saveAsRasterFile()
     fileWriter.setMaxTileHeight( d.maximumTileSizeY() );
   }
 
-  QProgressDialog pd( QString(), tr( "Abort..." ), 0, 0 );
-  // Show the dialo immediately because cloning pipe can take some time (WCS)
-  pd.setLabelText( tr( "Reading raster" ) );
-  pd.setWindowTitle( tr( "Saving raster" ) );
-  pd.show();
-  pd.setWindowModality( Qt::WindowModal );
-
   // TODO: show error dialogs
   // TODO: this code should go somewhere else, but probably not into QgsRasterFileWriter
   // clone pipe/provider is not really necessary, ready for threads
@@ -6525,35 +6519,51 @@ void QgisApp::saveAsRasterFile()
   fileWriter.setPyramidsFormat( d.pyramidsFormat() );
   fileWriter.setPyramidsConfigOptions( d.pyramidsConfigOptions() );
 
-  QgsRasterFileWriter::WriterError err = fileWriter.writeRaster( pipe.get(), d.nColumns(), d.nRows(), d.outputRectangle(), d.outputCrs(), &pd );
-  if ( err != QgsRasterFileWriter::NoError )
-  {
-    QMessageBox::warning( this, tr( "Error" ),
-                          tr( "Cannot write raster error code: %1" ).arg( err ),
-                          QMessageBox::Ok );
+  bool tileMode = d.tileMode();
+  bool addToCanvas = d.addToCanvas();
+  QPointer< QgsRasterLayer > rlWeakPointer( rasterLayer );
 
-  }
-  else
+  QgsRasterFileWriterTask *writerTask = new QgsRasterFileWriterTask( fileWriter, pipe.release(), d.nColumns(), d.nRows(),
+      d.outputRectangle(), d.outputCrs() );
+
+  // when writer is successful:
+
+  connect( writerTask, &QgsRasterFileWriterTask::writeComplete, this, [this, tileMode, addToCanvas, rlWeakPointer ]( const QString & newFilename )
   {
-    QString fileName( d.outputFileName() );
-    if ( d.tileMode() )
+    QString fileName = newFilename;
+    if ( tileMode )
     {
       QFileInfo outputInfo( fileName );
       fileName = QStringLiteral( "%1/%2.vrt" ).arg( fileName, outputInfo.fileName() );
     }
 
-    if ( d.addToCanvas() )
+    if ( addToCanvas )
     {
       addRasterLayers( QStringList( fileName ) );
     }
+    if ( rlWeakPointer )
+      emit layerSavedAs( rlWeakPointer, fileName );
 
-    emit layerSavedAs( rasterLayer, fileName );
     messageBar()->pushMessage( tr( "Saving done" ),
                                tr( "Export to raster file has been completed" ),
                                QgsMessageBar::INFO, messageTimeout() );
-  }
+  } );
+
+  // when an error occurs:
+  connect( writerTask, &QgsRasterFileWriterTask::errorOccurred, this, [ = ]( int error )
+  {
+    if ( error != QgsRasterFileWriter::WriteCanceled )
+    {
+      QMessageBox::warning( this, tr( "Error" ),
+                            tr( "Cannot write raster error code: %1" ).arg( error ),
+                            QMessageBox::Ok );
+    }
+  } );
+
+  QgsApplication::taskManager()->addTask( writerTask );
 }
 
+
 void QgisApp::saveAsFile()
 {
   QgsMapLayer *layer = activeLayer();

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -336,6 +336,7 @@ SET(QGIS_CORE_SRCS
   raster/qgsrasterblock.cpp
   raster/qgsrasterchecker.cpp
   raster/qgsrasterdataprovider.cpp
+  raster/qgsrasterfilewritertask.cpp
   raster/qgsrasteridentifyresult.cpp
   raster/qgsrasterinterface.cpp
   raster/qgsrasteriterator.cpp
@@ -597,6 +598,7 @@ SET(QGIS_CORE_MOC_HDRS
   processing/qgsprocessingfeedback.h
   processing/qgsprocessingregistry.h
 
+  raster/qgsrasterfilewritertask.h
   raster/qgsrasterlayer.h
   raster/qgsrasterdataprovider.h
 

diff --git a/src/core/qgsvectorfilewritertask.cpp b/src/core/qgsvectorfilewritertask.cpp
@@ -19,7 +19,7 @@
 
 
 QgsVectorFileWriterTask::QgsVectorFileWriterTask( QgsVectorLayer *layer, const QString &fileName, const QgsVectorFileWriter::SaveVectorOptions &options )
-  : QgsTask( tr( "Saving %1 " ).arg( fileName ), QgsTask::CanCancel )
+  : QgsTask( tr( "Saving %1" ).arg( fileName ), QgsTask::CanCancel )
   , mLayer( layer )
   , mDestFileName( fileName )
   , mOptions( options )

diff --git a/src/core/qgsvectorfilewritertask.h b/src/core/qgsvectorfilewritertask.h
@@ -30,6 +30,7 @@
  * task. This can be used to save a vector layer out to a file without blocking the
  * QGIS interface.
  * \since QGIS 3.0
+ * \see QgsRasterFileWriterTask
  */
 class CORE_EXPORT QgsVectorFileWriterTask : public QgsTask
 {