Geopackage import rasters with drag and drop

This implementation uses GDALTranslate and
a QgsTask.

src/providers/ogr/CMakeLists.txt

@@ -8,6 +8,8 @@ SET (OGR_SRCS
     qgsogrsourceselect.cpp
     qgsgeopackagedataitems.cpp
     qgsgeopackageconnection.cpp
+    qgsgeopackagerasterwriter.cpp
+    qgsgeopackagerasterwritertask.cpp
 )
 
 SET(OGR_MOC_HDRS
@@ -17,6 +19,8 @@ SET(OGR_MOC_HDRS
     qgsogrsourceselect.h
     qgsgeopackagedataitems.h
     qgsgeopackageconnection.h
+    qgsgeopackagerasterwriter.h
+    qgsgeopackagerasterwritertask.h
 )
 
 ########################################################

src/providers/ogr/qgsgeopackagedataitems.h

@@ -82,6 +82,9 @@ class QgsGeoPackageConnectionItem : public QgsDataCollectionItem
     //! Return the layer type from \a geometryType
     static QgsLayerItem::LayerType layerTypeFromDb( const QString &geometryType );
 
+    //! Delete a geopackage layer
+    static bool deleteGeoPackageRasterLayer( const QString uri, QString &errCause );
+
   public slots:
 #ifdef HAVE_GUI
     void editConnection();

src/providers/ogr/qgsgeopackagerasterwriter.cpp

@@ -0,0 +1,74 @@
+/***************************************************************************
+  qgsgeopackagerasterwriter.cpp - QgsGeoPackageRasterWriter
+
+ ---------------------
+ begin                : 23.8.2017
+ copyright            : (C) 2017 by Alessandro Pasotti
+ email                : apasotti at boundlessgeo dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+///@cond PRIVATE
+
+#include "gdal.h"
+#include "gdal_utils.h"
+
+#include "qgsgeopackagerasterwriter.h"
+#include "qgscplerrorhandler.h"
+
+#include <QMessageBox>
+
+QgsGeoPackageRasterWriter::QgsGeoPackageRasterWriter( const QgsMimeDataUtils::Uri sourceUri, const QString outputUrl ):
+  mSourceUri( sourceUri ),
+  mOutputUrl( outputUrl )
+{
+
+}
+
+QgsGeoPackageRasterWriter::WriterError QgsGeoPackageRasterWriter::writeRaster( QgsFeedback *feedback, QString *errorMessage )
+{
+  const char *args[] = { "-of", "gpkg", "-co", QStringLiteral( "RASTER_TABLE=%1" ).arg( mSourceUri.name ).toUtf8().constData(), "-co", "APPEND_SUBDATASET=YES", nullptr };
+  // This sends OGR/GDAL errors to the message log
+  QgsCPLErrorHandler handler;
+  GDALTranslateOptions *psOptions = GDALTranslateOptionsNew( ( char ** )args, nullptr );
+
+  GDALTranslateOptionsSetProgress( psOptions, [ ]( double dfComplete, const char *pszMessage,  void *pProgressData ) -> int
+  {
+    Q_UNUSED( pszMessage );
+    QgsFeedback *feedback = static_cast< QgsFeedback * >( pProgressData );
+    feedback->setProgress( dfComplete * 100 );
+    return ! feedback->isCanceled();
+  }, feedback );
+
+  GDALDatasetH hSrcDS = GDALOpen( mSourceUri.uri.toUtf8().constData(), GA_ReadOnly );
+  if ( ! hSrcDS )
+  {
+    *errorMessage = QObject::tr( "Failed to open source layer %1! See the OGR panel in the message logs for details.\n\n" ).arg( mSourceUri.name );
+    mHasError = true;
+  }
+  else
+  {
+    CPLErrorReset();
+    GDALDatasetH hOutDS = GDALTranslate( mOutputUrl.toUtf8().constData(), hSrcDS, psOptions, NULL );
+    if ( ! hOutDS )
+    {
+      *errorMessage = QObject::tr( "Failed to import layer %1! See the OGR panel in the message logs for details.\n\n" ).arg( mSourceUri.name );
+      mHasError = true;
+    }
+    else // All good!
+    {
+      GDALClose( hOutDS );
+    }
+    GDALClose( hSrcDS );
+  }
+  GDALTranslateOptionsFree( psOptions );
+  return ( feedback && feedback->isCanceled() ) ? ErrUserCanceled : ( mHasError ? WriteError : NoError ) ;
+}
+
+///@endcond

src/providers/ogr/qgsgeopackagerasterwriter.h

@@ -0,0 +1,52 @@
+/***************************************************************************
+  qgsgeopackagerasterwriter.h - QgsGeoPackageRasterWriter
+
+ ---------------------
+ begin                : 23.8.2017
+ copyright            : (C) 2017 by Alessandro Pasotti
+ email                : apasotti at boundlessgeo dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#ifndef QGSGEOPACKAGERASTERWRITER_H
+#define QGSGEOPACKAGERASTERWRITER_H
+
+///@cond PRIVATE
+
+#define SIP_NO_FILE
+
+#include "qgsmimedatautils.h"
+#include "qgsfeedback.h"
+
+class QgsGeoPackageRasterWriter
+{
+  public:
+
+    //! Error codes
+    enum WriterError
+    {
+      NoError = 0, //!< No errors were encountered
+      WriteError, //! Generic GDAL Translate error
+      ErrUserCanceled, //!< User canceled the export
+    };
+
+    QgsGeoPackageRasterWriter( const QgsMimeDataUtils::Uri sourceUri, const QString destinationPath );
+    WriterError writeRaster( QgsFeedback *feedback, QString *errorMessage );
+    const QString outputUrl() const { return mOutputUrl; }
+
+  private:
+    QgsMimeDataUtils::Uri mSourceUri;
+    QString mOutputUrl;
+    bool mHasError = false;
+};
+
+
+///@endcond
+
+#endif // QGSGEOPACKAGERASTERWRITER_H
+

src/providers/ogr/qgsgeopackagerasterwritertask.cpp

@@ -0,0 +1,55 @@
+/***************************************************************************
+  qgsgeopackagerasterwritertask.cpp - QgsGeoPackageRasterWriterTask
+
+ ---------------------
+ begin                : 23.8.2017
+ copyright            : (C) 2017 by Alessandro Pasotti
+ email                : apasotti at boundlessgeo dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#include "qgsgeopackagerasterwritertask.h"
+
+
+///@cond PRIVATE
+
+
+QgsGeoPackageRasterWriterTask::QgsGeoPackageRasterWriterTask( const QgsMimeDataUtils::Uri sourceUri, const QString destinationPath )
+  : QgsTask( tr( "Saving %1" ).arg( destinationPath ), QgsTask::CanCancel )
+  , mWriter( sourceUri, destinationPath )
+  , mFeedback( new QgsFeedback() )
+{
+
+}
+
+void QgsGeoPackageRasterWriterTask::cancel()
+{
+  mError = QgsGeoPackageRasterWriter::WriterError::ErrUserCanceled;
+  mFeedback.get()->cancel();
+}
+
+bool QgsGeoPackageRasterWriterTask::run()
+{
+  connect( mFeedback.get(), &QgsFeedback::progressChanged, this, &QgsGeoPackageRasterWriterTask::setProgress );
+  mError = mWriter.writeRaster( mFeedback.get(), &mErrorMessage );
+  return mError == QgsGeoPackageRasterWriter::WriterError::NoError;
+}
+
+void QgsGeoPackageRasterWriterTask::finished( bool result )
+{
+  if ( result )
+  {
+    emit writeComplete( mWriter.outputUrl() );
+  }
+  else
+  {
+    emit errorOccurred( mError, mErrorMessage );
+  }
+}
+
+///@endcond

src/providers/ogr/qgsgeopackagerasterwritertask.h

@@ -0,0 +1,83 @@
+/***************************************************************************
+  qgsgeopackagerasterwritertask.h - QgsGeoPackageRasterWriterTask
+
+ ---------------------
+ begin                : 23.8.2017
+ copyright            : (C) 2017 by Alessandro Pasotti
+ email                : apasotti at boundlessgeo dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#ifndef QGSGEOPACKAGERASTERWRITERTASK_H
+#define QGSGEOPACKAGERASTERWRITERTASK_H
+
+
+///@cond PRIVATE
+
+#define SIP_NO_FILE
+
+#include "qgis_core.h"
+#include "qgsgeopackagerasterwriter.h"
+#include "qgstaskmanager.h"
+#include "qgsfeedback.h"
+
+
+/**
+ * \class QgsGeoPackageRasterWriterTask
+ * QgsTask task which performs a QgsGeoPackageRasterWriter 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.
+ * \since QGIS 3.0
+ * \see QgsGeoPackageRasterWriterTask
+ */
+class QgsGeoPackageRasterWriterTask : public QgsTask
+{
+    Q_OBJECT
+
+  public:
+
+    /**
+     * Constructor for QgsVectorFileWriterTask. Takes a source \a layer, destination \a fileName
+     * and save \a options.
+     */
+    QgsGeoPackageRasterWriterTask( const QgsMimeDataUtils::Uri sourceUri, const QString destinationPath );
+
+    virtual void cancel() override;
+
+  signals:
+
+    /**
+     * Emitted when writing the layer is successfully completed. The \a newFilename
+     * parameter indicates the file path for the written file.
+     */
+    void writeComplete( const QString &newFilename );
+
+    /**
+     * Emitted when an error occurs which prevented the file being written (or if
+     * the task is canceled). The writing \a error and \a errorMessage will be reported.
+     */
+    void errorOccurred( QgsGeoPackageRasterWriter::WriterError error, const QString &errorMessage );
+
+  protected:
+
+    virtual bool run() override;
+    virtual void finished( bool result ) override;
+
+  private:
+
+    QgsGeoPackageRasterWriter mWriter;
+    std::unique_ptr< QgsFeedback > mFeedback;
+    QgsGeoPackageRasterWriter::WriterError mError = QgsGeoPackageRasterWriter::WriterError::NoError ;
+    QString mErrorMessage;
+
+};
+
+
+///@endcond
+
+#endif // QGSGEOPACKAGERASTERWRITERTASK_H