Merge pull request #4134 from nyalldawson/save_task

[FEATURE] Background saving of vector layers
qgis · Feb 14, 2017 · edb30a2 · edb30a2
2 parents bd46b78 + 35bb5c6
commit edb30a2
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Showing 18 changed files with 497 additions and 91 deletions.
diff --git a/python/core/core.sip b/python/core/core.sip
@@ -149,6 +149,7 @@
 %Include qgsunittypes.sip
 %Include qgsvectordataprovider.sip
 %Include qgsvectorfilewriter.sip
+%Include qgsvectorfilewritertask.sip
 %Include qgsvectorlayer.sip
 %Include qgsvectorlayercache.sip
 %Include qgsvectorlayereditbuffer.sip

diff --git a/python/core/qgsfeedback.sip b/python/core/qgsfeedback.sip
@@ -36,8 +36,15 @@ class QgsFeedback : QObject
     //! Tells whether the operation has been canceled already
     bool isCanceled() const;
 
+    void setProgress( double progress );
+
+    double progress() const;
+
   signals:
     //! Internal routines can connect to this signal if they use event loop
     void canceled();
 
+    void progressChanged( double progress );
+
+
 };
diff --git a/python/core/qgstaskmanager.sip b/python/core/qgstaskmanager.sip
@@ -78,14 +78,7 @@ class QgsTask : QObject
      */
     double progress() const;
 
-    /**
-     * Notifies the task that it should terminate. Calling this is not guaranteed
-     * to immediately end the task, rather it sets the isCanceled() flag which
-     * task subclasses can check and terminate their operations at an appropriate
-     * time. Any subtasks owned by this task will also be canceled.
-     * @see isCanceled()
-     */
-    void cancel();
+    virtual void cancel();
 
     /**
      * Places the task on hold. If the task in not queued
@@ -133,19 +126,9 @@ class QgsTask : QObject
     void addSubTask( QgsTask* subTask /Transfer/, const QgsTaskList& dependencies = QgsTaskList(),
                      SubTaskDependency subTaskDependency = SubTaskIndependent );
 
-    /**
-     * Sets a list of layer IDs on which the task depends. The task will automatically
-     * be canceled if any of these layers are about to be removed.
-     * @see dependentLayerIds()
-     */
-    void setDependentLayers( const QStringList& dependentLayerIds );
+    void setDependentLayers( const QList<QgsMapLayer*>& dependentLayers );
 
-    /**
-     * Returns the list of layer IDs on which the task depends. The task will automatically
-     * be canceled if any of these layers are about to be removed.
-     * @see setDependentLayers()
-     */
-    QStringList dependentLayerIds() const;
+    QList< QgsMapLayer* > dependentLayers() const;
 
   signals:
 
@@ -324,19 +307,9 @@ class QgsTaskManager : QObject
     //! @note not available in Python bindings
     //QSet< long > dependencies( long taskId ) const;
 
-    /** Returns a list of layers on which as task is dependent. The task will automatically
-     * be canceled if any of these layers are above to be removed.
-     * @param taskId task ID
-     * @returns list of layer IDs
-     * @see tasksDependentOnLayer()
-     */
-    QStringList dependentLayers( long taskId ) const;
+    QList< QgsMapLayer* > dependentLayers( long taskId ) const;
 
-    /**
-     * Returns a list of tasks which depend on a layer.
-     * @see dependentLayers()
-     */
-    QList< QgsTask* > tasksDependentOnLayer( const QString& layerId ) const;
+    QList< QgsTask* > tasksDependentOnLayer( QgsMapLayer* layer ) const;
 
     /** Returns a list of the active (queued or running) tasks.
      * @see countActiveTasks()

diff --git a/python/core/qgsvectorfilewriter.sip b/python/core/qgsvectorfilewriter.sip
@@ -97,6 +97,7 @@ class QgsVectorFileWriter
       ErrProjection,
       ErrFeatureWriteFailed,
       ErrInvalidLayer,
+      Canceled,
     };
 
     enum SymbologyExport
@@ -323,6 +324,8 @@ class QgsVectorFileWriter
 
         /** Field value converter */
         QgsVectorFileWriter::FieldValueConverter* fieldValueConverter;
+
+        QgsFeedback* feedback;
     };
 
     /** Writes a layer out to a vector file.

diff --git a/python/core/qgsvectorfilewritertask.sip b/python/core/qgsvectorfilewritertask.sip
@@ -0,0 +1,25 @@
+class QgsVectorFileWriterTask : QgsTask
+{
+%TypeHeaderCode
+#include <qgsvectorfilewritertask.h>
+%End
+
+  public:
+
+    QgsVectorFileWriterTask( QgsVectorLayer* layer,
+                             const QString& fileName,
+                             const QgsVectorFileWriter::SaveVectorOptions& options );
+
+    virtual void cancel();
+
+  signals:
+
+    void writeComplete( const QString& newFilename );
+    void errorOccurred( int error, const QString& errorMessage );
+
+  protected:
+
+    virtual bool run();
+    virtual void finished( bool result );
+};
+
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -250,6 +250,7 @@
 #include "qgsvectorlayerjoininfo.h"
 #include "qgsvectorlayerutils.h"
 #include "qgshelp.h"
+#include "qgsvectorfilewritertask.h"
 
 #include "qgssublayersdialog.h"
 #include "ogr/qgsopenvectorlayerdialog.h"
@@ -6477,12 +6478,6 @@ void QgisApp::saveAsVectorFileGeneral( QgsVectorLayer* vlayer, bool symbologyOpt
       }
     }
 
-    // ok if the file existed it should be deleted now so we can continue...
-    QApplication::setOverrideCursor( Qt::WaitCursor );
-
-    QgsVectorFileWriter::WriterError error;
-    QString errorMessage;
-    QString newFilename;
     QgsRectangle filterExtent = dialog->filterExtent();
     QgisAppFieldValueConverter converter( vlayer, dialog->attributesAsDisplayedValues() );
     QgisAppFieldValueConverter* converterPtr = nullptr;
@@ -6510,32 +6505,41 @@ void QgisApp::saveAsVectorFileGeneral( QgsVectorLayer* vlayer, bool symbologyOpt
     options.attributes = dialog->selectedAttributes();
     options.fieldValueConverter = converterPtr;
 
-    error = QgsVectorFileWriter::writeAsVectorFormat(
-              vlayer, vectorFilename, options, &newFilename, &errorMessage );
+    bool addToCanvas = dialog->addToCanvas();
+    QString layerName = dialog->layername();
+    QgsVectorFileWriterTask* writerTask = new QgsVectorFileWriterTask( vlayer, vectorFilename, options );
 
-    QApplication::restoreOverrideCursor();
-
-    if ( error == QgsVectorFileWriter::NoError )
+    // when writer is successful:
+    connect( writerTask, &QgsVectorFileWriterTask::writeComplete, this, [this, addToCanvas, layerName, encoding, vectorFilename, vlayer]( const QString& newFilename )
     {
-      if ( dialog->addToCanvas() )
+      if ( addToCanvas )
       {
         QString uri( newFilename );
-        if ( !dialog->layername().isEmpty() )
-          uri += "|layername=" + dialog->layername();
-        addVectorLayers( QStringList( uri ), encoding, QStringLiteral( "file" ) );
+        if ( !layerName.isEmpty() )
+          uri += "|layername=" + layerName;
+        this->addVectorLayers( QStringList( uri ), encoding, QStringLiteral( "file" ) );
       }
-      emit layerSavedAs( vlayer, vectorFilename );
-      messageBar()->pushMessage( tr( "Saving done" ),
-                                 tr( "Export to vector file has been completed" ),
-                                 QgsMessageBar::INFO, messageTimeout() );
+      this->emit layerSavedAs( vlayer, vectorFilename );
+      this->messageBar()->pushMessage( tr( "Saving done" ),
+                                       tr( "Export to vector file has been completed" ),
+                                       QgsMessageBar::INFO, messageTimeout() );
     }
-    else
+           );
+
+    // when an error occurs:
+    connect( writerTask, &QgsVectorFileWriterTask::errorOccurred, this, [=]( int error, const QString & errorMessage )
     {
-      QgsMessageViewer *m = new QgsMessageViewer( nullptr );
-      m->setWindowTitle( tr( "Save error" ) );
-      m->setMessageAsPlainText( tr( "Export to vector file failed.\nError: %1" ).arg( errorMessage ) );
-      m->exec();
+      if ( error != QgsVectorFileWriter::Canceled )
+      {
+        QgsMessageViewer *m = new QgsMessageViewer( nullptr );
+        m->setWindowTitle( tr( "Save error" ) );
+        m->setMessageAsPlainText( tr( "Export to vector file failed.\nError: %1" ).arg( errorMessage ) );
+        m->exec();
+      }
     }
+           );
+
+    QgsApplication::taskManager()->addTask( writerTask );
   }
 
   delete dialog;
@@ -8440,7 +8444,7 @@ void QgisApp::removeLayer()
   QStringList activeTaskDescriptions;
   Q_FOREACH ( QgsMapLayer * layer, mLayerTreeView->selectedLayers() )
   {
-    QList< QgsTask* > tasks = QgsApplication::taskManager()->tasksDependentOnLayer( layer->id() );
+    QList< QgsTask* > tasks = QgsApplication::taskManager()->tasksDependentOnLayer( layer );
     if ( !tasks.isEmpty() )
     {
       Q_FOREACH ( QgsTask* task, tasks )
@@ -9645,7 +9649,7 @@ bool QgisApp::checkTasksDependOnProject()
 
   for ( ; layerIt != layers.constEnd(); ++layerIt )
   {
-    QList< QgsTask* > tasks = QgsApplication::taskManager()->tasksDependentOnLayer( layerIt.key() );
+    QList< QgsTask* > tasks = QgsApplication::taskManager()->tasksDependentOnLayer( layerIt.value() );
     if ( !tasks.isEmpty() )
     {
       Q_FOREACH ( QgsTask* task, tasks )

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -237,6 +237,7 @@ SET(QGIS_CORE_SRCS
   qgsunittypes.cpp
   qgsvectordataprovider.cpp
   qgsvectorfilewriter.cpp
+  qgsvectorfilewritertask.cpp
   qgsvectorlayer.cpp
   qgsvectorlayercache.cpp
   qgsvectorlayerdiagramprovider.cpp
@@ -528,6 +529,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgstransactiongroup.h
   qgsunittypes.h
   qgsvectordataprovider.h
+  qgsvectorfilewritertask.h
   qgsvectorlayercache.h
   qgsvectorlayereditbuffer.h
   qgsvectorlayereditpassthrough.h

diff --git a/src/core/qgsfeedback.h b/src/core/qgsfeedback.h
@@ -61,13 +61,44 @@ class CORE_EXPORT QgsFeedback : public QObject
     //! Tells whether the operation has been canceled already
     bool isCanceled() const { return mCanceled; }
 
+    /**
+     * Sets the current progress for the feedback object. The \a progress
+     * argument is in percentage and valid values range from 0-100.
+     * @see progress()
+     * @see progressChanged()
+     * @note added in QGIS 3.0
+     */
+    void setProgress( double progress ) { mProgress = progress; emit progressChanged( mProgress ); }
+
+    /**
+     * Returns the current progress reported by the feedback object. Depending on how the
+     * feedback object is used progress reporting may not be supported. The returned value
+     * is in percentage and ranges from 0-100.
+     * @see setProgress()
+     * @see progressChanged()
+     * @note added in QGIS 3.0
+     */
+    double progress() const { return mProgress; }
+
   signals:
     //! Internal routines can connect to this signal if they use event loop
     void canceled();
 
+    /**
+     * Emitted when the feedback object reports a progress change. Depending on how the
+     * feedback object is used progress reporting may not be supported. The \a progress
+     * argument is in percentage and ranges from 0-100.
+     * @note added in QGIS 3.0
+     * @see setProgress()
+     * @see progress()
+     */
+    void progressChanged( double progress );
+
   private:
     //! Whether the operation has been canceled already. False by default.
     bool mCanceled;
+
+    double mProgress = 0.0;
 };
 
 #endif // QGSFEEDBACK_H
diff --git a/src/core/qgstaskmanager.cpp b/src/core/qgstaskmanager.cpp
@@ -17,6 +17,7 @@
 
 #include "qgstaskmanager.h"
 #include "qgsproject.h"
+#include "qgsmaplayerlistutils.h"
 #include <QtConcurrentRun>
 
 
@@ -136,9 +137,14 @@ void QgsTask::addSubTask( QgsTask* subTask, const QgsTaskList& dependencies,
   connect( subTask, &QgsTask::statusChanged, this, &QgsTask::subTaskStatusChanged );
 }
 
-void QgsTask::setDependentLayers( const QStringList& dependentLayerIds )
+QList<QgsMapLayer*> QgsTask::dependentLayers() const
 {
-  mDependentLayerIds = dependentLayerIds;
+  return _qgis_listQPointerToRaw( mDependentLayers );
+}
+
+void QgsTask::setDependentLayers( const QList< QgsMapLayer* >& dependentLayers )
+{
+  mDependentLayers = _qgis_listRawToQPointer( dependentLayers );
 }
 
 void QgsTask::subTaskStatusChanged( int status )
@@ -325,8 +331,8 @@ QgsTaskManager::QgsTaskManager( QObject* parent )
     , mTaskMutex( new QMutex( QMutex::Recursive ) )
     , mNextTaskId( 0 )
 {
-  connect( QgsProject::instance(), SIGNAL( layersWillBeRemoved( QStringList ) ),
-           this, SLOT( layersWillBeRemoved( QStringList ) ) );
+  connect( QgsProject::instance(), static_cast < void ( QgsProject::* )( const QList< QgsMapLayer* >& ) > ( &QgsProject::layersWillBeRemoved ),
+           this, &QgsTaskManager::layersWillBeRemoved );
 }
 
 QgsTaskManager::~QgsTaskManager()
@@ -376,8 +382,8 @@ long QgsTaskManager::addTaskPrivate( QgsTask* task, QgsTaskList dependencies, bo
   {
     mParentTasks << task;
   }
-  if ( !task->dependentLayerIds().isEmpty() )
-    mLayerDependencies.insert( taskId, task->dependentLayerIds() );
+  if ( !task->dependentLayers().isEmpty() )
+    mLayerDependencies.insert( taskId, _qgis_listRawToQPointer( task->dependentLayers() ) );
   mTaskMutex->unlock();
 
   connect( task, &QgsTask::statusChanged, this, &QgsTaskManager::taskStatusChanged );
@@ -546,20 +552,20 @@ bool QgsTaskManager::hasCircularDependencies( long taskId ) const
   return !resolveDependencies( taskId, taskId, d );
 }
 
-QStringList QgsTaskManager::dependentLayers( long taskId ) const
+QList<QgsMapLayer*> QgsTaskManager::dependentLayers( long taskId ) const
 {
   QMutexLocker ml( mTaskMutex );
-  return mLayerDependencies.value( taskId, QStringList() );
+  return _qgis_listQPointerToRaw( mLayerDependencies.value( taskId, QgsWeakMapLayerPointerList() ) );
 }
 
-QList<QgsTask*> QgsTaskManager::tasksDependentOnLayer( const QString& layerId ) const
+QList<QgsTask*> QgsTaskManager::tasksDependentOnLayer( QgsMapLayer* layer ) const
 {
   QMutexLocker ml( mTaskMutex );
   QList< QgsTask* > tasks;
-  QMap< long, QStringList >::const_iterator layerIt = mLayerDependencies.constBegin();
+  QMap< long, QgsWeakMapLayerPointerList >::const_iterator layerIt = mLayerDependencies.constBegin();
   for ( ; layerIt != mLayerDependencies.constEnd(); ++layerIt )
   {
-    if ( layerIt.value().contains( layerId ) )
+    if ( _qgis_listQPointerToRaw( layerIt.value() ).contains( layer ) )
     {
       QgsTask* layerTask = task( layerIt.key() );
       if ( layerTask )
@@ -648,21 +654,21 @@ void QgsTaskManager::taskStatusChanged( int status )
 
 }
 
-void QgsTaskManager::layersWillBeRemoved( const QStringList& layerIds )
+void QgsTaskManager::layersWillBeRemoved( const QList< QgsMapLayer* >& layers )
 {
   mTaskMutex->lock();
   // scan through layers to be removed
-  QMap< long, QStringList > layerDependencies = mLayerDependencies;
+  QMap< long, QgsWeakMapLayerPointerList > layerDependencies = mLayerDependencies;
   layerDependencies.detach();
   mTaskMutex->unlock();
 
-  Q_FOREACH ( const QString& layerId, layerIds )
+  Q_FOREACH ( QgsMapLayer* layer, layers )
   {
     // scan through tasks with layer dependencies
-    for ( QMap< long, QStringList >::const_iterator it = layerDependencies.constBegin();
+    for ( QMap< long, QgsWeakMapLayerPointerList >::const_iterator it = layerDependencies.constBegin();
           it != layerDependencies.constEnd(); ++it )
     {
-      if ( !it.value().contains( layerId ) )
+      if ( !( _qgis_listQPointerToRaw( it.value() ).contains( layer ) ) )
       {
         //task not dependent on this layer
         continue;