[FEATURE][processing] Add undo/redo support to model designer

Makes QGIS more forgiving for users! Sponsored by NRCan
qgis · Mar 10, 2020 · e7b5c26 · e7b5c26
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commit e7b5c26
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Showing 17 changed files with 373 additions and 8 deletions.
diff --git a/python/gui/auto_generated/processing/models/qgsmodelcomponentgraphicitem.sip.in b/python/gui/auto_generated/processing/models/qgsmodelcomponentgraphicitem.sip.in
@@ -87,6 +87,8 @@ Sets the ``font`` used to render text in the item.
 
     virtual void mouseDoubleClickEvent( QGraphicsSceneMouseEvent *event );
 
+    virtual void mouseReleaseEvent( QGraphicsSceneMouseEvent *event );
+
     virtual void hoverEnterEvent( QGraphicsSceneHoverEvent *event );
 
     virtual void hoverMoveEvent( QGraphicsSceneHoverEvent *event );
@@ -172,6 +174,15 @@ The default implementation does nothing.
     void requestModelRepaint();
 %Docstring
 Emitted by the item to request a repaint of the parent model scene.
+%End
+
+    void aboutToChange( const QString &text, int id = 0 );
+%Docstring
+Emitted when the definition of the associated component is about to be changed
+by the item.
+
+The ``text`` argument gives the translated text describing the change about to occur, and the
+optional ``id`` can be used to group the associated undo commands.
 %End
 
     void changed();

diff --git a/python/gui/auto_generated/processing/models/qgsmodeldesignerdialog.sip.in b/python/gui/auto_generated/processing/models/qgsmodeldesignerdialog.sip.in
@@ -30,10 +30,21 @@ Model designer dialog base class
   public:
 
     QgsModelDesignerDialog( QWidget *parent /TransferThis/ = 0, Qt::WindowFlags flags = 0 );
+    ~QgsModelDesignerDialog();
 
     virtual void closeEvent( QCloseEvent *event );
 
 
+    void beginUndoCommand( const QString &text, int id = 0 );
+%Docstring
+Starts an undo command. This should be called before any changes are made to the model.
+%End
+
+    void endUndoCommand();
+%Docstring
+Ends the current undo command. This should be called after changes are made to the model.
+%End
+
   protected:
 
     virtual void repaintModel( bool showControls = true ) = 0;

diff --git a/python/gui/auto_generated/processing/models/qgsmodelgraphicsscene.sip.in b/python/gui/auto_generated/processing/models/qgsmodelgraphicsscene.sip.in
@@ -87,6 +87,14 @@ Populates the scene by creating items representing the specified ``model``.
     void rebuildRequired();
 %Docstring
 Emitted when a change in the model requires a full rebuild of the scene.
+%End
+
+    void componentAboutToChange( const QString &text, int id = 0 );
+%Docstring
+Emitted whenever a component of the model is about to be changed.
+
+The ``text`` argument gives the translated text describing the change about to occur, and the
+optional ``id`` can be used to group the associated undo commands.
 %End
 
     void componentChanged();

diff --git a/python/plugins/processing/modeler/ModelerDialog.py b/python/plugins/processing/modeler/ModelerDialog.py
@@ -91,6 +91,7 @@ def __init__(self, model=None, parent=None):
         self.scene = ModelerScene(self)
         self.scene.setSceneRect(QRectF(0, 0, self.CANVAS_SIZE, self.CANVAS_SIZE))
         self.scene.rebuildRequired.connect(self.repaintModel)
+        self.scene.componentAboutToChange.connect(self.componentAboutToChange)
         self.scene.componentChanged.connect(self.componentChanged)
 
         self.view().setScene(self.scene)
@@ -125,8 +126,9 @@ def editHelp(self):
         dlg = HelpEditionDialog(alg)
         dlg.exec_()
         if dlg.descriptions:
+            self.beginUndoCommand(self.tr('Edit Model Help'))
             self.model().setHelpContent(dlg.descriptions)
-            self.setDirty(True)
+            self.endUndoCommand()
 
     def runModel(self):
         if len(self.model().childAlgorithms()) == 0:
@@ -257,10 +259,14 @@ def repaintModel(self, showControls=True):
         self.view().setScene(self.scene)
 
         self.scene.rebuildRequired.connect(self.repaintModel)
+        self.scene.componentAboutToChange.connect(self.componentAboutToChange)
         self.scene.componentChanged.connect(self.componentChanged)
 
+    def componentAboutToChange(self, description, id):
+        self.beginUndoCommand(description, id)
+
     def componentChanged(self):
-        self.setDirty(True)
+        self.endUndoCommand()
 
     def create_widget_context(self):
         """
@@ -326,10 +332,11 @@ def addInput(self, paramType, pos=None):
                 component.size().width(),
                 -1.5 * component.size().height()))
 
+            self.beginUndoCommand(self.tr('Add Model Input'))
             self.model().addModelParameter(new_param, component)
             self.repaintModel()
             # self.view().ensureVisible(self.scene.getLastParameterItem())
-            self.setDirty(True)
+            self.endUndoCommand()
 
     def getPositionForParameterItem(self):
         MARGIN = 20
@@ -365,9 +372,10 @@ def addAlgorithm(self, alg_id, pos=None):
                 alg.modelOutput(out).setPosition(alg.position() + QPointF(output_offset_x, output_offset_y))
                 output_offset_y += 1.5 * alg.modelOutput(out).size().height()
 
+            self.beginUndoCommand(self.tr('Add Algorithm'))
             self.model().addChildAlgorithm(alg)
             self.repaintModel()
-            self.setDirty(True)
+            self.endUndoCommand()
 
     def getPositionForAlgorithmItem(self):
         MARGIN = 20

diff --git a/python/plugins/processing/modeler/ModelerGraphicItem.py b/python/plugins/processing/modeler/ModelerGraphicItem.py
@@ -90,6 +90,7 @@ def edit(self, edit_comment=False):
                 comment = dlg.comments()
 
         if new_param is not None:
+            self.aboutToChange.emit(self.tr('Edit {}').format(new_param.description()))
             self.model().removeModelParameter(self.component().parameterName())
             self.component().setParameterName(new_param.name())
             self.component().setDescription(new_param.name())
@@ -128,6 +129,7 @@ def edit(self, edit_comment=False):
             alg = dlg.createAlgorithm()
             alg.setChildId(self.component().childId())
             alg.copyNonDefinitionPropertiesFromModel(self.model())
+            self.aboutToChange.emit(self.tr('Edit {}').format(alg.description()))
             self.model().setChildAlgorithm(alg)
             self.requestModelRepaint.emit()
             self.changed.emit()
@@ -165,6 +167,7 @@ def edit(self, edit_comment=False):
             model_output.setDefaultValue(dlg.param.defaultValue())
             model_output.setMandatory(not (dlg.param.flags() & QgsProcessingParameterDefinition.FlagOptional))
             model_output.comment().setDescription(dlg.comments())
+            self.aboutToChange.emit(self.tr('Edit {}').format(model_output.description()))
             self.model().updateDestinationParameters()
             self.requestModelRepaint.emit()
             self.changed.emit()

diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
@@ -282,6 +282,7 @@ SET(QGIS_GUI_SRCS
   processing/models/qgsmodelgraphicitem.cpp
   processing/models/qgsmodelgraphicsscene.cpp
   processing/models/qgsmodelgraphicsview.cpp
+  processing/models/qgsmodelundocommand.cpp
 
   providers/gdal/qgsgdalsourceselect.cpp
   providers/gdal/qgsgdalguiprovider.cpp
@@ -942,6 +943,7 @@ SET(QGIS_GUI_HDRS
   processing/models/qgsmodelgraphicitem.h
   processing/models/qgsmodelgraphicsscene.h
   processing/models/qgsmodelgraphicsview.h
+  processing/models/qgsmodelundocommand.h
 
   providers/gdal/qgsgdalguiprovider.h
   providers/gdal/qgsgdalsourceselect.h

diff --git a/src/gui/processing/models/qgsmodelcomponentgraphicitem.cpp b/src/gui/processing/models/qgsmodelcomponentgraphicitem.cpp
@@ -105,6 +105,16 @@ void QgsModelComponentGraphicItem::mouseDoubleClickEvent( QGraphicsSceneMouseEve
   editComponent();
 }
 
+void QgsModelComponentGraphicItem::mouseReleaseEvent( QGraphicsSceneMouseEvent *event )
+{
+  if ( mIsMoving && event->button() == Qt::LeftButton )
+  {
+    // released the move drag button, so we've finalised the move operation
+    emit changed();
+    mIsMoving = false;
+  }
+}
+
 void QgsModelComponentGraphicItem::hoverEnterEvent( QGraphicsSceneHoverEvent *event )
 {
   updateToolTip( event->pos() );
@@ -133,10 +143,23 @@ QVariant QgsModelComponentGraphicItem::itemChange( QGraphicsItem::GraphicsItemCh
     case QGraphicsItem::ItemPositionHasChanged:
     {
       emit updateArrowPaths();
+
+      if ( !mInitialized || pos() == mComponent->position() )
+        break;
+
       mComponent->setPosition( pos() );
 
       // also need to update the model's stored component's position
+      if ( !mIsMoving )
+      {
+        // we are just starting a move operation - so create the undo command using the existing state
+        emit aboutToChange( tr( "Move %1" ).arg( mComponent->description() ) );
+      }
       updateStoredComponentPosition( pos() );
+
+      // we don't emit the changed signal to trigger the end of the undo command until the whole move operation finishes
+      // (i.e. we do that in mouseReleaseEvent)
+      mIsMoving = true;
       break;
     }
     case QGraphicsItem::ItemSelectedChange:
@@ -164,6 +187,7 @@ QVariant QgsModelComponentGraphicItem::itemChange( QGraphicsItem::GraphicsItemCh
           mExpandBottomButton = new QgsModelDesignerFoldButtonGraphicItem( this, mComponent->linksCollapsed( Qt::BottomEdge ), pt );
           connect( mExpandBottomButton, &QgsModelDesignerFoldButtonGraphicItem::folded, this, [ = ]( bool folded ) { fold( Qt::BottomEdge, folded ); } );
         }
+        mInitialized = true;
       }
       break;
     }
@@ -340,6 +364,7 @@ void QgsModelComponentGraphicItem::updateToolTip( const QPointF &pos )
 
 void QgsModelComponentGraphicItem::fold( Qt::Edge edge, bool folded )
 {
+  emit aboutToChange( !folded ? tr( "Expand Item" ) : tr( "Collapse Item" ) );
   mComponent->setLinksCollapsed( edge, folded );
   // also need to update the model's stored component
 
@@ -353,6 +378,7 @@ void QgsModelComponentGraphicItem::fold( Qt::Edge edge, bool folded )
 
   prepareGeometryChange();
   emit updateArrowPaths();
+  emit changed();
   update();
 }
 
@@ -602,6 +628,7 @@ void QgsModelParameterGraphicItem::deleteComponent()
     }
     else
     {
+      emit aboutToChange( tr( "Delete Input %1" ).arg( param->description() ) );
       model()->removeModelParameter( param->parameterName() );
       emit changed();
       emit requestModelRepaint();
@@ -772,6 +799,7 @@ void QgsModelChildAlgorithmGraphicItem::deleteComponent()
 {
   if ( const QgsProcessingModelChildAlgorithm *child = dynamic_cast< const QgsProcessingModelChildAlgorithm * >( component() ) )
   {
+    emit aboutToChange( tr( "Remove %1" ).arg( child->algorithm() ? child->algorithm()->displayName() : tr( "Algorithm" ) ) );
     if ( !model()->removeChildAlgorithm( child->childId() ) )
     {
       QMessageBox::warning( nullptr, QObject::tr( "Could not remove algorithm" ),
@@ -875,6 +903,7 @@ void QgsModelOutputGraphicItem::deleteComponent()
 {
   if ( const QgsProcessingModelOutput *output = dynamic_cast< const QgsProcessingModelOutput * >( component() ) )
   {
+    emit aboutToChange( tr( "Delete Output %1" ).arg( output->description() ) );
     model()->childAlgorithm( output->childId() ).removeModelOutput( output->name() );
     model()->updateDestinationParameters();
     emit changed();
@@ -967,6 +996,7 @@ void QgsModelCommentGraphicItem::deleteComponent()
 {
   if ( QgsProcessingModelComment *comment = modelComponent() )
   {
+    emit aboutToChange( tr( "Delete Comment" ) );
     comment->setDescription( QString() );
     emit changed();
     emit requestModelRepaint();

diff --git a/src/gui/processing/models/qgsmodelcomponentgraphicitem.h b/src/gui/processing/models/qgsmodelcomponentgraphicitem.h
@@ -108,6 +108,7 @@ class GUI_EXPORT QgsModelComponentGraphicItem : public QGraphicsObject
     void setFont( const QFont &font );
 
     void mouseDoubleClickEvent( QGraphicsSceneMouseEvent *event ) override;
+    void mouseReleaseEvent( QGraphicsSceneMouseEvent *event ) override;
     void hoverEnterEvent( QGraphicsSceneHoverEvent *event ) override;
     void hoverMoveEvent( QGraphicsSceneHoverEvent *event ) override;
     void hoverLeaveEvent( QGraphicsSceneHoverEvent *event ) override;
@@ -188,6 +189,15 @@ class GUI_EXPORT QgsModelComponentGraphicItem : public QGraphicsObject
      */
     void requestModelRepaint();
 
+    /**
+     * Emitted when the definition of the associated component is about to be changed
+     * by the item.
+     *
+     * The \a text argument gives the translated text describing the change about to occur, and the
+     * optional \a id can be used to group the associated undo commands.
+     */
+    void aboutToChange( const QString &text, int id = 0 );
+
     /**
      * Emitted when the definition of the associated component is changed
      * by the item.
@@ -288,6 +298,7 @@ class GUI_EXPORT QgsModelComponentGraphicItem : public QGraphicsObject
     QFont mFont;
 
     bool mIsHovering = false;
+    bool mIsMoving = false;
 
 };
 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsModelComponentGraphicItem::Flags )