Disable undo/redo menu items if no action available in the stack

src/Gui/MainWindow.cpp

@@ -111,6 +111,15 @@ MainWindow::MainWindow( QWidget *parent ) :
     connect( ProjectManager::getInstance(), SIGNAL( projectUpdated( const QString&, bool ) ),
              this, SLOT( projectUpdated( const QString&, bool ) ) );
 
+    // Undo/Redo
+    connect( UndoStack::getInstance( this ), SIGNAL( canRedoChanged( bool ) ),
+             this, SLOT( canRedoChanged( bool ) ) );
+    connect( UndoStack::getInstance( this ), SIGNAL( canUndoChanged( bool ) ),
+             this, SLOT( canUndoChanged( bool ) ) );
+    canRedoChanged( UndoStack::getInstance( this )->canRedo() );
+    canUndoChanged( UndoStack::getInstance( this )->canUndo() );
+
+
     // Wizard
     m_pWizard = new ProjectWizard( this );
     m_pWizard->setModal( true );
@@ -575,6 +584,16 @@ void    MainWindow::on_actionImport_triggered()
     m_importController->exec();
 }
 
+void    MainWindow::canUndoChanged( bool canUndo )
+{
+    m_ui.actionUndo->setEnabled( canUndo );
+}
+
+void    MainWindow::canRedoChanged( bool canRedo )
+{
+    m_ui.actionRedo->setEnabled( canRedo );
+}
+
 #ifdef DEBUG_CRASHHANDLER
 void    MainWindow::setupCrashTester()
 {

src/Gui/MainWindow.h

@@ -109,6 +109,8 @@ private slots:
     void                    toolButtonClicked( int id );
     void                    projectUpdated( const QString& projectName, bool savedStatus );
     void                    keyboardShortcutChanged( const QString&, const QString& );
+    void                    canUndoChanged( bool canUndo );
+    void                    canRedoChanged( bool canRedo );
 
 signals:
     void translateDockWidgetTitle();

src/Gui/UndoStack.cpp

@@ -40,6 +40,9 @@ UndoStack::UndoStack( QWidget* parent ) : QUndoView( parent )
     connect( ProjectManager::getInstance(), SIGNAL( projectSaved() ),
              m_undoStack, SLOT( setClean() ) );
 
+    connect( m_undoStack, SIGNAL( canRedoChanged(bool) ), this, SIGNAL( canRedoChanged(bool) ) );
+    connect( m_undoStack, SIGNAL( canUndoChanged(bool) ), this, SIGNAL( canUndoChanged(bool) ) );
+
     connect( ProjectManager::getInstance(), SIGNAL( projectClosed() ), this, SLOT( clear() ) );
 }
 
@@ -58,6 +61,16 @@ void    UndoStack::endMacro()
     m_undoStack->endMacro();
 }
 
+bool    UndoStack::canUndo()
+{
+    m_undoStack->canUndo();
+}
+
+bool    UndoStack::canRedo()
+{
+    m_undoStack->canRedo();
+}
+
 void    UndoStack::clear()
 {
     m_undoStack->clear();

src/Gui/UndoStack.h

@@ -40,6 +40,8 @@ class UndoStack : public QUndoView, public QSingleton<UndoStack>
         void        push( QUndoCommand* command );
         void        beginMacro( const QString& text );
         void        endMacro();
+        bool        canUndo();
+        bool        canRedo();
 
     private:
         UndoStack( QWidget* parent );
@@ -53,6 +55,8 @@ class UndoStack : public QUndoView, public QSingleton<UndoStack>
 
     signals:
         void            cleanChanged( bool val );
+        void            canRedoChanged( bool canRedo );
+        void            canUndoChanged( bool canUndo );
 
     friend class        QSingleton<UndoStack>;
 };