Index: src/app/qgisappinterface.h
===================================================================
--- src/app/qgisappinterface.h	(revision 11821)
+++ src/app/qgisappinterface.h	(working copy)
@@ -87,6 +87,10 @@
     /** Return a pointer to the map canvas used by qgisapp */
     QgsMapCanvas * mapCanvas();
 
+#ifdef HAVE_TABS
+    /** Return a pointer to the main tab widget that containing map canvas */
+    QgsDeskTabWidgetInterface * deskTabWidget();
+#endif
     /** Gives access to main QgisApp object
 
         Plugins don't need to know about QgisApp, as we pass it as QWidget,
Index: src/app/composer/qgscomposer.cpp
===================================================================
--- src/app/composer/qgscomposer.cpp	(revision 11821)
+++ src/app/composer/qgscomposer.cpp	(working copy)
@@ -48,6 +48,11 @@
 #include <QMessageBox>
 #include <QPainter>
 
+#ifdef HAVE_TABS
+#include <QDockWidget>
+#include <QStatusBar>
+#endif
+
 #include <QPrinter>
 #include <QPrintDialog>
 #include <QSettings>
@@ -1264,6 +1269,36 @@
   on_mActionSelectMoveItem_triggered();
 }
 
+#ifdef HAVE_TABS
+void QgsComposer::prepareTabbing()
+{
+  QList< QToolBar * > tbs = mQgis->findChildren< QToolBar * >();
+  foreach( QToolBar *tb, tbs)
+    tb->hide();
+
+//  mQgis->legendDock()->hide();
+//  mQgis->overviewDock()->hide();
+  mQgis->statusBar()->hide();
+
+  mQgis->addToolBar( toolBar );
+  toolBar->show();
+}
+
+void QgsComposer::restoreState( int index )
+{
+  int tabIdx = property( "tabIdx" ).toInt();
+  if ( tabIdx == index )
+  {
+    QByteArray ba = property( "state" ).toByteArray();
+    qDebug() << mQgis->restoreState( ba, index );
+  }
+  else
+  {
+    toolBar->hide();
+  }
+}
+#endif
+
 bool QgsComposer::containsWMSLayer() const
 {
   QMap<QgsComposerItem*, QWidget*>::const_iterator item_it = mItemWidgetMap.constBegin();
Index: src/app/composer/qgscomposer.h
===================================================================
--- src/app/composer/qgscomposer.h	(revision 11821)
+++ src/app/composer/qgscomposer.h	(working copy)
@@ -19,6 +19,7 @@
 #define QGSCOMPOSER_H
 #include "ui_qgscomposerbase.h"
 #include "qgscomposeritem.h"
+#include "qgsconfig.h"
 
 class QgisApp;
 class QgsComposerLabel;
@@ -221,6 +222,11 @@
 
     void setSelectionTool();
 
+#ifdef HAVE_TABS
+    void prepareTabbing();
+    void restoreState( int index );
+#endif
+
   protected:
 
     void paintEvent( QPaintEvent* event );
@@ -231,7 +237,6 @@
     void activate();
 
   private:
-
     /**Establishes the signal slot connection for the class*/
     void connectSlots();
 
Index: src/app/qgisapp.h
===================================================================
--- src/app/qgisapp.h	(revision 11821)
+++ src/app/qgisapp.h	(working copy)
@@ -68,6 +68,14 @@
 #include "qgsfeature.h"
 #include "qgspoint.h"
 
+#ifdef HAVE_TABS
+class QgsFrameWidget;
+class QgsMapOverviewCanvas;
+class QgsDeskTabWidget;
+class QgsLegendTabWidget;
+class QgsAddTabDialog;
+#endif
+
 /*! \class QgisApp
  * \brief Main window for the Qgis application
  */
@@ -141,8 +149,13 @@
     //!Overloaded version of the private function with same name that takes the imagename as a parameter
     void saveMapAsImage( QString, QPixmap * );
     /** Get the mapcanvas object from the app */
-    QgsMapCanvas * mapCanvas() { return mMapCanvas; };
-
+    QgsMapCanvas * mapCanvas() { return mMapCanvas; }
+#ifdef HAVE_TABS
+    /** Get the main (desk) tabwidget object from the app */
+    QgsDeskTabWidget *deskTabWidget() { return mDeskTabWidget; }
+    /** Get the legend tabwidget object from the app */
+    QgsLegendTabWidget *legendTabWidget() { return mLegendTabWidget; }
+#endif
     QgsComposer* printComposer() {return mComposer;}
 
     //! Set theme (icons)
@@ -184,11 +197,12 @@
      * After adding the dock widget to the ui (by delegating to the QMainWindow
      * parent class, it will also add it to the View menu list of docks.*/
     void addDockWidget( Qt::DockWidgetArea area, QDockWidget * dockwidget );
+#ifndef HAVE_TABS
     /** Add a toolbar to the main window. Overloaded from QMainWindow.
      * After adding the toolbar to the ui (by delegating to the QMainWindow
      * parent class, it will also add it to the View menu list of toolbars.*/
     QToolBar *addToolBar( QString name );
-
+#endif
     /** Add window to Window menu. The action title is the window title
      * and the action should raise, unminimize and activate the window. */
     void addWindow( QAction *action );
@@ -198,6 +212,12 @@
 
     //! Actions to be inserted in menus and toolbars
     QAction *actionNewProject() { return mActionNewProject; }
+#ifdef HAVE_TABS
+    QAction *actionNewTab() { return mActionAddTabDialog; }
+    QAction *actionNewCanvasTab() { return mActionCanvasTab; }
+    QAction *actionCloseTab() { return mActionCloseTab; }
+    QAction *actionRestoreTab() { return mActionRestoreTab; }
+#endif
     QAction *actionOpenProject() { return mActionOpenProject; }
     QAction *actionFileSeparator1() { return mActionFileSeparator1; }
     QAction *actionSaveProject() { return mActionSaveProject; }
@@ -393,6 +413,7 @@
     //#endif
     /** toggles whether the current selected layer is in overview or not */
     void isInOverview();
+#ifndef HAVE_TABS
     //! Slot to show the map coordinate position of the mouse cursor
     void showMouseCoordinate( const QgsPoint & );
     //! Slot to show current map scale;
@@ -401,6 +422,7 @@
     void userScale();
     //! Slot to handle user center input;
     void userCenter();
+#endif
     //! Remove a layer from the map and legend
     void removeLayer();
     //! zoom to extent of layer
@@ -432,6 +454,16 @@
     //! Open the project file corresponding to the
     //! text)= of the given action.
     void openProject( QAction *action );
+#ifdef HAVE_TABS
+    void addTabDialog();
+    void addCanvasTab();
+    void closeTab();
+    void restoreTab();
+    void nextTab();
+    void previousTab();
+
+    void updateFrame( QgsFrameWidget *frame );
+#endif
     //! Save the map view as an image - user is prompted for image name using a dialog
     void saveMapAsImage();
     //! Open a project
@@ -482,8 +514,10 @@
     void socketError( QAbstractSocket::SocketError e );
     //! Set project properties, including map untis
     void projectProperties();
+#ifndef HAVE_TABS
     //! Open project properties dialog and show the projections tab
     void projectPropertiesProjections();
+#endif
     /*  void urlData(); */
     //! Show the spatial bookmarks dialog
     void showBookmarks();
@@ -536,20 +570,28 @@
     //! starts/stops editing mode of the current layer
     void toggleEditing();
 
+#ifndef HAVE_TABS
     //! map tool changed
     void mapToolChanged( QgsMapTool *tool );
+#endif
 
     /** Activates or deactivates actions depending on the current maplayer type.
     Is called from the legend when the current legend item has changed*/
     void activateDeactivateLayerRelatedActions( QgsMapLayer* layer );
 
+#ifndef HAVE_TABS
     void showProgress( int theProgress, int theTotalSteps );
     void extentsViewToggled( bool theFlag );
     void showExtents();
     void showStatusMessage( QString theMessage );
+#endif
+#ifdef HAVE_TABS
     void updateMouseCoordinatePrecision();
+#endif
+#ifndef HAVE_TABS
     void hasCrsTransformEnabled( bool theFlag );
     void destinationSrsChanged();
+#endif
     //    void debugHook();
     //! Add a vector layer to the map
     void addVectorLayer();
@@ -591,10 +633,10 @@
 
     //! Toggle map tips on/off
     void toggleMapTips();
-
+#ifndef HAVE_TABS
     //! Show the map tip
     void showMapTip();
-
+#endif
     //! Toggle full screen mode
     void toggleFullScreen();
 
@@ -658,6 +700,7 @@
     bool isValidVectorFileName( QString theFileNameQString );
     /** Overloaded version of the above function provided for convenience that takes a qstring pointer */
     bool isValidVectorFileName( QString * theFileNameQString );
+
     /** add this file to the recently opened/saved projects list
      *  pass settings by reference since creating more than one
      * instance simultaneously results in data loss.
@@ -686,13 +729,22 @@
     void createActionGroups();
     void createMenus();
     void createToolBars();
+#ifndef HAVE_TABS
     void createStatusBar();
+#endif
     void setupConnections();
+#ifndef HAVE_TABS
     void createLegend();
+#else
     void createOverview();
+    void createLegendDock();
+    void createOverviewDock();
+#endif
     void createCanvas();
     bool createDB();
+#ifndef HAVE_TABS
     void createMapTips();
+#endif
 
     // toolbars ---------------------------------------
     QToolBar *mFileToolBar;
@@ -707,6 +759,14 @@
     // actions for menus and toolbars -----------------
 
     QAction *mActionNewProject;
+#ifdef HAVE_TABS
+    QAction *mActionAddTabDialog;
+    QAction *mActionCanvasTab;
+    QAction *mActionNextTab;
+    QAction *mActionPreviousTab;
+    QAction *mActionCloseTab;
+    QAction *mActionRestoreTab;
+#endif
     QAction *mActionOpenProject;
     QAction *mActionFileSeparator1;
     QAction *mActionSaveProject;
@@ -845,6 +905,9 @@
     class Tools
     {
       public:
+#ifdef HAVE_TABS
+        ~Tools();
+#endif
         QgsMapTool* mZoomIn;
         QgsMapTool* mZoomOut;
         QgsMapTool* mPan;
@@ -868,10 +931,15 @@
         QgsMapTool* mDeletePart;
         QgsMapTool* mNodeTool;
         QgsMapTool* mRotatePointSymbolsTool;
+#ifndef HAVE_TABS
     } mMapTools;
+#else
+        QgsMapTool* mCurrentTool;
+    } *mMapTools;
+#endif
 
     QgsMapTool *mNonEditMapTool;
-
+#ifndef HAVE_TABS
     //! Widget that will live on the statusbar to display "scale 1:"
     QLabel * mScaleLabel;
     //! Widget that will live on the statusbar to display scale value
@@ -894,6 +962,7 @@
     QToolButton* mStopRenderButton;
     //! Widget in status bar used to show status of on the fly projection
     QToolButton * mOnTheFlyProjectionStatusButton;
+#endif
     //! Popup menu
     QMenu * mPopupMenu;
     //! Top level plugin menu
@@ -906,6 +975,17 @@
     QMenu *toolPopupCapture;
     //! Map canvas
     QgsMapCanvas *mMapCanvas;
+#ifdef HAVE_TABS
+    friend class QgsFrameWidget;
+    //! Desk (main) tab widget
+    QgsDeskTabWidget *mDeskTabWidget;
+    //! Map overview canvas
+    QgsMapOverviewCanvas *mMapOverviewCanvas;
+    //! Legend tab widget
+    QgsLegendTabWidget *mLegendTabWidget;
+    //! Dialog for adding tab
+    QgsAddTabDialog *mAddTabDialog;
+#endif
     //! Table of contents (legend) for the map
     QgsLegend *mMapLegend;
     //! Cursor for the overview map
@@ -937,8 +1017,10 @@
     //! How to determine the number of decimal places used to
     //! display the mouse position
     bool mMousePrecisionAutomatic;
+#ifdef HAVE_TABS
     //! The number of decimal places to use if not automatic
     unsigned int mMousePrecisionDecimalPlaces;
+#endif
     /** QGIS-internal vector feature clipboard */
     QgsClipboard* mInternalClipboard;
     //! Flag to indicate how the project properties dialog was summoned
@@ -952,6 +1034,7 @@
       */
     QString mRasterFileFilter;
 
+#ifndef HAVE_TABS
     /** Timer for map tips
      */
     QTimer *mpMapTipsTimer;
@@ -966,6 +1049,7 @@
 
     // Flag to indicate if maptips are on or off
     bool mMapTipsVisible;
+#endif
 
     //!flag to indicate whether we are in fullscreen mode or not
     bool mFullScreenMode;
Index: src/app/CMakeLists.txt
===================================================================
--- src/app/CMakeLists.txt	(revision 11821)
+++ src/app/CMakeLists.txt	(working copy)
@@ -108,6 +108,11 @@
   attributetable/qgsattributetabledelegate.cpp
   )
 
+IF (HAVE_TABS)
+  SET (QGIS_APP_SRCS ${QGIS_APP_SRCS}
+    qgsframewidget.cpp
+  )
+ENDIF (HAVE_TABS)
 
 SET (QGIS_APP_MOC_HDRS
   qgisapp.h
@@ -193,6 +198,12 @@
   attributetable/qgsattributetabledelegate.h
   )
 
+IF (HAVE_TABS)
+  SET (QGIS_APP_MOC_HDRS ${QGIS_APP_MOC_HDRS}
+    qgsframewidget.h
+  )
+ENDIF (HAVE_TABS)
+
 IF (POSTGRES_FOUND)
   IF(HAVE_PGCONFIG)
     ADD_DEFINITIONS(-DHAVE_PGCONFIG=1)
Index: src/app/qgisapp.cpp
===================================================================
--- src/app/qgisapp.cpp	(revision 11821)
+++ src/app/qgisapp.cpp	(working copy)
@@ -138,6 +138,12 @@
 #include "qgsvectorlayer.h"
 #include "ogr/qgsopenvectorlayerdialog.h"
 #include "qgsattributetabledialog.h"
+#ifdef HAVE_TABS
+#include "qgsframewidget.h"
+#include "tabs/qgsaddtabdialog.h"
+#include "tabs/qgsdesktabwidget.h"
+#include "tabs/qgslegendtabwidget.h"
+#endif
 //
 // Gdal/Ogr includes
 //
@@ -326,6 +332,10 @@
 // constructor starts here
 QgisApp::QgisApp( QSplashScreen *splash, QWidget * parent, Qt::WFlags fl )
     : QMainWindow( parent, fl ),
+#ifdef HAVE_TABS
+    mMapCanvas( 0 ),
+    mMapLegend( 0 ),
+#endif
     mSplash( splash ),
     mComposer( 0 ),
     mPythonConsole( NULL ),
@@ -356,22 +366,34 @@
 
   mSplash->showMessage( tr( "Setting up the GUI" ), Qt::AlignHCenter | Qt::AlignBottom );
   qApp->processEvents();
-
-
-
+#ifdef HAVE_TABS
+  setDockOptions(QMainWindow::ForceTabbedDocks);
+#endif
   createActions();
   createActionGroups();
   createMenus();
   createToolBars();
+#ifndef HAVE_TABS
   createStatusBar();
+#endif
+#ifdef HAVE_TABS
+  createOverview();
+  createOverviewDock();
+#endif
   createCanvas();
   mMapCanvas->freeze();
+#ifdef HAVE_TABS
+  createLegendDock();
+#else
   createLegend();
   createOverview();
   createMapTips();
+#endif
   readSettings();
   updateRecentProjectPaths();
-
+#ifdef HAVE_TABS
+  mAddTabDialog = new QgsAddTabDialog(); // Dialog for opening tabs
+#endif
   mComposer = new QgsComposer( this ); // Map composer
   mInternalClipboard = new QgsClipboard; // create clipboard
   mQgisInterface = new QgisAppInterface( this ); // create the interfce
@@ -452,9 +474,9 @@
   restoreWindowState();
 
   mSplash->showMessage( tr( "QGIS Ready!" ), Qt::AlignHCenter | Qt::AlignBottom );
-
+#ifndef HAVE_TABS
   mMapTipsVisible = false;
-
+#endif
   // setup drag drop
   setAcceptDrops( true );
 
@@ -471,9 +493,7 @@
 
 QgisApp::~QgisApp()
 {
-  delete mInternalClipboard;
-  delete mQgisInterface;
-
+#ifndef HAVE_TABS
   delete mMapTools.mZoomIn;
   delete mMapTools.mZoomOut;
   delete mMapTools.mPan;
@@ -496,7 +516,11 @@
   delete mMapTools.mDeletePart;
   delete mMapTools.mAddIsland;
   delete mMapTools.mNodeTool;
+#endif
 
+  delete mInternalClipboard;
+  delete mQgisInterface;
+
   delete mPythonConsole;
   delete mPythonUtils;
 
@@ -599,6 +623,44 @@
   mActionExit->setMenuRole( QAction::QuitRole ); // put in Application menu on Mac OS X
   connect( mActionExit, SIGNAL( triggered() ), this, SLOT( fileExit() ) );
 
+#ifdef HAVE_TABS
+  mActionAddTabDialog = new QAction( getThemeIcon( "mActionAddTabDialog.png" ), tr( "New &Tab" ), this );
+  shortcuts->registerAction( mActionAddTabDialog, tr( "Ctrl+T", "New Tab" ) );
+  //  mActionNewCanvas->setShortcut( QKeySequence::AddTab );
+  mActionAddTabDialog->setStatusTip( tr( "New Tab" ) );
+  connect( mActionAddTabDialog, SIGNAL( triggered() ), this, SLOT(addTabDialog()) );
+
+  mActionCanvasTab = new QAction( getThemeIcon( "mActionCanvasTab.png" ), tr( "New &canvas" ), this );
+//  shortcuts->registerAction( mActionCanvasTab, tr( "Ctrl+T", "New Canvas" ) );
+  //  mActionNewCanvas->setShortcut( QKeySequence::AddTab );
+  mActionCanvasTab->setStatusTip( tr( "New canvas" ) );
+  connect( mActionCanvasTab, SIGNAL( triggered() ), this, SLOT(addCanvasTab()) );
+
+  mActionCloseTab = new QAction( getThemeIcon( "mActionCloseTab.png" ), tr( "&Close Tab" ), this );
+  shortcuts->registerAction( mActionCloseTab, tr( "Ctrl+W", "Close Tab" ) );
+  //  mActionCloseTab->setShortcut( QKeySequence::Close );
+  mActionCloseTab->setStatusTip( tr( "Close Tab" ) );
+  connect( mActionCloseTab, SIGNAL( triggered() ), this, SLOT(closeTab()) );
+
+  mActionRestoreTab = new QAction( getThemeIcon( "mActionRestoreTab.png" ), tr( "&Restore Tab" ), this );
+  shortcuts->registerAction( mActionRestoreTab, tr( "Ctrl+Shift+T", "Restore Tab" ) );
+  mActionRestoreTab->setStatusTip( tr( "Restore Tab" ) );
+  mActionRestoreTab->setEnabled( false );
+  connect( mActionRestoreTab, SIGNAL( triggered() ), this, SLOT(restoreTab()) );
+
+  // create actions that helps user to navigate in tabs
+  mActionNextTab = new QAction(this);
+  shortcuts->registerAction( mActionNextTab, tr( "Ctrl+Tab", "Goto next tab" ) );
+    mActionNextTab->setShortcut(QKeySequence::NextChild);
+  connect(mActionNextTab, SIGNAL(triggered()), this, SLOT(nextTab()));
+  addAction(mActionNextTab);
+
+  mActionPreviousTab = new QAction(this);
+  shortcuts->registerAction( mActionPreviousTab, tr( "Ctrl+Shift+Tab", "Goto previous tab" ) );
+  //  mActionPreviousTab->setShortcut(QKeySequence::PreviousChild);
+  connect(mActionPreviousTab, SIGNAL(triggered()), this, SLOT(previousTab()));
+  addAction(mActionPreviousTab);
+#endif
   // Edit Menu Items
 
 #if 0
@@ -1146,6 +1208,10 @@
 
   mFileMenu->addAction( mActionNewProject );
   mFileMenu->addAction( mActionOpenProject );
+#ifdef HAVE_TABS
+  mFileMenu->addAction( mActionAddTabDialog );
+  mFileMenu->addAction( mActionCanvasTab );
+#endif
   mRecentProjectsMenu = mFileMenu->addMenu( tr( "&Open Recent Projects" ) );
   // Connect once for the entire submenu.
   connect( mRecentProjectsMenu, SIGNAL( triggered( QAction * ) ),
@@ -1166,6 +1232,10 @@
   mFileMenu->addAction( mActionPrintComposer );
   mActionFileSeparator4 = mFileMenu->addSeparator();
 
+#ifdef HAVE_TABS
+  mFileMenu->addAction( mActionRestoreTab );
+  mFileMenu->addAction( mActionCloseTab );
+#endif
   mFileMenu->addAction( mActionExit );
 
   // Edit Menu
@@ -1465,6 +1535,7 @@
   mToolbarMenu->addAction( mHelpToolBar->toggleViewAction() );
 }
 
+#ifndef HAVE_TABS
 void QgisApp::createStatusBar()
 {
   //
@@ -1596,6 +1667,7 @@
   statusBar()->addPermanentWidget( mOnTheFlyProjectionStatusButton, 0 );
   statusBar()->showMessage( tr( "Ready" ) );
 }
+#endif
 
 
 void QgisApp::setTheme( QString theThemeName )
@@ -1623,11 +1695,17 @@
   QgsApplication::setThemeName( theThemeName );
   //QgsDebugMsg("Setting theme to \n" + theThemeName);
   mActionNewProject->setIcon( getThemeIcon( "/mActionFileNew.png" ) );
+#ifdef HAVE_TABS
+  mActionCanvasTab->setIcon( getThemeIcon( "/mActionCanvasTab.png" ) );
+#endif
   mActionOpenProject->setIcon( getThemeIcon( "/mActionFileOpen.png" ) );
   mActionSaveProject->setIcon( getThemeIcon( "/mActionFileSave.png" ) );
   mActionSaveProjectAs->setIcon( getThemeIcon( "/mActionFileSaveAs.png" ) );
   mActionPrintComposer->setIcon( getThemeIcon( "/mActionFilePrint.png" ) );
   mActionSaveMapAsImage->setIcon( getThemeIcon( "/mActionSaveMapAsImage.png" ) );
+#ifdef HAVE_TABS
+  mActionCloseTab->setIcon( getThemeIcon( "/mActionCloseTab.png" ) );
+#endif
   mActionExit->setIcon( getThemeIcon( "/mActionFileExit.png" ) );
   mActionAddOgrLayer->setIcon( getThemeIcon( "/mActionAddOgrLayer.png" ) );
   mActionAddRasterLayer->setIcon( getThemeIcon( "/mActionAddRasterLayer.png" ) );
@@ -1703,6 +1781,7 @@
 {
   // connect the "cleanup" slot
   connect( qApp, SIGNAL( aboutToQuit() ), this, SLOT( saveWindowState() ) );
+#ifndef HAVE_TABS
   //connect the legend, mapcanvas and overview canvas to the registry
 
   // connect map layer registry signals to legend
@@ -1736,21 +1815,66 @@
   // Do we really need this ??? - its already connected to the esc key...TS
   //
   connect( mStopRenderButton, SIGNAL( clicked() ), this, SLOT( stopRendering() ) );
-
+#endif
   // Connect warning dialog from project reading
   connect( QgsProject::instance(), SIGNAL( oldProjectVersionWarning( QString ) ),
            this, SLOT( oldProjectVersionWarning( QString ) ) );
-
+#ifndef HAVE_TABS
   connect( QgsProject::instance(), SIGNAL( layerLoaded( int, int ) ), this, SLOT( showProgress( int, int ) ) );
-
+#endif
   // setup undo/redo actions
   connect( mActionUndo, SIGNAL( triggered() ), mUndoWidget, SLOT( undo() ) );
   connect( mActionRedo, SIGNAL( triggered() ), mUndoWidget, SLOT( redo() ) );
   connect( mUndoWidget, SIGNAL( undoStackChanged() ), this, SLOT( updateUndoActions() ) );
 }
 
+#ifdef HAVE_TABS
+// it needs here to init map canvas, map legend, map overview and tools
+void QgisApp::updateFrame( QgsFrameWidget *frame )
+{
+  // update main controls of QGis
+  mMapCanvas = frame->mapCanvas();
+  mMapLegend = frame->mapLegend();
+  mMapTools = frame->mapTools();
+  mMapOverviewCanvas = frame->mapOverviewCanvas();
+
+  // update state of controls
+  mMapCanvas->setMapTool( mMapTools->mCurrentTool );
+  mMapLegend->setMapCanvas( mMapCanvas );
+
+  mMapCanvas->enableOverviewMode( mMapOverviewCanvas );
+  mMapOverviewCanvas->setMapCanvas( mMapCanvas );
+  mOverviewDock->setWidget(mMapOverviewCanvas);
+
+  int idx = frame->mapCanvas()->property("idx").toInt();
+  mLegendTabWidget->setCurrentIndex(idx);
+
+  // set status bar for tabbed mapCanvas
+  if (frame->objectName() != "theFrameWidgetFloat")
+  {
+    // set parent of current statusBar to NULL if do not do it statusBar will be removed
+    if (findChild<QStatusBar *>())
+      statusBar()->setParent( 0 );
+    setStatusBar( frame->statusBar() );
+  }
+//  mMapCanvas->refresh(); // TODO is it needed ???
+//  mMapCanvas->setExtent(mMapCanvas->extent());
+}
+#endif
+
 void QgisApp::createCanvas()
 {
+#ifdef HAVE_TABS
+  // create the main tab widgets
+  mDeskTabWidget = new QgsDeskTabWidget( this );
+  mLegendTabWidget = new QgsLegendTabWidget(this);
+
+  // create frame (map canvas, map legend, map overview and tools) and add map canvas to tab
+  mDeskTabWidget->addFrameTab( "Canvas 1" );
+  mDeskTabWidget->updateFrameAt(0);
+
+  setCentralWidget( mDeskTabWidget );
+#else
   // "theMapCanvas" used to find this canonical instance later
   mMapCanvas = new QgsMapCanvas( this, "theMapCanvas" );
   mMapCanvas->setWhatsThis( tr( "Map canvas. This is where raster and vector "
@@ -1811,11 +1935,28 @@
   mMapTools.mRotatePointSymbolsTool->setAction( mActionRotatePointSymbols );
   //ensure that non edit tool is initialised or we will get crashes in some situations
   mNonEditMapTool = mMapTools.mPan;
+#endif
 }
 
+#ifdef HAVE_TABS
 void QgisApp::createOverview()
 {
   // overview canvas
+  mMapOverviewCanvas = new QgsMapOverviewCanvas();
+  mMapOverviewCanvas->setWhatsThis( tr( "Map overview canvas. This canvas can be used to display a locator map that shows the current extent of the map canvas. The current extent is shown as a red rectangle. Any layer on the map can be added to the overview canvas." ) );
+
+  QBitmap overviewPanBmp = QBitmap::fromData( QSize( 16, 16 ), pan_bits );
+  QBitmap overviewPanBmpMask = QBitmap::fromData( QSize( 16, 16 ), pan_mask_bits );
+  mOverviewMapCursor = new QCursor( overviewPanBmp, overviewPanBmpMask, 0, 0 ); //set upper left corner as hot spot - this is better when extent marker is small; hand won't cover the marker
+  mMapOverviewCanvas->setCursor( *mOverviewMapCursor );
+}
+
+void QgisApp::createOverviewDock()
+{
+#else
+void QgisApp::createOverview()
+{
+  // overview canvas
   QgsMapOverviewCanvas* overviewCanvas = new QgsMapOverviewCanvas( NULL, mMapCanvas );
   overviewCanvas->setWhatsThis( tr( "Map overview canvas. This canvas can be used to display a locator map that shows the current extent of the map canvas. The current extent is shown as a red rectangle. Any layer on the map can be added to the overview canvas." ) );
 
@@ -1823,14 +1964,21 @@
   QBitmap overviewPanBmpMask = QBitmap::fromData( QSize( 16, 16 ), pan_mask_bits );
   mOverviewMapCursor = new QCursor( overviewPanBmp, overviewPanBmpMask, 0, 0 ); //set upper left corner as hot spot - this is better when extent marker is small; hand won't cover the marker
   overviewCanvas->setCursor( *mOverviewMapCursor );
+#endif
+
 //  QVBoxLayout *myOverviewLayout = new QVBoxLayout;
 //  myOverviewLayout->addWidget(overviewCanvas);
 //  overviewFrame->setLayout(myOverviewLayout);
   mOverviewDock = new QDockWidget( tr( "Overview" ), this );
   mOverviewDock->setObjectName( "Overview" );
   mOverviewDock->setAllowedAreas( Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea );
+#ifndef HAVE_TABS
   mOverviewDock->setWidget( overviewCanvas );
+#else
+  mOverviewDock->setWidget( mMapOverviewCanvas );
+#endif
   addDockWidget( Qt::LeftDockWidgetArea, mOverviewDock );
+#ifndef HAVE_TABS
   // add to the Panel submenu
   mPanelMenu->addAction( mOverviewDock->toggleViewAction() );
 
@@ -1844,6 +1992,7 @@
   int action = mySettings.value( "/qgis/wheel_action", 0 ).toInt();
   double zoomFactor = mySettings.value( "/qgis/zoom_factor", 2 ).toDouble();
   mMapCanvas->setWheelAction(( QgsMapCanvas::WheelAction ) action, zoomFactor );
+#endif
 }
 
 void QgisApp::addDockWidget( Qt::DockWidgetArea theArea, QDockWidget * thepDockWidget )
@@ -1859,11 +2008,13 @@
   mPanelMenu->addAction( thepDockWidget->toggleViewAction() );
 
   thepDockWidget->show();
-
+#ifndef HAVE_TABS
   // refresh the map canvas
   mMapCanvas->refresh();
+#endif
 }
 
+#ifndef HAVE_TABS
 QToolBar *QgisApp::addToolBar( QString name )
 {
   QToolBar *toolBar = QMainWindow::addToolBar( name );
@@ -1871,7 +2022,17 @@
   mToolbarMenu->addAction( toolBar->toggleViewAction() );
   return toolBar;
 }
+#endif
+#ifdef HAVE_TABS
+void QgisApp::createLegendDock()
+{
+  mLegendDock = new QDockWidget( tr( "Layers" ), this );
+  mLegendDock->setObjectName( "Legend" );
+  mLegendDock->setAllowedAreas( Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea );
+  mLegendDock->setWidget( mLegendTabWidget );
 
+  addDockWidget( Qt::LeftDockWidgetArea, mLegendDock );
+#else
 void QgisApp::createLegend()
 {
   //legend
@@ -1891,6 +2052,7 @@
   // add to the Panel submenu
   mPanelMenu->addAction( mLegendDock->toggleViewAction() );
   return;
+#endif
 }
 
 bool QgisApp::createDB()
@@ -1920,6 +2082,7 @@
   return TRUE;
 }
 
+#ifndef HAVE_TABS
 void QgisApp::createMapTips()
 {
   // Set up the timer for maptips. The timer is reset everytime the mouse is moved
@@ -1931,6 +2094,7 @@
   // Create the maptips object
   mpMaptip = new QgsMapTip();
 }
+#endif
 
 // Update file menu with the current list of recently accessed projects
 void QgisApp::updateRecentProjectPaths()
@@ -3139,8 +3303,13 @@
   mMapCanvas->mapRenderer()->setProjectionsEnabled( FALSE );
 
   // set the initial map tool
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mPan );
+  mNonEditMapTool = mMapTools->mPan;  // signals are not yet setup to catch this
+#else
   mMapCanvas->setMapTool( mMapTools.mPan );
   mNonEditMapTool = mMapTools.mPan;  // signals are not yet setup to catch this
+#endif
 } // QgisApp::fileNew(bool thePromptToSaveFlag)
 
 
@@ -3621,6 +3790,39 @@
 
 } // QgisApp::openProject
 
+#ifdef HAVE_TABS
+void QgisApp::addTabDialog()
+{
+  mAddTabDialog->show();
+}
+
+void QgisApp::addCanvasTab()
+{
+  int index = mDeskTabWidget->addFrameTab( tr("Canvas %1").arg( mDeskTabWidget->count() + 1 ) );
+  mDeskTabWidget->setCurrentIndex( index );
+}
+
+void QgisApp::closeTab()
+{
+  mDeskTabWidget->removeTab( mDeskTabWidget->currentIndex() );
+}
+
+void QgisApp::restoreTab()
+{
+  mDeskTabWidget->restoreTab();
+}
+
+void QgisApp::nextTab()
+{
+  mDeskTabWidget->nextTab();
+}
+
+void QgisApp::previousTab()
+{
+  mDeskTabWidget->previousTab();
+}
+#endif
+
 /**
   Open the specified project file; prompt to save previous project if necessary.
   Used to process a commandline argument or OpenDocument AppleEvent.
@@ -3831,11 +4033,11 @@
       // showMaxmized() is a work-around. Turn off rendering for this as it
       // would otherwise cause two re-renders of the map, which can take a
       // long time.
-      bool renderFlag = mapCanvas()->renderFlag();
-      mapCanvas()->setRenderFlag( false );
+      bool renderFlag = mMapCanvas->renderFlag();
+      mMapCanvas->setRenderFlag( false );
       showNormal();
       showMaximized();
-      mapCanvas()->setRenderFlag( renderFlag );
+      mMapCanvas->setRenderFlag( renderFlag );
       mPrevScreenModeMaximized = false;
     }
     else
@@ -3930,7 +4132,7 @@
 {
   QgsDebugMsg( "hiding all layers!" );
 
-  legend()->selectAll( false );
+  mMapLegend->selectAll( false );
 }
 
 
@@ -3939,7 +4141,7 @@
 {
   QgsDebugMsg( "Showing all layers!" );
 
-  legend()->selectAll( true );
+  mMapLegend->selectAll( true );
 }
 
 
@@ -3947,7 +4149,11 @@
 {
   QgsDebugMsg( "Setting map tool to zoomIn" );
 
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mZoomIn );
+#else
   mMapCanvas->setMapTool( mMapTools.mZoomIn );
+#endif
 
   // notify the project we've made a change
   QgsProject::instance()->dirty( true );
@@ -3956,8 +4162,11 @@
 
 void QgisApp::zoomOut()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mZoomOut );
+#else
   mMapCanvas->setMapTool( mMapTools.mZoomOut );
-
+#endif
   // notify the project we've made a change
   QgsProject::instance()->dirty( true );
 }
@@ -3972,7 +4181,11 @@
 
 void QgisApp::pan()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mPan );
+#else
   mMapCanvas->setMapTool( mMapTools.mPan );
+#endif
 }
 
 void QgisApp::zoomFull()
@@ -4006,17 +4219,29 @@
 
 void QgisApp::identify()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mIdentify );
+#else
   mMapCanvas->setMapTool( mMapTools.mIdentify );
+#endif
 }
 
 void QgisApp::measure()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mMeasureDist );
+#else
   mMapCanvas->setMapTool( mMapTools.mMeasureDist );
+#endif
 }
 
 void QgisApp::measureArea()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mMeasureArea );
+#else
   mMapCanvas->setMapTool( mMapTools.mMeasureArea );
+#endif
 }
 
 void QgisApp::attributeTable()
@@ -4100,22 +4325,38 @@
 
 void QgisApp::moveFeature()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mMoveFeature );
+#else
   mMapCanvas->setMapTool( mMapTools.mMoveFeature );
+#endif
 }
 
 void QgisApp::simplifyFeature()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mSimplifyFeature );
+#else
   mMapCanvas->setMapTool( mMapTools.mSimplifyFeature );
+#endif
 }
 
 void QgisApp::deleteRing()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mDeleteRing );
+#else
   mMapCanvas->setMapTool( mMapTools.mDeleteRing );
+#endif
 }
 
 void QgisApp::deletePart()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mDeletePart );
+#else
   mMapCanvas->setMapTool( mMapTools.mDeletePart );
+#endif
 }
 
 QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList )
@@ -4273,22 +4514,38 @@
 
 void QgisApp::nodeTool()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mNodeTool );
+#else
   mMapCanvas->setMapTool( mMapTools.mNodeTool );
+#endif
 }
 
 void QgisApp::rotatePointSymbols()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mRotatePointSymbolsTool );
+#else
   mMapCanvas->setMapTool( mMapTools.mRotatePointSymbolsTool );
+#endif
 }
 
 void QgisApp::splitFeatures()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mSplitFeatures );
+#else
   mMapCanvas->setMapTool( mMapTools.mSplitFeatures );
+#endif
 }
 
 void QgisApp::reshapeFeatures()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mReshapeFeatures );
+#else
   mMapCanvas->setMapTool( mMapTools.mReshapeFeatures );
+#endif
 }
 
 void QgisApp::capturePoint()
@@ -4299,7 +4556,11 @@
   }
 
   // set current map tool to select
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mCapturePoint );
+#else
   mMapCanvas->setMapTool( mMapTools.mCapturePoint );
+#endif
 }
 
 void QgisApp::captureLine()
@@ -4309,7 +4570,11 @@
     return;
   }
 
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mCaptureLine );
+#else
   mMapCanvas->setMapTool( mMapTools.mCaptureLine );
+#endif
 }
 
 void QgisApp::capturePolygon()
@@ -4318,12 +4583,20 @@
   {
     return;
   }
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mCapturePolygon );
+#else
   mMapCanvas->setMapTool( mMapTools.mCapturePolygon );
+#endif
 }
 
 void QgisApp::select()
 {
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mSelect );
+#else
   mMapCanvas->setMapTool( mMapTools.mSelect );
+#endif
 }
 
 
@@ -4333,7 +4606,11 @@
   {
     return;
   }
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mVertexAdd );
+#else
   mMapCanvas->setMapTool( mMapTools.mVertexAdd );
+#endif
 
 }
 
@@ -4343,7 +4620,11 @@
   {
     return;
   }
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mVertexMove );
+#else
   mMapCanvas->setMapTool( mMapTools.mVertexMove );
+#endif
 }
 
 void QgisApp::addRing()
@@ -4352,7 +4633,11 @@
   {
     return;
   }
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mAddRing );
+#else
   mMapCanvas->setMapTool( mMapTools.mAddRing );
+#endif
 }
 
 void QgisApp::addIsland()
@@ -4361,7 +4646,11 @@
   {
     return;
   }
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mAddIsland );
+#else
   mMapCanvas->setMapTool( mMapTools.mAddIsland );
+#endif
 }
 
 
@@ -4371,7 +4660,11 @@
   {
     return;
   }
+#ifdef HAVE_TABS
+  mMapCanvas->setMapTool( mMapTools->mVertexDelete );
+#else
   mMapCanvas->setMapTool( mMapTools.mVertexDelete );
+#endif
 }
 
 
@@ -4481,12 +4774,12 @@
 
 void QgisApp::toggleMapTips()
 {
-  mMapTipsVisible = !mMapTipsVisible;
-  // if off, stop the timer
-  if ( !mMapTipsVisible )
-  {
-    mpMapTipsTimer->stop();
-  }
+//  mMapTipsVisible = !mMapTipsVisible;
+//  // if off, stop the timer
+//  if ( !mMapTipsVisible )
+//  {
+//    mpMapTipsTimer->stop();
+//  }  // TODO !!!
 }
 
 void QgisApp::toggleEditing()
@@ -4568,6 +4861,7 @@
   vlayer->triggerRepaint();
 }
 
+#ifndef HAVE_TABS
 void QgisApp::showMouseCoordinate( const QgsPoint & p )
 {
   if ( mMapTipsVisible )
@@ -4601,7 +4895,6 @@
   }
 }
 
-
 void QgisApp::showScale( double theScale )
 {
   if ( theScale >= 1.0 )
@@ -4662,8 +4955,8 @@
   );
   mMapCanvas->refresh();
 }
+#endif
 
-
 // toggle overview status
 void QgisApp::isInOverview()
 {
@@ -5264,6 +5557,7 @@
   mPluginToolBar->removeAction( qAction );
 }
 
+#ifndef HAVE_TABS
 void QgisApp::destinationSrsChanged()
 {
   // save this information to project
@@ -5354,8 +5648,8 @@
     mCoordsEdit->setMinimumWidth( mCoordsEdit->width() );
   }
 } // QgisApp::showExtents
-
-
+#endif
+#ifdef HAVE_TABS
 void QgisApp::updateMouseCoordinatePrecision()
 {
   // Work out what mouse display precision to use. This only needs to
@@ -5383,7 +5677,8 @@
 
   mMousePrecisionDecimalPlaces = dp;
 }
-
+#endif
+#ifndef HAVE_TABS
 void QgisApp::showStatusMessage( QString theMessage )
 {
   statusBar()->showMessage( theMessage );
@@ -5423,6 +5718,7 @@
     }
   }
 }
+
 void QgisApp::projectPropertiesProjections()
 {
   // Driver to display the project props dialog and switch to the
@@ -5430,7 +5726,7 @@
   mShowProjectionTab = true;
   projectProperties();
 }
-
+#endif
 void QgisApp::projectProperties()
 {
   if ( mMapCanvas && mMapCanvas->isDrawing() )
@@ -6273,3 +6569,30 @@
   mActionUndo->setEnabled( canUndo );
   mActionRedo->setEnabled( canRedo );
 }
+
+#ifdef HAVE_TABS
+QgisApp::Tools::~Tools()
+{
+  delete mZoomIn;
+  delete mZoomOut;
+  delete mPan;
+  delete mIdentify;
+  delete mMeasureDist;
+  delete mMeasureArea;
+  delete mCapturePoint;
+  delete mCaptureLine;
+  delete mCapturePolygon;
+  delete mMoveFeature;
+  delete mSplitFeatures;
+  delete mSelect;
+  delete mVertexAdd;
+  delete mVertexMove;
+  delete mVertexDelete;
+  delete mAddRing;
+  delete mAddIsland;
+  delete mSimplifyFeature;
+  delete mDeleteRing;
+  delete mDeletePart;
+  delete mNodeTool;
+}
+#endif
Index: src/app/qgisappinterface.cpp
===================================================================
--- src/app/qgisappinterface.cpp	(revision 11821)
+++ src/app/qgisappinterface.cpp	(working copy)
@@ -30,6 +30,9 @@
 #include "qgsmapcanvas.h"
 #include "qgslegend.h"
 #include "qgsshortcutsmanager.h"
+#ifdef HAVE_TABS
+#include "tabs/qgsdesktabwidget.h"
+#endif
 
 QgisAppInterface::QgisAppInterface( QgisApp * _qgis )
     : qgis( _qgis )
@@ -142,6 +145,13 @@
   return qgis->mapCanvas();
 }
 
+#ifdef HAVE_TABS
+QgsDeskTabWidgetInterface * QgisAppInterface::deskTabWidget()
+{
+  return qgis->deskTabWidget();
+}
+#endif
+
 QWidget * QgisAppInterface::mainWindow()
 {
   return qgis;
Index: src/gui/qgsmapoverviewcanvas.h
===================================================================
--- src/gui/qgsmapoverviewcanvas.h	(revision 11821)
+++ src/gui/qgsmapoverviewcanvas.h	(working copy)
@@ -62,6 +62,10 @@
 
     void updateFullExtent( const QgsRectangle& rect );
 
+#ifdef HAVE_TABS
+    void setMapCanvas( QgsMapCanvas * canvas ) {mMapCanvas = canvas;}
+#endif
+
   public slots:
 
     void hasCrsTransformEnabled( bool flag );
Index: src/gui/CMakeLists.txt
===================================================================
--- src/gui/CMakeLists.txt	(revision 11821)
+++ src/gui/CMakeLists.txt	(working copy)
@@ -28,6 +28,20 @@
 qgsvertexmarker.cpp
 )
 
+IF (HAVE_TABS)
+  SET (QGIS_GUI_SRCS ${QGIS_GUI_SRCS}
+    tabs/qgsaddtabdialog.cpp
+    tabs/qgsdesktabbar.cpp
+    tabs/qgsdesktabwidget.cpp
+    tabs/qgsdesktabwidgetinterface.cpp
+    tabs/qgsfloatcanvaswindow.cpp
+    tabs/qgslegendtabbar.cpp
+    tabs/qgslegendtabwidget.cpp
+    tabs/qgstabbarbase.cpp
+    tabs/qgswidgetregistry.cpp
+  )
+ENDIF (HAVE_TABS)
+ 
 SET(QGIS_GUI_MOC_HDRS
 qgscomposerview.h
 qgsdetaileditemdelegate.h
@@ -43,6 +57,20 @@
 qgsquickprint.h
 )
 
+IF (HAVE_TABS)
+  SET (QGIS_GUI_MOC_HDRS ${QGIS_GUI_MOC_HDRS}
+    tabs/qgsaddtabdialog.h
+    tabs/qgsdesktabbar.h
+    tabs/qgsdesktabwidget.h
+    tabs/qgsdesktabwidgetinterface.h
+    tabs/qgsfloatcanvaswindow.h
+    tabs/qgslegendtabbar.h
+    tabs/qgslegendtabwidget.h
+    tabs/qgstabbarbase.h
+    tabs/qgswidgetregistry.h
+  )
+ENDIF (HAVE_TABS)
+
 QT4_WRAP_CPP(QGIS_GUI_MOC_SRCS ${QGIS_GUI_MOC_HDRS})
 
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR} ../core
@@ -51,6 +79,9 @@
      ${CMAKE_CURRENT_BINARY_DIR}/../ui
      ${GEOS_INCLUDE_DIR}
 )
+IF (HAVE_TABS)
+     INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR} tabs)
+ENDIF (HAVE_TABS)
 IF (WITH_INTERNAL_SPATIALITE)
   INCLUDE_DIRECTORIES(../core/spatialite/headers/spatialite)
 ELSE (WITH_INTERNAL_SPATIALITE)
@@ -130,7 +161,6 @@
 ${CMAKE_CURRENT_BINARY_DIR}/../ui/ui_qgsprojectionselectorbase.h
 )
 
-
 INSTALL(CODE "MESSAGE(\"Installing GUI headers...\")")
 INSTALL(FILES ${QGIS_GUI_HDRS} ${QGIS_GUI_MOC_HDRS} DESTINATION ${QGIS_INCLUDE_DIR})
 
Index: src/gui/qgisinterface.h
===================================================================
--- src/gui/qgisinterface.h	(revision 11821)
+++ src/gui/qgisinterface.h	(working copy)
@@ -19,8 +19,13 @@
 #ifndef QGISINTERFACE_H
 #define QGISINTERFACE_H
 
+#include "qgsconfig.h"
+
 class QAction;
 class QMenu;
+#ifdef HAVE_TABS
+class QIcon;
+#endif
 class QToolBar;
 class QDockWidget;
 class QMainWindow;
@@ -30,6 +35,9 @@
 
 #include <map>
 
+#ifdef HAVE_TABS
+#include "tabs/qgsdesktabwidgetinterface.h"
+#endif
 
 class QgisApp;
 class QgsComposerView;
@@ -107,6 +115,11 @@
     /** Return a pointer to the map canvas */
     virtual QgsMapCanvas * mapCanvas() = 0;
 
+#ifdef HAVE_TABS
+    /** Return a pointer to the main tab widget */
+    virtual QgsDeskTabWidgetInterface * deskTabWidget() = 0;
+#endif
+
     /** Return a pointer to the main window (instance of QgisApp in case of QGIS) */
     virtual QWidget * mainWindow() = 0;
 
Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt	(revision 11821)
+++ CMakeLists.txt	(working copy)
@@ -64,6 +64,13 @@
   ENDIF (WITH_INTERNAL_SPATIALITE)
 ENDIF (WITH_SPATIALITE)
 
+# whether build gui with tabs
+SET (TABBED_GUI TRUE CACHE BOOL "Build QGIS with tabs?")
+
+IF (TABBED_GUI)
+  SET(HAVE_TABS TRUE)
+ENDIF(TABBED_GUI)
+
 # try to configure and build python bindings by default
 SET (WITH_BINDINGS TRUE CACHE BOOL "Determines whether python bindings should be built")
 IF (WITH_BINDINGS)
Index: cmake_templates/qgsconfig.h.in
===================================================================
--- cmake_templates/qgsconfig.h.in	(revision 11821)
+++ cmake_templates/qgsconfig.h.in	(working copy)
@@ -29,5 +29,7 @@
 
 #cmakedefine HAVE_PYTHON
 
+#cmakedefine HAVE_TABS
+
 #endif