Add QMainWindow::GroupedDragging DockOption

If this setting is enabled, the entire group of docked tabs will
be draggable by the title bar of the group and and individual dock
can be dragged by dragging the tab.

When tabs are detached, the docks that are contained are reparented to
a QDockWidgetGroupWindow.

[ChangeLog][QtWidgets][QMainWindow] Added GroupedDragging as a DockOption
which allow users to drag all the tabs together when dragging the
title of a QDockWidget which is tabbed with others.

Change-Id: I5285685b129770498eb3e4fd5f4556e41225a595
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Paul Olav Tvete <paul.tvete@theqtcompany.com>

1 files changed, 22 insertions, 2 deletions

diff --git a/src/widgets/widgets/qmainwindowlayout_p.h b/src/widgets/widgets/qmainwindowlayout_p.h
index 8ccb4d303f..9155c5fb23 100644
--- a/src/widgets/widgets/qmainwindowlayout_p.h
+++ b/src/widgets/widgets/qmainwindowlayout_p.h
@@ -77,6 +77,23 @@ QT_BEGIN_NAMESPACE
 class QToolBar;
 class QRubberBand;
 
+#ifndef QT_NO_DOCKWIDGET
+class QDockWidgetGroupWindow : public QWidget
+{
+    Q_OBJECT
+public:
+    explicit QDockWidgetGroupWindow(QWidget* parent = 0, Qt::WindowFlags f = 0)
+        : QWidget(parent, f) {}
+    QDockAreaLayoutInfo *layoutInfo() const;
+    QDockWidget *topDockWidget() const;
+    void destroyIfEmpty();
+    void adjustFlags();
+protected:
+    bool event(QEvent *) Q_DECL_OVERRIDE;
+    void paintEvent(QPaintEvent*) Q_DECL_OVERRIDE;
+};
+#endif
+
 /* This data structure represents the state of all the tool-bars and dock-widgets. It's value based
    so it can be easilly copied into a temporary variable. All operations are performed without moving
    any widgets. Only when we are sure we have the desired state, we call apply(), which moves the
@@ -196,10 +213,11 @@ public:
                          QDockWidget *dockwidget,
                          Qt::Orientation orientation);
     void tabifyDockWidget(QDockWidget *first, QDockWidget *second);
-    Qt::DockWidgetArea dockWidgetArea(QDockWidget *dockwidget) const;
+    Qt::DockWidgetArea dockWidgetArea(QWidget* widget) const;
     void raise(QDockWidget *widget);
     void setVerticalTabsEnabled(bool enabled);
     bool restoreDockWidget(QDockWidget *dockwidget);
+    QDockAreaLayoutInfo *dockInfo(QWidget *w);
 
 #ifndef QT_NO_TABBAR
     bool _documentMode;
@@ -224,6 +242,8 @@ public:
     void setTabShape(QTabWidget::TabShape tabShape);
     QTabWidget::TabPosition tabPosition(Qt::DockWidgetArea area) const;
     void setTabPosition(Qt::DockWidgetAreas areas, QTabWidget::TabPosition tabPosition);
+
+    QDockWidgetGroupWindow *createTabbedDockWindow();
 #endif // QT_NO_TABWIDGET
 #endif // QT_NO_TABBAR
 
@@ -273,7 +293,7 @@ public:
 
     QList<int> hover(QLayoutItem *widgetItem, const QPoint &mousePos);
     bool plug(QLayoutItem *widgetItem);
-    QLayoutItem *unplug(QWidget *widget);
+    QLayoutItem *unplug(QWidget *widget, bool group = false);
     void revert(QLayoutItem *widgetItem);
     void updateGapIndicator();
     void paintDropIndicator(QPainter *p, QWidget *widget, const QRegion &clip);