Add signal QMainWindow::tabifiedDockWidgetActivated

Task-number: QTBUG-52175
Change-Id: I0d133e9fee1a0d7a7e06b1156c868471c2b3c29f
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Andy Shaw <andy.shaw@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

5 files changed, 30 insertions, 4 deletions

diff --git a/src/widgets/widgets/qdockarealayout.cpp b/src/widgets/widgets/qdockarealayout.cpp
index c14fd5a942..3b185a5e67 100644
--- a/src/widgets/widgets/qdockarealayout.cpp
+++ b/src/widgets/widgets/qdockarealayout.cpp
@@ -1493,8 +1493,10 @@ bool QDockAreaLayoutInfo::hasFixedSize() const
     return perp(o, minimumSize()) == perp(o, maximumSize());
 }
 
-
-void QDockAreaLayoutInfo::apply(bool animate)
+/*! \internal
+    Applies the layout and returns the activated QDockWidget or nullptr.
+ */
+QDockWidget *QDockAreaLayoutInfo::apply(bool animate)
 {
     QWidgetAnimator &widgetAnimator = mainWindowLayout()->widgetAnimator;
 
@@ -1533,6 +1535,8 @@ void QDockAreaLayoutInfo::apply(bool animate)
     }
 #endif // QT_NO_TABBAR
 
+    QDockWidget *activated = nullptr;
+
     for (int i = 0; i < item_list.size(); ++i) {
         QDockAreaLayoutItem &item = item_list[i];
 
@@ -1561,6 +1565,7 @@ void QDockAreaLayoutInfo::apply(bool animate)
             } else if (r.isValid()
                         && (geo.right() < 0 || geo.bottom() < 0)) {
                 emit dw->visibilityChanged(true);
+                activated = dw;
             }
         }
     }
@@ -1568,6 +1573,8 @@ void QDockAreaLayoutInfo::apply(bool animate)
     if (*sep == 1)
         updateSeparatorWidgets();
 #endif //QT_NO_TABBAR
+
+    return activated;
 }
 
 static void paintSep(QPainter *p, QWidget *w, const QRect &r, Qt::Orientation o, bool mouse_over)
diff --git a/src/widgets/widgets/qdockarealayout_p.h b/src/widgets/widgets/qdockarealayout_p.h
index 0ae1350394..591b156902 100644
--- a/src/widgets/widgets/qdockarealayout_p.h
+++ b/src/widgets/widgets/qdockarealayout_p.h
@@ -174,7 +174,7 @@ public:
     QList<int> indexOf(QWidget *widget) const;
     QList<int> indexOfPlaceHolder(const QString &objectName) const;
 
-    void apply(bool animate);
+    QDockWidget *apply(bool animate);
 
     void paintSeparators(QPainter *p, QWidget *widget, const QRegion &clip,
                             const QPoint &mouse) const;
diff --git a/src/widgets/widgets/qmainwindow.cpp b/src/widgets/widgets/qmainwindow.cpp
index f86244172d..5dfa439b2e 100644
--- a/src/widgets/widgets/qmainwindow.cpp
+++ b/src/widgets/widgets/qmainwindow.cpp
@@ -377,6 +377,18 @@ void QMainWindowPrivate::init()
     \sa setToolButtonStyle()
 */
 
+#ifndef QT_NO_DOCKWIDGET
+/*!
+    \fn void QMainWindow::tabifiedDockWidgetActivated(QDockWidget *dockWidget)
+
+    This signal is emitted when the tabified dock widget is activated by
+    selecting the tab. The activated dock widget is passed in \a dockWidget.
+
+    \since 5.8
+    \sa tabifyDockWidget(), tabifiedDockWidgets()
+*/
+#endif
+
 /*!
     Constructs a QMainWindow with the given \a parent and the specified
     widget \a flags.
diff --git a/src/widgets/widgets/qmainwindow.h b/src/widgets/widgets/qmainwindow.h
index aab1448b8f..4622d89e4c 100644
--- a/src/widgets/widgets/qmainwindow.h
+++ b/src/widgets/widgets/qmainwindow.h
@@ -195,6 +195,9 @@ public Q_SLOTS:
 Q_SIGNALS:
     void iconSizeChanged(const QSize &iconSize);
     void toolButtonStyleChanged(Qt::ToolButtonStyle toolButtonStyle);
+#ifndef QT_NO_DOCKWIDGET
+    void tabifiedDockWidgetActivated(QDockWidget *dockWidget);
+#endif
 
 protected:
 #ifndef QT_NO_CONTEXTMENU
diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index 6c05887705..ee6da73302 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -1686,7 +1686,11 @@ void QMainWindowLayout::tabChanged()
     QDockAreaLayoutInfo *info = dockInfo(tb);
     if (info == 0)
         return;
-    info->apply(false);
+
+    QDockWidget *activated = info->apply(false);
+
+    if (activated)
+        emit static_cast<QMainWindow *>(parentWidget())->tabifiedDockWidgetActivated(activated);
 
     if (QWidget *w = centralWidget())
         w->raise();