QDockWidgetGroupWindow::adjustFlags() - don't show() empty group window

The method calls show() on a dock widget group window, when the window
flags have changed. When all of its contained, tabbed dock widgets are
programmatically hidden or docked on the main window, an empty group
window is shown.

This patch implements bool hasVisibleDockWidgets(). It returns true, if
at least one of the group window's dockwidget children is not hidden.
It replaces show() by setVisible(), passing the return value of
hasVisibleChildren().

It adapts tst_QDockWidget::floatingTabs() to test the fix.
(Drive-by: remove dead code)

Fixes: QTBUG-115058
Pick-to: 6.6 6.5 6.2
Change-Id: Ifb8e2450e91a7c78decc06f592e160631ca2faf5
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 12 insertions, 3 deletions

diff --git a/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp b/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
index a91ea4a37a..0de5fadfc5 100644
--- a/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
+++ b/tests/auto/widgets/widgets/qdockwidget/tst_qdockwidget.cpp
@@ -1362,8 +1362,6 @@ void tst_QDockWidget::floatingTabs()
 
     // Both dock widgets must no longer be floating
     // disabled due to flakiness on macOS and Windows
-    //QTRY_VERIFY(!d1->isFloating());
-    //QTRY_VERIFY(!d2->isFloating());
     if (d1->isFloating())
         qWarning("OS flakiness: D1 is docked and reports being floating");
     if (d2->isFloating())
@@ -1371,7 +1369,18 @@ void tst_QDockWidget::floatingTabs()
 
     // Now MainWindow has to have a floatingTab child
     QPointer<QDockWidgetGroupWindow> ftabs;
-    QTRY_VERIFY(checkFloatingTabs(mainWindow, ftabs, QList<QDockWidget*>() << d1 << d2));
+    QTRY_VERIFY(checkFloatingTabs(mainWindow, ftabs, QList<QDockWidget *>() << d1 << d2));
+
+    // Hide both dock widgets. Verify that the group window is also hidden.
+    qCDebug(lcTestDockWidget) << "*** Hide and show tabbed dock widgets ***";
+    d1->hide();
+    d2->hide();
+    QTRY_VERIFY(ftabs->isHidden());
+
+    // Show both dockwidgets again. Verify that the group window is visible.
+    d1->show();
+    d2->show();
+    QTRY_VERIFY(ftabs->isVisible());
 
     /*
      * replug both dock widgets into their initial position