Floating QDockWidget not re-docked by QMainWindow::restoreState

[norobro]

Looks like a bug to me too. But what do we know? Here is the info in the docs for the latest Qt version.

One thing I did notice is (using your scenario):

• Call QMainWindow::saveState on a main window with two docked QDockWidgets which are nested/tabbed
• Float one of the nested/tabbed QDockWidgets, i.e. one will be docked and the other floating
• Call QMainWindow::restoreState - doesn't work.

If you then click the float button (or double click on the top bar) the floating widget will return to tabbed mode. So the app is retaining the information about the previous location of the floated tab. Apparently "saveState()" doesn't return that information to "QSettings.setValue".

I've never filed a bug report either. I'd appreciate it if you'd post back about what happens.

[stefanadelbert]

I get the same behaviour on my side when double clicking the QDockWidget titlebar.

I'll go one step further though and say that it's not the previous state that is being "remembered" by the application. I think the application has the correct state stored for the QDockWidget, but it just isn't applying the "float" property correctly. I suspect this because I'm building an app that has a layout manager allowing the user to save an arbitrary number of layouts (or QMainWindow states) and then restore them from a list in the menu. When switching back to a layout that has tabbed QDockWidgets, the floating ones aren't restored (a la this bug), but double clicking their title bars does restore them correctly. So the app knows where they should be placed (i.e. QMainWindow state was actually restored correctly), but maybe just doesn't call QDockWidget::setFloating correctly.

[stefanadelbert]

Bug already logged (http://bugreports.qt.nokia.com/browse/QTBUG-7921). Would be great if some of you could vote for it to get fixed!

[zulis]

Floating dock widget problem still exists in Qt 5.0.1 I found a workaround. After state restore do this:

if(yourDockWidget->isFloating())
{
    yourDockWidget->setFloating(true);
}

if(yourDockWidget->isFloating())
{
    yourDockWidget->setFloating(true);
}

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And widget becomes dock able again.