Problems when adding a combo box to a toolbar and KActionCollection in KF6

[Stefano Crocco]

On lunedì 30 ottobre 2023 01:11:27 CET Nicolas Fella wrote:
> On 10/29/23 18:38, Stefano Crocco wrote:
> > Hello to everyone,
> > while porting Konqueror to KF6, I've hit a problem I don't know how to
> > solve. The issue is that it's impossible to give focus to the location
> > bar by clicking on it with the mouse as you can do in KF5.
> > 
> > After spending some hours trying to find out the cause of this, I reached
> > the conclusion that it has something to do with the main window's
> > actionCollection. A shortened version of the code which creates the
> > location bar is the following:
> > 
> > KonqMainWindow::KonqMainWindow() : KParts::MainWindow()
> > {
> > 
> >    //...
> >    m_combo = new KonqCombo(nullptr) //KonqCombo derives from
> >    KHistoryComboBox
> >    //...
> >    QWidgetAction *comboAction = new QWidgetAction(this);
> >    actionCollection()->addAction(QStringLiteral("toolbar_url_combo"),
> > 
> > comboAction);
> > 
> >   comboAction->setDefaultWidget(m_combo);
> >   
> >    //...
> >    setXMLFile(QStringLiteral("konqueror.rc"));
> >    createGUI(nullptr);
> > 
> > //"locationToolBar" is the name of the toolbar where the widget should be
> > //inserted
> > 
> >    m_combo->setParent(toolBar(QStringLiteral("locationToolBar")));
> >    m_combo->show();
> >   
> >   //...
> > 
> > }
> > 
> > If I remove the addAction method, the location bar is, of course,
> > displayed
> > floating above the toolbar and it can be given focus clicking on it with
> > the mouse. The same happens if I remove the setDefaultWidget line. I
> > tried adding the action to the toolbar using
> > 
> > QAction *a =
> > toolBar(QStringLiteral("locationToolBar"))->addWidget(m_combo);
> > actionCollection()->addAction(QStringLiteral("toolbar_url_combo"), a);
> > 
> > This gives the same problem as the previous code; however, if I remove the
> > second line, the focus works correctly again. This is what made me suppose
> > the problem is related to KActionCollection.
> > 
> > Initially, I thought that the problem was caused by some event filter or
> > event handler, so I tried creating a different action with new QComboBox,
> > new action name and so on, but the results were the same. Also, using a
> > QLineEdit instead of a QComboBox changed nothing.
> > 
> > I tried looking at the source code of KActionCollection, but I couldn't
> > find any significant difference between the KF5 and the KF6 version. The
> > same can be said for Konqueror source code, however.
> > 
> > Can someone give me some hints about what's happening?
> > 
> > Thanks in advance
> > 
> > Stefano
> 
> Hi,
> 
> focus and toolbar brings
> https://invent.kde.org/frameworks/kxmlgui/-/merge_requests/188 to my
> mind. Can  you check whether it works as you expect before that change?

Yes, without that change, everything works correctly. Thanks for the 
information.

Do you think it would make sense to create a merge request for kxmlgui so that 
the focus policy is only changed if it doesn't include TabFocus? Otherwise, I 
can just manually set the combo box focus policy.

Stefano