[Interest] How to implement 3 level windows in Qt (Windows)

[Furkan Uzumcu]

I had a similar problem to this for a Qt Quick application.

I don’t think there’s a Qt specific solution to it on Windows. What I ended up doing is dynamically changing the transient parent of the windows to maintain a particular z-order.

The main window would be the base parent, then when the top level windows become active I change their transient parent to the mid level ones and alter the logic to fit our need. I achieved this with an attached type that exposes a property to specify which order the window should be in and an event filter to watch for window events.

Regards,
Furkan Üzümcü
On Apr 24, 2024 at 10:18 -0400, sivan nanthiran <nanthiran2005 at gmail.com>, wrote:
> Hi all,
>
> I am trying to create a dual screen application which should support 3 levels (z-order) of windows/dialogs. Each level of widgets should be preserved at any given time.
>
> At the base level, a main widget (MainWidget) and an aux dialog (AuxDialog) with MainWidget as its parent. These 2 widgets are ensured that they won't overlap each other as the geometry is handled at all times.
>
> At the mid level, several dialogs can be opened by clicking buttons in the main/aux widget. This dialog is created with Qt::Tool flag and MainWidget as its parent.
>
> The highest level is a modal dialog that can be opened by mid level dialogs or the base level widgets.
>
> > MainWidget mainWidget;
> > AuxDialog auxDialog(mainWidget);
> > MidLevelDialog dlg (Qt::Tool, mainWidget);
> > QDialog dlg; // modal dialog using ::exec()
>
> The following implementation works in MacOS as expected. However, in Windows, midLevel dialog can get behind the Aux dialog.
>
> I have tried the following steps, but it's still not working:
> a) Add Qt::WindowStaysOnTopHint to the midLevelDialog on top of Qt::Tool. This causes the modal dialog to go behind midLevelDialog.
> b) Create midLevelDialog with AuxDialog as the parent instead of MainWidget. Although this works, I still think it should not be this way. Furthermore, in reality, the AuxDialog may/may not be created, and might get deleted midway.
> c) Create modal dialog with midLevel dialog as the parent. But this is not feasible as there can be several midLevel dialogs opened at the same time and only one can be parent.
>
> Could anyone please advice on how to prevent the dialog/widget from getting into the wrong z-order.
>
> Regards,
> Sivan
> _______________________________________________
> Interest mailing list
> Interest at qt-project.org
> https://lists.qt-project.org/listinfo/interest
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20240514/d30b09e6/attachment.htm>