Z-order Raise() Lower() erroneous behavior

[zxfox]

Please see this video, two windows are drawn and process mouse messages in different order

[zxfox]

Lower(), and Raise() doesn't help

[vaclavslavik]

It's not at all clear even what the problem is from this, let alone what you *do* in your code. Please actually describe what the exact(!) problem is, in what wx version, and what you do -- preferably in the form of small patch against one of the wx samples that allows us to reproduce it.

[sf-robot]

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[Catalin]

Hi,
I encountered the same issue as the one in the video; the video is actually good, but it is not explained.
I suppose this the case in the video too: If you have 2 overlapping panels, an have for them
OnLeftDown( wxMouseEvent& event )
{

this->Lower();

}
you get the behavior in the video - The "lowered" window (panel) will no longer receive the event, but it will still be drawn on top; nothing changes if you also call SetFocus() or Refresh() on the "lowered" window.

It is not a programming error because if you will build the "resizable controls sample" with wxWidgets 2.8.8, and you will overlap the panels and do something to refresh the main window (resize the main window), you will see the odd behavior (it is not exactly as the one in the video but it is related to it, as it uses Raise()). In the original build (with 2.4.2) this does not happen!

 http://de.geocities.com/markusgreither/resizec.htm

On short,
Raise() will make the window that it is called upon to start receiving the mouse events, but from the graphic point of view it is not "on top" - it will be corrupted by the window(s) that should be beneath it
Lower() will make the window stop receiving the events but the window will be drawn on top of all other windows that should overlap it.

I did not check, but I suspect it only happens on wxMSW...

[vadz]

wxWidgets doesn't support overlapped child windows, I really don't think it's worth the hassle and it just doesn't seem to be worth it. Simply don't use them.

[Catalin]

ok, well, allow me to be puzzled, this is a functionality that worked some versions ago and now is broken (it is BROKEN); and then again, what is the purpose of Raise() and Lower() ??
also, forgive my daring, but i really need that functionality, exactly for overlapping child windows (I know, this is a free/open/no charge framework), and the amazing thing is that it was there, and now the answer is that it is not supported?? c'mon.. it sounds like dumb 'corporate' answer to a relevant issue...

[vadz]

If it worked, it was an accident (and I'm far from sure it really always worked, in fact I'm rather sure it didn't work with all windows), feel free looking into mailing list archives for posts in which I advise people not to use overlapping child windows many years ago.

Raise() and Lower() are for top level windows only although, because wxTopLevelWindow didn't originally exist, they unfortunately happen to be defined in wxWindow itself.

Finally, I'm sorry that you're unhappy about my answer but it is not supported, I don't know what is involved in supporting it but it will almost surely result in other problems under other platforms and so I have no intention to do it. If you have a patch fixing this problem without introducing too much complexity and, of course, without breaking anything else, then we'd be glad to apply it but that's about it.

[Catalin]

ok... than this is really bad news...for me. thanks for your quick answers

[wojdyr]

Documentation says:

void wxWindow::Raise()
Raises the window to the top of the window hierarchy (Z-order). In current version of wxWidgets this works both for managed and child windows.

also #799 and #7061 suggest it should work for non-TLW.

If these functions are meant only for TLW, this is a documentation bug.

[FM]

(In [56982]) clarified that Raise() and Lower() only work for wxTopLevelWindows (closes #4717)