OpenDisplay action side effects on Linux and Windows

[georgweiss]

My users have spotted a new behavior when an action opens a display with target "New Window": the new window will be rendered, resized and moved, but unfortunately put behind the window from which the action was invoked. Upon next action the window - as it already is available - is put to front.

Initial conclusion was that first time the window is not rendered, but this is not the case. It's simply obscured.

Note that this was seen on CentOS7 with xcfe. This behavior is not seen on MacOS (Monterrey). Windows not tested.

If I comment out in DockStage:

 stage.setAlwaysOnTop(true);
 stage.setAlwaysOnTop(false);

I get the wanted/expcted behavior on CentOS7, and I cannot spot any other side effects from commenting these lines.
Seems this was added in commit ecbe7ea.

[kasemir]

The somewhat overkill sequence of

stage.show();
stage.toFront();
stage.setAlwaysOnTop(true);
stage.setAlwaysOnTop(false);

was suggested in #2341 as a part of supporting target=window@1038.. but I think allowing to set the location and size is fundamentally different from popping the window to the front. If the plain show() suffices, I say go with that.

[georgweiss]

For the sake of completeness: the observed issue was also seen on Windows.