To allow restoring layout of windows after client reconnect it's necessary to uniquely identify each window. One such way would be to extend formatting of --title to add @windowid@ to show id of the window on the server. It would also be useful to add such formatting capabilities to window class and instance strings (WM_CLASS) on which windowmanagers often classify the windows.
I think we can easily add support for:
These could be supported too:
But since they are already forwarded, I don't understand why the window manager does not distinguish the windows already using these properties.
I would not want to start modifying the wm-class, I think that will create more problems than it solves.
After looking at the code, I realized that all the attributes are already available for substitution, the only one that needed to be added was "windowid". r12946 does that.
Please close if this works for you.
Not heard back, closing.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1243