Comment 23 for bug 124315

This is not the job of the window because it can't possible done correctly in the window manager. It's that simple. I'd love to have this working correctly in the window manager, but it's logically impossible without application support. Because the window manager doesn't have any way to know that a particular window is "the same" as another.

Devils Pie doesn't work correctly. It uses the names of the windows and the name of the program. Both of these will inevitably fail, as the window title may change according to the document open, the current folder, the current language, and many other factors. Devils Pie has a sophisticated rule system to get around this, however these rules have to be created by a human who knows what he wants. They can't be generated programatically and still do the right thing every time.

It is my opinion that the 100% proper way to handle this would be that the applications could specify a unique id for every window or window "class". Then the window manager could remember the positions correctly.

Maybe X atoms could be used for communicating this ID to the window manager. If the window manager doesn't support this convention, no harm, if an application doesn't support this convention, no harm. But the unfortunate point is, that it still requires application support.

Because currently, applications don't specify anything that would allow the window manager to properly know that some windows are "the same" despite a different window title (and that some windows are not the "same" despite similar window title). And since it can't possible be done correctly in the window manager we have to do it in the applications.