Re: Proposing _NET_WM_STATE_FULLSCREEN_EXCLUSIVE

["Ryan C. Gordon" <icculus icculus org>]

> The remaining TODOs, before I post another version, are figuring out how to specify a monitor to go fullscreen on (for Raster's multi-screen coordination scenario), and making sure I didn't have a massive failure to understand X11 (which is totally possible, especially with the root window properties).

Ok, just to make sure this is a sane idea before I write it up:

We want to be able to request a specific monitor to go fullscreen on, and also be able to say "we don't specifically care." The former is to cover Raster's case of a multi-monitor game, and the latter is in hope that the Window Manager will know what the "best" monitor is (maybe a config option for fullscreen things to always be on a certain monitor, or it chooses the "primary" monitor always, etc).

Do we set a hint, totally separate from _NET_WM_STATE for this? _NET_WM_STATE is only concerned with boolean flags: you're either fullscreen or you're not, for example, you can't say "I want to be fullscreen on _this_ specific monitor" within the confines of that hint, because it just wants atoms to be present or not.

So perhaps we set a separate _NET_WM_FULLSCREEN_MONITOR hint with the screen we want, and the WM can act on this hint when it decides to make a window go fullscreen. If this hint isn't set, it means "we don't care what monitor, just give us the resolution we want."

If this approach is totally wrong, I'd love to hear other options.


Two other unrelated n00b questions from me, to make sure I'm understanding the system correctly:

- Should all the places we say "screen" in this spec really say "monitor"? I'm using a lot of overloaded X11 vocabulary interchangeably, and I probably shouldn't.

- Is there always one root window per monitor? I have text for setting a root window property, and it's more useful if it can note the current fullscreen window for that monitor (to cover Martin's concerns). If there's only one root window that covers all monitors, I need to change this to be an array. My understanding is that Xinerama stretches the root window across multiple monitors, but my reading of XRandR is that this isn't true there. You can see the text in question, in both forms, here:

     http://hg.icculus.org/icculus/wm-fullscreen-spec/rev/50b9d9a09539

... the _NET_RESOLUTIONS property as it currently stands is only useful if the app can effectively enumerate multiple root windows, too, or if the app doesn't care what monitor it lands on.

--ryan.