[sugar] Supporting desktop applications, extending the EWMH spec

[Sayamindu Dasgupta]

Hello all,
Marco and I have been discussing on how to make a window manager like
Metacity fit into the Sugar environment, and based on our current
discussions, as well as past discussions, it seems clear that we need
changes to the Extended Window Manager Hints spec[1]. For details on
why we want to do that, take a look at the first draft of the proposal
at http://dev.laptop.org/~sayamindu/sugar_metacity/draft_1.txt

The simplest way to do this is mentioned in the draft, namely, to have
a new _NET_WM_WINDOW_TYPE hint, called _NET_WM_WINDOW_TYPE_NETBOOK_APP
(feel free to suggest a better name :-P). All sugar activities are
hinted as _NET_WM_WINDOW_TYPE_NETBOOK_APP, and the window manager
maximizes and undecorates them.

However, Marco suggests that for applications like Firefox, or
Thunderbird, we may actually want them to be in maximized+undecorated
in Sugar as well, to maximize screen real estate usage. In such a
situation, things become a bit more complicated. Marco suggests a
double hint, some thing like _NET_WM_WINDOW_TYPE_NORMAL |
_NET_WM_WINDOW_TYPE_APPLICATION. In a "normal" desktop environment the
second _NET_WM_WINDOW_TYPE_APPLICATION will not have any effect, but
in Sugar, _NET_WM_WINDOW_TYPE_APPLICATION will be honoured, and
windows having this hint will be maximized + undecorated.

However, this brings up two problems
a) applications like firefox will need to be modified so that they set
the _NET_WM_WINDOW_TYPE_APPLICATION hint (ideally we would like to run
the applications unmodified).
b) one of the major reasons why we can do away with the decorations in
case of sugar activities is that they are designed to work well
without decorations (eg: a large close button on the window itself).
otoh, most desktop applications do not have this, and the close button
is usually somewhere hidden in the menu. In some cases the close
button may not be accessible at all (eg: a rogue popup in firefox
which somehow circumvents the popup blocker and disables the menubar).
Note that this is a problem with the existing Firefox activity as
well.

We would like to have inputs and suggestions on this issue before
going ahead and making a proposal to the EWMH maintainers.

Thanks,
Sayamindu


[1] http://standards.freedesktop.org/wm-spec/wm-spec-1.3.html

-- 
Sayamindu Dasgupta
[http://sayamindu.randomink.org/ramblings]