[sugar] Supporting desktop applications, extending the EWMH spec

[david at lang.hm]

On Fri, 19 Sep 2008, Sayamindu Dasgupta wrote:

> 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.

_NET_WM_WINDOW_KIOSK would seem to be a little better to me.

netbook_app seems to imply something hardware specific, and it's not at 
all clear that it's appropriate for all netbooks.

kiosk mode implies a specific type of use, which isn't quite the same 
thing, but I think the effect of it would be the same, and that is a term 
that's already understood.

> 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.

you can't cover every case, but even if the menubar is disabled, the 
keystroke combination to close the window works.

David Lang