Re: Decorations (again)

[Michael ROGERS <M Rogers cs ucl ac uk>]

>I hadn't noticed that we had dropped the Desktop and Dock categories.
>Sorry.  I think that they should be categories, as they are two distinct
>types of window that require special treatment.

I see the categories as visual rather than functional descriptions, hence the 
undecorated category. Functional categories would be nice, but we would have 
to specify a large number of categories to accomodate all possible
behaviours. The combination of visual categories and layer hints allows more
versatility - for example, instead of adding a "pinnable menu" category, we
can combine "toolbar" decorations with the "on top" hint.

I think a combination of the "undecorated" visual category with the 
"below/desktop" hint is enough to distinguish desktop features from other 
windows. Docks might need their own category because the WM will probably 
want to keep them in the same place when the viewport is scrolled. However,
they are not visually any different from other undecorated windows, so it
might be better to add a "sticky" hint (no stacking order connotations 
intended). This would also allow decorated windows to request this behaviour.

>As for only needing 3 layers, what I meant was that a normal window should
>only be able to hint itself into three different positions - normal,
>ontop, below.  We are no longer prescibing how many "layers" there should
>be.  Instead, we tell the WM what *types* of window we have (using the
>categories above) and the WM can sort them into internal "layers" as (and
>if) it sees fit.

I don't think we need layers to allow application windows to be kept on top 
or kept below according to the user's preference. As Dominik has pointed out, 
that option is best provided by the window manager. However, layer hints 
allow an application to specify that a window is *not* a normal application
window, and should be stacked differently *by default* (eg pinnable menus,
desktop shortcuts).

>The more information you give a WM about what the purpose of its windows
>is, the more it can do with them.  I think someone was talking about a WM
>feature whereby all desktop features were temporarily raised to be on top
>of all other windows.  Neat, and it can do this now because desktop
>windows are now labeled as such, and distinguished from normal windows
>that just prefer to be stacked below other windows.

I would call anything which wants to be stacked below other windows a "desktop
feature". That's why I agree with Marko's suggestion of renaming the hint
"desktop".


Michael