Can STRUTS and DoNotCover coexist ?

[Sasha Vasko <sasha aftercode net>]

Hi all

Sorry to put salt on old wounds, but there are some issues with using 
STRUTS that just don't go away.

Don't get me wrong - I like STRUTS. It is a very good approach to handle 
 any panels that are adjacent to the screen edge, and by no means I 
want to argue points brought forth by

http://mail.gnome.org/archives/wm-spec-list/1999-October/msg00007.html

Now, what I'd like to point out is the problem of panels/docks/taskbars 
that are not placed at the edge of the screen. For example if user wants 
to place kicker/dock/wharf/gpanel/whatever right in the middle of the 
screen ? Not altogether impossible situation if one owns 21" monitor and 
 in fact does not use much more then bunch of terms opened up at the 
same time, making maximization to full screen rather undesirable.
Besides that somewhat extreme situation, there are a plenty of reasons 
for placing docks/panels sufficiently off the edge of the screen.
Additionally there is that issue of handling situation of several 
panels/taskbars piled up on one side of the screen.

For all of the above it involves rather ugly hacks to use STRUTS to 
achieve NoCover semantics, not to say, that sometimes its even 
impossible. Which brings us back to questionable DoNotCover hint.

Its seems evident that something is needed to compliment STRUTS to cover 
 above mentioned situations. It was suggested long ago that we should 
add DoNotCover hint , that when set, will cause window manager to avoid 
placing other windows in entire area covered by the window. Valid 
concerns here were that when something like that is used for AutoHide 
panels - that will cause other windows moved/resized when panels 
unhides. As the result STRUTS was accepted as better alternative.

Here is the idea - instead of proping STRUTS and DoNotCover against each 
other - why don't we make them compliment each other? Apps that are 
placed at the edge of the screen and/or using AutoHide should use 
STRUTS, and those that are in the middle of the screen should use 
DoNotCover.

Now there is another issue with DoNotCover hint. Thing is that 
DoNotCover is somewhat implied for window types of _NET_WM_WINDOW_TYPE_DOCK
_NET_WM_WINDOW_TYPE_TOOLBAR

Therefore it is proposed that instead of adding new _NET_WM_STATE atom - 
we should elaborate more on behaviour of this two types. Adding 
something like that to the _NET_WM_WINDOW_TYPE section:



NET_WM_WINDOW_TYPE_DOCK,_NET_WM_WINDOW_TYPE_TOOLBAR both imply that 
Window manager should use Do Not Cover policy for this windows:
 1) avoid placing other windows in area occupied by windows with this 
types.
 2) whenever window of this type moves or changes its size - other 
windows should be moved/resized to avoid occupying new area of the window.
 3) if _NET_WM_STRUT or _NET_WM_STRUT_PARTIAL is set on the window of 
one of this types - it takes precedence, and Do Not Cover policy will be 
applied to the area specifyed by struts, instead of the whole area of 
the window.



Sasha Vasko