Re: Improving work areas with multiple monitors

[Martin Flöser <mgraesslin kde org>]

Am 2018-12-27 22:22, schrieb Alberts Muktupāvels via wm-spec-list:
> Hi,
>
> I would like to improve work area situation with multiple monitors.
> Before writing patches I would like to hear what you think about my
> idea.
>
> First I think there should be new property for struts because existing
> properties can not be used to set struts on edges between two
> monitors. New property could be named _NET_WM_STRUT_AREA and used to
> define rectangular area (x, y, width and height) that should be
> excluded from work area. This property will need to follow at least
> two rules:
> - at least one edge of area must match with monitor edge. The window
> manager must ignore strut if it is not placed at monitor edge.
> - if strut appears on edge between two monitors it should be ignored
> when calculating _NET_WORKAREA to ensure backward compatibility.

sounds fine to me.

As a note: in KWin we allow panels on shared edges to set a strut with 
the existing protocol. We just decided that a strut is not allowed to 
cover a complete screen. Technically it's a violation of the current 
protocol, but might be a better idea than introducing yet another 
property.

It could be a simple textual addition like: "Struts covering a monitor 
completely are ignored for that monitor"

> Next and more important part is new property to allow set work areas
> for multiple monitors. Currently I am thinking it could be
> _NET_WORKAREAS_Dn where n is desktop number. For example if
> _NET_NUMBER_OF_DESKTOPS is set to 3 then there must be
> _NET_WORKAREAS_D0, _NET_WORKAREAS_D1 and _NET_WORKAREAS_D2 properties.
>
> Property would have one or multiple work areas:
> _NET_WORKAREAS_Dn, x, y, width, height CARDINAL[][4]/32

This property I do not understand. What is the area of x, y, width, 
height? Why per desktop?

> Window managers adding support for this would need to add
> _NET_WORKAREAS hint to _NET_SUPPORTED.

And also for the new strut property.

> Does anyone see reasons why this would not work and/or have better
> suggestions?

As a note: KWin is feature frozen for X11. This means we will not add 
support for this. I don't know whether other window managers are still 
interested in extending the protocol. For me it's a thing which has been 
broken for ages and we found a workaround for the problem. I don't see a 
need to fix the "legacy" protocol.

Cheers
Martin