Re: Compositing managers spec

[Fredrik Höglund <fredrik kde org>]

On Wednesday 30 January 2008 23:41, Carsten Haitzler wrote:
[...]
> * please provide a solid background even if my window is ARGB because i am
> allowing the wm border/decoration to define the backing of my window and the
> contents should be composited over whatever backing the WM provides (the
> problem with window decorations is that they are separate from window
> background. it is impossible to reliably have a titlebar seamlessly continue
> into the app window with textures, patterns, shading etc. without fastidiously
> fixing up themes/widgets/whatever of every toolkit. if toolkits were to render
> to ARGB dest windows and simply NOT render a background color/pattern for the
> window, but leave it transparent with all buttons, other widgets, labels
> rendered onto a dest-alpha transparent ARGB window, then the window content is
> a composited overlay on top of a window frame "Decoration" that also defines
> the decorations UNDER the window contents, allowing for smooth transitions from
> titlebars and borders into the window contents).

I think this is a good idea, and it's a problem I've been thinking about
for a while myself.

One comment though is that I think the application still needs to be
able to specify an area (a rectangular one will probably suffice), where
the window background really should be transparent. An application like
konsole or gnome-terminal may want to be able to combine having a
toolbar that blends seamlessly with the window decoration, while at
the same time having a translucent terminal area.

Window managers will also have to advertise support for this feature so
applications can know if they can use it. I imagine that support for this
feature may also depend on the window manager theme being used.

Regards,
Fredrik