Transparent Overlays in C?

Colin Guthrie gmane at
Wed Jan 3 15:50:40 PST 2007

Wolfgang Meyerle wrote:
> Hello,
> currently I'm working on a call monitor applet which shows me the phone
> numbers of the incoming calls on my display via osd.
> For that I'm using the libxosd for now. But I want to overlay more
> phantastic things via OSD like a photo of the caller or sth like that.
> My question is now where can i start off first. Which functions could I
> use for that implementation. I want to use functions that Xorg provides.
> Has anybody done this before?

It's really not as low level as you'd like but have you considered using
"notification daemon"?

Linked from but I cannot access just now
for some reason.

It is a DBus based Freedesktop standard for passive popup style

While it cannot do fancy GL based overlays I've for a long time wanted
someone to create a "theme" for it that makes use of a compositing
manager to make the "notifications" much nicer - transparent etc. etc.!

You can already time you notifications to disappear automatically (with
a countdown timer if you desire) and also embed buttons with callbacks
etc. when clicked.

It would be nice if your project could fit in somehow with this
framework and give something back that would benefit other applications
too :)

Just a thought.


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