Ok commandos, you’ve been asking for it all week

Everyone seemed concerned about window previews in the alt-tab dialog…

20 minutes coding, 30 lines of code added, this composite lark is easy (yeah, right…). Not committed yet, a few bugs remain (note the glitches in the Gossip window corners and the terminal window doesn’t get previewed yet, and obviously the scaling), but I’m confident I’ll be committing it soon.

Changes since the last blog entry: Fix weird crashes at startup, correctly mark screens as having a composite manager, and do drawings on an idle function so that we can compact redraw operations.

To answer some questions that came up in the comments last time round:

* No, you don’t need 3D acceleration for this compositor, so cards with sucky GL will be able to use it. You will however need a good  and fast XRender implementation. I’m using the both the binary NVidia driver and the opensource Intel driver. The NVidia driver works well, the Intel one (as shipped by Gutsy) works ok, but CPU usage can get high. I’ve been told the Fiesty Intel driver is quite slow.

* Yes, we can have window previews :)

* When I talked about people wanting translucent windows, I meant more that people wanted some parts of windows to be able to be translucent, which is used for things like AWN and cairo-clock stuff. I don’t really see the point of windows which are all transparent (although I did see a friend using some photo editor on the Mac tonight that had translucent dialogs, seemed a bit weird though. . . )

3 Comments

  1. Leen Toelen
    Posted November 19, 2007 at 8:59 am | Permalink

    Hi,

    it would be great to have an API where applications can provide their own window previews. A chat application can show more valuable information then “only” a screen shot for instance, the same for gimp and media players.
    I believe awn implements a plugin system like this (http://wiki.awn-project.org/index.php?title=Plugins)

    Regards,
    Leen

  2. Posted November 19, 2007 at 1:03 pm | Permalink

    Leen: While that could be quite cool, it would be out of scope for the window manager, and would really be something that would be implemented in a WM spec and then implemented somewhere like wnck (I expect).

    But that would be quite cool, I’ll talk to njp about it

  3. Posted November 27, 2007 at 2:47 pm | Permalink

    It would be interesting to use the technique described in http://www.parc.com/janssen/pubs/TR-04-11.pdf to scale the window previews. It uses a logarithmic scaling to preserve relative size between items, while obtaining previews of comparable size.