Composite WM and events

Kalle Vahlman kalle.vahlman at
Tue May 27 00:32:45 PDT 2008

2008/5/26 Quentin Carbonneaux <qcarbonneaux at>:
> If I redirect a window with this extension without updating the root window
> with the contents of the window concerned, how can the application be
> informed when that the user clicked on a button or typed a char on his
> keyboard since these events are sent to the only window available on screen
> : the root win.

You said it yourself, you only redirect the _contents_ of the window
so even if you don't update the contents, the window still exists in
its coordinates and receives input events as usual.

> Moreover, in a composite WM I think Xlib functions which aim to manage the
> focus, for instance, cannot be used, so is it the role of the WM to do all
> this work ?

Composite managers are not (necessarily) window managers, they just
control the rendering of the screen. xcompmgr is a perfect example of
this, all it basically does is redirect window contents and add
optional alpha & shadows when rendering. There's no window management
functionality in xcompmgr.

Kalle Vahlman, zuh at
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