Wayland Window Management Proposal

Bill Spitzak spitzak at gmail.com
Fri May 13 16:48:20 PDT 2011

Michal Suchanek wrote:

> It may be rubber-band or it may be some other effect but either way
> you need something to draw on the screen until the client performs the
> update which will draw a "not fully updated window" in case the client
> does not update fast enough and by some is "unacceptable in wayland".

A rubber band resize is part of the window management design and is not 
a partial update, any more than the mouse cursor atop a window means it 
is not fully updated. The image is fully expected to appear when the 
user drags the mouse.

A rubber band that appears after a timeout when it detects the client is 
locked up is what you say, as the user will see an image that they would 
not see if the client was responsive. However there is nothing wrong 
with wrong images when the compositor detects that the client is not 
responding. What is necessary however is that a client that reacts 
within a timeout will never display a partially updated image.

> Also note that this requires agreement between Wayland and the
> application whether the window is resizable to a particular size.
> Otherwise you might end up with a rubber band displayed forever and
> both Wayland and the client thinking everything is OK.

The client has to acknoledge the event, even if the size (when rounded 
to what it allows) is the same as it's current size and it therefore 
does not have to do anything else. The compositor can remove the rubber 
band image when it sees the acknoledgement.

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