Touch events

Bill Spitzak spitzak at
Tue Feb 21 21:15:57 PST 2012

Daniel Stone wrote:
> Hi,
> On 22 February 2012 00:13, Bill Spitzak <spitzak at> wrote:
>> It seems like it would be better if clients got the touch events first, and
>> the compositor only did things if the client said it was uninterested in the
>> events. For a lot of touch events this can be decided immediately on the
>> touch-down, since the client knows the user is pushing nothing.
> No, this just isn't true.  You want global gestures (e.g. three finger
> swipe to change desktop) to take precedence over local shortcuts.  And
> you cannot -- cannot -- know at touch-down time who's going to be
> ultimately interested in it.  Because for a three-finger swipe, there
> will be a time when there's only one finger down, or two.  At which
> point the client will say, 'ah yes, I'm interested in this!'.  And
> then the third finger lands and you regret a terrible design decision
> you made.

I would think the client could say "not interested" when it sees the 
third finger.

If the clients can look at things first, this would allow the compositor 
to do things like "one finger can be used to change desktops if the 
underlying program does not use it".

Solutions like "three fingers are needed" are just like the solutions 
for shortcuts where you have to hold Alt and Ctrl and the right-hand 
Shift and push the key, in an attempt to not collide with keystrokes the 
program wants.

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