Pointer lock and warping

[Pekka Paalanen]

On Mon, 22 Apr 2013 19:48:14 -0700
Bill Spitzak <spitzak at gmail.com> wrote:

> Thinking about Todd Showalter's requests for pointer warping, I think
> in fact a correctly-behaving Wayland app will always want pointer
> warping and incremental update when the mouse is held down. This
> would require a major change in the mouse api, though I think the
> differences in back-compatibility can be worked around in the client
> library. This has the side effect of also getting the "slow
> scrollbar" effect requested, and edge resistance, and an equivalent
> of the pointer-lock proposal into a single api.
> 
> The purpose is to produce non-jittery dragging of objects. If the
> user drags an object drawn in the window, if the pointer image and
> drawn image move out of sync they will jitter in respect to each
> other. The solution is to synchronize the pointer movement with the
> drawing using the commit mechanism.

Here's a lot simpler solution for non-jittery dragging of objects: just
hide the pointer cursor, when starting the move. If you still want the
pointer cursor visible, draw it yourself with the object you are
moving. That is already possible today, and sub-surfaces will make that
even simpler to implement in the future.


Thanks,
pq