The way to use system cursor and custom(client) cursor

[Bill Spitzak]

On 06/09/2013 11:02 PM, Pekka Paalanen wrote:

>> Is this approach possible? I want to listen your opinions.
>
> Hi Elvis,
>
> do I understand right, that you would like to add the concept of a
> system cursor?
>
> I guess it would be possible, but why?
>
> It seems the system cursor you propose would be one arbitrary cursor
> without any meaning. When and why would applications ever want to use
> it?
>
> The compositor usually cannot, and there is no need to, switch to a
> system cursor on its own, so it would always be requested by a client.
> I can understand applications wanting a specific cursor, or no cursor,
> but what would be the purpose of a system cursor?
>
> If you also consider cursor themes, the system cursor would be from one
> theme. An application using a system cursor would need to use the same
> theme for its other cursors to look consistent.
>
> We already have libwayland-cursor to help you load a cursor theme, so
> using a proper cursor should not be too hard.

If a client does nothing after an enter event it will get the system 
cursor. If they change the cursor they cannot return to the system 
cursor without either replicating a lot of implementation (possibly 
incorrectly) or by waiting for the user to move the mouse to point at 
the desktop and re-enter. This seems wrong to me. It should always be 
possible for the client to put themselves into a default state.

Having no buffer act the same as "a buffer that is entirely transparent" 
might be a good idea for all surfaces.