protocol questions

[Daniel Stone]

Hi,

On 3 April 2013 03:09, Kristian Høgsberg <hoegsberg at gmail.com> wrote:
> On Sat, Mar 30, 2013 at 01:31:34AM -0400, Matthias Clasen wrote:
>> - It looks like I can't trigger a popup from a key or touch event,
>> because set_popup requires a serial that corresponds to an implicit
>> pointer grab. That is sad, I like the menu key...
>
> Yes, it looks like we'll need new protocol for that.  It's also not
> possible to trigger keyboard move or resize of windows.

Hm, do we really need new protocol for this, or, given that serials
are display-global, can we just bump wl_shell_surface to v2 and note
that v2 and above accept _either_ a key or button press for the serial
argument to set_popup? I don't see any potential for confusion or
getting things wrong, and it saves everyone a lot of really tedious
typing.

>> - The wl_pointer interface seems to be a bit weak wrt to device
>> properties. I would at least expect to learn about the number of
>> buttons and right-handed vs left-handed, etc.
>
> Daniel covered this, though I do think that we should be able to
> determine the set of all buttons supported by all mice and communicate
> to the client if there's a case for that.

Certainly evdev lets you see which buttons are supported by a pointer,
as well as which keys are supported by a keyboard - at least to the
extent that the hardware actually exposes this through HID, which is
even less reliable than EDID.  But it's definitely possible to do, and
AFAICT hardware tends to err on the side of exposing too many
capabilities, rather than too few (i.e. you're not going to get an
event for a mouse button we previously claimed not to have).

While we're here though, I'd love to clarify what a value of 1.0 in a
wl_pointer::axis event means.  Right now, anything with a wheel will
send 1.0 per wheel click, whereas two-finger scrolling on touchpads
will send 1.0 per pixel.  This makes axis events totally unusable for
when you have a mouse and touchpad both: half your scrolls are going
to be wrong.  Can we settle on, and document, 1.0 as an arbitrary unit
roughly equivalent to one 'click' of a wheel, and scale appropriately
in the touchpad driver?

And if we're going to stick with evdev BTN_* codes for button events,
we should probably document that one too.

Cheers,
Daniel