wl_tablet specification draft

[Bill Spitzak]

On 07/01/2014 04:06 PM, Jason Gerecke wrote:

>> yep, Lyude's latest protocol draft (in the works) does/will have that in it,
>> to have the built-in/display tablets not use a cursor, the external ones
>> have a cursor. we haven't really worried about the client-drawing area mode
>> yet because it'll likely be a request that doesn't change that much in the
>> scope of the protocol other than grabbing the device for a single client.
>> But you're right, having a built-in/display tablet use the area-mapping
>> doesn't make sense.
>>
> I assume this would only affect the rendering of a "default" cursor
> sprite, and not prevent clients from setting or clearing it on their
> own? Not showing a cursor for tabletscreens and showing one for other
> tablets is reasonable for the average application, but pretty much
> every painting application will render a brush-shaped cursor while
> above the canvas regardless.

I think currently such tablets always draw a cursor. This is because 
there is a thickness of glass between the touch surface and the actual 
led's, making a parallax problem that most easily worked around by 
adding an indicator to the image. Still it seems useful to make the 
cursor much lighter and thinner, such as a crosshairs, as it only has to 
be seen in closeup when the user is concentrating on the tip of the pen.

If by any chance technology improves so that the image is on the front 
surface, I think the cursors may disappear.

In any case it seems like the client is going to have to know that the 
tablet is of this type. You can't just hide the cursor always, or always 
replace it with a crosshairs, because you want it to show a drag & drop 
item, and other such feedback. The client may even want to alter the 
drag & drop icon (ie whether it contains a fake cursor). Also clients 
need to know this so they don't attempt to map the tablet to a region.