[Development] multiple pointers with Wayland Platform?

[Rick Stockton]

BACKGROUND:

I saw that one of the Wayland Devs has eventually reached the same 
Design I already chose for Mouse Buttons in Qt- but his update copies 
the entire "button translation" code block from X11's within X11's evdev 
(Driver), which translates "button" keycodes from the evdev module (in 
the kernel). The current Wayland code supports Three ranges of pointer 
device 'buttons' keycodes coming from the evdev module. Each is 16 bits 
wide:

The generic 'BTN_0... BTN_1... BTN_2' range Starts at 0x100.
The mouse  'BNT_MOUSE' range begins with alias 'BTN_LEFT' at 0x110.
And the 'BTN_JOYSTICK' range begins with alias 'BTN_TRIGGER' at 0x120.

but, there's another range which might be of concern in Qt5:

Beginning with 'BTN_TOOL_PEN' = 0x140, there is another range containing 
a bunch of entries. The #define statements include:
BTN_TOOL_RUBBER 0x141;    BTN_TOOL_BRUSH 0x142;
BTN_TOOL_PENCIL 0x143;   BTN_TOOL_AIRBRUSH 0x144;

and others named FINGER, MOUSE, LENS, TOUCH, STYLUS, STYLUS2, DOUBLETAP, 
TRIPLETAP, and QUADTAP.

- - - - - -
QUESTION:

After it becomes possible to Build the Qt5.0.0. Wayland Platform Plugin 
and Compositor against current Wayland code, should I assign these 
alternate button ranges to the SAME Qt::MouseButton values? If I do 
that, it wouldn't matter whether your 'Pointer Device' resulted in a 
BTN_JOYSTICK, or BTN_0, or BTN_LEFT Wayland event ---> we'd map them all 
as a case of Qt::LeftButton.

Or should I be thinking in terms of separate event types for the "Pen" 
range, the "Joystick" range, and the "Generic" device ranges?
Right now, I'm imagining that "Pen" might be handled as a unique type of 
device, while the other 3 can all be mapped as 'THE' mouse-like 
MouseButton() primary pointer device whenever it shows up. But if you 
all plan for Qt5 to distinguish between a 'Joystick device' and a 'Mouse 
device', or to support multiple pointer/pen devices concurrently, then 
I'll need to keep them separated at this event interface.

As always, I'll thank you for your advice: Thanks!