Re: [w3c/gamepad] Add trackpad button support (Issue #191)

I think we should not add assign a Standard Gamepad button index specifically for the trackpad button. The Standard Gamepad buttons are defined by their layout on the gamepad rather than their intended functionality. Instead of a trackpad button, call it "fourth button in center cluster" or something like that so we can map it on gamepads with no trackpad.

Specifying trackpad button at index 17 would match Chromium's mappings for DualShock4 and DualSense but would invalidate several other mappings that map other buttons to button index 17. For example, Capture button on Switch controllers and Share button on Xbox controllers are both mapped to button 17. If we don't require button 17 to be a trackpad button then we can keep the existing mappings.

> Uniform Button Array Size

Limiting the button array size would be confusing and frustrating to users. Gamepads with more than 18 buttons will have "dead" buttons that can't be used in games. For example, Stadia Controller has 19 buttons total. Even if we add button 17 we'll still have to pick a button to leave unmapped.

Using a uniform button array size to limit fingerprinting makes little sense unless the ID string is also uniform because the length of the buttons array doesn't expose any more fingerprinting surface than the ID string itself. Two gamepads with the same ID string will typically have the same number of buttons.

I think it's reasonable to expose a limited view of the gamepad as long as there's a simple way for the user to unlock the full view. In the past we've discussed the possibility of adding a Gamepad permission. Perhaps we can expose a limited view of the gamepad when a page lacks the Gamepad permission and a full view once the permission is granted.

-- 
Reply to this email directly or view it on GitHub:
https://github.com/w3c/gamepad/issues/191#issuecomment-1874772314
You are receiving this because you are subscribed to this thread.

Message ID: <w3c/gamepad/issues/191/1874772314@github.com>