Bug 212933 – GameController.framework gamepads should support Home buttons

• Component: WebKit API
• Status: RESOLVED FIXED

Testing on iOS and iPadOS 13.4.1 has revealed that Xbox and PS4 controllers are detected and input events are received over Bluetooth, but some buttons are missing and D-Pad buttons are received as axes input. Looking at the WebKit GameControllerGamepad (https://github.com/WebKit/webkit/blob/89c28d471fae35f1788a0f857067896a10af8974/Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm) implementation on GitHub it appears that the WebKit Game Controller Framework (https://developer.apple.com/documentation/gamecontroller) integration doesn’t include the new controller buttons added to GCF last year (https://developer.apple.com/videos/play/wwdc2019/616/). For instance, buttonMenu (https://developer.apple.com/documentation/gamecontroller/gcextendedgamepad/3237238-buttonmenu) appears to be missing. Can WebKit fix the the DPad and add the additional buttons?

[Alexey Proskuryakov]

rdar://problem/63500696

[Justin Uberti]

This looks like a pretty straightforward change. Is any work planned here? If not, happy to contribute a patch.

Looks like the changes have been made: https://github.com/WebKit/webkit/blob/master/Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm#L100. However, it still doesn't appear to work on Safari on iOS 13.5.1 (testing with https://html5gamepad.com/). When will this be deployed to iOS and iPadOS?

[Justin Uberti]

Agreed, also doesn't work in Safari Mac 14.0, or in Safari iPadOS 14 beta 1.

[Brady Eidson]

(In reply to goehdavi from comment #3)
> When will this be deployed to iOS and iPadOS?

That's a question beyond the WebKit open source project - Apple releases those products, and generally doesn't comment on future releases, etc.

(In reply to Justin Uberti from comment #4)
> Agreed, also doesn't work in Safari Mac 14.0, or in Safari iPadOS 14 beta 1.

These are two different issues.

1st is that macOS WebKit doesn't use GC framework.

2nd is that there's a known issues in another system component preventing all Gamepads from work on iOS 14 beta 1.

[Justin Uberti]

Thanks, I understand that there are a number of moving parts and organizational complexities here, and appreciate the clarification regarding the root cause of the iOS 14b1 issues.

Anything you can share regarding GC provider on macOS?

[Brady Eidson]

This bug got way overloaded with lots of various Gamepad issues.

I'm going back to the original report:

"Gamepad support on iOS doesn't support the new GameControllerFramework buttons like Menu and Options"

That support was added in https://trac.webkit.org/changeset/256215/webkit, and I believe is working in iOS 14 b2 (which fixed the general "Gamepads aren't working" bug)

However, there's yet-another-button that would be great to support and that's the Home button.

So let's repurpose this bug for that.

Whoever feels like other things discussed here still deserve discussion, please make separate bugzillas for separate issues.

[Brady Eidson]

Created attachment 403971 [details]
Patch

[Tim Horton]

Comment on attachment 403971 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=403971&action=review

> Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm:57
> +static GCControllerButtonInput *homeButtonFromExtendedGamepad(GCExtendedGamepad *gamepad)

I don't love the `valueForKey`s. Is there an SPI property you can use? Is the string available anywhere?

> Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm:78
> +    m_buttonValues.resize(homeButton ? 17 : 16);

These magic numbers are pretty weird!

> Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm:114
> +        bindButton(homeButton, 16);

Do the numbers match something in another project, or are they ours? If they're ours, can we structure this in a less bizarre way?

[Brady Eidson]

(In reply to Tim Horton from comment #9)
> Comment on attachment 403971 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=403971&action=review
> 
> > Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm:57
> > +static GCControllerButtonInput *homeButtonFromExtendedGamepad(GCExtendedGamepad *gamepad)
> 
> I don't love the `valueForKey`s. Is there an SPI property you can use? Is
> the string available anywhere?

For the underscored version, this is it.
For the non-underscored I can do something different.

> > Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm:78
> > +    m_buttonValues.resize(homeButton ? 17 : 16);
> 
> These magic numbers are pretty weird!

They are from the "standard layout" of the Gamepad API
> 
> > Source/WebCore/platform/gamepad/cocoa/GameControllerGamepad.mm:114
> > +        bindButton(homeButton, 16);
> 
> Do the numbers match something in another project, or are they ours?

They're ours (Gamepad API spec)

> If they're ours, can we structure this in a less bizarre way?

The whole thing could be structured more better. I'll fix it up in a separate patch.

[Brady Eidson]

Created attachment 404010 [details]
PFL

[EWS]

Committed r264246: <https://trac.webkit.org/changeset/264246>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 404010 [details].

[Brady Eidson]

(In reply to Brady Eidson from comment #10)
> (In reply to Tim Horton from comment #9)
> > Do the numbers match something in another project, or are they ours?
> 
> They're ours (Gamepad API spec)
> 
> > If they're ours, can we structure this in a less bizarre way?
> 
> The whole thing could be structured more better. I'll fix it up in a
> separate patch.

Fixing over in https://bugs.webkit.org/show_bug.cgi?id=214210