Add extended buttons to support trackpad (#191)

index.html

@@ -820,8 +820,13 @@ <h3>
  <li>[=list/For each=] |rawInputIndex:long| of [=the range=] from 0 to
  |inputCount| − 1:
  <ol>
- <li>If the the gamepad button at index |rawInputIndex|
- [=represents a Standard Gamepad button=]:
+ <li>Determine the type of the button at index |rawInputIndex|
+ [=represents a Standard Gamepad button=] or Extended button
+ types as described in the {{ExtendedMapping}} using the provided
+ buttonTypes array. If the button does not have a canonical type,
+ use GamePadButtonType.non_canonical.
+ </li>
+ <li>If the button type is not GamepadButtonType.non_canonical:
  <ol>
  <li>Let |canonicalIndex:long| be the [=canonical index=] for
  the button.
@@ -878,8 +883,15 @@ <h3>
  <li>Initialize |buttons| to be an empty [=list=].
  </li>
  <li>[=list/For each=] |buttonIndex:long| of [=the range=] from 0 to
- |buttonsSize| − 1, [=list/append=] a [=new=] {{GamepadButton}} to
- |buttons|.
+ |buttonsSize| − 1:
+ <ol>
+ <li>Determine the type of the button from the provided buttonTypes
+ array, defaulting to null if not specified.
+ </li>
+ <li>[=list/Append=] a [=new=] {{GamepadButton}} to |buttons|
+ with the determined button type.
+ </li>
+ </ol>
  </li>
  <li>Return |buttons|.
  </li>
@@ -900,6 +912,7 @@ <h2>
  readonly attribute boolean pressed;
  readonly attribute boolean touched;
  readonly attribute double value;
+ readonly attribute GamepadButtonType type;
  };
  </pre>
  <p>
@@ -1018,6 +1031,13 @@ <h2>
  </li>
  </ol>
  </dd>
+ <dt>
+ <dfn>type</dfn> attribute
+ </dt>
+ <dd>
+ An enumerated {{GamepadButtonType}} attribute that classifies the current button's type in relation to an
+ extended mapping.
+ </dd>
  </dl>
  </section>
  <section data-dfn-for="GamepadMappingType">
@@ -2031,6 +2051,62 @@ <h2>
  Visual representation of a [=Standard Gamepad=] layout.
  </figcaption>
  </figure>
+ <section data-dfn-for="ExtendedMapping" data-link-for="ExtendedMapping">
+ <h3>
+ <dfn>ExtendedMapping</dfn>
+ </h3>
+ <p>
+ This section introduces an extended gamepad button mapping beyond the Standard Gamepad layout.
+ These additional buttons are commonly found on certain gamepad models.
+ The following table defines the extended buttons used by some gamepad models.
+ It's important to note that this list is not exhaustive, and user agents may utilize different
+ or additional buttons for these or other gamepad models.
+ Consequently, the number of buttons on the {{Gamepad}} is not limited to the standard mapping of 17 buttons.
+ </p>
+ <p>
+ To accommodate extended gamepads, we have incorporated an "extended" mapping enumeration
+ into the {{GamepadMappingType}}. Additionally, we have defined an enumeration for the various
+ button types termed {{GamepadButtonType}}, and have expanded the {{GamepadButton}}
+ interface to encompass this new button type enumeration.
+ </p>
+ <section>
+ <h3>
+ <dfn>GamepadButtonType</dfn> Enum
+ </h3>
+ <p>
+ This enum defines the set of possible button types.
+ </p>
+ <pre class="idl">
+ enum GamepadButtonType {
+ "standard",
+ "non-canonical",
+ "trackpad", 
+ // ... More enum types to be defined by the separate W3C wiki page.
+ };
+ </pre>
+ <dl data-dfn-for="GamepadButtonType">
+ <dt>
+ <dfn>standard</dfn>
+ </dt>
+ <dd>
+ Represent a button has a button type defined in the standard mapping.
+ </dd>
+ <dt>
+ <dfn>non-canonical</dfn>
+ </dt>
+ <dd>
+ Represents a button that exists but doesn't have a canonical name.
+ </dd>
+ <dt>
+ <dfn>trackpad</dfn>
+ </dt>
+ <dd>
+ Represent a trackpad input type which beyonds the scope of the standard mapping.
+ <p>More enum types to be defined by the separate W3C wiki page.
+ </dd>
+ </dl>
+ </section>
+ </section>
  <section>
  <h3>
  Fingerprinting mitigation