Presentation API

From Accessible Platform Architectures Working Group

Presentation API


  1. This specification describes API for connections for the most part; not UI or other end-user-consumable information.
  2. In 6.3.2, there is the following text:

    The details of implementing the permission request and display selection are left to the user agent; for example it may show the user a dialog and allow the user to select an available display (granting permission), or cancel the selection (denying permission). Implementers are encouraged to show the user whether an available display is currently in use, to facilitate presentations that can make use of multiple displays.

    It should be safe to assume such dialogs will be accessible in accordance with existing standards, requirements -- and if such dialogs are not, they're in violation of those other standards and requirements.

    Conclusion: Nothing needs to be added to this spec in this regard.

  3. In that same section, in the list of steps for starting a presentation, step 20 states:

    If any of the following steps fails, abort all remaining steps and close the presentation connection S with error as closeReason, and a human readable message describing the failure as closeMessage.

    (A similar statement is under section 6.5.4)

    Conclusion: Unless we want to ask the Cognitive task force for feedback, nothing needs to be added to this spec in this regard.

  4. There are quite a few references to "using an implementation specific mechanism." Generally speaking, such phrases tend to make me nervous in terms of the accessibility implementations. But these seem to be connection related; not end-user-consumed UI or information.

    Conclusion: Nothing needs to be added to this spec in this regard.
  5. Before I read the spec, the concern I had was about the rendering of the presentation in the receiving browsing context. (E.g. is it being rendered as a web page which could be accessed via assistive technologies, modified by user style sheets, etc.? Or could it be rendered as an image?).

    The spec text indicates that presentations within its scope will be rendered as web pages:
    • 6.3.2 step 22. "Navigate R to presentation URL"
    • 6.3.2 note: "The presentationUrl should name a resource accessible to the local or a remote user agent. This specification defines behavior for presentationUrl using the http or https schemes; behavior for other schemes is not defined by this specification."
    Conclusion: Nothing needs to be added to this spec in this regard.