Re: [Events] continuous event types added to support direct manipulation of some physical interfaces

James Craig <jcraig@apple.com> wrote:
> It became apparent when planning a JavaScript polyfill of
> UIScrollRequestEvent that its current form would only support discrete user
> actions (keyboard control and AT control) but not continuous user actions
> including some types of mouse, touch, or wheel events. 

Given what James proposed at the meeting today to handle
UIValueChangeRequestevent, one way of understanding the solution is in two
phases:

1: We provide a general abstraction for direct manipulation
(ContinuousUIManipulationRequestEvents), which are independent of the input
device used - touch, mouse, wheel, camera/gesture, etc.

2: We then associate these continuous UI manipulations with events that modify
the state of a widget, such as UIValueChangeRequestEvent. That the element
which receives the direct manipulation events need not be the same as that
which listens for higher-level value and other changes is a matter of detail
that can be handled in the design.

In this approach, the application supplies code to establish the
correspondence between continuous UI manipulations and value changes, allowing
the visual interface to be constructed according to the author's preferences.

Received on Thursday, 6 March 2014 09:55:29 UTC