340672 - New ATK: Expose Value Change events

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Aaron Leventhal]

We currently don't expose value change events, although they are very important for support of progress meters and sliders:

We don't expose these events because it was too difficult to find the old value. Let's find a way to expose the event without providing the old value. The spec does not say that detail1 has to be the old value.

See the code:
http://lxr.mozilla.org/seamonkey/source/accessible/src/base/nsRootAccessible.cpp#83

837 #if 0
838   // XXX todo: value change events for ATK are done with 
839   // AtkPropertyChange, PROP_VALUE. Need the old and new value.
840   // Not sure how we'll get the old value.
841   // Aaron: I think this is a problem with the ATK API -- its much harder to
842   // grab the old value for all the application developers than it is for
843   // AT's to cache old values when they need to (when would that be!?)
844   else if (eventType.LowerCaseEqualsLiteral("valuechange")) { 
845     privAcc->FireToolkitEvent(nsIAccessibleEvent::EVENT_VALUE_CHANGE, 
846                               accessible, nsnull);
847   }
848 #endif

Comment 1

[Aaron Leventhal]

Attachment: Simple patch

Comment 2

[Aaron Leventhal]

Attachment: Having trouble testing this because of AT poke freezes, but looks right

Would like to test with http://www.mozilla.org/access/dhtml/slider

Comment 3

[Aaron Leventhal]

Attachment: Having trouble testing this because of AT poke freezes, but looks right

Comment 4

[Evan Yan]

Comment on attachment 226690 [details] [diff] [review]
Having trouble testing this because of AT poke freezes, but looks right

r=me