[Gallery apps Accessibility]: improve window transition semantics for accessibility services on Android

[JoseAlba]

Symptom

When moving between the screens inside Gallery apps, such as Shrine or Rally, TalkBack does not place the focus on the first item on the screen.

Steps to reproduce

• Install and launch Flutter Gallery app.
• Start TalkBack, Settings > Accessibility > TalkBack.
• Open either Shrine or Rally examples.
• Click around on various screens, including the "back" button and observe spoken feedback.

Expected results

As the screens change, Talkback should (possibly) announce the title of the new fragment / activity and/or place the focus on the first item on the screen.

Possible cause

TalkBack does not receive accessibility window events that signal appearance or disappearance of windows or fragments. If TalkBack is not aware that windows have changed, no focus management strategy can be applied and no window title changes can be spoken.

CC/ @goderbauer

#material-components/material-components-flutter-gallery#517

[goderbauer]

Have a look at the scopesRoute and namesRoute options of the Semantics widget. Those values are used to indicate to TalkBack that the route visible on the screen has changed and triggers the appropriate announcements.

[hiashutoshsingh]

is there any way to get callback in our app which external app is open and what data they are typing or clicking ?

[guidezpl]

@hiashutoshsingh I'm not sure, but this seems to be a question better suited for StackOverflow or the Flutter Discord channel

[guidezpl]

Blocking bug is in Android b/261500250