Adding scroll actions to accessibility node info.
1. Scrolling actions are crucial for enabling a gesture based
traversal of the UI and specifically scrollable containers
especially lists and anything backed by an adapter. Since
accessibility focus can land only attached views, it cannot
visit views for adapter items not shown on the screen.
Auto scrolling the list as a result of putting access focus
ot a list item does not work well since the user may get
trapped in a long list. Adding an accessibility node provider
to emit virtual views for one view before the first and one
after the last is complex and suffers the limitation of trapping
the user. Accessibility service need an explicit scroll actions
which may be performed upon an explicit user action. Hence,
the user is informed for the start/end of the visible part of
the list and he makes a deliberate choice to scroll. This will
benefit also people developing Braille devices since they can
scroll the content without telling the user to stop using the
Braille controller and take the device out of his pocket to scroll
and go back to the Braille controller.
NOTE: Without these action large portions of the screen will be
hard to access since users will have to touch and explore to
find and scroll the list.
Change-Id: Iafcf54d4967893205872b3649025a4e347a299ed
6 files changed