Jelly Bean: Accessibility Gestures Explained
1 Jelly Bean: Accessibility Gestures Explained
This article details accessibility gestures in Jelly Bean and is a follow-up to Jelly Bean Accessibility Explained. It gives a conceptual overview of the 16 possible gestures and describes how they are used. The interaction behavior described here holds for all aspects of the Android user interface, including interactive Web pages within Chrome and the Android Web Browser.
1.1 Conceptual Overview Of The Gestures
Placing a finger on the screen speaks the item under the finger by first placing Accessibility Focus on that item. Moving the finger triggers touch exploration which moves Accessibility Focus.
To generate any of the Accessibility Gestures discussed below, one moves the finger much faster — how much faster is something we will tune over time, and if needed, make user customizable.
To remember the gestures, think of the four directions, Up, Down, Left and Right. In addition to these four basic navigational gestures, we defined an additional 12 gestures by picking pairwise combinations of these directional flicks, e.g., Left then Down — this gives a total of 16 possible gestures. In what follows, left then down means swipe left, and continue with a down flick. Note that in performing these additional gestures, speed matters the most. As an example, it is not essential that you make a perfect Capital L when performing the Down then Right gesture for instance; speed throughout the gesture, as well as ensuring that the finger moves some distance in each direction is key to avoid these being misinterpreted as basic navigational gestures.
1.2 Accessibility Focus And Accessibility Gestures
Accessibility Focus is moved using the four basic directional gestures. For now we have aliased Left with Up, and Downwith Right; i.e., both Left and Up move to the previous item, whereas Down and Right move to the next item. Note that this is not the same as moving with a physical D-Pad or keyboard on Android; the Android platform moves System Focus in response to the D-Pad. Thus, moving with a D-Pad or trackball moves you through the various interactive controls on the screen; moving Accessibility Focus via the Accessibility Gestures moves you through everything on the screen.
1.3 Accessibility Gestures For Common Actions
In addition to the basic navigation describe above, we define the following gestures for common actions:
- Navigation Granularity
- You can increase or decrease navigation granularity by rapidly stroking Up then Down or Down then Up.
- Scrolling Lists
- You can scroll a list forward by rapidly stroking Right then Left; the reverse, i.e., Left then Right scrolls the list backward by a screenful.
1.4 User Configurable Gestures
Gestures Down then Left, Up then Left, Down then Right and Up then Rightare user configurable; their default assignments are shown below.
- Gesture Down then Left is the same as pressing the Back button.
- Up then Left has the same effect as pressing the Home button.
- Status Bar
- Gesture Up then Right opens Status Notifications.
- Down then Right has the same effect as pressing the Recent Applications button.
Gestures for manipulating and working with Accessibility Focus are an evolving part of the Android Accessibility; we will continue to refine these based on user experience. At this point, you are probably saying:
But wait, you said 16 gestures, but only told us the meanings of 12 of them
You are correct — we have left ourselves some gestures to use for future features.