Remove "enhance web scripts" from settings and make it requested by plug-ins.

Currently we have an "enhance web accessibility" setting that has to be
enabled to make sure web content is accessible. We added the setting to
get user consent because we are injecting JavaScript-based screen-reader
pulled from the Google infrastructure. However, many users do not know
that and (as expected) do not read the user documentation, resulting in
critique for lacking accessibility support in WebViews with JavaScript
enabled (Browser, Gmail, etc).

To smoothen the user experience now "enhance web accessibility" is a
feature an accessibility plug-in can request, similarly to explore by
touch. Now a user does not need to know that she has to explicitly
enable the setting and web accessibility will work out-of-the-box.

Before we were showing a dialog when a plug-in tries to put the device
in a touch exploration mode. However, now that we have one more feature
a plug-in can request, showing two dialogs (assume a plug-in wants both
features) will mean that a user should potentially deal with three
dialogs, one for enabling the service, and one for each feature. We
could merge the dialogs but still the user has to poke two dialogs.

It seems that the permission mechanism is a perfect fit for getting
user permission for an app to do something, in this case to enable
an accessibility feature. We need a separate permission for explore
by touch and enhance web accessibility since the former changes the
interaction model and the latter injects JavaScript in web pages. It
is critical to get user consent for the script injection part so we
need a well-documented permission rather a vague umbrella permission
for poking accessibility features. To allow better grouping of the
accessibility permissions this patch adds a permission group as well.

bug:8089372

Change-Id: Ic125514c34f191aea0416a469e4b3481ab3200b9

1 files changed, 13 insertions, 1 deletions

diff --git a/core/java/android/accessibilityservice/AccessibilityServiceInfo.java b/core/java/android/accessibilityservice/AccessibilityServiceInfo.java
index 2006bc7..2dc0501 100644
--- a/core/java/android/accessibilityservice/AccessibilityServiceInfo.java
+++ b/core/java/android/accessibilityservice/AccessibilityServiceInfo.java
@@ -153,13 +153,25 @@ public class AccessibilityServiceInfo implements Parcelable {
     public static final int FLAG_REQUEST_TOUCH_EXPLORATION_MODE= 0x0000004;
 
     /**
+     * This flag requests from the system to enable web accessibility enhancing
+     * extensions. Such extensions aim to provide improved accessibility support
+     * for content presented in a {@link android.webkit.WebView}. An example of such
+     * an extension is injecting JavaScript from Google. The system will enable
+     * enhanced web accessibility if there is at least one accessibility service
+     * that has this flag set. Hence, clearing this flag does not guarantee that the
+     * device will not have enhanced web accessibility enabled since there may be
+     * another enabled service that requested it.
+     */
+    public static final int FLAG_REQUEST_ENHANCED_WEB_ACCESSIBILITY = 0x00000008;
+
+    /**
      * This flag requests that the {@link AccessibilityNodeInfo}s obtained
      * by an {@link AccessibilityService} contain the id of the source view.
      * The source view id will be a fully qualified resource name of the
      * form "package:id/name", for example "foo.bar:id/my_list", and it is
      * useful for UI test automation. This flag is not set by default.
      */
-    public static final int FLAG_REPORT_VIEW_IDS = 0x00000008;
+    public static final int FLAG_REPORT_VIEW_IDS = 0x00000010;
 
     /**
      * The event types an {@link AccessibilityService} is interested in.