More work on collecting assist data.

Optimize parceling of AssistData (which is now renamed to
AssistStructure) by pooling duplicated class name strings.

Change text associated with a view node to a CharSequence,
so styling information comes along.

Include global text attributes -- size, colors, etc.

Introduce a new AssistContent structure, which allows us
to propagate information about the intent and data the
activity is looking at.  This further allows us to propagate
permission grants, so the assistant can dig in to that data.
The default implementation propagates the base intent of an
activity, so if for example you bring up the assistant while
doing a share the assistant itself has the same information
and access that was given to the share activity (so it could
for example share it in another way if it wanted to).

Did some optimization of loading PersistableBundle from xml,
to avoid duplicating hash maps and such.

Changed how we dispatch ACTION_ASSIST to no longer include
the more detailed AssistStructure (and new AssistContent)
data when launching; now the example code that intercepts
that needs to be sure to ask for assist data when it starts
its session.  This is more like it will finally be, and allows
us to get to the UI more quickly.

Change-Id: I88420a55761bf48d34ce3013e81bd96a0e087637

1 files changed, 23 insertions, 5 deletions

diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index 9f8befe..02f33b4 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -1547,17 +1547,35 @@ public class Activity extends ContextThemeWrapper
      * {@link Intent#ACTION_ASSIST} Intent with all of the context of the current
      * application.  You can override this method to place into the bundle anything
      * you would like to appear in the {@link Intent#EXTRA_ASSIST_CONTEXT} part
-     * of the assist Intent.  The default implementation automatically generates a
-     * {@link AssistData} from your activity and places it in to the Bundle; if you
-     * don't want your UI reported to the assistant, don't call this default
-     * implementation.
+     * of the assist Intent.
      *
      * <p>This function will be called after any global assist callbacks that had
      * been registered with {@link Application#registerOnProvideAssistDataListener
      * Application.registerOnProvideAssistDataListener}.
      */
     public void onProvideAssistData(Bundle data) {
-        data.putParcelable(AssistData.ASSIST_KEY, new AssistData(this));
+    }
+
+    /**
+     * This is called when the user is requesting an assist, to provide references
+     * to content related to the current activity.  Before being called, the
+     * {@code outContent} Intent is filled with the base Intent of the activity (the Intent
+     * returned by {@link #getIntent()}).  The Intent's extras are stripped of any types
+     * that are not valid for {@link PersistableBundle} or non-framework Parcelables, and
+     * the flags {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION} and
+     * {@link Intent#FLAG_GRANT_PERSISTABLE_URI_PERMISSION} are cleared from the Intent.
+     *
+     * <p>Custom implementation may adjust the content intent to better reflect the top-level
+     * context of the activity, and fill in its ClipData with additional content of
+     * interest that the user is currently viewing.  For example, an image gallery application
+     * that has launched in to an activity allowing the user to swipe through pictures should
+     * modify the intent to reference the current image they are looking it; such an
+     * application when showing a list of pictures should add a ClipData that has
+     * references to all of the pictures currently visible on screen.</p>
+     *
+     * @param outContent The assist content to return.
+     */
+    public void onProvideAssistContent(AssistContent outContent) {
     }
 
     /**