Use feature instead of hidden config for multi-display

Using a feature will allow app developers to find out if a
particular device supports running activities on secondary
screens before using the APIs.

Bug: 36776777
Test: android.server.cts.ActivityManagerDisplayTests
Change-Id: I7121bdb782cac9df70121e9df5cbf3fcb76f4a93

1 files changed, 8 insertions, 0 deletions

diff --git a/core/java/android/app/ActivityOptions.java b/core/java/android/app/ActivityOptions.java
index aa7cdf7b475e..02d18841f489 100644
--- a/core/java/android/app/ActivityOptions.java
+++ b/core/java/android/app/ActivityOptions.java
@@ -155,6 +155,7 @@ public class ActivityOptions {
 
     /**
      * The display id the activity should be launched into.
+     * @see #setLaunchDisplayId(int)
      * @hide
      */
     private static final String KEY_LAUNCH_DISPLAY_ID = "android.activity.launchDisplayId";
@@ -1038,6 +1039,7 @@ public class ActivityOptions {
      * Gets the id of the display where activity should be launched.
      * @return The id of the display where activity should be launched,
      *         {@link android.view.Display#INVALID_DISPLAY} if not set.
+     * @see #setLaunchDisplayId(int)
      */
     public int getLaunchDisplayId() {
         return mLaunchDisplayId;
@@ -1045,6 +1047,12 @@ public class ActivityOptions {
 
     /**
      * Sets the id of the display where activity should be launched.
+     * An app can launch activities on public displays or private displays that are owned by the app
+     * or where an app already has activities. Otherwise, trying to launch on a private display
+     * or providing an invalid display id will result in an exception.
+     * <p>
+     * Setting launch display id will be ignored on devices that don't have
+     * {@link android.content.pm.PackageManager#FEATURE_ACTIVITIES_ON_SECONDARY_DISPLAYS}.
      * @param launchDisplayId The id of the display where the activity should be launched.
      * @return {@code this} {@link ActivityOptions} instance.
      */