From 9e2c7ecf64e11e69dceb40fba6fd740e41a32417 Mon Sep 17 00:00:00 2001
From: Jiaquan He <hejq@google.com>
Date: Mon, 23 May 2016 11:00:12 -0700
Subject: [PATCH] Add support for android.R.attr#onTopLauncher

This allows a launcher activity to always stay on top of all other
activities.

Bug: 28425537
Change-Id: Iad39a076b1e8c6a8304c3b218883a172c913a602
---
 core/java/android/content/pm/ActivityInfo.java            | 8 ++++++++
 core/java/android/content/pm/PackageParser.java           | 5 +++++
 core/res/res/values/attrs_manifest.xml                    | 3 +++
 .../core/java/com/android/server/am/ActivityRecord.java   | 5 +++++
 4 files changed, 21 insertions(+)

diff --git a/core/java/android/content/pm/ActivityInfo.java b/core/java/android/content/pm/ActivityInfo.java
index 5a09c0028cdce..94c406a882e23 100644
--- a/core/java/android/content/pm/ActivityInfo.java
+++ b/core/java/android/content/pm/ActivityInfo.java
@@ -332,6 +332,14 @@ public class ActivityInfo extends ComponentInfo
      */
     public static final int FLAG_ALWAYS_FOCUSABLE = 0x40000;
 
+    /**
+     * Bit in {@link #flags} indicating if the activity is a launcher activity which should always
+     * show up on the top of others.
+     * See android.R.attr#onTopLauncher.
+     * @hide
+     */
+    public static final int FLAG_ON_TOP_LAUNCHER = 0x80000;
+
     /**
      * @hide Bit in {@link #flags}: If set, this component will only be seen
      * by the system user.  Only works with broadcast receivers.  Set from the
diff --git a/core/java/android/content/pm/PackageParser.java b/core/java/android/content/pm/PackageParser.java
index adf9fe62c37e5..7b40cc5cb2c2b 100644
--- a/core/java/android/content/pm/PackageParser.java
+++ b/core/java/android/content/pm/PackageParser.java
@@ -79,6 +79,7 @@ import libcore.io.IoUtils;
 
 import static android.content.pm.ActivityInfo.FLAG_ALWAYS_FOCUSABLE;
 import static android.content.pm.ActivityInfo.FLAG_IMMERSIVE;
+import static android.content.pm.ActivityInfo.FLAG_ON_TOP_LAUNCHER;
 import static android.content.pm.ActivityInfo.RESIZE_MODE_FORCE_RESIZEABLE;
 import static android.content.pm.ActivityInfo.RESIZE_MODE_RESIZEABLE;
 import static android.content.pm.ActivityInfo.RESIZE_MODE_RESIZEABLE_AND_PIPABLE;
@@ -3567,6 +3568,10 @@ public class PackageParser {
                 a.info.flags |= FLAG_ALWAYS_FOCUSABLE;
             }
 
+            if (sa.getBoolean(R.styleable.AndroidManifestActivity_onTopLauncher, false)) {
+                a.info.flags |= FLAG_ON_TOP_LAUNCHER;
+            }
+
             a.info.lockTaskLaunchMode =
                     sa.getInt(R.styleable.AndroidManifestActivity_lockTaskMode, 0);
 
diff --git a/core/res/res/values/attrs_manifest.xml b/core/res/res/values/attrs_manifest.xml
index d69d73db60916..e1bbef7555ab8 100644
--- a/core/res/res/values/attrs_manifest.xml
+++ b/core/res/res/values/attrs_manifest.xml
@@ -1898,6 +1898,9 @@
              in a task/stack that isn't focusable. This flag allows them to be focusable.-->
         <attr name="alwaysFocusable" format="boolean" />
         <attr name="enableVrMode" />
+        <!-- @hide This activity is a launcher which should always show up on the top of others.
+             This attribute is ignored if the activity isn't a launcher. -->
+        <attr name="onTopLauncher" format="boolean" />
     </declare-styleable>
 
     <!-- The <code>activity-alias</code> tag declares a new
diff --git a/services/core/java/com/android/server/am/ActivityRecord.java b/services/core/java/com/android/server/am/ActivityRecord.java
index 0408cc1f85139..1dffb3673c0cd 100755
--- a/services/core/java/com/android/server/am/ActivityRecord.java
+++ b/services/core/java/com/android/server/am/ActivityRecord.java
@@ -19,6 +19,7 @@ package com.android.server.am;
 import static android.app.ActivityManager.StackId;
 import static android.app.ActivityManager.StackId.FREEFORM_WORKSPACE_STACK_ID;
 import static android.app.ActivityManager.StackId.PINNED_STACK_ID;
+import static android.content.pm.ActivityInfo.FLAG_ON_TOP_LAUNCHER;
 import static android.content.pm.ActivityInfo.RESIZE_MODE_CROP_WINDOWS;
 import static android.content.pm.ActivityInfo.FLAG_ALWAYS_FOCUSABLE;
 import static android.content.pm.ActivityInfo.RESIZE_MODE_RESIZEABLE;
@@ -858,6 +859,10 @@ final class ActivityRecord {
         return (info.flags & FLAG_ALWAYS_FOCUSABLE) != 0;
     }
 
+    boolean isOnTopLauncher() {
+        return isHomeActivity() && (info.flags & FLAG_ON_TOP_LAUNCHER) != 0;
+    }
+
     void makeFinishingLocked() {
         if (!finishing) {
             if (task != null && task.stack != null