From eb69e24e852be0dec25929aadf62a7a62f020e60 Mon Sep 17 00:00:00 2001
From: John Spurlock <jspurlock@google.com>
Date: Tue, 17 Feb 2015 17:15:04 -0500
Subject: [PATCH] Volume prototypes: Allow delegate volume UI to set remote
 controller.

Allow the blessed component (stored in secure settings) to replace
the remote volume controller (for media sessions) in addition
to the volume controller - needed in order to properly support
cast etc.

Bug: 19260237
Change-Id: I7ecc79cb4249744e8d4ffedcab737a35331e220f
---
 .../android/server/media/MediaSessionService.java  | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/media/MediaSessionService.java b/services/core/java/com/android/server/media/MediaSessionService.java
index 1a0f81dec3e9a..06c154e682405 100644
--- a/services/core/java/com/android/server/media/MediaSessionService.java
+++ b/services/core/java/com/android/server/media/MediaSessionService.java
@@ -31,6 +31,7 @@ import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.database.ContentObserver;
 import android.media.AudioManager;
+import android.media.AudioManagerInternal;
 import android.media.AudioSystem;
 import android.media.IAudioService;
 import android.media.IRemoteVolumeController;
@@ -59,6 +60,7 @@ import android.util.Log;
 import android.util.SparseArray;
 import android.view.KeyEvent;
 
+import com.android.server.LocalServices;
 import com.android.server.SystemService;
 import com.android.server.Watchdog;
 import com.android.server.Watchdog.Monitor;
@@ -94,6 +96,7 @@ public class MediaSessionService extends SystemService implements Monitor {
     private KeyguardManager mKeyguardManager;
     private IAudioService mAudioService;
     private AudioManager mAudioManager;
+    private AudioManagerInternal mAudioManagerInternal;
     private ContentResolver mContentResolver;
     private SettingsObserver mSettingsObserver;
 
@@ -121,6 +124,7 @@ public class MediaSessionService extends SystemService implements Monitor {
                 (KeyguardManager) getContext().getSystemService(Context.KEYGUARD_SERVICE);
         mAudioService = getAudioService();
         mAudioManager = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
+        mAudioManagerInternal = LocalServices.getService(AudioManagerInternal.class);
         mContentResolver = getContext().getContentResolver();
         mSettingsObserver = new SettingsObserver();
         mSettingsObserver.observe();
@@ -343,7 +347,13 @@ public class MediaSessionService extends SystemService implements Monitor {
         }
     }
 
-    private void enforceStatusBarPermission(String action, int pid, int uid) {
+    private void enforceSystemUiPermission(String action, int pid, int uid) {
+        if (mAudioManagerInternal != null) {
+            final int vcuid = mAudioManagerInternal.getVolumeControllerUid();
+            if (vcuid > 0 && uid == vcuid) {
+                return;
+            }
+        }
         if (getContext().checkPermission(android.Manifest.permission.STATUS_BAR_SERVICE,
                 pid, uid) != PackageManager.PERMISSION_GRANTED) {
             throw new SecurityException("Only system ui may " + action);
@@ -789,7 +799,7 @@ public class MediaSessionService extends SystemService implements Monitor {
             final int uid = Binder.getCallingUid();
             final long token = Binder.clearCallingIdentity();
             try {
-                enforceStatusBarPermission("listen for volume changes", pid, uid);
+                enforceSystemUiPermission("listen for volume changes", pid, uid);
                 mRvc = rvc;
             } finally {
                 Binder.restoreCallingIdentity(token);