AudioPolicy: add test flagging for focus policy tests

(Note there is no @TestApi for @SystemApi, so rely
  on javadoc to document that the new method is
  for testing purposes only)
Add method to flag a focus policy as a test policy for
  devices that run their own focus policy to customize
  audio focus management. When a test policy is installed
  it will replace the current one, and will restore it
  when it is unregistered.
Add nullability annotations in Builder.

Bug: 123717363
Test: make system-api-stubs-docs-update-current-api
Test: gts-tradefed run gts --skip-device-info --skip-system-status-check com.android.compatibility.common.tradefed.targetprep.NetworkConnectivityChecker -m GtsGmscoreHostTestCases -t 'com.google.android.gts.audiopolicy.AudioPolicyHostTest#testFocusPolicy'
Change-Id: I572487bb53f85aade22da8529db9491a542ef0db

6 files changed, 72 insertions, 19 deletions

diff --git a/api/system-current.txt b/api/system-current.txt
index 0b8b8e45062b..8880f99dffaa 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -3664,13 +3664,14 @@ package android.media.audiopolicy {
 
   public static class AudioPolicy.Builder {
     ctor public AudioPolicy.Builder(android.content.Context);
-    method public android.media.audiopolicy.AudioPolicy.Builder addMix(@NonNull android.media.audiopolicy.AudioMix) throws java.lang.IllegalArgumentException;
-    method public android.media.audiopolicy.AudioPolicy build();
+    method @NonNull public android.media.audiopolicy.AudioPolicy.Builder addMix(@NonNull android.media.audiopolicy.AudioMix) throws java.lang.IllegalArgumentException;
+    method @NonNull public android.media.audiopolicy.AudioPolicy build();
     method public void setAudioPolicyFocusListener(android.media.audiopolicy.AudioPolicy.AudioPolicyFocusListener);
     method public void setAudioPolicyStatusListener(android.media.audiopolicy.AudioPolicy.AudioPolicyStatusListener);
-    method public android.media.audiopolicy.AudioPolicy.Builder setAudioPolicyVolumeCallback(@NonNull android.media.audiopolicy.AudioPolicy.AudioPolicyVolumeCallback);
-    method public android.media.audiopolicy.AudioPolicy.Builder setIsAudioFocusPolicy(boolean);
-    method public android.media.audiopolicy.AudioPolicy.Builder setLooper(@NonNull android.os.Looper) throws java.lang.IllegalArgumentException;
+    method @NonNull public android.media.audiopolicy.AudioPolicy.Builder setAudioPolicyVolumeCallback(@NonNull android.media.audiopolicy.AudioPolicy.AudioPolicyVolumeCallback);
+    method @NonNull public android.media.audiopolicy.AudioPolicy.Builder setIsAudioFocusPolicy(boolean);
+    method @NonNull public android.media.audiopolicy.AudioPolicy.Builder setIsTestFocusPolicy(boolean);
+    method @NonNull public android.media.audiopolicy.AudioPolicy.Builder setLooper(@NonNull android.os.Looper) throws java.lang.IllegalArgumentException;
   }
 
   public final class AudioProductStrategies implements java.lang.Iterable<android.media.audiopolicy.AudioProductStrategy> android.os.Parcelable {
diff --git a/media/java/android/media/AudioManager.java b/media/java/android/media/AudioManager.java
index f9080a70206e..998849c3d421 100644
--- a/media/java/android/media/AudioManager.java
+++ b/media/java/android/media/AudioManager.java
@@ -3307,7 +3307,8 @@ public class AudioManager {
         try {
             MediaProjection projection = policy.getMediaProjection();
             String regId = service.registerAudioPolicy(policy.getConfig(), policy.cb(),
-                    policy.hasFocusListener(), policy.isFocusPolicy(), policy.isVolumeController(),
+                    policy.hasFocusListener(), policy.isFocusPolicy(), policy.isTestFocusPolicy(),
+                    policy.isVolumeController(),
                     projection == null ? null : projection.getProjection());
             if (regId == null) {
                 return ERROR;
diff --git a/media/java/android/media/IAudioService.aidl b/media/java/android/media/IAudioService.aidl
index c29f355181f4..a1fde52a89cc 100644
--- a/media/java/android/media/IAudioService.aidl
+++ b/media/java/android/media/IAudioService.aidl
@@ -195,6 +195,7 @@ interface IAudioService {
 
     String registerAudioPolicy(in AudioPolicyConfig policyConfig,
             in IAudioPolicyCallback pcb, boolean hasFocusListener, boolean isFocusPolicy,
+            boolean isTestFocusPolicy,
             boolean isVolumeController, in IMediaProjection projection);
 
     oneway void unregisterAudioPolicyAsync(in IAudioPolicyCallback pcb);
diff --git a/media/java/android/media/audiopolicy/AudioPolicy.java b/media/java/android/media/audiopolicy/AudioPolicy.java
index 978583e99971..00f601388164 100644
--- a/media/java/android/media/audiopolicy/AudioPolicy.java
+++ b/media/java/android/media/audiopolicy/AudioPolicy.java
@@ -75,6 +75,7 @@ public class AudioPolicy {
     private String mRegistrationId;
     private AudioPolicyStatusListener mStatusListener;
     private boolean mIsFocusPolicy;
+    private boolean mIsTestFocusPolicy;
 
     /**
      * The list of AudioTrack instances created to inject audio into the associated mixes
@@ -121,6 +122,10 @@ public class AudioPolicy {
     /** @hide */
     public boolean isFocusPolicy() { return mIsFocusPolicy; }
     /** @hide */
+    public boolean isTestFocusPolicy() {
+        return mIsTestFocusPolicy;
+    }
+    /** @hide */
     public boolean isVolumeController() { return mVolCb != null; }
     /** @hide */
     public @Nullable MediaProjection getMediaProjection() {
@@ -128,10 +133,11 @@ public class AudioPolicy {
     }
 
     /**
-     * The parameter is guaranteed non-null through the Builder
+     * The parameters are guaranteed non-null through the Builder
      */
     private AudioPolicy(AudioPolicyConfig config, Context context, Looper looper,
-            AudioPolicyFocusListener fl, AudioPolicyStatusListener sl, boolean isFocusPolicy,
+            AudioPolicyFocusListener fl, AudioPolicyStatusListener sl,
+            boolean isFocusPolicy, boolean isTestFocusPolicy,
             AudioPolicyVolumeCallback vc, @Nullable MediaProjection projection) {
         mConfig = config;
         mStatus = POLICY_STATUS_UNREGISTERED;
@@ -148,6 +154,7 @@ public class AudioPolicy {
         mFocusListener = fl;
         mStatusListener = sl;
         mIsFocusPolicy = isFocusPolicy;
+        mIsTestFocusPolicy = isTestFocusPolicy;
         mVolCb = vc;
         mProjection = projection;
     }
@@ -163,6 +170,7 @@ public class AudioPolicy {
         private AudioPolicyFocusListener mFocusListener;
         private AudioPolicyStatusListener mStatusListener;
         private boolean mIsFocusPolicy = false;
+        private boolean mIsTestFocusPolicy = false;
         private AudioPolicyVolumeCallback mVolCb;
         private MediaProjection mProjection;
 
@@ -181,6 +189,7 @@ public class AudioPolicy {
          * @return the same Builder instance.
          * @throws IllegalArgumentException
          */
+        @NonNull
         public Builder addMix(@NonNull AudioMix mix) throws IllegalArgumentException {
             if (mix == null) {
                 throw new IllegalArgumentException("Illegal null AudioMix argument");
@@ -195,6 +204,7 @@ public class AudioPolicy {
          * @return the same Builder instance.
          * @throws IllegalArgumentException
          */
+        @NonNull
         public Builder setLooper(@NonNull Looper looper) throws IllegalArgumentException {
             if (looper == null) {
                 throw new IllegalArgumentException("Illegal null Looper argument");
@@ -220,12 +230,28 @@ public class AudioPolicy {
          * @param enforce true if the policy will govern audio focus decisions.
          * @return the same Builder instance.
          */
+        @NonNull
         public Builder setIsAudioFocusPolicy(boolean isFocusPolicy) {
             mIsFocusPolicy = isFocusPolicy;
             return this;
         }
 
         /**
+         * Test method to declare whether this audio focus policy is for test purposes only.
+         * Having a test policy registered will disable the current focus policy and replace it
+         * with this test policy. When unregistered, the previous focus policy will be restored.
+         * <p>A value of <code>true</code> will be ignored if the AudioPolicy is not also
+         * focus policy.
+         * @param isTestFocusPolicy true if the focus policy to register is for testing purposes.
+         * @return the same Builder instance
+         */
+        @NonNull
+        public Builder setIsTestFocusPolicy(boolean isTestFocusPolicy) {
+            mIsTestFocusPolicy = isTestFocusPolicy;
+            return this;
+        }
+
+        /**
          * Sets the audio policy status listener.
          * @param l a {@link AudioPolicy.AudioPolicyStatusListener}
          */
@@ -240,6 +266,7 @@ public class AudioPolicy {
          * @param vc
          * @return the same Builder instance.
          */
+        @NonNull
         public Builder setAudioPolicyVolumeCallback(@NonNull AudioPolicyVolumeCallback vc) {
             if (vc == null) {
                 throw new IllegalArgumentException("Invalid null volume callback");
@@ -256,6 +283,7 @@ public class AudioPolicy {
          *
          * @hide
          */
+        @NonNull
         public Builder setMediaProjection(@NonNull MediaProjection projection) {
             if (projection == null) {
                 throw new IllegalArgumentException("Invalid null volume callback");
@@ -273,6 +301,7 @@ public class AudioPolicy {
          *     {@link AudioPolicy.AudioPolicyStatusListener} but the policy was configured
          *     as an audio focus policy with {@link #setIsAudioFocusPolicy(boolean)}.
          */
+        @NonNull
         public AudioPolicy build() {
             if (mStatusListener != null) {
                 // the AudioPolicy status listener includes updates on each mix activity state
@@ -285,7 +314,8 @@ public class AudioPolicy {
                         + "an AudioPolicyFocusListener");
             }
             return new AudioPolicy(new AudioPolicyConfig(mMixes), mContext, mLooper,
-                    mFocusListener, mStatusListener, mIsFocusPolicy, mVolCb, mProjection);
+                    mFocusListener, mStatusListener, mIsFocusPolicy, mIsTestFocusPolicy,
+                    mVolCb, mProjection);
         }
     }
 
diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index a14a638395db..26f82bbf4dea 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -6290,8 +6290,8 @@ public class AudioService extends IAudioService.Stub
     // Audio policy management
     //==========================================================================================
     public String registerAudioPolicy(AudioPolicyConfig policyConfig, IAudioPolicyCallback pcb,
-            boolean hasFocusListener, boolean isFocusPolicy, boolean isVolumeController,
-            IMediaProjection projection) {
+            boolean hasFocusListener, boolean isFocusPolicy, boolean isTestFocusPolicy,
+            boolean isVolumeController, IMediaProjection projection) {
         AudioSystem.setDynamicPolicyCallback(mDynPolicyCallback);
 
         if (!isPolicyRegisterAllowed(policyConfig, projection)) {
@@ -6312,7 +6312,7 @@ public class AudioService extends IAudioService.Stub
                     return null;
                 }
                 AudioPolicyProxy app = new AudioPolicyProxy(policyConfig, pcb, hasFocusListener,
-                        isFocusPolicy, isVolumeController);
+                        isFocusPolicy, isTestFocusPolicy, isVolumeController);
                 pcb.asBinder().linkToDeath(app, 0/*flags*/);
                 regId = app.getRegistrationId();
                 mAudioPolicies.put(pcb.asBinder(), app);
@@ -6730,9 +6730,11 @@ public class AudioService extends IAudioService.Stub
          */
         int mFocusDuckBehavior = AudioPolicy.FOCUS_POLICY_DUCKING_DEFAULT;
         boolean mIsFocusPolicy = false;
+        boolean mIsTestFocusPolicy = false;
 
         AudioPolicyProxy(AudioPolicyConfig config, IAudioPolicyCallback token,
-                boolean hasFocusListener, boolean isFocusPolicy, boolean isVolumeController) {
+                boolean hasFocusListener, boolean isFocusPolicy, boolean isTestFocusPolicy,
+                boolean isVolumeController) {
             super(config);
             setRegistration(new String(config.hashCode() + ":ap:" + mAudioPolicyCounter++));
             mPolicyCallback = token;
@@ -6743,7 +6745,8 @@ public class AudioService extends IAudioService.Stub
                 // can only ever be true if there is a focus listener
                 if (isFocusPolicy) {
                     mIsFocusPolicy = true;
-                    mMediaFocusControl.setFocusPolicy(mPolicyCallback);
+                    mIsTestFocusPolicy = isTestFocusPolicy;
+                    mMediaFocusControl.setFocusPolicy(mPolicyCallback, mIsTestFocusPolicy);
                 }
             }
             if (mIsVolumeController) {
@@ -6771,7 +6774,7 @@ public class AudioService extends IAudioService.Stub
 
         void release() {
             if (mIsFocusPolicy) {
-                mMediaFocusControl.unsetFocusPolicy(mPolicyCallback);
+                mMediaFocusControl.unsetFocusPolicy(mPolicyCallback, mIsTestFocusPolicy);
             }
             if (mFocusDuckBehavior == AudioPolicy.FOCUS_POLICY_DUCKING_IN_POLICY) {
                 mMediaFocusControl.setDuckingInExtPolicyAvailable(false);
diff --git a/services/core/java/com/android/server/audio/MediaFocusControl.java b/services/core/java/com/android/server/audio/MediaFocusControl.java
index d028e88fa160..1e58b454a15b 100644
--- a/services/core/java/com/android/server/audio/MediaFocusControl.java
+++ b/services/core/java/com/android/server/audio/MediaFocusControl.java
@@ -17,6 +17,7 @@
 package com.android.server.audio;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.app.AppOpsManager;
 import android.content.Context;
 import android.media.AudioAttributes;
@@ -458,7 +459,15 @@ public class MediaFocusControl implements PlayerFocusEnforcer {
         }
     }
 
-    private IAudioPolicyCallback mFocusPolicy = null;
+    /** The current audio focus policy */
+    @GuardedBy("mAudioFocusLock")
+    @Nullable private IAudioPolicyCallback mFocusPolicy = null;
+    /**
+     * The audio focus policy that was registered before a test focus policy was registered
+     * during a test
+     */
+    @GuardedBy("mAudioFocusLock")
+    @Nullable private IAudioPolicyCallback mPreviousFocusPolicy = null;
 
     // Since we don't have a stack of focus owners when using an external focus policy, we keep
     // track of all the focus requesters in this map, with their clientId as the key. This is
@@ -466,22 +475,30 @@ public class MediaFocusControl implements PlayerFocusEnforcer {
     private HashMap<String, FocusRequester> mFocusOwnersForFocusPolicy =
             new HashMap<String, FocusRequester>();
 
-    void setFocusPolicy(IAudioPolicyCallback policy) {
+    void setFocusPolicy(IAudioPolicyCallback policy, boolean isTestFocusPolicy) {
         if (policy == null) {
             return;
         }
         synchronized (mAudioFocusLock) {
+            if (isTestFocusPolicy) {
+                mPreviousFocusPolicy = mFocusPolicy;
+            }
             mFocusPolicy = policy;
         }
     }
 
-    void unsetFocusPolicy(IAudioPolicyCallback policy) {
+    void unsetFocusPolicy(IAudioPolicyCallback policy, boolean isTestFocusPolicy) {
         if (policy == null) {
             return;
         }
         synchronized (mAudioFocusLock) {
             if (mFocusPolicy == policy) {
-                mFocusPolicy = null;
+                if (isTestFocusPolicy) {
+                    // restore the focus policy that was there before the focus policy test started
+                    mFocusPolicy = mPreviousFocusPolicy;
+                } else {
+                    mFocusPolicy = null;
+                }
             }
         }
     }