cmsdk: Add CMAudioManager

 * This is a rework of the session callback API which previously
   lived in the framework due to JNI usage. This has been split out
   and cleaned up for CMSDK.
 * The JNI library lives on the server side, and the app-level
   callback has been changed to a protected broadcast. This allows
   us to wake up registered services when these events occur.
 * Additionally, we support listing all active audio sessions.
 * Also brings some JNI love/hate over to CMSDK.

Change-Id: I31c293943474419e3db088bb7ffab75f7440ac0f

5 files changed, 409 insertions, 0 deletions

diff --git a/sdk/src/java/cyanogenmod/app/CMContextConstants.java b/sdk/src/java/cyanogenmod/app/CMContextConstants.java
index 07a2980..43c700b 100644
--- a/sdk/src/java/cyanogenmod/app/CMContextConstants.java
+++ b/sdk/src/java/cyanogenmod/app/CMContextConstants.java
@@ -138,6 +138,14 @@ public final class CMContextConstants {
      */
     public static final String CM_LIVEDISPLAY_SERVICE = "cmlivedisplay";
 
+
+    /**
+     * Manages enhanced audio functionality
+     *
+     * @hide
+     */
+    public static final String CM_AUDIO_SERVICE = "cmaudio";
+
     /**
      * Features supported by the CMSDK.
      */
@@ -229,5 +237,13 @@ public final class CMContextConstants {
          */
         @SdkConstant(SdkConstant.SdkConstantType.FEATURE)
         public static final String LIVEDISPLAY = "org.cyanogenmod.livedisplay";
+
+        /**
+         * Feature for {@link PackageManager#getSystemAvailableFeatures} and
+         * {@link PackageManager#hasSystemFeature}: The device includes the CM audio extensions
+         * utilized by the cmsdk.
+         */
+        @SdkConstant(SdkConstant.SdkConstantType.FEATURE)
+        public static final String AUDIO = "org.cyanogenmod.audio";
     }
 }
diff --git a/sdk/src/java/cyanogenmod/media/AudioSessionInfo.aidl b/sdk/src/java/cyanogenmod/media/AudioSessionInfo.aidl
new file mode 100644
index 0000000..4a44239
--- /dev/null
+++ b/sdk/src/java/cyanogenmod/media/AudioSessionInfo.aidl
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cyanogenmod.media;
+
+parcelable AudioSessionInfo;
diff --git a/sdk/src/java/cyanogenmod/media/AudioSessionInfo.java b/sdk/src/java/cyanogenmod/media/AudioSessionInfo.java
new file mode 100644
index 0000000..5f688cc
--- /dev/null
+++ b/sdk/src/java/cyanogenmod/media/AudioSessionInfo.java
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cyanogenmod.media;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.util.Objects;
+
+import cyanogenmod.os.Build;
+import cyanogenmod.os.Concierge;
+import cyanogenmod.os.Concierge.ParcelInfo;
+
+/**
+ * AudioSessionInfo represents a single instance of an audio session.
+ * Audio sessions are created when a new AudioTrack is started, and
+ * removed when the track is released. Audio session identifiers
+ * are unique (but may be reused) and are used as a handle by which
+ * an application may create audio effects on the output stream.
+ *
+ * A list of global audio sessions can be obtained by calling
+ * listAudioSessions() via {@link CMAudioManager}, or a component can listen
+ * for the {@link CMAudioManager#ACTION_AUDIO_SESSIONS_CHANGED} broadcast.
+ *
+ * @hide
+ */
+public final class AudioSessionInfo implements Parcelable {
+
+    /**
+     * Unique session id
+     */
+    private  final int mSessionId;
+    /**
+     * Stream type - see audio_stream_type_t
+     */
+    private  final int mStream;
+    /**
+     * Output flags - see audio_output_flags_t
+     */
+    private final int mFlags;
+    /**
+     * Channel mask - see audio_channel_mask_t
+     */
+    private final int mChannelMask;
+    /**
+     * UID of the source application
+     */
+    private final int mUid;
+
+    public AudioSessionInfo(int sessionId, int stream, int flags, int channelMask, int uid) {
+        mSessionId = sessionId;
+        mStream = stream;
+        mFlags = flags;
+        mChannelMask = channelMask;
+        mUid = uid;
+    }
+
+    private AudioSessionInfo(Parcel in) {
+        // Read parcelable version via the Concierge
+        ParcelInfo parcelInfo = Concierge.receiveParcel(in);
+        int parcelableVersion = parcelInfo.getParcelVersion();
+
+        /* -- FIG -- */
+        mSessionId = in.readInt();
+        mStream = in.readInt();
+        mFlags = in.readInt();
+        mChannelMask = in.readInt();
+        mUid = in.readInt();
+
+        if (parcelableVersion > Build.CM_VERSION_CODES.FIG) {
+            // next-gen mind-altering shit goes here
+        }
+
+        // Complete parcel info for the concierge
+        parcelInfo.complete();
+    }
+
+    public int getSessionId() {
+        return mSessionId;
+    }
+
+    public int getStream() {
+        return mStream;
+    }
+
+    public int getFlags() {
+        return mFlags;
+    }
+
+    public int getChannelMask() {
+        return mChannelMask;
+    }
+
+    public int getUid() {
+        return mUid;
+    }
+
+    @Override
+    public String toString() {
+        return String.format(
+                "audioSessionInfo[sessionId=%d, stream=%d, flags=%d, channelMask=%d, uid=%d",
+                mSessionId, mStream, mFlags, mChannelMask, mUid);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mSessionId, mStream, mFlags, mChannelMask, mUid);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null || !(obj instanceof AudioSessionInfo)) {
+            return false;
+        }
+
+        final AudioSessionInfo other = (AudioSessionInfo)obj;
+        return this == other ||
+                (mSessionId == other.mSessionId &&
+                 mStream == other.mStream &&
+                 mFlags == other.mFlags &&
+                 mChannelMask == other.mChannelMask &&
+                 mUid == other.mUid);
+    }
+
+    /** @hide */
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    /** @hide */
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        // Tell the concierge to prepare the parcel
+        ParcelInfo parcelInfo = Concierge.prepareParcel(dest);
+
+        /* -- FIG -- */
+        dest.writeInt(mSessionId);
+        dest.writeInt(mStream);
+        dest.writeInt(mFlags);
+        dest.writeInt(mChannelMask);
+        dest.writeInt(mUid);
+
+        parcelInfo.complete();
+    }
+
+    /** @hide */
+    public static final Creator<AudioSessionInfo> CREATOR = new Creator<AudioSessionInfo>() {
+
+        @Override
+        public AudioSessionInfo createFromParcel(Parcel source) {
+            return new AudioSessionInfo(source);
+        }
+
+        @Override
+        public AudioSessionInfo[] newArray(int size) {
+            return new AudioSessionInfo[size];
+        }
+    };
+}
+
+
diff --git a/sdk/src/java/cyanogenmod/media/CMAudioManager.java b/sdk/src/java/cyanogenmod/media/CMAudioManager.java
new file mode 100644
index 0000000..801cab4
--- /dev/null
+++ b/sdk/src/java/cyanogenmod/media/CMAudioManager.java
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cyanogenmod.media;
+
+import android.content.Context;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.os.ServiceManager;
+import android.util.Log;
+
+import java.util.Collections;
+import java.util.List;
+
+import cyanogenmod.app.CMContextConstants;
+
+/**
+ * Manager for extended audio system capabilities provided by
+ * CyanogenMod.
+ *
+ * Currently, this API provides an application the ability to
+ * query active global audio sessions, and receive broadcasts
+ * when new audio sessions are created and destroyed.
+ *
+ * Applications wishing to receive audio session information
+ * should register for the {@link ACTION_AUDIO_SESSIONS_CHANGED}
+ * broadcast. This broadcast requires an application to hold the
+ * {@link cyanogenmod.permission.OBSERVE_AUDIO_SESSIONS}
+ * permission. When receiving the broadcast, {@link EXTRA_SESSION_INFO}
+ * will hold the {@link AudioSessionInfo} object associated
+ * with the session. {@link EXTRA_SESSION_ADDED} will hold
+ * a boolean value, true if the session is added, false if it
+ * is being removed.
+ *
+ * It is important for applications to be cautious about which
+ * audio streams effects are attached to when using this API as
+ * it may interfere with their normal operation. An equalizer
+ * application for example would only want to react to streams
+ * with the type of {@link android.media.AudioManager.STREAM_MUSIC}.
+ *
+ * @see android.media.AudioManager
+ *
+ * @hide
+ */
+public final class CMAudioManager {
+
+    private static final String TAG = "CMAudioManager";
+
+    /**
+     * Broadcast sent when audio session are added and removed.
+     */
+    public static final String ACTION_AUDIO_SESSIONS_CHANGED =
+            "cyanogenmod.intent.action.ACTION_AUDIO_SESSIONS_CHANGED";
+
+    /**
+     * Extra containing {@link AudioSessionInfo}
+     */
+    public static final String EXTRA_SESSION_INFO = "session_info";
+
+    /**
+     * Boolean extra, true if session is being added.
+     */
+    public static final String EXTRA_SESSION_ADDED = "added";
+
+    private Context mContext;
+
+    private static CMAudioManager sInstance;
+    private static ICMAudioService sService;
+
+    /**
+     * @hide to prevent subclassing from outside of the framework
+     */
+    private CMAudioManager(Context context) {
+        Context appContext = context.getApplicationContext();
+        if (appContext != null) {
+            mContext = appContext;
+        } else {
+            mContext = context;
+
+        }
+        sService = getService();
+
+        if (!context.getPackageManager().hasSystemFeature(
+                CMContextConstants.Features.AUDIO) || !checkService()) {
+            throw new RuntimeException("Unable to get CMAudioService. The service either" +
+                    " crashed, was not started, or the interface has been called to early in" +
+                    " SystemServer init");
+        }
+    }
+
+    /**
+     * Get or create an instance of the {@link cyanogenmod.media.CMAudioManager}
+     * @param context
+     * @return {@link CMAudioManager}
+     */
+    public synchronized static CMAudioManager getInstance(Context context) {
+        if (sInstance == null) {
+            sInstance = new CMAudioManager(context);
+        }
+        return sInstance;
+    }
+
+    /** @hide */
+    public static ICMAudioService getService() {
+        if (sService != null) {
+            return sService;
+        }
+        IBinder b = ServiceManager.getService(CMContextConstants.CM_AUDIO_SERVICE);
+        if (b != null) {
+            sService = ICMAudioService.Stub.asInterface(b);
+            return sService;
+        }
+        return null;
+    }
+
+    /**
+     * @return true if service is valid
+     */
+    private boolean checkService() {
+        if (sService == null) {
+            Log.w(TAG, "not connected to CMAudioService");
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * List audio sessions for the given stream type defined in
+     * {@link android.media.AudioManager}, for example,
+     * {@link android.media.AudioManager#STREAM_MUSIC}.
+     *
+     * @param streamType from {@link android.media.AudioManager}
+     * @return list of {@link AudioSessionInfo}, or empty list if none found
+     * @see android.media.AudioManager
+     */
+    public List<AudioSessionInfo> listAudioSessions(int streamType) {
+        if (checkService()) {
+            try {
+                final List<AudioSessionInfo> sessions = sService.listAudioSessions(streamType);
+                if (sessions != null) {
+                    return Collections.unmodifiableList(sessions);
+                }
+            } catch (RemoteException e) {
+                Log.e(TAG, "Failed to list audio sessions!", e);
+            }
+        }
+        return Collections.emptyList();
+    }
+
+    /**
+     * List all audio sessions.
+     *
+     * @return list of {@link AudioSessionInfo}, or empty list if none found
+     * @see android.media.AudioManager
+     */
+    public List<AudioSessionInfo> listAudioSessions() {
+        return listAudioSessions(-1);
+    }
+}
diff --git a/sdk/src/java/cyanogenmod/media/ICMAudioService.aidl b/sdk/src/java/cyanogenmod/media/ICMAudioService.aidl
new file mode 100644
index 0000000..7edcb16
--- /dev/null
+++ b/sdk/src/java/cyanogenmod/media/ICMAudioService.aidl
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cyanogenmod.media;
+
+import cyanogenmod.media.AudioSessionInfo;
+
+/** @hide */
+interface ICMAudioService {
+
+    List<AudioSessionInfo> listAudioSessions(int streamType);
+
+}