Merge "Add a platform library for remote display providers." into klp-dev

Android.mk

@@ -255,6 +255,8 @@ LOCAL_SRC_FILES += \
 	media/java/android/media/IMediaScannerService.aidl \
 	media/java/android/media/IRemoteControlClient.aidl \
 	media/java/android/media/IRemoteControlDisplay.aidl \
+	media/java/android/media/IRemoteDisplayCallback.aidl \
+	media/java/android/media/IRemoteDisplayProvider.aidl \
 	media/java/android/media/IRemoteVolumeObserver.aidl \
 	media/java/android/media/IRingtonePlayer.aidl \
 	telephony/java/com/android/internal/telephony/IPhoneStateListener.aidl \

core/res/AndroidManifest.xml

@@ -1992,6 +1992,14 @@
         android:description="@string/permdesc_bindWallpaper"
         android:protectionLevel="signature|system" />
 
+    <!-- Must be required by a {@link com.android.media.remotedisplay.RemoteDisplayProvider},
+         to ensure that only the system can bind to it.
+         @hide -->
+    <permission android:name="android.permission.BIND_REMOTE_DISPLAY"
+        android:label="@string/permlab_bindRemoteDisplay"
+        android:description="@string/permdesc_bindRemoteDisplay"
+        android:protectionLevel="signature" />
+
     <!-- Must be required by device administration receiver, to ensure that only the
          system can interact with it. -->
     <permission android:name="android.permission.BIND_DEVICE_ADMIN"

core/res/res/values/strings.xml

@@ -1051,6 +1051,12 @@
     <string name="permdesc_bindWallpaper">Allows the holder to bind to the top-level
         interface of a wallpaper. Should never be needed for normal apps.</string>
 
+    <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permlab_bindRemoteDisplay">bind to a remote display</string>
+    <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permdesc_bindRemoteDisplay">Allows the holder to bind to the top-level
+        interface of a remote display. Should never be needed for normal apps.</string>
+
     <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
     <string name="permlab_bindRemoteViews">bind to a widget service</string>
     <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->

media/java/android/media/IRemoteDisplayCallback.aidl

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2013 The Android Open Source 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 android.media;
+
+import android.media.RemoteDisplayState;
+
+/**
+ * {@hide}
+ */
+oneway interface IRemoteDisplayCallback {
+    void onStateChanged(in RemoteDisplayState state);
+}

media/java/android/media/IRemoteDisplayProvider.aidl

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2013 The Android Open Source 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 android.media;
+
+import android.media.IRemoteDisplayCallback;
+
+/**
+ * {@hide}
+ */
+oneway interface IRemoteDisplayProvider {
+    void setCallback(in IRemoteDisplayCallback callback);
+    void setDiscoveryMode(int mode);
+    void connect(String id);
+    void disconnect(String id);
+    void setVolume(String id, int volume);
+    void adjustVolume(String id, int delta);
+}

media/java/android/media/RemoteDisplayState.aidl

@@ -0,0 +1,18 @@
+/* Copyright 2013, The Android Open Source 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 android.media;
+
+parcelable RemoteDisplayState;

media/java/android/media/RemoteDisplayState.java

@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2013 The Android Open Source 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 android.media;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.text.TextUtils;
+
+import java.util.ArrayList;
+
+/**
+ * Information available from IRemoteDisplayProvider about available remote displays.
+ *
+ * Clients must not modify the contents of this object.
+ * @hide
+ */
+public final class RemoteDisplayState implements Parcelable {
+    // Note: These constants are used by the remote display provider API.
+    // Do not change them!
+    public static final String SERVICE_INTERFACE =
+            "com.android.media.remotedisplay.RemoteDisplayProvider";
+    public static final int DISCOVERY_MODE_NONE = 0;
+    public static final int DISCOVERY_MODE_PASSIVE = 1;
+    public static final int DISCOVERY_MODE_ACTIVE = 2;
+
+    /**
+     * A list of all remote displays.
+     */
+    public final ArrayList<RemoteDisplayInfo> displays;
+
+    public RemoteDisplayState() {
+        displays = new ArrayList<RemoteDisplayInfo>();
+    }
+
+    RemoteDisplayState(Parcel src) {
+        displays = src.createTypedArrayList(RemoteDisplayInfo.CREATOR);
+    }
+
+    public boolean isValid() {
+        if (displays == null) {
+            return false;
+        }
+        final int count = displays.size();
+        for (int i = 0; i < count; i++) {
+            if (!displays.get(i).isValid()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeTypedList(displays);
+    }
+
+    public static final Parcelable.Creator<RemoteDisplayState> CREATOR =
+            new Parcelable.Creator<RemoteDisplayState>() {
+        @Override
+        public RemoteDisplayState createFromParcel(Parcel in) {
+            return new RemoteDisplayState(in);
+        }
+
+        @Override
+        public RemoteDisplayState[] newArray(int size) {
+            return new RemoteDisplayState[size];
+        }
+    };
+
+    public static final class RemoteDisplayInfo implements Parcelable {
+        // Note: These constants are used by the remote display provider API.
+        // Do not change them!
+        public static final int STATUS_NOT_AVAILABLE = 0;
+        public static final int STATUS_IN_USE = 1;
+        public static final int STATUS_AVAILABLE = 2;
+        public static final int STATUS_CONNECTING = 3;
+        public static final int STATUS_CONNECTED = 4;
+
+        public static final int PLAYBACK_VOLUME_VARIABLE =
+                MediaRouter.RouteInfo.PLAYBACK_VOLUME_VARIABLE;
+        public static final int PLAYBACK_VOLUME_FIXED =
+                MediaRouter.RouteInfo.PLAYBACK_VOLUME_FIXED;
+
+        public String id;
+        public String name;
+        public String description;
+        public int status;
+        public int volume;
+        public int volumeMax;
+        public int volumeHandling;
+        public int presentationDisplayId;
+
+        public RemoteDisplayInfo(String id) {
+            this.id = id;
+            status = STATUS_NOT_AVAILABLE;
+            volumeHandling = MediaRouter.RouteInfo.PLAYBACK_VOLUME_FIXED;
+            presentationDisplayId = -1;
+        }
+
+        public RemoteDisplayInfo(RemoteDisplayInfo other) {
+            id = other.id;
+            name = other.name;
+            description = other.description;
+            status = other.status;
+            volume = other.volume;
+            volumeMax = other.volumeMax;
+            volumeHandling = other.volumeHandling;
+            presentationDisplayId = other.presentationDisplayId;
+        }
+
+        RemoteDisplayInfo(Parcel in) {
+            id = in.readString();
+            name = in.readString();
+            description = in.readString();
+            status = in.readInt();
+            volume = in.readInt();
+            volumeMax = in.readInt();
+            volumeHandling = in.readInt();
+            presentationDisplayId = in.readInt();
+        }
+
+        public boolean isValid() {
+            return !TextUtils.isEmpty(id) && !TextUtils.isEmpty(name);
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        @Override
+        public void writeToParcel(Parcel dest, int flags) {
+            dest.writeString(id);
+            dest.writeString(name);
+            dest.writeString(description);
+            dest.writeInt(status);
+            dest.writeInt(volume);
+            dest.writeInt(volumeMax);
+            dest.writeInt(volumeHandling);
+            dest.writeInt(presentationDisplayId);
+        }
+
+        @Override
+        public String toString() {
+            return "RemoteDisplayInfo{ id=" + id
+                    + ", name=" + name
+                    + ", description=" + description
+                    + ", status=" + status
+                    + ", volume=" + volume
+                    + ", volumeMax=" + volumeMax
+                    + ", volumeHandling=" + volumeHandling
+                    + ", presentationDisplayId=" + presentationDisplayId
+                    + " }";
+        }
+
+        @SuppressWarnings("hiding")
+        public static final Parcelable.Creator<RemoteDisplayInfo> CREATOR =
+                new Parcelable.Creator<RemoteDisplayInfo>() {
+            @Override
+            public RemoteDisplayInfo createFromParcel(Parcel in) {
+                return new RemoteDisplayInfo(in);
+            }
+
+            @Override
+            public RemoteDisplayInfo[] newArray(int size) {
+                return new RemoteDisplayInfo[size];
+            }
+        };
+    }
+}

media/lib/Android.mk

@@ -0,0 +1,46 @@
+#
+# Copyright (C) 2013 The Android Open Source 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.
+#
+LOCAL_PATH := $(call my-dir)
+
+# the library
+# ============================================================
+include $(CLEAR_VARS)
+
+LOCAL_MODULE:= com.android.media.remotedisplay
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES := \
+            $(call all-subdir-java-files) \
+            $(call all-aidl-files-under, java)
+
+include $(BUILD_JAVA_LIBRARY)
+
+
+# ====  com.android.media.remotedisplay.xml lib def  ========================
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := com.android.media.remotedisplay.xml
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_MODULE_CLASS := ETC
+
+# This will install the file in /system/etc/permissions
+#
+LOCAL_MODULE_PATH := $(TARGET_OUT_ETC)/permissions
+
+LOCAL_SRC_FILES := $(LOCAL_MODULE)
+
+include $(BUILD_PREBUILT)

media/lib/README.txt

@@ -0,0 +1,28 @@
+This library (com.android.media.remotedisplay.jar) is a shared java library
+containing classes required by unbundled remote display providers.
+
+--- Rules of this library ---
+o This library is effectively a PUBLIC API for unbundled remote display providers
+  that may be distributed outside the system image. So it MUST BE API STABLE.
+  You can add but not remove. The rules are the same as for the
+  public platform SDK API.
+o This library can see and instantiate internal platform classes, but it must not
+  expose them in any public method (or by extending them via inheritance). This would
+  break clients of the library because they cannot see the internal platform classes.
+
+This library is distributed in the system image, and loaded as
+a shared library. So you can change the implementation, but not
+the interface. In this way it is like framework.jar.
+
+--- Why does this library exists? ---
+
+Unbundled remote display providers (such as Cast) cannot use internal
+platform classes.
+
+This library will eventually be replaced when the media route provider
+infrastructure that is currently defined in the support library is reintegrated
+with the framework in a new API.  That API isn't ready yet so this
+library is a compromise to make new capabilities available to the system
+without exposing the full surface area of the support library media
+route provider protocol.
+

media/lib/com.android.media.remotedisplay.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 The Android Open Source 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.
+-->
+
+<permissions>
+    <library name="com.android.media.remotedisplay"
+            file="/system/framework/com.android.media.remotedisplay.jar" />
+</permissions>

media/lib/java/com/android/media/remotedisplay/RemoteDisplay.java

@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2013 The Android Open Source 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 com.android.media.remotedisplay;
+
+import com.android.internal.util.Objects;
+
+import android.media.MediaRouter;
+import android.media.RemoteDisplayState.RemoteDisplayInfo;
+import android.text.TextUtils;
+
+/**
+ * Represents a remote display that has been discovered.
+ */
+public class RemoteDisplay {
+    private final RemoteDisplayInfo mMutableInfo;
+    private RemoteDisplayInfo mImmutableInfo;
+
+    /**
+     * Status code: Indicates that the remote display is not available.
+     */
+    public static final int STATUS_NOT_AVAILABLE = RemoteDisplayInfo.STATUS_NOT_AVAILABLE;
+
+    /**
+     * Status code: Indicates that the remote display is in use by someone else.
+     */
+    public static final int STATUS_IN_USE = RemoteDisplayInfo.STATUS_IN_USE;
+
+    /**
+     * Status code: Indicates that the remote display is available for new connections.
+     */
+    public static final int STATUS_AVAILABLE = RemoteDisplayInfo.STATUS_AVAILABLE;
+
+    /**
+     * Status code: Indicates that the remote display is current connecting.
+     */
+    public static final int STATUS_CONNECTING = RemoteDisplayInfo.STATUS_CONNECTING;
+
+    /**
+     * Status code: Indicates that the remote display is connected and is mirroring
+     * display contents.
+     */
+    public static final int STATUS_CONNECTED = RemoteDisplayInfo.STATUS_CONNECTED;
+
+    /**
+     * Volume handling: Output volume can be changed.
+     */
+    public static final int PLAYBACK_VOLUME_VARIABLE =
+            RemoteDisplayInfo.PLAYBACK_VOLUME_VARIABLE;
+
+    /**
+     * Volume handling: Output volume is fixed.
+     */
+    public static final int PLAYBACK_VOLUME_FIXED =
+            RemoteDisplayInfo.PLAYBACK_VOLUME_FIXED;
+
+    /**
+     * Creates a remote display with the specified name and id.
+     */
+    public RemoteDisplay(String id, String name) {
+        if (TextUtils.isEmpty(id)) {
+            throw new IllegalArgumentException("id must not be null or empty");
+        }
+        mMutableInfo = new RemoteDisplayInfo(id);
+        setName(name);
+    }
+
+    public String getId() {
+        return mMutableInfo.id;
+    }
+
+    public String getName() {
+        return mMutableInfo.name;
+    }
+
+    public void setName(String name) {
+        if (!Objects.equal(mMutableInfo.name, name)) {
+            mMutableInfo.name = name;
+            mImmutableInfo = null;
+        }
+    }
+
+    public String getDescription() {
+        return mMutableInfo.description;
+    }
+
+    public void setDescription(String description) {
+        if (!Objects.equal(mMutableInfo.description, description)) {
+            mMutableInfo.description = description;
+            mImmutableInfo = null;
+        }
+    }
+
+    public int getStatus() {
+        return mMutableInfo.status;
+    }
+
+    public void setStatus(int status) {
+        if (mMutableInfo.status != status) {
+            mMutableInfo.status = status;
+            mImmutableInfo = null;
+        }
+    }
+
+    public int getVolume() {
+        return mMutableInfo.volume;
+    }
+
+    public void setVolume(int volume) {
+        if (mMutableInfo.volume != volume) {
+            mMutableInfo.volume = volume;
+            mImmutableInfo = null;
+        }
+    }
+
+    public int getVolumeMax() {
+        return mMutableInfo.volumeMax;
+    }
+
+    public void setVolumeMax(int volumeMax) {
+        if (mMutableInfo.volumeMax != volumeMax) {
+            mMutableInfo.volumeMax = volumeMax;
+            mImmutableInfo = null;
+        }
+    }
+
+    public int getVolumeHandling() {
+        return mMutableInfo.volumeHandling;
+    }
+
+    public void setVolumeHandling(int volumeHandling) {
+        if (mMutableInfo.volumeHandling != volumeHandling) {
+            mMutableInfo.volumeHandling = volumeHandling;
+            mImmutableInfo = null;
+        }
+    }
+
+    public int getPresentationDisplayId() {
+        return mMutableInfo.presentationDisplayId;
+    }
+
+    public void setPresentationDisplayId(int presentationDisplayId) {
+        if (mMutableInfo.presentationDisplayId != presentationDisplayId) {
+            mMutableInfo.presentationDisplayId = presentationDisplayId;
+            mImmutableInfo = null;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "RemoteDisplay{" + mMutableInfo.toString() + "}";
+    }
+
+    RemoteDisplayInfo getInfo() {
+        if (mImmutableInfo == null) {
+            mImmutableInfo = new RemoteDisplayInfo(mMutableInfo);
+        }
+        return mImmutableInfo;
+    }
+}

media/lib/java/com/android/media/remotedisplay/RemoteDisplayProvider.java

@@ -0,0 +1,371 @@
+/*
+ * Copyright (C) 2013 The Android Open Source 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 com.android.media.remotedisplay;
+
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.media.IRemoteDisplayCallback;
+import android.media.IRemoteDisplayProvider;
+import android.media.RemoteDisplayState;
+import android.os.Handler;
+import android.os.IBinder;
+import android.os.Looper;
+import android.os.Message;
+import android.os.RemoteException;
+import android.util.ArrayMap;
+
+import java.util.Collection;
+
+/**
+ * Base class for remote display providers implemented as unbundled services.
+ * <p>
+ * To implement your remote display provider service, create a subclass of
+ * {@link Service} and override the {@link Service#onBind Service.onBind()} method
+ * to return the provider's binder when the {@link #SERVICE_INTERFACE} is requested.
+ * </p>
+ * <pre>
+ *   public class SampleRemoteDisplayProviderService extends Service {
+ *       private SampleProvider mProvider;
+ *
+ *       public IBinder onBind(Intent intent) {
+ *           if (intent.getAction().equals(RemoteDisplayProvider.SERVICE_INTERFACE)) {
+ *               if (mProvider == null) {
+ *                   mProvider = new SampleProvider(this);
+ *               }
+ *               return mProvider.getBinder();
+ *           }
+ *           return null;
+ *       }
+ *
+ *       class SampleProvider extends RemoteDisplayProvider {
+ *           public SampleProvider() {
+ *               super(SampleRemoteDisplayProviderService.this);
+ *           }
+ *
+ *           // --- Implementation goes here ---
+ *       }
+ *   }
+ * </pre>
+ * <p>
+ * Declare your remote display provider service in your application manifest
+ * like this:
+ * </p>
+ * <pre>
+ *   &lt;application>
+ *       &lt;uses-library android:name="com.android.media.remotedisplay" />
+ *
+ *       &lt;service android:name=".SampleRemoteDisplayProviderService"
+ *               android:label="@string/sample_remote_display_provider_service"
+ *               android:exported="true"
+ *               android:permission="android.permission.BIND_REMOTE_DISPLAY">
+ *           &lt;intent-filter>
+ *               &lt;action android:name="com.android.media.remotedisplay.RemoteDisplayProvider" />
+ *           &lt;/intent-filter>
+ *       &lt;/service>
+ *   &lt;/application>
+ * </pre>
+ * <p>
+ * This object is not thread safe.  It is only intended to be accessed on the
+ * {@link Context#getMainLooper main looper thread} of an application.
+ * </p><p>
+ * IMPORTANT: This class is effectively a public API for unbundled applications, and
+ * must remain API stable. See README.txt in the root of this package for more information.
+ * </p>
+ */
+public abstract class RemoteDisplayProvider {
+    private static final int MSG_SET_CALLBACK = 1;
+    private static final int MSG_SET_DISCOVERY_MODE = 2;
+    private static final int MSG_CONNECT = 3;
+    private static final int MSG_DISCONNECT = 4;
+    private static final int MSG_SET_VOLUME = 5;
+    private static final int MSG_ADJUST_VOLUME = 6;
+
+    private final ProviderStub mStub;
+    private final ProviderHandler mHandler;
+    private final ArrayMap<String, RemoteDisplay> mDisplays =
+            new ArrayMap<String, RemoteDisplay>();
+    private IRemoteDisplayCallback mCallback;
+    private int mDiscoveryMode = DISCOVERY_MODE_NONE;
+
+    /**
+     * The {@link Intent} that must be declared as handled by the service.
+     * Put this in your manifest.
+     */
+    public static final String SERVICE_INTERFACE = RemoteDisplayState.SERVICE_INTERFACE;
+
+    /**
+     * Discovery mode: Do not perform any discovery.
+     */
+    public static final int DISCOVERY_MODE_NONE = RemoteDisplayState.DISCOVERY_MODE_NONE;
+
+    /**
+     * Discovery mode: Passive or low-power periodic discovery.
+     * <p>
+     * This mode indicates that an application is interested in knowing whether there
+     * are any remote displays paired or available but doesn't need the latest or
+     * most detailed information.  The provider may scan at a lower rate or rely on
+     * knowledge of previously paired devices.
+     * </p>
+     */
+    public static final int DISCOVERY_MODE_PASSIVE = RemoteDisplayState.DISCOVERY_MODE_PASSIVE;
+
+    /**
+     * Discovery mode: Active discovery.
+     * <p>
+     * This mode indicates that the user is actively trying to connect to a route
+     * and we should perform continuous scans.  This mode may use significantly more
+     * power but is intended to be short-lived.
+     * </p>
+     */
+    public static final int DISCOVERY_MODE_ACTIVE = RemoteDisplayState.DISCOVERY_MODE_ACTIVE;
+
+    /**
+     * Creates a remote display provider.
+     *
+     * @param context The application context for the remote display provider.
+     */
+    public RemoteDisplayProvider(Context context) {
+        mStub = new ProviderStub();
+        mHandler = new ProviderHandler(context.getMainLooper());
+    }
+
+    /**
+     * Gets the Binder associated with the provider.
+     * <p>
+     * This is intended to be used for the onBind() method of a service that implements
+     * a remote display provider service.
+     * </p>
+     *
+     * @return The IBinder instance associated with the provider.
+     */
+    public IBinder getBinder() {
+        return mStub;
+    }
+
+    /**
+     * Called when the current discovery mode changes.
+     *
+     * @param mode The new discovery mode.
+     */
+    public void onDiscoveryModeChanged(int mode) {
+    }
+
+    /**
+     * Called when the system would like to connect to a display.
+     *
+     * @param display The remote display.
+     */
+    public void onConnect(RemoteDisplay display) {
+    }
+
+    /**
+     * Called when the system would like to disconnect from a display.
+     *
+     * @param display The remote display.
+     */
+    public void onDisconnect(RemoteDisplay display) {
+    }
+
+    /**
+     * Called when the system would like to set the volume of a display.
+     *
+     * @param display The remote display.
+     * @param volume The desired volume.
+     */
+    public void onSetVolume(RemoteDisplay display, int volume) {
+    }
+
+    /**
+     * Called when the system would like to adjust the volume of a display.
+     *
+     * @param display The remote display.
+     * @param delta An increment to add to the current volume, such as +1 or -1.
+     */
+    public void onAdjustVolume(RemoteDisplay display, int delta) {
+    }
+
+    /**
+     * Gets the current discovery mode.
+     *
+     * @return The current discovery mode.
+     */
+    public int getDiscoveryMode() {
+        return mDiscoveryMode;
+    }
+
+    /**
+     * Gets the current collection of displays.
+     *
+     * @return The current collection of displays, which must not be modified.
+     */
+    public Collection<RemoteDisplay> getDisplays() {
+        return mDisplays.values();
+    }
+
+    /**
+     * Adds the specified remote display and notifies the system.
+     *
+     * @param display The remote display that was added.
+     * @throws IllegalStateException if there is already a display with the same id.
+     */
+    public void addDisplay(RemoteDisplay display) {
+        if (display == null || mDisplays.containsKey(display.getId())) {
+            throw new IllegalArgumentException("display");
+        }
+        mDisplays.put(display.getId(), display);
+        publishState();
+    }
+
+    /**
+     * Updates information about the specified remote display and notifies the system.
+     *
+     * @param display The remote display that was added.
+     * @throws IllegalStateException if the display was n
+     */
+    public void updateDisplay(RemoteDisplay display) {
+        if (display == null || mDisplays.get(display.getId()) != display) {
+            throw new IllegalArgumentException("display");
+        }
+        publishState();
+    }
+
+    /**
+     * Removes the specified remote display and tells the system about it.
+     *
+     * @param display The remote display that was removed.
+     */
+    public void removeDisplay(RemoteDisplay display) {
+        if (display == null || mDisplays.get(display.getId()) != display) {
+            throw new IllegalArgumentException("display");
+        }
+        mDisplays.remove(display.getId());
+        publishState();
+    }
+
+    void setCallback(IRemoteDisplayCallback callback) {
+        mCallback = callback;
+        publishState();
+    }
+
+    void setDiscoveryMode(int mode) {
+        if (mDiscoveryMode != mode) {
+            mDiscoveryMode = mode;
+            onDiscoveryModeChanged(mode);
+        }
+    }
+
+    void publishState() {
+        if (mCallback != null) {
+            RemoteDisplayState state = new RemoteDisplayState();
+            final int count = mDisplays.size();
+            for (int i = 0; i < count; i++) {
+                final RemoteDisplay display = mDisplays.valueAt(i);
+                state.displays.add(display.getInfo());
+            }
+            try {
+                mCallback.onStateChanged(state);
+            } catch (RemoteException ex) {
+                // system server died?
+            }
+        }
+    }
+
+    RemoteDisplay findRemoteDisplay(String id) {
+        return mDisplays.get(id);
+    }
+
+    final class ProviderStub extends IRemoteDisplayProvider.Stub {
+        @Override
+        public void setCallback(IRemoteDisplayCallback callback) {
+            mHandler.obtainMessage(MSG_SET_CALLBACK, callback).sendToTarget();
+        }
+
+        @Override
+        public void setDiscoveryMode(int mode) {
+            mHandler.obtainMessage(MSG_SET_DISCOVERY_MODE, mode, 0).sendToTarget();
+        }
+
+        @Override
+        public void connect(String id) {
+            mHandler.obtainMessage(MSG_CONNECT, id).sendToTarget();
+        }
+
+        @Override
+        public void disconnect(String id) {
+            mHandler.obtainMessage(MSG_DISCONNECT, id).sendToTarget();
+        }
+
+        @Override
+        public void setVolume(String id, int volume) {
+            mHandler.obtainMessage(MSG_SET_VOLUME, volume, 0, id).sendToTarget();
+        }
+
+        @Override
+        public void adjustVolume(String id, int delta) {
+            mHandler.obtainMessage(MSG_ADJUST_VOLUME, delta, 0, id).sendToTarget();
+        }
+    }
+
+    final class ProviderHandler extends Handler {
+        public ProviderHandler(Looper looper) {
+            super(looper, null, true);
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            switch (msg.what) {
+                case MSG_SET_CALLBACK: {
+                    setCallback((IRemoteDisplayCallback)msg.obj);
+                    break;
+                }
+                case MSG_SET_DISCOVERY_MODE: {
+                    setDiscoveryMode(msg.arg1);
+                    break;
+                }
+                case MSG_CONNECT: {
+                    RemoteDisplay display = findRemoteDisplay((String)msg.obj);
+                    if (display != null) {
+                        onConnect(display);
+                    }
+                    break;
+                }
+                case MSG_DISCONNECT: {
+                    RemoteDisplay display = findRemoteDisplay((String)msg.obj);
+                    if (display != null) {
+                        onDisconnect(display);
+                    }
+                    break;
+                }
+                case MSG_SET_VOLUME: {
+                    RemoteDisplay display = findRemoteDisplay((String)msg.obj);
+                    if (display != null) {
+                        onSetVolume(display, msg.arg1);
+                    }
+                    break;
+                }
+                case MSG_ADJUST_VOLUME: {
+                    RemoteDisplay display = findRemoteDisplay((String)msg.obj);
+                    if (display != null) {
+                        onAdjustVolume(display, msg.arg1);
+                    }
+                    break;
+                }
+            }
+        }
+    }
+}