Initial check-in of UAMP in Kotlin.

Change-Id: Ia8679b787dea3960e589a05cbe59123c236cb834

.gitignore

@@ -1,6 +1,8 @@
+*.iml
 .gradle
 /local.properties
 /.idea
 .DS_Store
 /build
-*.iml
+/captures
+.externalNativeBuild

app/.gitignore

@@ -0,0 +1 @@
+/build

app/build.gradle

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+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * 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.
+ */
+
+apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
+
+android {
+    compileSdkVersion 26
+    defaultConfig {
+        applicationId "com.example.android.uamp.next"
+        minSdkVersion 19
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation project(':media')
+
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
+
+    implementation 'com.android.support:appcompat-v7:26.1.0'
+    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
+    implementation "android.arch.lifecycle:extensions:1.0.0"
+
+    implementation 'com.android.support:support-v4:26.1.0'
+    implementation 'com.android.support:recyclerview-v7:26.1.0'
+
+    testImplementation 'junit:junit:4.12'
+
+    androidTestImplementation 'com.android.support.test:runner:1.0.1'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
+}

app/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2017 Google Inc. All rights reserved.
+  ~
+  ~ 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.
+  -->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="com.example.android.uamp">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity android:name=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

app/src/main/java/com/example/android/uamp/MainActivity.kt

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+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * 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.example.android.uamp
+
+import android.arch.lifecycle.ViewModelProviders
+import android.os.Bundle
+import android.support.v7.app.AppCompatActivity
+
+class MainActivity : AppCompatActivity(), ConnectionCallback {
+
+    private lateinit var mediaBrowserConnection: MediaBrowserViewModel
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
+
+        mediaBrowserConnection = ViewModelProviders.of(this).get(MediaBrowserViewModel::class.java)
+    }
+
+    override fun onStart() {
+        super.onStart()
+        mediaBrowserConnection.registerCallback(this)
+    }
+
+    override fun onStop() {
+        super.onStop()
+        mediaBrowserConnection.unregisterCallback(this)
+    }
+
+    override fun onConnected() {
+        super.onConnected()
+
+        navigateToBrowser(mediaBrowserConnection.getRoot())
+    }
+
+    private fun navigateToBrowser(mediaId: String) {
+        var fragment: MediaItemFragment? = getBrowseFragment(mediaId)
+
+        if (fragment == null) {
+            fragment = MediaItemFragment.newInstance(mediaId)
+            val transaction = supportFragmentManager.beginTransaction()
+            transaction.replace(R.id.browse_fragment, fragment, mediaId)
+
+            // If this is not the top level media (root), we add it to the fragment back stack,
+            // so that actionbar toggle and Back will work appropriately:
+            if (mediaId != mediaBrowserConnection.getRoot()) {
+                transaction.addToBackStack(null)
+            }
+            transaction.commit()
+        }
+    }
+
+    private fun getBrowseFragment(mediaId: String): MediaItemFragment? {
+        return fragmentManager.findFragmentByTag(mediaId) as MediaItemFragment?
+    }
+}

app/src/main/java/com/example/android/uamp/MediaBrowserViewModel.kt

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+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * 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.example.android.uamp
+
+import android.app.Application
+import android.arch.lifecycle.AndroidViewModel
+import android.content.ComponentName
+import android.support.annotation.NonNull
+import android.support.v4.media.MediaBrowserCompat
+import android.support.v4.media.session.MediaControllerCompat
+import android.util.Log
+import com.example.android.uamp.media.MusicService
+
+/**
+ * ViewModel that implements (and holds onto) a MediaBrowser connection.
+ */
+class MediaBrowserViewModel(application: Application) : AndroidViewModel(application) {
+
+    private val mediaBrowser: MediaBrowserCompat
+    private val mediaBrowserConnectionCallback = MediaBrowserConnectionCallback()
+    private val mediaControllerCallback = MediaControllerCallback()
+
+    private lateinit var mediaController: MediaControllerCompat
+
+    private val callbacks = ArrayList<ConnectionCallback>()
+
+    init {
+        mediaBrowser = MediaBrowserCompat(
+                application,
+                ComponentName(application, MusicService::class.java),
+                mediaBrowserConnectionCallback,
+                null)
+        mediaBrowser.connect()
+    }
+
+    fun registerCallback(callback: ConnectionCallback) {
+        if (!callbacks.contains(callback)) {
+            callbacks.add(callback)
+
+            if (mediaBrowser.isConnected) {
+                callback.onConnected()
+            }
+        }
+    }
+
+    fun unregisterCallback(callback: ConnectionCallback) {
+        if (callbacks.contains(callback)) {
+            callbacks.remove(callback)
+        }
+    }
+
+    fun subscribe(parentId: String, callback: MediaBrowserCompat.SubscriptionCallback) {
+        mediaBrowser.subscribe(parentId, callback)
+    }
+
+    fun unsubscribe(parentId: String, callback: MediaBrowserCompat.SubscriptionCallback) {
+        mediaBrowser.unsubscribe(parentId, callback)
+    }
+
+    fun getRoot(): String {
+        return mediaBrowser.root
+    }
+
+    private inner class MediaBrowserConnectionCallback : MediaBrowserCompat.ConnectionCallback() {
+        override fun onConnected() {
+            super.onConnected()
+
+            // Get a MediaController for the MediaSession.
+            mediaController = MediaControllerCompat(getApplication(), mediaBrowser.sessionToken)
+            mediaController.registerCallback(mediaControllerCallback)
+
+            callbacks.forEach { callback -> callback.onConnected() }
+        }
+
+        override fun onConnectionSuspended() {
+            super.onConnectionSuspended()
+
+            callbacks.forEach { callback -> callback.onConnectionSuspended() }
+        }
+
+        override fun onConnectionFailed() {
+            super.onConnectionFailed()
+
+            callbacks.forEach { callback -> callback.onConnectionFailed() }
+        }
+    }
+
+    private inner class MediaControllerCallback : MediaControllerCompat.Callback() {
+        override fun onSessionDestroyed() {
+            super.onSessionDestroyed()
+
+            // Normally if a MediaBrowserService drops its connection the callback comes via
+            // MediaControllerCompat.Callback (here). But since other connection status events
+            // are sent to MediaBrowserCompat.ConnectionCallback, we catch the disconnect here
+            // and send it on to the other callback.
+            callbacks.forEach { callback -> callback.onConnectionSuspended() }
+        }
+    }
+}
+
+/**
+ * Interface to allow a class to receive callbacks based on the changing state of a
+ * [MediaBrowser] connection.
+ */
+interface ConnectionCallback {
+    fun onConnected() {
+    }
+
+    fun onConnectionSuspended() {
+    }
+
+    fun onConnectionFailed() {
+    }
+}