Add audiofileplayer plugin

packages/audiofileplayer/.gitignore

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+.DS_Store
+.dart_tool/
+
+.packages
+.pub/
+
+build/

packages/audiofileplayer/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 8661d8aecd626f7f57ccbcb735553edc05a2e713
+  channel: stable
+
+project_type: plugin

packages/audiofileplayer/CHANGELOG.md

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+## 0.0.1 - 18 March 2019
+
+  * Initial open source release

packages/audiofileplayer/LICENSE

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+MIT License
+
+Copyright (c) 2019 Google Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/audiofileplayer/README.md

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+# audiofileplayer
+
+A Flutter plugin for audio playback. 
+Supports 
+  * Reading audio data from Flutter project assets, byte arrays, and remote URLs. 
+  * Seek to position.
+  * Continue playback while app is backgrounded.
+  * Callbacks for loaded audio duration, current position, and playback completion.
+  * Volume
+  * Looping
+  * Pause/Resume.
+  * Multiple audio players, with automatic memory management.
+
+## Getting Started
+
+To use this plugin, add `audiofileplayer` as a [dependency in your pubspec.yaml file](https://flutter.io/platform-plugins/).
+
+### Example
+
+``` dart
+// Play a sound as a one-shot, releasing its resources when it finishes playing.
+Audio.load('assets/foo.wav')..play()..dispose();
+```
+
+Please see the header comment of audiofileplayer.dart for more information, and see the example app of this plugin for an example showing multiple use cases.

packages/audiofileplayer/android/.gitignore

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+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build
+/captures

packages/audiofileplayer/android/build.gradle

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+group 'com.google.flutter.plugins.audiofileplayer'
+version '1.0-SNAPSHOT'
+
+buildscript {
+    repositories {
+        google()
+        jcenter()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.2.1'
+    }
+}
+
+rootProject.allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion 28
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    defaultConfig {
+        minSdkVersion 16
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    lintOptions {
+        disable 'InvalidPackage'
+    }
+}

packages/audiofileplayer/android/gradle.properties

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+org.gradle.jvmargs=-Xmx1536M

packages/audiofileplayer/android/settings.gradle

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+rootProject.name = 'audiofileplayer'

packages/audiofileplayer/android/src/main/AndroidManifest.xml

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+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="com.google.flutter.plugins.audiofileplayer">
+</manifest>

packages/audiofileplayer/android/src/main/java/com/google/flutter/plugins/audiofileplayer/AudiofileplayerPlugin.java

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+package com.google.flutter.plugins.audiofileplayer;
+
+import android.content.res.AssetFileDescriptor;
+import android.content.res.AssetManager;
+import android.util.Log;
+import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.MethodChannel;
+import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
+import io.flutter.plugin.common.MethodChannel.Result;
+import io.flutter.plugin.common.PluginRegistry.Registrar;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Flutter audio file player plugin.
+ *
+ * <p>Receives messages which create, trigger, and destroy instances of {@link ManagedMediaPlayer}.
+ */
+public class AudiofileplayerPlugin implements MethodCallHandler {
+  private static final String TAG = AudiofileplayerPlugin.class.getSimpleName();
+
+  // Method channel constants, matching those in the Dart and iOS plugin code.
+  private static final String CHANNEL = "audiofileplayer";
+  private static final String LOAD_METHOD = "load";
+  private static final String FLUTTER_PATH = "flutterPath";
+  private static final String AUDIO_BYTES = "audioBytes";
+  private static final String REMOTE_URL = "remoteUrl";
+  private static final String AUDIO_ID = "audioId";
+  private static final String LOOPING = "looping";
+  private static final String RELEASE_METHOD = "release";
+  private static final String PLAY_METHOD = "play";
+  private static final String PLAY_FROM_START = "playFromStart";
+  private static final String SEEK_METHOD = "seek";
+  private static final String SET_VOLUME_METHOD = "setVolume";
+  private static final String VOLUME = "volume";
+  private static final String PAUSE_METHOD = "pause";
+  private static final String ON_COMPLETE_CALLBACK = "onComplete";
+  private static final String ON_DURATION_CALLBACK = "onDuration";
+  private static final String DURATION_SECONDS = "duration_seconds";
+  private static final String ON_POSITION_CALLBACK = "onPosition";
+  private static final String POSITION_SECONDS = "position_seconds";
+  private static final String ERROR_CODE = "AudioPluginError";
+
+  private final Registrar registrar;
+  private final Map<String, ManagedMediaPlayer> mediaPlayers;
+  private final MethodChannel methodChannel;
+
+  public static void registerWith(Registrar registrar) {
+    final MethodChannel methodChannel =
+        new MethodChannel(registrar.messenger(), CHANNEL);
+    final AudiofileplayerPlugin instance =
+        new AudiofileplayerPlugin(registrar, methodChannel);
+    methodChannel.setMethodCallHandler(instance);
+  }
+
+  private AudiofileplayerPlugin(Registrar registrar, MethodChannel methodChannel) {
+    this.registrar = registrar;
+    this.methodChannel = methodChannel;
+    this.mediaPlayers = new HashMap<>();
+  }
+
+  @Override
+  public void onMethodCall(MethodCall call, Result result) {
+    Log.i(TAG, "onMethodCall: method = " + call.method);
+    if (call.method.equals(LOAD_METHOD)) {
+      onLoad(call, result);
+      return;
+    }
+    // All subsequent calls need a valid player.
+    ManagedMediaPlayer player = getAndVerifyPlayer(call, result);
+    if (call.method.equals(PLAY_METHOD)) {
+      Boolean playFromStartBoolean = call.argument(PLAY_FROM_START);
+      boolean playFromStart = playFromStartBoolean.booleanValue();
+      player.play(playFromStart);
+      result.success(null);
+    } else if (call.method.equals(RELEASE_METHOD)) {
+      player.release();
+      mediaPlayers.remove(player.getAudioId());
+      result.success(null);
+    } else if (call.method.equals(SEEK_METHOD)) {
+      Double positionSecondsDouble = call.argument(POSITION_SECONDS);
+      double positionSeconds = positionSecondsDouble.doubleValue();
+      player.seek(positionSeconds);
+      result.success(null);
+    } else if (call.method.equals(SET_VOLUME_METHOD)) {
+      Double volumeDouble = call.argument(VOLUME);
+      double volume = volumeDouble.doubleValue();
+      player.setVolume(volume);
+      result.success(null);
+    } else if (call.method.equals(PAUSE_METHOD)) {
+      player.pause();
+      result.success(null);
+    } else {
+      result.notImplemented();
+    }
+  }
+
+  private void onLoad(MethodCall call, Result result) {
+    String audioId = call.argument(AUDIO_ID);
+    if (audioId == null) {
+      result.error(ERROR_CODE, "Received load() call without an audioId", null);
+      return;
+    }
+    if (mediaPlayers.get(audioId) != null) {
+      result.error(
+          ERROR_CODE, "Tried to load an already-loaded player: " + audioId, null);
+      return;
+    }
+
+    Boolean loopingBoolean = call.argument(LOOPING);
+    boolean looping = false;
+    if (loopingBoolean != null) {
+      looping = loopingBoolean.booleanValue();
+    }
+
+    try {
+      if (call.argument(FLUTTER_PATH) != null) {
+        String flutterPath = call.argument(FLUTTER_PATH).toString();
+        AssetManager assetManager = registrar.context().getAssets();
+        String key = registrar.lookupKeyForAsset(flutterPath);
+        AssetFileDescriptor fd = assetManager.openFd(key);
+        ManagedMediaPlayer newPlayer = new LocalManagedMediaPlayer(audioId, fd, this, looping);
+        mediaPlayers.put(audioId, newPlayer);
+        handleDurationForPlayer(newPlayer, audioId);
+        result.success(null);
+      } else if (call.argument(AUDIO_BYTES) != null) {
+        byte[] audioBytes = call.argument(AUDIO_BYTES);
+        ManagedMediaPlayer newPlayer =
+            new LocalManagedMediaPlayer(
+                audioId, new BufferMediaDataSource(audioBytes), this, looping);
+        mediaPlayers.put(audioId, newPlayer);
+        handleDurationForPlayer(newPlayer, audioId);
+        result.success(null);
+      } else if (call.argument(REMOTE_URL) != null) {
+        String remoteUrl = call.argument(REMOTE_URL);
+        // Note that this will throw an exception on invalid URL or lack of network connectivity.
+        RemoteManagedMediaPlayer newPlayer =
+            new RemoteManagedMediaPlayer(audioId, remoteUrl, this, looping);
+        newPlayer.setOnRemoteLoadListener(
+            (success) -> {
+              if (success) {
+                handleDurationForPlayer(newPlayer, audioId);
+                result.success(null);
+              } else {
+                mediaPlayers.remove(audioId);
+                result.error(
+                    ERROR_CODE,
+                    "Remote URL loading failed for URL: " + remoteUrl,
+                    null);
+              }
+            });
+        // Add player to data structure immediately; will be removed if async loading fails.
+        mediaPlayers.put(audioId, newPlayer);
+      } else {
+        result.error(
+            ERROR_CODE,
+            "Could not create ManagedMediaPlayer with no flutterPath, audioBytes, nor remoteUrl.",
+            null);
+        return;
+      }
+    } catch (Exception e) {
+      result.error(
+          ERROR_CODE, "Could not create ManagedMediaPlayer:" + e.getMessage(), null);
+    }
+  }
+
+  private ManagedMediaPlayer getAndVerifyPlayer(MethodCall call, Result result) {
+    String audioId = call.argument(AUDIO_ID);
+    if (audioId == null) {
+      result.error(
+          ERROR_CODE,
+          String.format("Received %s call without an audioId", call.method),
+          null);
+      return null;
+    }
+    ManagedMediaPlayer player = mediaPlayers.get(audioId);
+    if (player == null) {
+      result.error(
+          ERROR_CODE,
+          String.format("Called %s on an unloaded player: %s", call.method, audioId),
+          null);
+    }
+    return player;
+  }
+
+  /** Called by {@link ManagedMediaPlayer} when (non-looping) file has finished playback. */
+  public void handleCompletion(String audioId) {
+    this.methodChannel.invokeMethod(
+        ON_COMPLETE_CALLBACK,
+        Collections.singletonMap(AUDIO_ID, audioId));
+  }
+
+  // Called on successful load.
+  public void handleDurationForPlayer(ManagedMediaPlayer player, String audioId) {
+    Map<String, Object> arguments = new HashMap<String, Object>();
+    arguments.put(AUDIO_ID, audioId);
+    // Note that player will report a negative value if duration is unavailable (for example,
+    // streaming certain types of remote audio).
+    double durationSeconds = player.getDurationSeconds();
+    arguments.put(DURATION_SECONDS, Double.valueOf(durationSeconds));
+    this.methodChannel.invokeMethod(ON_DURATION_CALLBACK, arguments);
+  }
+
+  /** Called repeatedly by {@link ManagedMediaPlayer} during playback. */
+  public void handlePosition(String audioId, double positionSeconds) {
+    Map<String, Object> arguments = new HashMap<String, Object>();
+    arguments.put(AUDIO_ID, audioId);
+    arguments.put(POSITION_SECONDS, Double.valueOf(positionSeconds));
+    this.methodChannel.invokeMethod(ON_POSITION_CALLBACK, arguments);
+  }
+}

packages/audiofileplayer/android/src/main/java/com/google/flutter/plugins/audiofileplayer/BufferMediaDataSource.java

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+package com.google.flutter.plugins.audiofileplayer;
+
+import android.media.MediaDataSource;
+import java.io.IOException;
+
+/** A MediaDataSource implementation to read a byte array of media data. */
+final class BufferMediaDataSource extends MediaDataSource {
+  private final byte[] bytes;
+
+  public BufferMediaDataSource(byte[] bytes) {
+    this.bytes = bytes;
+  }
+
+  @Override
+  public long getSize() {
+    return bytes.length;
+  }
+
+  @Override
+  public int readAt(long position, byte[] buffer, int offset, int size) {
+    if (position >= bytes.length) {
+      // Indicate end of stream with -1.
+      return -1;
+    }
+    int readSize = Math.min(size, Math.min(buffer.length - offset, bytes.length - (int) position));
+    System.arraycopy(bytes, (int) position, buffer, offset, readSize);
+    return readSize;
+  }
+
+  @Override
+  public void close() throws IOException {}
+}