Add Shoutcast Metadata Protocol (ICY) extension

Based on the OkHttp extension.

Resolves #3735

core_settings.gradle

@@ -28,6 +28,7 @@ include modulePrefix + 'testutils-robolectric'
 include modulePrefix + 'extension-ffmpeg'
 include modulePrefix + 'extension-flac'
 include modulePrefix + 'extension-gvr'
+include modulePrefix + 'extension-icy'
 include modulePrefix + 'extension-ima'
 include modulePrefix + 'extension-cast'
 include modulePrefix + 'extension-cronet'
@@ -50,6 +51,7 @@ project(modulePrefix + 'testutils-robolectric').projectDir = new File(rootDir, '
 project(modulePrefix + 'extension-ffmpeg').projectDir = new File(rootDir, 'extensions/ffmpeg')
 project(modulePrefix + 'extension-flac').projectDir = new File(rootDir, 'extensions/flac')
 project(modulePrefix + 'extension-gvr').projectDir = new File(rootDir, 'extensions/gvr')
+project(modulePrefix + 'extension-icy').projectDir = new File(rootDir, 'extensions/icy')
 project(modulePrefix + 'extension-ima').projectDir = new File(rootDir, 'extensions/ima')
 project(modulePrefix + 'extension-cast').projectDir = new File(rootDir, 'extensions/cast')
 project(modulePrefix + 'extension-cronet').projectDir = new File(rootDir, 'extensions/cronet')

extensions/icy/README.md

+# ExoPlayer Shoutcast Metadata Protocol (ICY) extension #
+The Shoutcast Metadata Protocol extension provides **IcyHttpDataSource** and
+**IcyHttpDataSourceFactory** which can parse ICY metadata information such as
+stream name and genre as well as current song information from a music stream.
+
+You can find the protocol description here:
+
+- https://cast.readme.io/v1.0/docs/icy
+- http://www.smackfu.com/stuff/programming/shoutcast.html
+
+## Getting the extension ##
+
+The easiest way to use the extension is to add it as a gradle dependency:
+
+```gradle
+implementation 'com.google.android.exoplayer:extension-icy:2.X.X'
+```
+
+where `2.X.X` is the version, which must match the version of the ExoPlayer
+library being used.
+
+Alternatively, you can clone the ExoPlayer repository and depend on the module
+locally. Instructions for doing this can be found in ExoPlayer's
+[top level README][].
+
+[top level README]: https://github.com/google/ExoPlayer/blob/release-v2/README.md
+
+## Using the extension ##
+
+To receive information about the current music stream (such as name and genre,
+see **IcyHeaders** class) as well as current song information (see
+**IcyMetadata** class), pass an instance of **IcyHttpDataSourceFactory** instead
+of an **DefaultHttpDataSourceFactory** like this (in Kotlin):
+
+```kotlin
+// ... exoPlayer instance already created
+
+// Custom HTTP data source factory which requests Icy metadata and parses it if
+// the stream server supports it
+val client = OkHttpClient.Builder().build()
+val icyHttpDataSourceFactory = IcyHttpDataSourceFactory.Builder(client)
+    .setUserAgent(userAgent)
+    .setIcyHeadersListener { icyHeaders ->
+        Log.d("XXX", "onIcyHeaders: %s".format(icyHeaders.toString()))
+    }
+    .setIcyMetadataChangeListener { icyMetadata ->
+        Log.d("XXX", "onIcyMetaData: %s".format(icyMetadata.toString()))
+    }
+    .build()
+
+// Produces DataSource instances through which media data is loaded
+val dataSourceFactory = DefaultDataSourceFactory(applicationContext, null, icyHttpDataSourceFactory)
+
+// The MediaSource represents the media to be played
+val mediaSource = ExtractorMediaSource.Factory(dataSourceFactory)
+    .setExtractorsFactory(DefaultExtractorsFactory())
+    .createMediaSource(sourceUri)
+
+// exoPlayer?.prepare(mediaSource) ...
+```
+
+## Links ##
+
+* [Javadoc][]: Classes matching `com.google.android.exoplayer2.ext.icy.*`
+  belong to this module.
+
+[Javadoc]: https://google.github.io/ExoPlayer/doc/reference/index.html

extensions/icy/build.gradle

+// Copyright (C) 2018 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.
+
+apply from: '../../constants.gradle'
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion project.ext.compileSdkVersion
+    buildToolsVersion project.ext.buildToolsVersion
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    defaultConfig {
+        minSdkVersion project.ext.minSdkVersion
+        targetSdkVersion project.ext.targetSdkVersion
+        consumerProguardFiles 'proguard-rules.txt'
+    }
+}
+
+dependencies {
+    implementation project(modulePrefix + 'extension-okhttp')
+    implementation 'com.android.support:support-annotations:' + supportLibraryVersion
+    compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
+    api 'com.google.android.exoplayer:extension-okhttp:' + releaseVersion
+    testImplementation 'junit:junit:' + junitVersion
+    testImplementation project(modulePrefix + 'testutils-robolectric')
+}
+
+ext {
+    javadocTitle = 'Shoutcast Metadata Protocol (ICY) extension'
+}
+apply from: '../../javadoc_library.gradle'
+
+ext {
+    releaseArtifact = 'extension-icy'
+    releaseDescription = 'Shoutcast Metadata Protocol (ICY) extension for ExoPlayer.'
+}
+apply from: '../../publish.gradle'

extensions/icy/proguard-rules.txt

+# Proguard rules specific to the Icy extension.
+

extensions/icy/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2016 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.
+-->
+
+<manifest package="com.google.android.exoplayer2.ext.icy"/>

extensions/icy/src/main/java/com/google/android/exoplayer2/ext/icy/IcyHttpDataSourceFactory.java

+package com.google.android.exoplayer2.ext.icy;
+
+import android.support.annotation.NonNull;
+
+import com.google.android.exoplayer2.ext.okhttp.OkHttpDataSource;
+import com.google.android.exoplayer2.upstream.HttpDataSource;
+import com.google.android.exoplayer2.util.Predicate;
+
+import okhttp3.CacheControl;
+import okhttp3.Call;
+
+/**
+ * A {@link HttpDataSource.Factory} that produces {@link IcyHttpDataSource} instances.
+ */
+public final class IcyHttpDataSourceFactory extends OkHttpDataSource.BaseFactory {
+
+  private Call.Factory callFactory;
+  private String userAgent;
+  private Predicate<String> contentTypePredicate;
+  private CacheControl cacheControl;
+  private IcyHttpDataSource.IcyHeadersListener icyHeadersListener;
+  private IcyHttpDataSource.IcyMetadataListener icyMetadataListener;
+
+  private IcyHttpDataSourceFactory() {
+    // See class Builder
+  }
+
+  /**
+   * Constructs a IcyHttpDataSourceFactory.
+   */
+  public final static class Builder {
+
+    private final IcyHttpDataSourceFactory factory;
+
+    public Builder(@NonNull Call.Factory callFactory) {
+      // Apply defaults
+      factory = new IcyHttpDataSourceFactory();
+      factory.callFactory = callFactory;
+    }
+
+    public Builder setUserAgent(@NonNull final String userAgent) {
+      factory.userAgent = userAgent;
+      return this;
+    }
+
+    public Builder setContentTypePredicate(@NonNull final Predicate<String> contentTypePredicate) {
+      factory.contentTypePredicate = contentTypePredicate;
+      return this;
+    }
+
+    public Builder setCacheControl(@NonNull final CacheControl cacheControl) {
+      factory.cacheControl = cacheControl;
+      return this;
+    }
+
+    public Builder setIcyHeadersListener(
+        @NonNull final IcyHttpDataSource.IcyHeadersListener icyHeadersListener) {
+      factory.icyHeadersListener = icyHeadersListener;
+      return this;
+    }
+
+    public Builder setIcyMetadataChangeListener(
+        @NonNull final IcyHttpDataSource.IcyMetadataListener icyMetadataListener) {
+      factory.icyMetadataListener = icyMetadataListener;
+      return this;
+    }
+
+    public IcyHttpDataSourceFactory build() {
+      return factory;
+    }
+  }
+
+  @Override
+  protected IcyHttpDataSource createDataSourceInternal(
+      @NonNull HttpDataSource.RequestProperties defaultRequestProperties) {
+    return new IcyHttpDataSource.Builder(callFactory)
+        .setUserAgent(userAgent)
+        .setContentTypePredicate(contentTypePredicate)
+        .setCacheControl(cacheControl)
+        .setDefaultRequestProperties(defaultRequestProperties)
+        .setIcyHeadersListener(icyHeadersListener)
+        .setIcyMetadataListener(icyMetadataListener)
+        .build();
+  }
+}

extensions/icy/src/test/java/com/google/android/exoplayer2/ext/icy/IcyHttpDataSourceFactoryTest.java

+package com.google.android.exoplayer2.ext.icy;
+
+import com.google.android.exoplayer2.upstream.HttpDataSource;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import okhttp3.OkHttpClient;
+import com.google.android.exoplayer2.ext.icy.test.Constants;
+
+import static org.junit.Assert.assertNotNull;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public final class IcyHttpDataSourceFactoryTest {
+
+  private final IcyHttpDataSource.IcyHeadersListener TEST_ICY_HEADERS_LISTENER = icyHeaders -> {
+  };
+  private final IcyHttpDataSource.IcyMetadataListener TEST_ICY_METADATA_LISTENER = icyMetadata -> {
+  };
+
+  @Test
+  public void createDataSourceViaFactoryFromFactoryBuilder() {
+    // Arrange
+    OkHttpClient client = new OkHttpClient.Builder().build();
+    IcyHttpDataSourceFactory factory = new IcyHttpDataSourceFactory.Builder(client)
+        .setUserAgent(Constants.TEST_USER_AGENT)
+        .setIcyHeadersListener(TEST_ICY_HEADERS_LISTENER)
+        .setIcyMetadataChangeListener(TEST_ICY_METADATA_LISTENER)
+        .build();
+    HttpDataSource.RequestProperties requestProperties = new HttpDataSource.RequestProperties();
+
+    // Act
+    IcyHttpDataSource source = factory.createDataSourceInternal(requestProperties);
+
+    // Assert
+    assertNotNull(source);
+  }
+}

extensions/icy/src/test/java/com/google/android/exoplayer2/ext/icy/IcyHttpDataSourceTest.java

+package com.google.android.exoplayer2.ext.icy;
+
+import com.google.android.exoplayer2.ext.icy.IcyHttpDataSource;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import okhttp3.OkHttpClient;
+import com.google.android.exoplayer2.ext.icy.test.Constants;
+
+import static org.junit.Assert.assertNotNull;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public final class IcyHttpDataSourceTest {
+
+  @Test
+  public void createDataSourceFromBuilder() {
+    // Arrange, act
+    OkHttpClient client = new OkHttpClient.Builder().build();
+    IcyHttpDataSource source = new IcyHttpDataSource.Builder(client)
+        .setUserAgent(Constants.TEST_USER_AGENT)
+        .build();
+
+    // Assert
+    assertNotNull(source);
+  }
+}

extensions/icy/src/test/java/com/google/android/exoplayer2/ext/icy/test/Constants.java

+package com.google.android.exoplayer2.ext.icy.test;
+
+public final class Constants {
+
+  public static final String TEST_USER_AGENT = "test-agent";
+}