Support key system in HTMLMediaElement.canPlayType (#4429)

b/378908084

cobalt/android/BUILD.gn

@@ -68,6 +68,7 @@ android_library("cobalt_apk_java") {
     "apk/app/src/main/java/dev/cobalt/coat/javabridge/AmatiDeviceInspector.java",
     "apk/app/src/main/java/dev/cobalt/coat/javabridge/CobaltJavaScriptAndroidObject.java",
     "apk/app/src/main/java/dev/cobalt/coat/javabridge/CobaltJavaScriptInterface.java",
+    "apk/app/src/main/java/dev/cobalt/coat/javabridge/HTMLMediaElementExtension.java",
 
     # "apk/app/src/main/java/dev/cobalt/coat/CobaltMediaSession.java",
     "apk/app/src/main/java/dev/cobalt/coat/CobaltService.java",
@@ -118,6 +119,7 @@ android_assets("cobalt_apk_assets") {
   testonly = true
   sources = [
     "apk/app/src/app/assets/amati_device_inspector.js",
+    "apk/app/src/app/assets/html_media_element_extension.js",
     "apk/app/src/app/assets/not_empty.txt",
     "apk/app/src/app/assets/test/not_empty.txt",
     "apk/app/src/app/assets/web/cobalt_blue_splash_screen.css",

cobalt/android/apk/app/src/app/assets/html_media_element_extension.js

@@ -0,0 +1,8 @@
+/**
+ * @license
+ * Copyright The Cobalt Authors.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+HTMLMediaElement.prototype.canPlayType = HTMLMediaElementExtension.canPlayType;
+console.log("HTMLMediaElement.canPlayType has been overwritten");

cobalt/android/apk/app/src/main/java/dev/cobalt/coat/CobaltActivity.java

@@ -39,6 +39,7 @@
 import dev.cobalt.coat.javabridge.AmatiDeviceInspector;
 import dev.cobalt.coat.javabridge.CobaltJavaScriptAndroidObject;
 import dev.cobalt.coat.javabridge.CobaltJavaScriptInterface;
+import dev.cobalt.coat.javabridge.HTMLMediaElementExtension;
 import dev.cobalt.media.AudioOutputManager;
 import dev.cobalt.media.MediaCodecCapabilitiesLogger;
 import dev.cobalt.media.VideoSurfaceView;
@@ -172,11 +173,12 @@ protected void createContent(final Bundle savedInstanceState) {
     }
     if (mStartupUrl == null || mStartupUrl.isEmpty()) {
       String[] args = getStarboardBridge().getArgs();
-      mStartupUrl = Arrays.stream(args)
-                     .filter(line -> line.contains(URL_ARG))
-                     .findAny()
-                     .map(arg -> arg.substring(arg.indexOf(URL_ARG) + URL_ARG.length()))
-                     .orElse(null);
+      mStartupUrl =
+          Arrays.stream(args)
+              .filter(line -> line.contains(URL_ARG))
+              .findAny()
+              .map(arg -> arg.substring(arg.indexOf(URL_ARG) + URL_ARG.length()))
+              .orElse(null);
     }
     if (!TextUtils.isEmpty(mStartupUrl)) {
       mShellManager.setStartupUrl(Shell.sanitizeUrl(mStartupUrl));
@@ -355,37 +357,47 @@ protected void onCreate(Bundle savedInstanceState) {
   }
 
   /**
-   * Initializes the Java Bridge to allow communication between Java and JavaScript.
-   * This method injects Java objects into the WebView and loads corresponding JavaScript code.
+   * Initializes the Java Bridge to allow communication between Java and JavaScript. This method
+   * injects Java objects into the WebView and loads corresponding JavaScript code.
    */
   private void initializeJavaBridge() {
     Log.i(TAG, "initializeJavaBridge");
 
     WebContents webContents = getActiveWebContents();
     if (webContents == null) {
-        // WebContents not initialized yet, post a delayed runnable to check again
-        new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
-            @Override
-            public void run() {
-                initializeJavaBridge(); // Recursive call to check again
-            }
-        }, JAVA_BRIDGE_INITIALIZATION_DELAY_MILLI_SECONDS);
-        return;
+      // WebContents not initialized yet, post a delayed runnable to check again
+      new Handler(Looper.getMainLooper())
+          .postDelayed(
+              new Runnable() {
+                @Override
+                public void run() {
+                  initializeJavaBridge(); // Recursive call to check again
+                }
+              },
+              JAVA_BRIDGE_INITIALIZATION_DELAY_MILLI_SECONDS);
+      return;
     }
 
     // --- Initialize the Java Bridge ---
 
     // 1. Gather all Java objects that need to be exposed to JavaScript.
+    // TODO(b/379701165): consider to refine the way to add JavaScript interfaces.
     javaScriptAndroidObjectList.add(new AmatiDeviceInspector(this));
+    javaScriptAndroidObjectList.add(new HTMLMediaElementExtension(this));
 
     // 2. Use JavascriptInjector to inject Java objects into the WebContents.
     //    This makes the annotated methods in these objects accessible from JavaScript.
     JavascriptInjector javascriptInjector = JavascriptInjector.fromWebContents(webContents, false);
 
     javascriptInjector.setAllowInspection(true);
     for (CobaltJavaScriptAndroidObject javascriptAndroidObject : javaScriptAndroidObjectList) {
-      Log.d(TAG, "Add JavaScriptAndroidObject:" + javascriptAndroidObject.getJavaScriptInterfaceName());
-      javascriptInjector.addPossiblyUnsafeInterface(javascriptAndroidObject, javascriptAndroidObject.getJavaScriptInterfaceName(), CobaltJavaScriptInterface.class);
+      Log.d(
+          TAG,
+          "Add JavaScriptAndroidObject:" + javascriptAndroidObject.getJavaScriptInterfaceName());
+      javascriptInjector.addPossiblyUnsafeInterface(
+          javascriptAndroidObject,
+          javascriptAndroidObject.getJavaScriptInterfaceName(),
+          CobaltJavaScriptInterface.class);
     }
 
     // 3. Load and evaluate JavaScript code that interacts with the injected Java objects.

cobalt/android/apk/app/src/main/java/dev/cobalt/coat/javabridge/HTMLMediaElementExtension.java

@@ -0,0 +1,44 @@
+// Copyright 2024 The Cobalt Authors. 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 dev.cobalt.coat.javabridge;
+
+import android.content.Context;
+
+/** Implementation of HTMLMediaElement extensions. */
+public class HTMLMediaElementExtension implements CobaltJavaScriptAndroidObject {
+
+  private final Context context;
+
+  public HTMLMediaElementExtension(Context context) {
+    this.context = context;
+  }
+
+  @Override
+  public String getJavaScriptInterfaceName() {
+    return "HTMLMediaElementExtension";
+  }
+
+  @Override
+  public String getJavaScriptAssetName() {
+    return "html_media_element_extension.js";
+  }
+
+  @CobaltJavaScriptInterface
+  public String canPlayType(String mimeType, String keySystem) {
+    return nativeCanPlayType(mimeType, keySystem);
+  }
+
+  private static native String nativeCanPlayType(String mimeType, String keySystem);
+}

starboard/android/shared/application_android.cc

@@ -38,6 +38,7 @@
 #include "starboard/common/time.h"
 #include "starboard/event.h"
 #include "starboard/key.h"
+#include "starboard/media.h"
 #include "starboard/shared/starboard/audio_sink/audio_sink_internal.h"
 
 namespace starboard {
@@ -124,6 +125,38 @@ Java_dev_cobalt_coat_CobaltSystemConfigChangeReceiver_nativeDateTimeConfiguratio
   tzset();
 }
 
+extern "C" SB_EXPORT_PLATFORM jstring
+Java_dev_cobalt_coat_javabridge_HTMLMediaElementExtension_nativeCanPlayType(
+    JniEnvExt* env,
+    jobject jcaller,
+    jstring j_mime_type,
+    jstring j_key_system) {
+  std::string mime_type, key_system;
+  if (j_mime_type) {
+    mime_type = env->GetStringStandardUTFOrAbort(j_mime_type);
+  }
+  if (j_key_system) {
+    key_system = env->GetStringStandardUTFOrAbort(j_key_system);
+  }
+  SbMediaSupportType support_type =
+      SbMediaCanPlayMimeAndKeySystem(mime_type.c_str(), key_system.c_str());
+  const char* ret;
+  switch (support_type) {
+    case kSbMediaSupportTypeNotSupported:
+      ret = "";
+      break;
+    case kSbMediaSupportTypeMaybe:
+      ret = "maybe";
+      break;
+    case kSbMediaSupportTypeProbably:
+      ret = "probably";
+      break;
+  }
+  SB_LOG(INFO) << __func__ << " (" << mime_type << ", " << key_system
+               << ") --> " << ret;
+  return env->NewStringStandardUTFOrAbort(ret);
+}
+
 int ApplicationAndroid::GetOverlayedIntValue(const char* var_name) {
   ScopedLock lock(overlay_mutex_);
   if (overlayed_int_variables_.find(var_name) !=