Refactor WebApkServiceConnectionManager.

chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkIdentityServiceClient.java

Index: chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkIdentityServiceClient.java
diff --git a/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkIdentityServiceClient.java b/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkIdentityServiceClient.java
new file mode 100644
index 0000000000000000000000000000000000000000..a671ab4247c3a9f87dc7a5ede8ea1e777d3aee7e
--- /dev/null
+++ b/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkIdentityServiceClient.java
@@ -0,0 +1,146 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.webapk.lib.client;
+
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.text.TextUtils;
+import android.util.Log;
+
+import org.chromium.webapk.lib.common.WebApkMetaDataKeys;
+import org.chromium.webapk.lib.common.identity_service.IIdentityService;
+
+/**
+ * Provides APIs that allow browsers communicating with WebAPK Identity services. Each WebAPK has
+ * its own "WebAPK Identity service".
+ */
+public class WebApkIdentityServiceClient {
+    /** Used to notify the consumer after checking whether the current app owns the WebAPK. */
+    public interface CheckBacksWebApkCallback { void onChecked(boolean isValid); }
+
+    /**
+     * Before shell APK version 6, all WebAPKs are installed from browsers, and that browser is the
+     * runtime host and specified in the WebAPK's AndroidManifest.xml. In shell APK version 6, we
+     * introduced a logic to allow user to choose runtime host browser for WebAPKs unbound without
+     * any browser, and for WebAPKs installed from browsers when the browser isn't installed.
+     * However, user can either clear WebAPK's data that may require to choose a runtime host again,
+     * or clear a browser's data that makes the browser loses its knowledge of owned WebAPKs.
+     * Therefore, we don't know exactly which browser is the runtime host of a WebAPK without asking
+     * the WebAPK. An Identity service is introduced in shell APK version 16 to allow browsers
+     * querying the runtime host of a WebAPK.
+     */
+    public static final int SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST = 6;
+
+    private static final String ACTION_WEBAPK_IDENTITY_SERVICE = "org.webapk.IDENTITY_SERVICE_API";
+    private static final String TAG = "cr_WebApkIdentityService";
+
+    private static WebApkIdentityServiceClient sInstance;
+
+    /** Manages connections between the browser application and WebAPK Identity services. */
+    private WebApkServiceConnectionManager mConnectionManager;
+
+    public static WebApkIdentityServiceClient getInstance() {
+        if (sInstance == null) {
+            sInstance = new WebApkIdentityServiceClient();
+        }
+        return sInstance;
+    }
+
+    private WebApkIdentityServiceClient() {
+        mConnectionManager = new WebApkServiceConnectionManager(
+                null /* action */, ACTION_WEBAPK_IDENTITY_SERVICE);
+    }
+
+    /**
+     * Checks the runtime host of a WebAPK and notifies the caller. The runtime host could be null
+     * if the WebAPK either doesn't have an Identity service or hasn't bind to any browser yet.
+     * @param context The app context.
+     * @param webApkPackageName The package name of the WebAPK.
+     * @param callback The callback to be called after querying the runtime host is done.
+     */
+    public static void checkBacksWebApkAsync(final Context context, final String webApkPackageName,

[pkotwicz, 2017/07/19 16:09:13]

Nit: Rename |context| to |browserContext|

[Xi Han, 2017/07/21 20:36:33]

Done.

+            final CheckBacksWebApkCallback callback) {
+        final String packageName = context.getPackageName();
+        WebApkServiceConnectionManager.ConnectionCallback connectionCallback =
+                new WebApkServiceConnectionManager.ConnectionCallback() {
+                    @Override
+                    public void onConnected(IBinder service) {
+                        if (service == null) {
+                            WebApkIdentityServiceClient.onGotWebApkRuntimeHost(packageName,
+                                    maybeExtractRuntimeHostFromMetaData(context, webApkPackageName),
+                                    callback);
+                            return;
+                        }
+
+                        IIdentityService identityService =
+                                IIdentityService.Stub.asInterface(service);
+                        String runtimeHost = null;
+                        try {
+                            runtimeHost = identityService.getRuntimeHostBrowserPackageName();
+                        } catch (RemoteException e) {
+                            Log.w(TAG, "Failed to get runtime host from the Identity service.");
+                        }
+                        WebApkIdentityServiceClient.onGotWebApkRuntimeHost(
+                                packageName, runtimeHost, callback);
+                    }
+                };
+        getInstance().mConnectionManager.connect(context, webApkPackageName, connectionCallback);
+    }
+
+    /**
+     * Called after fetching the WebAPK's runtime host browser.
+     * @param appPackageName The current app's package name.
+     * @param webApkRuntimeHostPackageName The package name of the WebAPK's runtime host browser.
+     * @param callback The callback to notify the called whether the runtime host matches the
+     *                 current app.
+     */
+    private static void onGotWebApkRuntimeHost(String appPackageName,
+            String webApkRuntimeHostPackageName, CheckBacksWebApkCallback callback) {
+        callback.onChecked(!TextUtils.isEmpty(webApkRuntimeHostPackageName)
+                && webApkRuntimeHostPackageName.contentEquals(appPackageName));
+    }
+
+    /**
+     * Extracts the runtime host from metadata if
+     * - the runtime host specified in the AndroidManifest.xml matches the current app name.
+     * AND
+     * - The shell APK version is less than SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST.
+     * See {@link WebApkIdentityServiceClient#SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST} for
+     * more details.
+     */
+    public static String maybeExtractRuntimeHostFromMetaData(
+            Context context, String webApkPackageName) {
+        Bundle metadata = readMetaData(context, webApkPackageName);
+        if (metadata.getInt(WebApkMetaDataKeys.SHELL_APK_VERSION)
+                >= SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST) {
+            return null;
+        }
+
+        return metadata.getString(WebApkMetaDataKeys.RUNTIME_HOST);
+    }
+
+    /** Returns the <meta-data> in the Android Manifest of the given package name. */
+    private static Bundle readMetaData(Context context, String packageName) {
+        ApplicationInfo ai = null;
+        try {
+            ai = context.getPackageManager().getApplicationInfo(
+                    packageName, PackageManager.GET_META_DATA);
+        } catch (PackageManager.NameNotFoundException e) {
+            return null;
+        }
+        return ai.metaData;
+    }
+
+    /** Disconnects all the connections from WebAPK Identity services. */
+    public static void disconnectWebApkIdentityService(Context appContext) {
+        if (sInstance == null) return;
+
+        sInstance.mConnectionManager.disconnect(appContext);
+    }
+}