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..6e7de61b3e4fb280ce18196c2e9bbaa03962f538
--- /dev/null
+++ b/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkIdentityServiceClient.java
@@ -0,0 +1,116 @@
+// 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.IdentityService.IIdentityService;
+import org.chromium.webapk.lib.common.WebApkMetaDataKeys;
+
+/**
+ * Manages static global connections between the Chrome application and "WebAPK Identity Service".
+ * Each WebAPK has its own "WebAPK Identity Service".
+ */
+public class WebApkIdentityServiceClient extends WebApkServiceConnectionManager {
+    /** Used to notified the consumer after checking the WebAPK's runtime host asynchronously. */
+    public interface CheckRuntimeHostCallback { void onCheckedRuntimeHost(boolean isValid); }
+
+    private static final String CATEGORY_WEBAPK_IDENTITY_SERVICE =
+            "org.webapk.IDENTITY_SERVICE_API";
+    private static final String TAG = "cr_WebApkIdentityService";
+    private static final int SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST = 6;
+
+    private static WebApkIdentityServiceClient sInstance;
+
+    public static WebApkIdentityServiceClient getInstance() {
+        if (sInstance == null) {
+            sInstance = new WebApkIdentityServiceClient();
+        }
+        return sInstance;
+    }
+
+    private WebApkIdentityServiceClient() {
+        super(CATEGORY_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 checkWebApkRuntimeHostAsync(final Context context,
+            final String webApkPackageName, final CheckRuntimeHostCallback callback) {
+        final String packageName = context.getPackageName();
+        WebApkServiceConnectionManager.ConnectionCallback connectionCallback =
+                new ConnectionCallback() {
+                    @Override
+                    public void onConnected(IBinder service) {
+                        if (service == null) {
+                            WebApkIdentityServiceClient.notify(packageName, callback,
+                                    maybeExtractRuntimeHostFromMetaData(
+                                            context, webApkPackageName));
+                            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.");
+                        } finally {
+                            WebApkIdentityServiceClient.notify(packageName, callback, runtimeHost);
+                        }
+                    }
+                };
+        getInstance().connect(context, webApkPackageName, connectionCallback);
+    }
+
+    /** Notifies the caller whether the runtime host matches the current app. */
+    public static void notify(
+            String appPackageName, CheckRuntimeHostCallback callback, String runtimeHost) {
+        callback.onCheckedRuntimeHost(
+                !TextUtils.isEmpty(runtimeHost) && runtimeHost.contentEquals(appPackageName));
+    }
+
+    /**
+     * Only returns the runtime host 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.
+     */
+    private 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;
+    }
+}