Upstream WebAPK notification related code

chrome/android/java/src/org/chromium/chrome/browser/notifications/WebApkNotificationClient.java

+// Copyright 2016 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.chrome.browser.notifications;
+
+import android.os.RemoteException;
+
+import org.chromium.base.Callback;
+import org.chromium.base.Log;
+import org.chromium.webapk.lib.client.WebApkServiceConnectionManager;
+import org.chromium.webapk.lib.runtime_library.IWebApkApi;
+
+/**
+ * WebApkNotificationClient provides API to open/close notifications from WebAPK.

[Peter Beverloo, 2016/05/19 15:59:00]

Comment suggestion:

 * This class provides an API to display and close notifications remotely in
context of a WebAPK,
 * enriching the notification with its small icon when available.

We retain the ability to modify this class, right? (Different from the
IWebApkApi living within the WebAPK.)

[pkotwicz, 2016/05/20 00:45:19]

Yes, we can modify this class as we please

+ */
+public class WebApkNotificationClient {
+    private static final String TAG = "cr_WebApk";
+
+    // Callback which catches RemoteExceptions thrown due to IWebApkApi failure.

[Peter Beverloo, 2016/05/19 15:59:00]

This seems like a very generic concept, is this the best place for this utility
to live in?

[pkotwicz, 2016/05/20 00:45:19]

I think of ApiUseCallback as a convenience class. WebApkNotificationClient
should know that calls to IWebApkApi can fail so I think that this convenience
class belongs here

+    private abstract static class ApiUseCallback implements Callback<IWebApkApi> {
+        public abstract void useApi(IWebApkApi api) throws RemoteException;
+
+        @Override
+        public void onResult(IWebApkApi api) {
+            try {
+                useApi(api);
+            } catch (RemoteException e) {
+                Log.w(TAG, "WebApkAPI use failed.", e);
+            }
+        }
+    }
+
+    /**
+     * Connect to a WebAPK's bound service, build a notification and hand it over to the WebAPK to
+     * display. Handing over the notification makes the notification look like it originated from
+     * the WebAPK - not Chrome - in the Android UI.
+     * @param webApkPackage Package of the WebAPK to bind to.
+     * @param notificationBuilder
+     * @param platformTag
+     * @param platformID

[Peter Beverloo, 2016/05/19 15:59:00]

nit: I think our style guide says that parameters to public methods should be
documented. I don't feel very strongly about adding stuff here since this is
just a pass-through function, but I do feel that mentioning the fact that these
parameters exist (which is obvious from the method's prototype!) without
documenting them just adds noise.

Would you mind either removing the @params from the doc-block, or adding
documentation to them?

[pkotwicz, 2016/05/20 00:45:19]

Removed the @params

+     */
+    public static void displayNotification(String webApkPackage,
+            final NotificationBuilderBase notificationBuilder, final String platformTag,
+            final int platformID) {
+        final ApiUseCallback connectionCallback = new ApiUseCallback() {
+            @Override
+            public void useApi(IWebApkApi api) throws RemoteException {
+                notificationBuilder.setSmallIcon(api.getSmallIconId());

[Peter Beverloo, 2016/05/19 15:59:00]

Is a WebAPK guaranteed to have a small icon Id specified? The notification
wouldn't show up in the status bar if the small icon Id is null.

[pkotwicz, 2016/05/20 00:45:19]

I am unsure what we will do in the long term. Right now all WebAPKs use the same
icon.

I am aware of badges being added to the JS notification API
(http://crbug.com/591394). It would be nice if WebAPKs could display badges on
all Android OS versions (not just M+) but I am not sure if that's possible.

[Peter Beverloo, 2016/05/20 14:12:15]

These badges are Bitmaps, which indeed require M+.

We've previously discussed adding support for this in WebAPKs by allowing a
WebAPK to define the small icon in their manifest. This still doesn't allow
per-notification selection, but it does give them much more flexibility than
they have today.

+                api.displayNotification(platformTag, platformID, notificationBuilder.build());
+            }
+        };
+
+        WebApkServiceConnectionManager.getInstance().connect(webApkPackage, connectionCallback);
+    }
+
+    /**
+     * Closes notification previously shown by WebAPK.
+     * @param webApkPackage Package of the WebAPK which displayed the notification.
+     * @param platformTag
+     * @param platformID
+     */
+    public static void closeNotification(
+            String webApkPackage, final String platformTag, final int platformID) {
+        final ApiUseCallback connectionCallback = new ApiUseCallback() {
+            @Override
+            public void useApi(IWebApkApi api) throws RemoteException {
+                api.closeNotification(platformTag, platformID);
+            }
+        };
+        WebApkServiceConnectionManager.getInstance().connect(webApkPackage, connectionCallback);
+    }
+}