Refactor desktop notification override

src/browser/js/notification.js

@@ -0,0 +1,80 @@
+const OriginalNotification = Notification;
+
+function override(eventHandlers) {
+  Notification = function(title, options) {
+    this.notification = new OriginalNotification(title, options);
+    if (eventHandlers.notification) {
+      eventHandlers.notification();
+    }
+  };
+
+  // static properties
+  Notification.__defineGetter__('permission', function() {
+    return OriginalNotification.permission;
+  });
+
+  // instance properties
+  var defineReadProperty = function(property) {
+    Notification.prototype.__defineGetter__(property, function() {
+      return this.notification[property];
+    });
+  };
+  defineReadProperty('title');
+  defineReadProperty('dir');
+  defineReadProperty('lang');
+  defineReadProperty('body');
+  defineReadProperty('tag');
+  defineReadProperty('icon');
+  defineReadProperty('data');
+  defineReadProperty('silent');
+
+  // unsupported properties
+  defineReadProperty('noscreen');
+  defineReadProperty('renotify');
+  defineReadProperty('sound');
+  defineReadProperty('sticky');
+  defineReadProperty('vibrate');
+
+  // event handlers
+  var defineEventHandler = function(event, callback) {
+    defineReadProperty(event);
+    Notification.prototype.__defineSetter__(event, function(originalCallback) {
+      this.notification[event] = function() {
+        callbackevent = {
+          preventDefault: function() {
+            this.isPrevented = true;
+          }
+        };
+        if (callback) {
+          callback(callbackevent);
+          if (!callbackevent.isPrevented) {
+            originalCallback();
+          }
+        }
+        else {
+          originalCallback();
+        }
+      }
+    });
+  }
+  defineEventHandler('onclick', eventHandlers.onclick);
+  defineEventHandler('onerror', eventHandlers.onerror);
+
+  // obsolete handlers
+  defineEventHandler('onclose', eventHandlers.onclose);
+  defineEventHandler('onshow', eventHandlers.onshow);
+
+  // static methods
+  Notification.requestPermission = function(callback) {
+    OriginalNotification.requestPermission(callback);
+  };
+
+  // instance methods
+  Notification.prototype.close = function() {
+    this.notification.close();
+  };
+}
+
+module.exports = {
+  override: override
+};

src/browser/webview/mattermost.js

@@ -2,7 +2,7 @@
 
 const electron = require('electron');
 const ipc = electron.ipcRenderer;
-const NativeNotification = Notification;
+const notification = require('../js/notification');
 
 var hasClass = function(element, className) {
   var rclass = /[\t\r\n\f]/g;
@@ -107,35 +107,21 @@ function isLowerThanOrEqualWindows8_1() {
   return (osVersion.major <= 6 && osVersion.minor <= 3);
 };
 
-// Show balloon when notified.
-function overrideNotificationWithBalloon() {
-  Notification = function(title, options) {
-    ipc.send('notified', {
-      title: title,
-      options: options
-    });
-  };
-  Notification.permission = NativeNotification.permission;
-  Notification.requestPermission = function(callback) {
-    callback('granted');
-  };
-  Notification.prototype.close = function() {};
-};
-
-// Show window even if it is hidden/minimized when notification is clicked.
-function overrideNotification() {
-  Notification = function(title, options) {
-    this.notification = new NativeNotification(title, options);
-  };
-  Notification.permission = NativeNotification.permission;
-  Notification.requestPermission = function(callback) {
-    callback('granted');
-  };
-  Notification.prototype.close = function() {
-    this.notification.close();
-  };
-  Notification.prototype.__defineSetter__('onclick', function(callback) {
-    this.notification.onclick = function() {
+if (process.platform === 'win32' && isLowerThanOrEqualWindows8_1()) {
+  // Show balloon when notified.
+  notification.override({
+    notification: function(title, options) {
+      ipc.send('notified', {
+        title: title,
+        options: options
+      });
+    }
+  });
+}
+else {
+  // Show window even if it is hidden/minimized when notification is clicked.
+  notification.override({
+    onclick: function() {
       if (process.platform === 'win32') {
         // show() breaks Aero Snap state.
         electron.remote.getCurrentWindow().focus();
@@ -144,14 +130,6 @@ function overrideNotification() {
         electron.remote.getCurrentWindow().show();
       }
       ipc.sendToHost('onNotificationClick');
-      callback();
-    };
+    }
   });
 }
-
-if (process.platform === 'win32' && isLowerThanOrEqualWindows8_1()) {
-  overrideNotificationWithBalloon();
-}
-else {
-  overrideNotification();
-}