Add initialization view

_locales/en/messages.json

@@ -39,6 +39,10 @@
       "message": "Loading...",
       "description": "Message shown on the loading screen before we've loaded any messages"
     },
+    "optimizingApplication": {
+      "message": "Optimizing application...",
+      "description": "Message shown on the loading screen while we are doing application optimizations"
+    },
     "chooseDirectory": {
       "message": "Choose folder",
       "description": "Button to allow the user to find a folder on disk"

js/modules/views/initialization.js

@@ -0,0 +1,33 @@
+/* eslint-env browser */
+
+/* global i18n: false */
+
+
+const OPTIMIZATION_MESSAGE_DISPLAY_THRESHOLD = 2000; // milliseconds
+
+// type Canceler = () => Eff Unit
+//
+//    setMessage :: Unit -> Eff (dom :: DOM) Canceler
+const setMessage = () => {
+  const message = document.querySelector('.app-loading-screen .message');
+  if (!message) {
+    return () => {};
+  }
+  message.innerText = i18n('loading');
+
+  const optimizingMessageTimeoutId = setTimeout(() => {
+    const innerMessage = document.querySelector('.app-loading-screen .message');
+    if (!innerMessage) {
+      return;
+    }
+    innerMessage.innerText = i18n('optimizingApplication');
+  }, OPTIMIZATION_MESSAGE_DISPLAY_THRESHOLD);
+
+  return () => {
+    clearTimeout(optimizingMessageTimeoutId);
+  };
+};
+
+module.exports = {
+  setMessage,
+};

preload.js

@@ -140,6 +140,8 @@
   window.Signal.Types.Message = Message;
   window.Signal.Types.MIME = require('./js/modules/types/mime');
   window.Signal.Types.Settings = require('./js/modules/types/settings');
+  window.Signal.Views = {};
+  window.Signal.Views.Initialization = require('./js/modules/views/initialization');
   window.Signal.Workflow = {};
   window.Signal.Workflow.IdleDetector = IdleDetector;
   window.Signal.Workflow.MessageDataMigrator =