show welcome notification on first launch with dependency check

- check atom-ide-ui dependency
- TODO programatically input text in settings page

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 npm-debug.log
+WELCOME_SHOWN

src/main.js

@@ -2,9 +2,11 @@ const path = require('path')
 const { AutoLanguageClient } = require('atom-languageclient')
 const { registerConfigOnChangeHandlers } = require('./util')
 const { registerHelpCommands } = require('./help_cmd')
+const { showWelcomeNotification } = require('./welcome_notification')
 
 registerConfigOnChangeHandlers()
 registerHelpCommands()
+showWelcomeNotification()
 
 class HTMLLanguageClient extends AutoLanguageClient {
   getGrammarScopes () {

src/welcome_notification.js

@@ -0,0 +1,76 @@
+// show welcome message on first installation
+const path = require('path')
+const fs = require('fs')
+
+const WELCOME_SHOWN = path.join(__dirname, '..', 'WELCOME_SHOWN')
+
+const generateWelcomeMsg = () => {
+  return `## Welcome to ide-html\n\nQuick start for ide-html:\n${[
+    'Open a HTML file from the Project',
+    'Dispatch command `Outline View: Toggle`',
+  ].map((str, i) => `${i}. ${str}\n`).join('')
+  }\nHappy Using Atom IDE : )`
+}
+
+const generateWarnMsg = () => {
+  return `## Welcome to ide-html\n\nPlease install following requirements:\n${[
+    '[`atom-ide-ui`](https://atom.io/packages/atom-ide-ui)',
+  ].map((str, i) => `${i}. ${str}\n`).join('')
+  }\nso that ide-html can work properly`
+}
+
+const helpButton = [
+  {
+    text: ' Help',
+    onDidClick: () => { atom.commands.dispatch(
+      atom.views.getView(atom.workspace.getActivePane()),
+      'ide-html:help'
+    )},
+    className: 'btn btn-success btn-lg icon-light-bulb',
+  },
+]
+
+const settingsButton = [
+  {
+    text: ' Open Settings Page',
+    onDidClick: () => {
+      atom.commands.dispatch(
+        atom.views.getView(atom.workspace.getActivePane()),
+        'settings-view:install-packages-and-themes'
+      )
+    },
+    className: 'btn btn-success btn-lg icon-tools',
+  },
+]
+
+const showWelcomeNotification = () => {
+  try {
+    fs.accessSync(WELCOME_SHOWN)
+  } catch (err) {
+    if (atom.packages.isPackageLoaded('atom-ide-ui')) {
+      atom.notifications.addSuccess(
+        generateWelcomeMsg(),
+        {
+          buttons: helpButton,
+          dismissable: true,
+          icon: 'thumbsup',
+        }
+      )
+      fs.closeSync(fs.openSync(WELCOME_SHOWN, 'w'))
+    } else {
+      atom.notifications.addWarning(
+        generateWarnMsg(),
+        {
+          buttons: settingsButton,
+          dismissable: true,
+          icon: 'info',
+        }
+      )
+    }
+  }
+}
+
+
+module.exports = {
+  showWelcomeNotification,
+}