Refactor into functions

Author: sudonatalie

js/background.js

@@ -7,14 +7,14 @@ chrome.webNavigation.onHistoryStateUpdated.addListener(function(details) {
   // Setup page for layout changes and show page action
   if (match) {
     chrome.tabs.executeScript(null, {
-      file: 'js/setup-css.js'
+      file: 'js/init.js'
     });
   }
 });
 
 chrome.pageAction.onClicked.addListener(function(tab) {
   chrome.tabs.executeScript(null, {
-    file: 'js/toggle-layout.js'
+    code: 'toggleLayout()'
   });
 });
 

js/init.js

@@ -0,0 +1,49 @@
+function insertCss() {
+  const cssFile = chrome.extension.getURL('css/layout.css');
+  const cssId = 'layoutcss';
+
+  if (document.getElementById(cssId) === null) {
+    let css = document.createElement('link');
+    css.id = cssId;
+    css.type = 'text/css';
+    css.rel = 'stylesheet';
+    css.href = cssFile;
+    document.getElementsByTagName('head')[0].appendChild(css);
+  }
+}
+
+function syncState() {
+  chrome.storage.sync.get('classList', function(result) {
+    let board = document.getElementById('board');
+
+    if (result.classList) {
+      board.classList.add(result.classList);
+    }
+  });
+}
+
+function toggleLayout() {
+  const classVertical = 'layout-trello-vertical';
+  const classMixed = 'layout-trello-mixed';
+
+  let board = document.getElementById('board');
+
+  if (board.classList.contains(classMixed)) {
+    board.classList.remove(classMixed);
+    board.classList.add(classVertical);
+    chrome.storage.sync.set({
+      'classList': classVertical
+    });
+  } else if (board.classList.contains(classVertical)) {
+    board.classList.remove(classVertical);
+    chrome.storage.sync.remove('classList');
+  } else {
+    board.classList.add(classMixed);
+    chrome.storage.sync.set({
+      'classList': classMixed
+    });
+  }
+}
+
+insertCss();
+syncState();