Improve element detection for certain sites & reduce focus delay

By initiating at DOMContentLoaded instead of load elements can be focused without waiting for whole page to load. Content script will also retry the init function up to three times with a 100ms delay if no elements were found (which seems to happen for certain SPA and AMP sites)

src/content_script.js

@@ -2,6 +2,7 @@ const inputTypes = ['search','text'];
 let inputEls;
 let targetElement;
 let contextMenuElement; // To be set by event listener
+let retryCount = 0;
 
 // Check if host is blacklisted by user
 isDisabled(location.hostname,(isDisabled) => {
@@ -14,15 +15,28 @@ isDisabled(location.hostname,(isDisabled) => {
     if (document.readyState == 'complete') {
         init();
     } else {
-        window.addEventListener('load',function load() {
-            window.removeEventListener('load',load,false);
+        window.addEventListener('DOMContentLoaded',function domLoaded() {
+            window.removeEventListener('DOMContentLoaded',domLoaded,false);
             init();
         });
+        window.addEventListener('load', function load() {
+            window.removeEventListener('load',load,false);
+            // Refocus element if focus changed between DOMContentLoaded & load (see https://reddit.com)
+            if (targetElement && document.activeElement != targetElement) {
+                focusElement(targetElement);
+            }
+        });
     }
 });
 
 function init() {
     inputEls = [...document.getElementsByTagName('input')];
+    // If no elements were found, try again in case DOM wasn't fully loaded (see https://justwatch.com)
+    if (inputEls.length == 0 && retryCount < 3) {
+        retryCount++;
+        setTimeout(() => init(),100);
+        return;
+    }
     // First find out if user has a custom mapping for this hostname
     searchMappings('custom',(element) => {
         if (element == null) {

src/manifest.json

@@ -2,7 +2,7 @@
     "manifest_version": 2,
     "name": "Autofocus",
     "description": "Search faster - Puts the cursor in the search box on page load",
-    "version": "0.1.1",
+    "version": "0.2",
     "icons" : {
         "16": "img/icon-16.png",
         "48": "img/icon-48.png",
@@ -13,7 +13,7 @@
         {
             "matches": ["<all_urls>"],
             "js": ["content_script.js"],
-            "run_at": "document_end"
+            "run_at": "document_start"
         }
     ],
     "browser_action": {