more reliable focus management based on https://supernapie.com/blog/keyboard-focus-in-an-iframe/

src/kiri/init.js

@@ -1142,7 +1142,7 @@
             },
 
             load:               $('load-file'),
-            focuser:            $('focuser'),
+            // focuser:            $('focuser'),
 
             container:          container,
             rotate:             $('lt-rotate'),
@@ -1834,9 +1834,6 @@
         // update everything dependent on the platform size
         platform.update_size();
 
-        // ensure hot keys work even in iframes
-        API.focus();
-
         // restore expert setting preference
         API.mode.set_expert(control.expert);
 
@@ -1882,6 +1879,14 @@
             $('gdpr').style.display = 'flex';
         }
 
+        // add keyboard focus handler (must use for iframes)
+        WIN.addEventListener('load', function () {
+            WIN.focus();
+            DOC.body.addEventListener('click', function() {
+                WIN.focus();
+            },false);
+        });
+
         // dismiss gdpr alert
         $('gotit').onclick = () => {
             $('gdpr').style.display = 'none';

src/kiri/main.js

@@ -152,7 +152,7 @@
         js2o: js2o,
         ajax: ajax,
         clone: clone,
-        focus: setFocus,
+        focus: () => {},
         stats: STATS,
         catalog: CATALOG,
         conf: {
@@ -1889,17 +1889,6 @@
             });
     }
 
-    function setFocus(el) {
-        el = [ el || UI.focuser, UI.load, UI.sizeX, DOC.body ];
-        for (let es, i=0; i<el.length; i++) {
-            es = el[i];
-            es.focus();
-            if (DOC.activeElement === es) {
-                break;
-            }
-        }
-    }
-
     function setViewMode(mode) {
         let oldMode = viewMode;
         viewMode = mode;

web/kiri/index.css

@@ -979,13 +979,6 @@ and (orientation : landscape) {
     align-items: stretch;
 }
 
-#focuser {
-    position: fixed;
-    z-index: -100;
-    left: -100%;
-    top: -100%;
-}
-
 #gdpr {
     position: absolute;
     display: none;

web/kiri/index.html

@@ -21,7 +21,6 @@
     <script src="/code/kiri.js?{{version}}"></script>
 </head>
 <body class="col">
-    <input id="focuser" size=10></input>
     <div id="curtain" class="j-center a-center">loading...</div>
     <div id="container"></div>
     <div id="tracker"></div>