Fix IE token navigation problem. (Fixes #258)

Currently tokeninput sometimes loses focus when navigating
between tokens using the keyboard in Internet Explorer.
Here we apply what seems to be the common workaround for problems
with focus behavior in IE, namely wrapping requests for focus
inside a setTimeout.

Author: ryguasu

src/jquery.tokeninput.js

@@ -301,7 +301,7 @@ $.TokenList = function (input, url_or_data, settings) {
                            .hide()
                            .val("")
                            .focus(function () {
-                               input_box.focus();
+                               focus_with_timeout(input_box);
                            })
                            .blur(function () {
                                input_box.blur();
@@ -326,7 +326,7 @@ $.TokenList = function (input, url_or_data, settings) {
                 }
 
                 // Focus input box
-                input_box.focus();
+                focus_with_timeout(input_box);
             }
         })
         .mouseover(function (event) {
@@ -540,7 +540,7 @@ $.TokenList = function (input, url_or_data, settings) {
             if(found_existing_token) {
                 select_token(found_existing_token);
                 input_token.insertAfter(found_existing_token);
-                input_box.focus();
+                focus_with_timeout(input_box);
                 return;
             }
         }
@@ -594,7 +594,7 @@ $.TokenList = function (input, url_or_data, settings) {
         }
 
         // Show the input box and give it focus again
-        input_box.focus();
+        focus_with_timeout(input_box);
     }
 
     // Toggle selection of a token in the token list
@@ -626,7 +626,7 @@ $.TokenList = function (input, url_or_data, settings) {
         selected_token = null;
 
         // Show the input box and give it focus again
-        input_box.focus();
+        focus_with_timeout(input_box);
 
         // Remove this token from the saved list
         saved_tokens = saved_tokens.slice(0,index).concat(saved_tokens.slice(index+1));
@@ -640,8 +640,8 @@ $.TokenList = function (input, url_or_data, settings) {
         if(settings.tokenLimit !== null) {
             input_box
                 .show()
-                .val("")
-                .focus();
+                .val("");
+            focus_with_timeout(input_box);
         }
 
         // Execute the onDelete callback if defined
@@ -867,6 +867,16 @@ $.TokenList = function (input, url_or_data, settings) {
         }
         return url;
     }
+
+    // Bring browser focus to the specified object.
+    // Use of setTimeout is to get around an IE bug.
+    // (See, e.g., http://stackoverflow.com/questions/2600186/focus-doesnt-work-in-ie)
+    // 
+    // obj: a jQuery object to focus()
+    function focus_with_timeout(obj) {
+        setTimeout(function() { obj.focus(); }, 50);
+    }
+
 };
 
 // Really basic cache for the results