move caret to the end of a text input field AND make the end visible

问题

I'm going insane. I have an autosuggest box where users choose a suggestion. On the next suggestion selection the value of the text input box exceeds its size. I can move the carat to the end of the input field crossbrowser, no problem. But on Chrome and Safari I cannot SEE the carat at the end. The end of the text is not visible.

Is there a way to move the carat to the end of a text input field AND have the end of the field visible so that the user is not confused about where the input carat went?

what I got so far:

<html>
<head><title>Field update test</title></head>

<body>
<form action="#" method="POST" name="testform">

<p>After a field is updated the carat should be at the end of the text field AND the end of the text should be visible</p>

<input type="text" name="testbox" value="" size="40">

<p><a href="javascript:void(0);" onclick="add_more_text();">add more text</a></p>

</form>

<script type="text/javascript">
<!--
var count = 0;

function add_more_text() {
   var textfield = document.testform.elements['testbox'];

   textfield.focus();

   if (count == 0) textfield.value = ''; // clear old

   count++;
   textfield.value = textfield.value + (textfield.value.length ? ', ' : '') + count + ": This is some sample text";

   // move to the carat to the end of the field
   if (textfield.setSelectionRange) {
      textfield.setSelectionRange(textfield.value.length, textfield.value.length);
   } else if (textfield.createTextRange) {
      var range = textfield.createTextRange();
      range.collapse(true);
      range.moveEnd('character', textfield.value.length);
      range.moveStart('character', textfield.value.length);
      range.select();
   }

   // force carat visibility for some browsers
   if (document.createEvent) {
      // Trigger a space keypress.
      var e = document.createEvent('KeyboardEvent');
      if (typeof(e.initKeyEvent) != 'undefined') {
         e.initKeyEvent('keypress', true, true, null, false, false, false, false, 0, 32);
      } else {
         e.initKeyboardEvent('keypress', true, true, null, false, false, false, false, 0, 32);
      }
      textfield.dispatchEvent(e);

      // Trigger a backspace keypress.
      e = document.createEvent('KeyboardEvent');
      if (typeof(e.initKeyEvent) != 'undefined') {
         e.initKeyEvent('keypress', true, true, null, false, false, false, false, 8, 0);
      } else {
         e.initKeyboardEvent('keypress', true, true, null, false, false, false, false, 8, 0);
      }
      textfield.dispatchEvent(e);
   }
}
// -->
</script>

</body>
</html>

Thanks

回答1:

I came up with a solution. Webkit (Safari and Chrome) needs a kick in the pants to perform the keyboard event correctly. Add a blur() and then focus() before the backspace:

  textfield.blur(); // Webkit wake-up hack
  textfield.focus();
  textfield.dispatchEvent(e);

Thanks. Works in Safari, Chrome, FF, IE on Mac and Windows now.

来源：https://stackoverflow.com/questions/2692009/move-caret-to-the-end-of-a-text-input-field-and-make-the-end-visible

标签

javascript

javascript-events

input

textinput