textareaSelectEndPoint.js : テキストボックスにフォーカスした時、文字列の最後にカーソルが移動させる。(IE8 はデフォルトでカーソルが先頭に移動する)

textareaSelectEndPoint.js

/**
 * textareaSelectEndPoint.js
 *
 * @version 1.0.4
 * @author think49
 * @url https://gist.github.com/885009
 */

(function () {

  function handleLoad (event) {
    var doc, inputs, input, textareas, i, len;

    doc = event.target || document;
    inputs = doc.querySelectorAll ? doc.querySelectorAll('input[type="text"]') : doc.getElementsByTagName('input');
    textareas = doc.getElementsByTagName('textarea');

    for (i = 0, len = inputs.length; i < len; ++i) {
      input = inputs[i];

      if (input.type === 'text') {
        addEvent(input, 'select', handleFocus, false);
      }
    }

    for (var i = 0, l = textareas.length; i < l; i++) {
      addEvent(textareas[i], 'focus', handleFocus, false);
    }
  }

  function handleFocus (event) {
    var target, range, length;

    target = event.target || event.srcElement;

    if (target.tagName === 'INPUT' && target.type === 'text' || target.tagName === 'TEXTAREA') {
      console.log(event.type);
      if ('setSelectionRange' in target) {       // GoogleChrome5, Opera10.60, Firefox3.6.6
//        console.log('selectionStart');
        length = target.value.length;
        target.setSelectionRange(length, length);
      } else if ('createTextRange' in target) {  // IE8
//        console.log('createTextRange');
        range = target.createTextRange();
        range.move('character', target.value.length);
        range.select();
      }
    }
  }

  function handleUnload () {
    var caches, i, len;

    caches = listenersCache.getAll();

    for (i = 0, len = caches.length; i < len; ++i) {
      removeEvent.apply(caches[i]);
    }

    listenersCache.clearAll();
//    alert('unload');
  }


  var listenersCache = (function () {
    var caches;

    caches = [];

    return {
      getAll: function getAll () {
        return caches;
      },
      set: function set (node, type, listener, useCapture) {
        return caches.push([node, type, listener, useCapture]);
      },
      clearAll: function clearAll () {
        caches = null;
      }
    };
  })();

  var addEvent = (function () {

    if (typeof addEventListener === 'function') {
      return function (node, type, listener, useCapture) {
        listenersCache.set(node, type, listener, useCapture);
        return node ? node.addEventListener(type, listener, useCapture) : addEventListener(type, listener, useCapture);
      };
    }

    if (typeof attachEvent === 'object' || typeof attachEvent === 'function') {
      return function (node, type, handleEvent) {
        return node ? node.attachEvent('on' + type, handleEvent) : attachEvent('on' + type, handleEvent);
      };
    }

    throw new Error('addEvent is not defined');
  })();

  var removeEvent = (function () {

    if (typeof removeEventListener === 'function') {
      return function (node, type, listener, useCapture) {
        return node ? node.removeEventListener(type, listener, useCapture) : removeEventListener(type, listener, useCapture);
      };
    }

    if (typeof detachEvent === 'object' || typeof detachEvent === 'function') {
      return function (node, type, handleEvent) {
        return node ? node.detachEvent('on' + type, handleEvent) : detachEvent('on' + type, handleEvent);
      };
    }

    throw new Error('removeEvent is not defined');
  })();


  // --- Initialize

  if (typeof document.addEventListener === 'function') {
    document.addEventListener('DOMContentLoaded', handleLoad, false);
    listenersCache.set(document, 'DOMContentLoaded', handleLoad, false);
  } else if (typeof attachEvent === 'object' || typeof attachEvent === 'function') {
    attachEvent('onload', handleLoad);
    listenersCache.set(null, 'load', handleLoad);
  }

  addEvent(null, 'unload', handleUnload, false);
})();