Эффект пишущей машинки с jQuery

Ответ 1

demo: http://jsbin.com/araget/5/

плагин

(function ($) {
  // writes the string
  //
  // @param jQuery $target
  // @param String str
  // @param Numeric cursor
  // @param Numeric delay
  // @param Function cb
  // @return void
  function typeString($target, str, cursor, delay, cb) {
    $target.html(function (_, html) {
      return html + str[cursor];
    });

    if (cursor < str.length - 1) {
      setTimeout(function () {
        typeString($target, str, cursor + 1, delay, cb);
      }, delay);
    }
    else {
      cb();
    }
  }

  // clears the string
  //
  // @param jQuery $target
  // @param Numeric delay
  // @param Function cb
  // @return void
  function deleteString($target, delay, cb) {
    var length;

    $target.html(function (_, html) {
      length = html.length;
      return html.substr(0, length - 1);
    });

    if (length > 1) {
      setTimeout(function () {
        deleteString($target, delay, cb);
      }, delay);
    }
    else {
      cb();
    }
  }

  // jQuery hook
  $.fn.extend({
    teletype: function (opts) {
      var settings = $.extend({}, $.teletype.defaults, opts);

      return $(this).each(function () {
        (function loop($tar, idx) {
          // type
          typeString($tar, settings.text[idx], 0, settings.delay, function () {
            // delete
            setTimeout(function () {
              deleteString($tar, settings.delay, function () {
                loop($tar, (idx + 1) % settings.text.length);
              });
            }, settings.pause);
          });

        }($(this), 0));
      });
    }
  });

  // plugin defaults  
  $.extend({
    teletype: {
      defaults: {
        delay: 100,
        pause: 5000,
        text: []
      }
    }
  });
}(jQuery));

HTML

<span id="target"></span>
<span id="cursor"></span> <!-- used for the blinking cursor effect -->

INIT

$('#target').teletype({
  text: [
    'Lorem ipsum dolor sit amet, consetetur sadipscing elitr,',
    'sed diam nonumy eirmod tempor invidunt ut labore et dolore',
    'magna aliquyam erat, sed diam voluptua. At vero eos et',
    'accusam et justo duo dolores et ea rebum. Stet clita kasd',
    'gubergren, no sea takimata sanctus est Lorem ipsum dolor sit',
    'amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr,',
    'sed diam nonumy eirmod tempor invidunt ut labore et dolore',
    'magna aliquyam erat, sed diam voluptua. At vero eos et accusam',
    'et justo duo dolores et ea rebum. Stet clita kasd gubergren,',
    'no sea takimata sanctus est Lorem ipsum dolor sit amet.'
  ]
});

$('#cursor').teletype({
  text: ['_', ' '],
  delay: 0,
  pause: 500
});

Ответ 2

Добавлена ​​простая функция в конце и несколько переменных между ними...

Fiddle

var where, when; //added

$.fn.teletype = function(opts){
    var $this = this,
        defaults = {
            animDelay: 50
        },
        settings = $.extend(defaults, opts);

    var letters = settings.text.length; //added

    where = '#' + $($this).attr('id'); //added
    when = settings.animDelay; //added

    $.each(settings.text, function(i, letter){
        setTimeout(function(){
            $this.html($this.html() + letter);

            if( $($this).html().length == letters ){ reverse(); } // Added to trigger reversing function

        }, settings.animDelay * i);
    });
};

$(function(){
    $('#container').teletype({
        animDelay: 100,
        text: 'Now is the time for all good men to come to the aid of their country...'
    });
});


// Added Reversing Function

    function reverse(){

        if ($(where).html().length > 0){          
            x = $(where).html().length - 1;
            y = $(where).html().substr(0, x);
            $(where).html(y);
            setTimeout(reverse , when);
        }else{
            console.log('Reverse Complete');
            clearTimeout(reverse);
        }
    }