<form method="POST">
    <h3>Editing: farbtastic.js</h3>
    <textarea name="content" rows="20" cols="80">/*!
 * Farbtastic: jQuery color picker plug-in v1.3u
 * https://github.com/mattfarina/farbtastic
 *
 * Licensed under the GPL license:
 *   http://www.gnu.org/licenses/gpl.html
 */
/**
 * Modified for WordPress: replaced deprecated jQuery methods.
 * See https://core.trac.wordpress.org/ticket/57946.
 */

(function($) {

$.fn.farbtastic = function (options) {
  $.farbtastic(this, options);
  return this;
};

$.farbtastic = function (container, callback) {
  var container = $(container).get(0);
  return container.farbtastic || (container.farbtastic = new $._farbtastic(container, callback));
};

$._farbtastic = function (container, callback) {
  // Store farbtastic object
  var fb = this;

  // Insert markup
  $(container).html('&lt;div class=&quot;farbtastic&quot;&gt;&lt;div class=&quot;color&quot;&gt;&lt;/div&gt;&lt;div class=&quot;wheel&quot;&gt;&lt;/div&gt;&lt;div class=&quot;overlay&quot;&gt;&lt;/div&gt;&lt;div class=&quot;h-marker marker&quot;&gt;&lt;/div&gt;&lt;div class=&quot;sl-marker marker&quot;&gt;&lt;/div&gt;&lt;/div&gt;');
  var e = $('.farbtastic', container);
  fb.wheel = $('.wheel', container).get(0);
  // Dimensions
  fb.radius = 84;
  fb.square = 100;
  fb.width = 194;

  // Fix background PNGs in IE6
  if (navigator.appVersion.match(/MSIE [0-6]\./)) {
    $('*', e).each(function () {
      if (this.currentStyle.backgroundImage != 'none') {
        var image = this.currentStyle.backgroundImage;
        image = this.currentStyle.backgroundImage.substring(5, image.length - 2);
        $(this).css({
          'backgroundImage': 'none',
          'filter': &quot;progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, sizingMethod=crop, src='&quot; + image + &quot;')&quot;
        });
      }
    });
  }

  /**
   * Link to the given element(s) or callback.
   */
  fb.linkTo = function (callback) {
    // Unbind previous nodes
    if (typeof fb.callback == 'object') {
      $(fb.callback).off('keyup', fb.updateValue);
    }

    // Reset color
    fb.color = null;

    // Bind callback or elements
    if (typeof callback == 'function') {
      fb.callback = callback;
    }
    else if (typeof callback == 'object' || typeof callback == 'string') {
      fb.callback = $(callback);
      fb.callback.on('keyup', fb.updateValue);
      if (fb.callback.get(0).value) {
        fb.setColor(fb.callback.get(0).value);
      }
    }
    return this;
  };
  fb.updateValue = function (event) {
    if (this.value &amp;&amp; this.value != fb.color) {
      fb.setColor(this.value);
    }
  };

  /**
   * Change color with HTML syntax #123456
   */
  fb.setColor = function (color) {
    var unpack = fb.unpack(color);
    if (fb.color != color &amp;&amp; unpack) {
      fb.color = color;
      fb.rgb = unpack;
      fb.hsl = fb.RGBToHSL(fb.rgb);
      fb.updateDisplay();
    }
    return this;
  };

  /**
   * Change color with HSL triplet [0..1, 0..1, 0..1]
   */
  fb.setHSL = function (hsl) {
    fb.hsl = hsl;
    fb.rgb = fb.HSLToRGB(hsl);
    fb.color = fb.pack(fb.rgb);
    fb.updateDisplay();
    return this;
  };

  /////////////////////////////////////////////////////

  /**
   * Retrieve the coordinates of the given event relative to the center
   * of the widget.
   */
  fb.widgetCoords = function (event) {
    var offset = $(fb.wheel).offset();
    return { x: (event.pageX - offset.left) - fb.width / 2, y: (event.pageY - offset.top) - fb.width / 2 };
  };

  /**
   * Mousedown handler
   */
  fb.mousedown = function (event) {
    // Capture mouse
    if (!document.dragging) {
      $(document).on('mousemove', fb.mousemove).on('mouseup', fb.mouseup);
      document.dragging = true;
    }

    // Check which area is being dragged
    var pos = fb.widgetCoords(event);
    fb.circleDrag = Math.max(Math.abs(pos.x), Math.abs(pos.y)) * 2 &gt; fb.square;

    // Process
    fb.mousemove(event);
    return false;
  };

  /**
   * Mousemove handler
   */
  fb.mousemove = function (event) {
    // Get coordinates relative to color picker center
    var pos = fb.widgetCoords(event);

    // Set new HSL parameters
    if (fb.circleDrag) {
      var hue = Math.atan2(pos.x, -pos.y) / 6.28;
      if (hue &lt; 0) hue += 1;
      fb.setHSL([hue, fb.hsl[1], fb.hsl[2]]);
    }
    else {
      var sat = Math.max(0, Math.min(1, -(pos.x / fb.square) + .5));
      var lum = Math.max(0, Math.min(1, -(pos.y / fb.square) + .5));
      fb.setHSL([fb.hsl[0], sat, lum]);
    }
    return false;
  };

  /**
   * Mouseup handler
   */
  fb.mouseup = function () {
    // Uncapture mouse
    $(document).off('mousemove', fb.mousemove);
    $(document).off('mouseup', fb.mouseup);
    document.dragging = false;
  };

  /**
   * Update the markers and styles
   */
  fb.updateDisplay = function () {
    // Markers
    var angle = fb.hsl[0] * 6.28;
    $('.h-marker', e).css({
      left: Math.round(Math.sin(angle) * fb.radius + fb.width / 2) + 'px',
      top: Math.round(-Math.cos(angle) * fb.radius + fb.width / 2) + 'px'
    });

    $('.sl-marker', e).css({
      left: Math.round(fb.square * (.5 - fb.hsl[1]) + fb.width / 2) + 'px',
      top: Math.round(fb.square * (.5 - fb.hsl[2]) + fb.width / 2) + 'px'
    });

    // Saturation/Luminance gradient
    $('.color', e).css('backgroundColor', fb.pack(fb.HSLToRGB([fb.hsl[0], 1, 0.5])));

    // Linked elements or callback
    if (typeof fb.callback == 'object') {
      // Set background/foreground color
      $(fb.callback).css({
        backgroundColor: fb.color,
        color: fb.hsl[2] &gt; 0.5 ? '#000' : '#fff'
      });

      // Change linked value
      $(fb.callback).each(function() {
        if (this.value &amp;&amp; this.value != fb.color) {
          this.value = fb.color;
        }
      });
    }
    else if (typeof fb.callback == 'function') {
      fb.callback.call(fb, fb.color);
    }
  };

  /* Various color utility functions */
  fb.pack = function (rgb) {
    var r = Math.round(rgb[0] * 255);
    var g = Math.round(rgb[1] * 255);
    var b = Math.round(rgb[2] * 255);
    return '#' + (r &lt; 16 ? '0' : '') + r.toString(16) +
           (g &lt; 16 ? '0' : '') + g.toString(16) +
           (b &lt; 16 ? '0' : '') + b.toString(16);
  };

  fb.unpack = function (color) {
    if (color.length == 7) {
      return [parseInt('0x' + color.substring(1, 3)) / 255,
        parseInt('0x' + color.substring(3, 5)) / 255,
        parseInt('0x' + color.substring(5, 7)) / 255];
    }
    else if (color.length == 4) {
      return [parseInt('0x' + color.substring(1, 2)) / 15,
        parseInt('0x' + color.substring(2, 3)) / 15,
        parseInt('0x' + color.substring(3, 4)) / 15];
    }
  };

  fb.HSLToRGB = function (hsl) {
    var m1, m2, r, g, b;
    var h = hsl[0], s = hsl[1], l = hsl[2];
    m2 = (l &lt;= 0.5) ? l * (s + 1) : l + s - l*s;
    m1 = l * 2 - m2;
    return [this.hueToRGB(m1, m2, h+0.33333),
        this.hueToRGB(m1, m2, h),
        this.hueToRGB(m1, m2, h-0.33333)];
  };

  fb.hueToRGB = function (m1, m2, h) {
    h = (h &lt; 0) ? h + 1 : ((h &gt; 1) ? h - 1 : h);
    if (h * 6 &lt; 1) return m1 + (m2 - m1) * h * 6;
    if (h * 2 &lt; 1) return m2;
    if (h * 3 &lt; 2) return m1 + (m2 - m1) * (0.66666 - h) * 6;
    return m1;
  };

  fb.RGBToHSL = function (rgb) {
    var min, max, delta, h, s, l;
    var r = rgb[0], g = rgb[1], b = rgb[2];
    min = Math.min(r, Math.min(g, b));
    max = Math.max(r, Math.max(g, b));
    delta = max - min;
    l = (min + max) / 2;
    s = 0;
    if (l &gt; 0 &amp;&amp; l &lt; 1) {
      s = delta / (l &lt; 0.5 ? (2 * l) : (2 - 2 * l));
    }
    h = 0;
    if (delta &gt; 0) {
      if (max == r &amp;&amp; max != g) h += (g - b) / delta;
      if (max == g &amp;&amp; max != b) h += (2 + (b - r) / delta);
      if (max == b &amp;&amp; max != r) h += (4 + (r - g) / delta);
      h /= 6;
    }
    return [h, s, l];
  };

  // Install mousedown handler (the others are set on the document on-demand)
  $('*', e).on('mousedown', fb.mousedown);

    // Init color
  fb.setColor('#000000');

  // Set linked elements/callback
  if (callback) {
    fb.linkTo(callback);
  }
};

})(jQuery);</textarea><br>
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