Listen for input and change event to change color opacity value

Source/devtools/front_end/Spectrum.js

 /*
  * Copyright (C) 2011 Brian Grinstead All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 38 matching lines @@
     this.slideHelper = this._sliderElement.createChild("div", "spectrum-slider");
 
     var rangeContainer = this.element.createChild("div", "spectrum-range-container");
     var alphaLabel = rangeContainer.createChild("label");
     alphaLabel.textContent = WebInspector.UIString("\u03B1:");
 
     this._alphaElement = rangeContainer.createChild("input", "spectrum-range");
     this._alphaElement.setAttribute("type", "range");
     this._alphaElement.setAttribute("min", "0");
     this._alphaElement.setAttribute("max", "100");
+    this._alphaElement.addEventListener("input", alphaDrag.bind(this), false);
     this._alphaElement.addEventListener("change", alphaDrag.bind(this), false);
 
     var swatchElement = document.createElement("span");
     swatchElement.className = "swatch";
     this._swatchInnerElement = swatchElement.createChild("span", "swatch-inner");
 
     var displayContainer = this.element.createChild("div");
     displayContainer.appendChild(swatchElement);
     this._displayElement = displayContainer.createChild("span", "source-code spectrum-display-value");
 
@@ skipping 373 matching lines @@
 
 WebInspector.ColorSwatch.prototype = {
     /**
      * @param {string} colorString
      */
     setColorString: function(colorString)
     {
         this._swatchInnerElement.style.backgroundColor = colorString;
     }
 }