//alert("domapi.js");

function DOMAPI() {
  // Properties.
  this.isCSS = null;
  this.isW3C = null;
  this.isIE4 = null;
  this.isNN4 = null;
  this.isIE6CSS = null;

  // Initialize properties.
  this.init = function init()
  {
    if (document.images) {
      this.isCSS = (document.body && document.body.style) ? true : false;
      this.isW3C = (this.isCSS && document.getElementById) ? true : false;
      this.isIE4 = (this.isCSS && document.all) ? true : false;
      this.isNN4 = (document.layers) ? true : false;
      this.isIE6CSS = (document.compatMode && document.compatMode.indexOf("CSS1") >= 0) ? true : false;
    }
  }

  // Methods.

  // Seek nested NN4 layer from string name.
  this.seekLayer = function seekLayer(doc, name)
  {
    var theObj;
    for (var i = 0; i < doc.layers.length; i++) {
      if (doc.layers[i].name == name) {
        theObj = doc.layers[i];
        break;
      }
      // Dive into nested layers if necessary.
      if (doc.layers[i].document.layers.length > 0) {
        theObj = seekLayer(document.layers[i].document, name);
      }
    }
    return theObj;
  }

  // Convert object name string or object reference into a valid element object reference.
  this.getRawObject = function getRawObject(obj)
  {
    var theObj;
    if (typeof obj == "string") {
      if (this.isW3C) {
        theObj = document.getElementById(obj);
      } else if (this.isIE4) {
        theObj = document.all(obj);
      } else if (this.isNN4) {
        theObj = seekLayer(document, obj);
      }
    } else {
      // Pass through object reference.
      theObj = obj;
    }
    return theObj;
  }

  // Convert object name string or object reference into a valid style (or NN4 layer) reference.
  this.getObject = function getObject(obj)
  {
    var theObj = this.getRawObject(obj);
    if (theObj && this.isCSS) {
      theObj = theObj.style;
    }
    return theObj;
  }

  // Retrieve the x coordinate of a positionable object.
  this.getObjectLeft = function getObjectLeft(obj)
  {
    var elem = this.getRawObject(obj);
    var domStyle = this.getObject(obj);
    var result = 0;
    if (elem.style) {
      if (domStyle.left) {
        result = domStyle.left;
      }
      if (domStyle.pixelLeft) {
        result = domStyle.pixelLeft;
      }
	  if (elem.offsetLeft) {
        result = elem.offsetLeft;
      }
    } else if (document.defaultView) {
      var style = document.defaultView;
      var cssDecl = style.getComputedStyle(elem, "");
      result = cssDecl.getPropertyValue("left");
    } else if (elem.currentStyle) {
      result = elem.currentStyle.left;
    } else if (this.isNN4) {
      result = elem.left;
    }
    return parseInt(result);
  }
   
  // Retrieve the y coordinate of a positionable object.
  this.getObjectTop = function getObjectTop(obj)
  {
    var elem = this.getRawObject(obj);
    var domStyle = this.getObject(obj);
    var result = 0;
    if (elem.style) {
      if (domStyle.left) {
        result = domStyle.left;
      }
      if (domStyle.pixelTop) {
        result = domStyle.pixelTop;
      }
	  if (elem.offsetTop) {
        result = elem.offsetTop;
      }
    } else if (document.defaultView) {
      var style = document.defaultView;
      var cssDecl = style.getComputedStyle(elem, "");
      result = cssDecl.getPropertyValue("top");
    } else if (elem.currentStyle) {
      result = elem.currentStyle.top;
    } else if (this.isNN4) {
      result = elem.top;
    }
    return parseInt(result);
  }

  // Retrieve the rendered width of an element.
  this.getObjectWidth = function getObjectWidth(obj)
  {
    var elem = this.getRawObject(obj);
    var result = 0;
    if (elem.offsetWidth) {
      result = elem.offsetWidth;
    } else if (elem.clip && elem.clip.width) {
      result = elem.clip.width;
    } else if (elem.style && elem.style.pixelWidth) {
      result = elem.style.pixelWidth;
    }
    return parseInt(result);
  }
   
  // Retrieve the rendered height of an element.
  this.getObjectHeight = function getObjectHeight(obj)
  {
    var elem = this.getRawObject(obj);
    var result = 0;
    if (elem.offsetHeight) {
      result = elem.offsetHeight;
    } else if (elem.clip && elem.clip.height) {
      result = elem.clip.height;
    } else if (elem.style && elem.style.pixelHeight) {
      result = elem.style.pixelHeight;
    }
    return parseInt(result);
  }

  // Position an object at a specific pixel coordinate.
  this.shiftTo = function shiftTo(obj, x, y)
  {
    var theObj = this.getObject(obj);
    if (theObj) {
      if (this.isCSS) {
        // Equalize incorrect numeric value type..
        var units = (typeof theObj.left == "string") ? "px" : 0;
        theObj.left = x + units;
        theObj.top = y + units;
      } else if (this.isNN4) {
        theObj.moveTo(x,y)
      }
    }
  }
   
  // Move an object by x and/or y pixels.
  this.shiftBy = function shiftBy(obj, deltaX, deltaY)
  {
    var theObj = this.getObject(obj);
    if (theObj) {
      if (this.isCSS) {
        // Equalize incorrect numeric value type.
        var units = (typeof theObj.left == "string") ? "px" : 0;
        theObj.left = this.getObjectLeft(obj) + deltaX + units;
        theObj.top = this.getObjectTop(obj) + deltaY + units;
      } else if (this.isNN4) {
        theObj.moveBy(deltaX, deltaY);
      }
    }
  }

  // Set the z-order of an object.
  this.setZIndex = function setZIndex(obj, zOrder)
  {
    var theObj = this.getObject(obj);
    if (theObj) {
      theObj.zIndex = zOrder;
    }
  }
   
  // Set the background color of an object.
  this.setBGColor = function setBGColor(obj, color)
  {
    var theObj = this.getObject(obj);
    if (theObj) {
      if (this.isNN4) {
        theObj.bgColor = color;
      } else if (this.isCSS) {
        theObj.backgroundColor = color;
      }
    }
  }

  // Set the visibility of an object to visible.
  this.show = function show(obj)
  {
    var theObj = this.getObject(obj);
    if (theObj) {
      theObj.visibility = "visible";
    }
  }
   
  // Set the visibility of an object to hidden.
  this.hide = function hide(obj)
  {
    var theObj = this.getObject(obj);
    if (theObj) {
      theObj.visibility = "hidden";
    }
  }

  // Return the available content width space in browser window.
  this.getInsideWindowWidth = function getInsideWindowWidth()
  {
    if (window.innerWidth) {
      return window.innerWidth;
    } else if (this.isIE6CSS) {
      // Measure the html element's clientWidth.
      return document.body.parentElement.clientWidth;
    } else if (document.body && document.body.clientWidth) {
      return document.body.clientWidth;
    }
    return 0;
  }
   
  // Return the available content height space in browser window.
  this.getInsideWindowHeight = function getInsideWindowHeight()
  {
    if (window.innerHeight) {
      return window.innerHeight;
    } else if (this.isIE6CSS) {
      // Measure the html element's clientHeight.
      return document.body.parentElement.clientHeight;
    } else if (document.body && document.body.clientHeight) {
      return document.body.clientHeight;
    }
    return 0;
  }

  // Set the contents of a div.
  this.setContents = function setContents(obj, content)
  {
    var elem = this.getRawObject(obj);
    if (this.isNN4) {
      elem.write(content);
      elem.close();
    } else {
      elem.innerHTML = content;
    }
  }

  this.getClass = function getClass(obj)
  {
    var elem = this.getRawObject(obj);
    return elem.className;
  }

  this.setClass = function setClass(obj, className)
  {
    var elem = this.getRawObject(obj);
    elem.className = className;
  }

  // Automatically initialize when instantiating a new object.
  this.init();
}