// link_indicator.js
// == written by Takuya Otani <takuya.otani@gmail.com> ===
// == Copyright (C) 2006 SimpleBoxes/SerendipityNZ Ltd. ==
/*
  Copyright (C) 2006 Takuya Otani/SimpleBoxes - http://serennz.cool.ne.jp/sb/
  Copyright (C) 2006 SerendipityNZ - http://serennz.cool.ne.jp/snz/

  This script is licensed under the Creative Commons Attribution 2.5 License
  http://creativecommons.org/licenses/by/2.5/

  basically, do anything you want, just leave my name and link.
*/
// === utilities ===
function addEvent(object, type, handler)
{
  if (object.addEventListener) {
    object.addEventListener(type, handler, false);
  } else if (object.attachEvent) {
    object.attachEvent(['on',type].join(''),handler);
  } else {
    object[['on',type].join('')] = handler;
  }
}
function getEvent(evt)
{
  return (evt) ? evt : ((window.event) ? window.event : null);
}
function WindowSize()
{ // window size object
  this.w = 0;
  this.h = 0;
  return this.update();
}
WindowSize.prototype.update = function()
{
  var d = document;
  this.w =
    (window.innerWidth) ? window.innerWidth
  : (d.documentElement && d.documentElement.clientWidth) ? d.documentElement.clientWidth
  : d.body.clientWidth;
  this.h =
    (window.innerHeight) ? window.innerHeight
  : (d.documentElement && d.documentElement.clientHeight) ? d.documentElement.clientHeight
  : d.body.clientHeight;
  return this;
};
function PageSize()
{ // page size object
  this.win = new WindowSize();
  this.w = 0;
  this.h = 0;
  return this.update();
}
PageSize.prototype.update = function()
{
  var d = document;
  this.w =
    (window.innerWidth && window.scrollMaxX) ? window.innerWidth + window.scrollMaxX
  : (d.body.scrollWidth > d.body.offsetWidth) ? d.body.scrollWidth
  : d.body.offsetWidt;
  this.h =
    (window.innerHeight && window.scrollMaxY) ? window.innerHeight + window.scrollMaxY
  : (d.body.scrollHeight > d.body.offsetHeight) ? d.body.scrollHeight
  : d.body.offsetHeight;
  this.win.update();
  if (this.w < this.win.w) this.w = this.win.w;
  if (this.h < this.win.h) this.h = this.win.h;
  return this;
};
function PagePos()
{ // page position object
  this.x = 0;
  this.y = 0;
  return this.update();
}
PagePos.prototype.update = function()
{
  var d = document;
  this.x =
    (window.pageXOffset) ? window.pageXOffset
  : (d.documentElement && d.documentElement.scrollLeft) ? d.documentElement.scrollLeft
  : (d.body) ? d.body.scrollLeft
  : 0;
  this.y =
    (window.pageYOffset) ? window.pageYOffset
  : (d.documentElement && d.documentElement.scrollTop) ? d.documentElement.scrollTop
  : (d.body) ? d.body.scrollTop
  : 0;
  return this;
};
function UserAgent()
{ // user agent information
  var ua = navigator.userAgent;
  this.isWinIE = this.isMacIE = false;
  this.isGecko  = ua.match(/Gecko\//);
  this.isSafari = ua.match(/AppleWebKit/);
  this.isOpera  = window.opera;
  if (document.all && !this.isGecko && !this.isSafari && !this.isOpera) {
    this.isWinIE = ua.match(/Win/);
    this.isMacIE = ua.match(/Mac/);
    this.isNewIE = (ua.match(/MSIE 5\.5/) || ua.match(/MSIE 6\.0/));
  }
  this.isCompat = true; // true means quirks mode.
  if (document.compatMode) this.isCompat = (document.compatMode != 'CSS1Compat')
  return this;
}
// === indicator ===
function LinkIndicator(option)
{
  var self = this;
  self.borderWidth = (option.borderWidth) ? option.borderWidth : '1px';
  self._img = null;
  self._box = null;
  self._pos = new PagePos();
  self._ua  = new UserAgent();
  self._page = new PageSize();
  self._base = self._init_path(window.location);
  return self._init(option);
}
LinkIndicator.prototype = {
  _init : function(option)
  {
    var self = this;
    var d = document;
    if (!d.getElementsByTagName) return;
    var links = d.getElementsByTagName("a");
    for (var i=0;i<links.length;i++) {
      var href = links[i].getAttribute("href");
      if (!href) continue;
      var elem = {inner:null,target:null};
      var href = links[i].getAttribute('href');
      var targ = links[i].getAttribute('target');
      if (href.match(/(.*)\#(.+)/)) {
        var check = RegExp.$1;
        var name = RegExp.$2;
        if (check.length == 0 || check == self._base) {
          if (d.getElementById(name))
            elem.inner = d.getElementById(name);
          else if (d.getElementsByName(name))
            elem.inner = d.getElementsByName(name)[0];
          if (links[i] == elem.inner) elem.inner = null;
        }
      }
      if (targ && targ != '_self' && targ != '_parent' && targ != '_top') elem.target = targ;
      if (elem.inner || elem.target) {
        addEvent(links[i],"mouseover",self._handler(links[i],elem));
        addEvent(links[i],"mouseout",function() { self._reset() } );
        addEvent(links[i],"mousemove",function(event) { self._move(event) } );
      }
    } // end of for (var i=0;i<links.length;i++)
    self._init_parts(option);
    return self;
  },
  _init_path : function(l)
  {
    var self = this;
    var path = [l.protocol,l.host].join('//');
    path = [path,l.pathname].join('');
    return path;
  },
  _init_parts : function(option)
  {
    var self = this;
    var d = document;
    var body = d.getElementsByTagName("body")[0];
    var box = d.createElement('div');
    box.id = 'indicator-line';
    with (box.style) {
      display = 'none';
      position = 'absolute';
      borderWidth = '0px';
      zIndex = 100;
    }
    if (option.pointerImg) {
      var pointer = d.createElement('img');
      pointer.style.position = 'absolute';
      pointer.style.zIndex = 100;
      pointer.src = option.pointerImg;
      box.appendChild(pointer);
    }
    body.appendChild(box);
    self._box = box;
    if (option.linkToBlank) {
      var img = new Image;
      img.onload = function() {
        var marker = d.createElement('div');
        var mark_img = d.createElement('img');
        mark_img.src = img.src;
        marker.id = 'indicator-symbol';
        with (marker.style) {
          display = 'none';
          position = 'absolute';
          width = [img.width,'px'].join('');
          height = [img.height,'px'].join('');
          zIndex = 100;
        }
        marker.appendChild(mark_img);
        body.appendChild(marker);
        self._img = marker;
      };
      img.src = option.linkToBlank;
    }
  },
  _handler : function(link,option)
  {
    var self = this;
    return function(event) { self._indicate(link,option,event); };
  },
  _reset : function()
  {
    var self = this;
    if (self._img && self._img.style) self._img.style.display = 'none';
    if (self._box && self._box.style) self._box.style.display = 'none';
  },
  _cursor_position : function(event)
  {
    var self = this;
    var pos = {
      x: event.clientX || event.offsetX || event.x,
      y: event.clientY || event.offsetY || event.y
    }
    if (self._ua.isGecko) {
      self._pos.update();
      pos.x += self._pos.x;
      pos.y += self._pos.y;
    }
    return pos;
  },
  _move : function(event)
  {
    var self = this;
    var pos  = self._cursor_position(getEvent(event));
    if (self._img && self._img.style.display != 'none') {
      self._img.style.left = [pos.x + 10,'px'].join('');
      self._img.style.top  = [pos.y + 4,'px'].join('');
    }
  },
  _object_position : function(obj)
  {
    var self = this;
    var pos = {x:obj.offsetLeft, y:obj.offsetTop};
    if (self._ua.isNewIE) return pos;
    var parent = obj.offsetParent;
    while (parent) {
      pos.x += parent.offsetLeft;
      pos.y += parent.offsetTop;
      parent = parent.offsetParent;
    }
    return pos;
  },
  _region : function(src,dest)
  {
    var self = this;
    var bgn = self._object_position(src);
    var end = self._object_position(dest);
    var min = {x:(bgn.x < end.x) ? bgn.x : end.x, y:(bgn.y < end.y) ? bgn.y : end.y};
    var max = {x:(bgn.x < end.x) ? end.x : bgn.x, y:(bgn.y < end.y) ? end.y : bgn.y};
    return {
      left:min.x + 5,
      top:min.y + 5,
      width:(max.x - min.x) || 1,
      height:(max.y - min.y) || 1,
      vartical:(bgn.x < end.x) ? 'borderRightWidth' : 'borderLeftWidth',
      horizontal:(bgn.y < end.y) ? 'borderTopWidth' : 'borderBottomWidth',
      targetX:(bgn.x < end.x) ? (max.x - min.x) - 8 : -8,
      targetY:(bgn.y < end.y) ? (max.y - min.y) - 8 : -8
    };
  },
  _indicate : function(link,option,event)
  {
    var self = this;
    var pos  = self._cursor_position(getEvent(event));
    if (self._img && option.target) {
      self._img.style.display = 'block';
      self._img.style.left = [pos.x + 10,'px'].join('');
      self._img.style.top  = [pos.y + 4,'px'].join('');
    }
    if (option.inner && link.offsetLeft && self._box) {
      var region = self._region(link,option.inner);
      with (self._box.style) {
        display = 'block';
        borderWidth = '0px';
        left = [region.left,'px'].join('');
        top = [region.top,'px'].join('');
        width = [region.width,'px'].join('');
        height = [region.height,'px'].join('');
      }
      self._box.style[region.vartical] = self.borderWidth;
      self._box.style[region.horizontal] = self.borderWidth;
      if (self._box.firstChild && self._box.firstChild.style) {
        self._box.firstChild.style.left = [region.targetX,'px'].join('');
        self._box.firstChild.style.top = [region.targetY,'px'].join('');
      }
    }
  }
};
// === main ===
addEvent(window,"load",function() {
  var indicator = new LinkIndicator({
    linkToBlank:'images/addwin.gif',
    pointerImg:'images/pointer.gif',
    borderWidth:'2px'
  });
});