// find_position.js - Find html item position
// uses( Browsers.js);
function IsByWindowPosition( w)
{
  if ( !w)
    w = window;
  if ( typeof( w.pageYOffset) == 'number')
    return true;
  return false;
}
function IsByDocumentElementPosition( doc)
{
  if ( !doc)
    doc = document;
  if (( doc.documentElement)
    &&(( doc.documentElement.clientWidth)
     ||( doc.documentElement.clientHeight)
      )
     )
  {
    return true;
  }
  return false;
}
function IsByBodyPosition( doc)
{
  if ( !doc)
    doc = document;
  if (( doc.body)
    &&(( doc.body.clientWidth)
     ||( doc.body.clientHeight)
      )
     )
  {
    return true;
  }
  return false;
}

function BrowserWindowWidth( w)
{
  //alert( 'document.documentElement.clientWidth = '+document.documentElement.clientWidth
  //      +' document.body.clientWidth = '+document.body.clientWidth
  //      +' window.innerWidth = '+window.innerWidth
  //      );

  var doc = null;
  if ( w)
    doc = w.document;
  else
    doc = document;

  if ( IsByDocumentElementPosition( doc))
    return doc.documentElement.clientWidth;
  return doc.body.clientWidth;
}

function BrowserWindowHeight( w)
{
  var nHeight = null;
  var doc = null;
  if ( w)
    doc = w.document;
  else
  {
    doc = document;
    w = window;
  }
    

  var bByWindow = IsByWindowPosition( w);
  var bByDocumentElement = IsByDocumentElementPosition( doc);
  var bByBody = IsByBodyPosition( doc);

  if ( bByDocumentElement)
    nHeight = doc.documentElement.clientHeight;
  else
  if ( bByBody)
    nHeight = doc.body.clientHeight;

  if ( bByWindow)
  if ( bByDocumentElement)
  if ( bByBody)
  {
    //ShowBrowserDataInAlert();

    var nBodyHeight = doc.body.clientHeight;
    var nDocumentHeigh = doc.documentElement.clientHeight;
    var nWindowHeight = w.innerHeight;
    
    nHeight = nWindowHeight;// + nBodyHeight - nDocumentHeigh;

    if ( !IsSafari())
    {
      if ( nWindowHeight >= nDocumentHeigh)
      {
        nHeight = nDocumentHeigh;
        //if ( IsOpera())
        if ( nWindowHeight >= nBodyHeight)
        if ( nBodyHeight > nDocumentHeigh)
          nHeight = nBodyHeight;
      }
      else
      if ( nWindowHeight >= nBodyHeight)
      {
        nHeight = nBodyHeight;
      }
    }
  }
  return nHeight;
}

function ScrollWindowPosition( w)
{
  var doc = null;
  if ( w)
    doc = w.document;
  else
  {
    doc = document;
    w = window;
  }

  var nScrollX = 0;
  var nScrollY = 0
  if ( IsByWindowPosition( w))
  {
    nScrollX = w.pageXOffset;
    nScrollY = w.pageYOffset;
  }
  else
  if ( IsByDocumentElementPosition( doc))
  {
    nScrollX = doc.documentElement.scrollLeft;
    nScrollY = doc.documentElement.scrollTop;
  }
  else
  if ( IsByBodyPosition( doc))
  {
    nScrollX = doc.body.scrollLeft;
    nScrollY = doc.body.scrollTop;
  }
  return [nScrollX, nScrollY];
}

function FindPosition(obj, bWithScrolling) 
{
  var curleft = 0;
  var curtop = 0;
  if ( obj)
  {
    //if (obj.offsetParent) 
    //{
      curleft = obj.offsetLeft;
      curtop = obj.offsetTop;
      while (obj.offsetParent) 
      {
        obj = obj.offsetParent;
        curleft += obj.offsetLeft;
        curtop += obj.offsetTop;
      }
    //}
  
    if ( bWithScrolling)
    {
      var arScrollPosition = ScrollWindowPosition();
      //alert( 'Scroll X = '+arScrollPosition[0]+' Y = '+arScrollPosition[1]);
      curleft -= arScrollPosition[ 0];
      curtop -= arScrollPosition[ 1];
    }

  }
  return [curleft,curtop];
}

function TopPosition( obj)
{
  var arPos = FindPosition(obj);
  return arPos[1];
}

function DocumentScrollHeight( w)
{
  var doc = null;
  if ( w)
    doc = w.document;
  else
    doc = document;
  /*
  var nHeight = null;
  var bByDocumentElement = IsByDocumentElementPosition();
  var bByBody = IsByBodyPosition();

  if ( bByBody)
  {
    nHeight = doc.body.scrollHeight;
  }

  if ( bByDocumentElement)
  if ( !nHeight)
  {
    nHeight = doc.documentElement.scrollHeight;
  }

  //if ( bByDocumentElement)
  //if ( bByBody)
  //{
  //  ShowBrowserDataInAlert( w);
  //}
  //return nHeight;
  */
  return doc.body.offsetHeight;
}

/*
var g_bFirstAlert = true;
function ShowBrowserDataInAlert( w)
{
  if ( g_bFirstAlert)
  {
    var doc = null;
    if ( w)
      doc = w.document;
    else
    {
      doc = document;
      w = window;
    }
    g_bFirstAlert = false;
    alert( ' document.body.offsetHeight, scrollHeight, clientHeight = '
          +doc.body.offsetHeight
          +', '+doc.body.scrollHeight
          +', '+doc.body.clientHeight
          +"\n"
          +' document.documentElement.offsetHeight, scrollHeight, clientHeight = '
          +doc.documentElement.offsetHeight
          +', '+doc.documentElement.scrollHeight
          +', '+doc.documentElement.clientHeight
          +"\n"
          +' window.innerHeight = '
          +w.innerHeight
          );
  }
}
*/