// ==UserScript==
// @name          MsgPreview
// @author        Joshua Heyer
// @namespace  http://shog9.com/greasemonkey/scripts/
// @description   Show preview "tooltips" for messages
// @version        0.1.0
// @include       http://*.codeproject.com/*
// @include       http://*.codetools.com/*
// @include       http://*.thecodeproject.com/*
// @include       http://codeproject.com/*
// @include       http://codetools.com/*
// @include       http://thecodeproject.com/*
// ==/UserScript==

var pane = null;
var msgHeaders = XPathNodes(document, "//tr[substring-before(@id, '_h0')]", false);
for (var i=0; i<msgHeaders.snapshotLength; ++i)
{
   var header = msgHeaders.snapshotItem(i);
   header.addEventListener('mouseover', ShowMessagePreview, false);
   header.addEventListener('mouseout', HideMessagePreview, false);
}

function ShowMessagePreview()
{
   if ( pane && pane.source == this )
      return;
   HideMessagePreview();
   pane = CreateMessagePreview(this);
   pane.source = this;
   var opacity = 0.0;
   var ani = window.setInterval(function() 
      {
         opacity += 0.5;
          if ( opacity >= 1.0 )
            window.clearInterval(ani);
         if ( pane )
            pane.style.MozOpacity = opacity;
      }, 100);
}

function HideMessagePreview(e)
{
   if ( (!e || !isDescendant(e.relatedTarget, this)) && pane)
   {
      pane.parentNode.removeChild(pane);
      pane = null; 
   }
}

function CreateMessagePreview(header)
{
   var pane = document.createElement("DIV");
   pane.style.left = "0px";
   pane.style.top = "0px";
   pane.style.width = Math.min(document.body.clientWidth, header.offsetWidth) + "px";
   pane.style.border = "1px solid orange";
   pane.style.position = "absolute";
   pane.style.zIndex = 2;
   pane.style.textAlign = "left";
   pane.style.padding = "2px";
   pane.style.MozOpacity = 0;
   pane.innerHTML = '<div style="position:relative;cursor:default;max-height:2.3em;line-height:1.125em;overflow:hidden;">'
      +GetMessageText(header.id.substring(0,header.id.length-3))
      +'   <div style="position:absolute;top:0px;left:0px;width:100%;height:100%;background:orange;-moz-opacity:0.6;z-index:-1"></div>'
      +'</div>'
      +'<div style="background-color:white; -moz-opacity:0.7; width:100%; height:100%; position:absolute; top:0px; left:0px; z-index:-1;"></div>';
   document.body.appendChild(pane);
   
   var left = getRealPos(header, "Left") - (pane.offsetWidth-header.offsetWidth)/2;
   var top = getRealPos(header, "Top") + header.offsetHeight;
   var minLeft = document.body.scrollLeft;
   var minTop = document.body.scrollTop;
   var maxLeft = minLeft + document.body.clientWidth - pane.offsetWidth;
   var maxTop = minTop + document.body.clientHeight - pane.offsetHeight;
   if ( left < minLeft )
      left = minLeft;
   if ( left > maxLeft )
      left = maxLeft;
   if ( top < minTop )
      top = minTop;
   if ( top > maxTop )
      top = maxTop;
   pane.style.left = left + "px";
   pane.style.top = top + "px";
   return pane;
}

function GetMessageText(id)
{
   var content = XPathNode(document, "//tr[@id='"+id+"_h1']/td/table/tbody/tr/td[2]/table/tbody/tr/td/table/tbody/tr/td");
   var range = document.createRange();
   range.selectNodeContents(content);

   var selection = window.getSelection();
   selection.removeAllRanges();
   selection.addRange(range);
   var text = selection.toString();
   selection.removeAllRanges();

   return text;
}

function isDescendant(el, par)
{
   if ( !el || !par )
      return false;
   if ( el == par )
      return true;
   return isDescendant(el.parentNode, par);
}

function XPathNode(el, xpath)
{
   var result = document.evaluate(xpath, el, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
   return (result && result.singleNodeValue ? result.singleNodeValue : null);
}

function XPathNodes(el, xpath, ordered)
{
   return document.evaluate(xpath, el, null,
      (ordered ? XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE : XPathResult.ORDERED_NODE_SNAPSHOT_TYPE),
      null);
}

function getRealPos(i,which) 
{
   iPos = 0
   while (i!=null) 
   {
      iPos += i["offset" + which];
      i = i.offsetParent;
   }
   return iPos
}