SOURCE CODE: Uize.Tooltip

/*______________
|       ______  |   U I Z E    J A V A S C R I P T    F R A M E W O R K
|     /      /  |   ---------------------------------------------------
|    /    O /   |    MODULE : Uize.Tooltip Package
|   /    / /    |
|  /    / /  /| |    ONLINE : http://uize.com
| /____/ /__/_| | COPYRIGHT : (c)2006-2009 UIZE
|          /___ |   LICENSE : Available under MIT License or GNU General Public License
|_______________|             http://uize.com/license.html
*/

/*ScruncherSettings Mappings="=" LineCompacting="TRUE"*/

/*?
  Introduction
    The =Uize.Tooltip= module manages the display of decorated HTML tooltips that follow the mouse as it moves and that are positioned to always be in view.

    *DEVELOPERS:* `Chris van Rensburg`

    The =Uize.Tooltip= module is a package under the =Uize= namespace.
*/

Uize.module ({
  name:'Uize.Tooltip',
  required:[
    'Uize.Node',
    'Uize.Fade'
  ],
  builder:function () {
    /*** Variables for Scruncher Optimization ***/
      var
        _package = function () {},
        _true = true,
        _false = false,
        _Uize_Node = Uize.Node
      ;

    /*** Global Variables ***/
      var
        _packageGuid = Uize.getGuid (),
        _tooltipNodes = [],
        _shownTooltipNode,
        _tooltipBreatherMargin = 16
      ;

    /*** Tooltip Display Management Functions ***/
      function _updateTooltipPos () {
        _Uize_Node.setAbsPos (_shownTooltipNode,_Uize_Node.getEventAbsPos (),_tooltipBreatherMargin);
      }
      function _setTooltip (_tooltipNode) {
        if (_tooltipNode != _shownTooltipNode) {
          if (_tooltipNode) {
            if (_shownTooltipNode) {
              _fade.stop ();
              _endFade ();
            }
            _Uize_Node.wire (document.body,'scroll',_updateTooltipPos,_packageGuid);
            _Uize_Node.wire (document.documentElement,'mousemove',_updateTooltipPos,_packageGuid);
            _shownTooltipNode = _tooltipNode;
            _Uize_Node.setStyle (
              _shownTooltipNode,
              {position:'absolute',zIndex:5000,left:-50000,top:-50000}
            );
            _Uize_Node.display (_shownTooltipNode);
            _updateTooltipPos ();
          } else {
            _fade.get ('duration') > 0 ? _fade.start () : _endFade ();
          }
        } else if (_tooltipNode) {
          _fade.stop ();
          _Uize_Node.setOpacity (_shownTooltipNode,1);
        }
      }

    /*** Public Static Methods ***/
      _package.showTooltip = function (_tooltipNode,_mustShow) {
        if (
          _tooltipNode = _Uize_Node.getById (typeof _tooltipNode == 'function' ? _tooltipNode () : _tooltipNode)
        ) {
          if (_mustShow !== _false) {
            _tooltipNodes.push (_tooltipNode);
          } else {
            var _tooltipNodeNo = Uize.indexIn (_tooltipNodes,_tooltipNode,_true);
            _tooltipNodeNo > -1 && _tooltipNodes.splice (_tooltipNodeNo,1);
          }
          _setTooltip (_tooltipNodes [_tooltipNodes.length - 1]);
        }
      };

      _package.hideTooltip = function (_tooltip) {_package.showTooltip (_tooltip,_false)};

    /*** Fadeout Management ***/
      var _fade = _package.fade = new Uize.Fade ({duration:0});
      function _endFade () {
        _Uize_Node.unwireEventsByOwnerId (_packageGuid);
        _Uize_Node.display (_shownTooltipNode,_false);
        _Uize_Node.setOpacity (_shownTooltipNode,1);
        _shownTooltipNode = null;
      }
      _fade.wire ({
        'Changed.value':function () {_Uize_Node.setOpacity (_shownTooltipNode,1 - _fade.get ('progress'))},
        Done:_endFade
      });

    return _package;
  }
});