//======
//======
//
// Template- EVENT_JS.IHT by T.Hughes 31-JUL-2006 /  6-MAR-07
//
// Purpose-
//
//	Generic event handling routines.
//
// Examples-
//
//	// Define the handler.
//	function form_submit_handler() {
//         // do something on form submit
//      }
//	// Define a function to attach the handler to all associated
//	// form elements.
//	function attach_form_submit_handler(form_submit_handler) {
//         Dym.attach_element_event("form","submit",form_submit_handler);
//	}
//	// Setup the function to be called when the page loads.
//	Dym.attachOnloadEvent(attach_form_submit_handler);
//
// Modifications-
//
//	10-AUG-06	TH / BH / TH 	12=18564
//	- Created.
//
//	 6-MAR-07	TH / BH / TH 	17=
//	- Add documentation on demonstrating problem with catching
//	  the return value of handlers added via addEventListener
//	  or AttachEvent in Firefox.
//
//	 6-MAR-07	TH / BH / TH 	17=
//	- Allow functions to be accessed via the dymaxion namespace
//	  rather than using the "dy_" prefix.  Use standard
//	  camelcase for new namespace protected names.
//
//	04-Jul-07	BG / BG / BG	12=18420
//	- Converted to from .iht to .js.
//
//======
//======

/*
   Purpose:
     Attach an event to a given document element.

   Inputs:
     elem
     - The element object
     eventName
     - event name without "on", eg "load", "click"
     eventHandler
     - Name of function to call on event.

   Notes:
      - Supported on staff web minimum versions, except
        IE5 on the Mac (which is a discontinued product).
        Fails silently where not supported.

     - The return value of this event is currently ignored on some browsers
       (eg: Firefox/Opera).  Attach events directly using assignment if
       the return value is desired (for example, when returning false
       to prevent a form submission).
       - To test see xrc_event_js.iht.
	 - The production version uses Dym.attachOnloadEvent to call
	   attach_alertMe_direct, which attaches an onsubmit handler via
	   direct assignment. This correctly short circuits the submit.
	 - If you comment this out and uncomment the call to
	   Dym.attachOnloadEvent that calls attach_alertMe, the
	   submit will not be short circiuted in Firefox (verified
	   at version 1.5).

   Example:
     Dym.attachEvent(window,"load",onLoadEventHandler);
*/

function dy_attach_event(elem, eventName, eventHandler) {
   // W3C DOM2
   if (elem.addEventListener) {
      elem.addEventListener(eventName,eventHandler,false);
   // Internet Explorer
   } else if (elem.attachEvent) {
      elem.attachEvent("on"+eventName,eventHandler);
   }
}
Dym.attachEvent = dy_attach_event;

/*
   Purpose:
     Attach an event event to every element of the specified type
     on the page.
*/
function dy_attach_element_event(elemName, eventName, eventHandler) {
   if (document.getElementsByTagName) {
      allElem = document.getElementsByTagName(elemName);
      if (allElem) {
         for (var i=0; i<allElem.length; i++) {
            dym.attachEvent(allElem[i],eventName,eventHandler);
         }
      }
   }
}
Dym.attachElementEvent = dy_attach_element_event;

/*
   Purpose:
     Attach an event to the page onload handling.
   Notes:
     This ensures the page is fully loaded, and all referenced HTML
     elements exist, before the event is triggered.
*/
function dy_attach_onload_event(eventHandler) {
   Dym.attachEvent(window,"load",eventHandler);
}
Dym.attachOnloadEvent = dy_attach_onload_event;

/*
   Purpose:
      Encapsulated cross browser event and target determination.
*/
function dy_get_event(ev) {
   if (!ev) ev = window.event;
   return ev;
}
Dym.getEvent = dy_get_event;

// Expects an event object such as returned by dym.getEvent()
// Returns the target object that triggered the event.
function dy_get_event_target(ev) {
   var evTarget;

   // Mozilla/Safari.
   if (ev.target) {
      // Safari sometimes returns the text node leaf as the target
      // rather than the enclosing element.
      evTarget = (ev.target.nodeType == 3) ? ev.target.parentNode :
         ev.target;
   // Windows.
   } else if (ev.srcElement) {
      evTarget = ev.srcElement
   }
   return evTarget;
}
Dym.getEventTarget = dy_get_event_target;

// Expects an event object such as returned by dym.getEvent()
function dy_get_event_keycode(ev) {
   var evKeyCode;

   // Internet Explorer
   if (ev.keyCode) {
      evKeyCode = ev.keyCode;
   // Netscape/Firefox/Opera
   } else if (ev.which) {
      evKeyCode = ev.which;
   }
   return evKeyCode;
}
Dym.getEventKeycode = dy_get_event_keycode;