class DomImplStandard extends DomImpl {

 Map<dart_html.Element, EventListener> _listener = new Map<dart_html.Element, EventListener>();

 DomImplStandard();

 dart_html.Element captureElem;

 static Function dispatchCapturedEvent;

 static Function dispatchCapturedMouseEvent;

 static Function dispatchDragEvent;

 static Function dispatchEvent;

 static Function dispatchUnhandledEvent;

 //*************************
 // Parent - child relations
 //*************************

 bool isOrHasChild(dart_html.Node parent, dart_html.Node child) {
   return parent.contains(child);
 }

 void insertChild(dart_html.Element parent, dart_html.Element toAdd, int index) {
   int count = 0;
   dart_html.Node child = parent.firstChild;
   dart_html.Node before;
   while (child != null) {
     if (child.nodeType == 1) { // dart_html.Node.ELEMENT_NODE
       if (count == index) {
         before = child;
         break;
       }
       ++count;
     }
     child = child.nextNode; //nextSibling;
   }

   if (before == null) {
     parent.append(toAdd);
   } else {
     parent.insertBefore(toAdd, before);
   }
 }

 dart_html.Element getChild(dart_html.Element elem, int index) {
   int count = 0;
   dart_html.Element child = elem.firstChild;
   while (child != null) {
     if (child.nodeType == 1) {
       if (index == count)
         return child;
       ++count;
     }
     child = child.nextElementSibling;
   }

   return null;
 }

 int getChildCount(dart_html.Element elem) {
   int count = 0;
   dart_html.Node child = elem.firstChild;
   while (child != null) {
     if (child.nodeType == 1) ++count;
     if (child is dart_html.Element) {
       child = (child as dart_html.Element).nextElementSibling;
     } else {
       child = child.nextNode;
     }
   }
   return count;
 }

 //********************
 // Position of Element
 //********************

 int getAbsoluteLeft(dart_html.Element elem) {
   var left = 0;
   dart_html.Element curr = elem;
   // This intentionally excludes body which has a null offsetParent.
   while (curr.offsetParent != null) {
     left -= curr.scrollLeft;
     curr = curr.parent;
   }
   while (elem != null) {
     left += elem.offset.left;
     elem = elem.offsetParent;
   }
   return left;
 }

 int getAbsoluteTop(dart_html.Element elem) {
   var top = 0;
   dart_html.Element curr = elem;
   // This intentionally excludes body which has a null offsetParent.
   while (curr.offsetParent != null) {
     top -= curr.scrollTop;
     curr = curr.parentNode;
   }
   while (elem != null) {
     top += elem.offset.top;
     elem = elem.offsetParent;
   }
   return top;
 }

 //*********
 // Capturte
 //*********

 void releaseCapture(dart_html.Element elem) {
   maybeInitializeEventSystem();
   _releaseCaptureImpl(elem);
 }

 void _releaseCaptureImpl(dart_html.Element elem) {
   if (elem == captureElem) {
     captureElem = null;
   }
 }

 void setCapture(dart_html.Element elem) {
   maybeInitializeEventSystem();
   _setCaptureImpl(elem);
 }

 void _setCaptureImpl(dart_html.Element elem) {
   captureElem = elem;
 }

 //******
 // Style
 //******
 
 String getStyleProperty(dart_html.Element elem, String name) {
   dart_html.CssStyleDeclaration style = elem.style;
   return style.getPropertyValue(name); 
 }
 
 void setStyleProperty(dart_html.Element elem, String name, String value) {
   dart_html.CssStyleDeclaration style = elem.style;
   style.setProperty(name, value, "");
 }
 
 //*******
 // Events
 //*******

 /**
  * Initializes the event dispatch system.
  */
 void initEventSystem() {
   dispatchCapturedEvent = (dart_html.Event evt) {
     if (!Dom.previewEvent(evt)) {
       evt.stopPropagation();
       evt.preventDefault();
       return false;
     }
     return true;
   };

   dispatchEvent = (dart_html.Event event) {
     EventListener listener;
     dart_html.Node curElem = event.currentTarget as dart_html.Node;

     while (curElem != null && (listener = _listener[curElem]) == null) {
       curElem = curElem.parentNode;
     }

     if (curElem != null && curElem.nodeType != 1) { // dart_html.Node.ELEMENT_NODE
       curElem = null;
     }

     if (listener != null) {
       Dom.dispatchEvent(event, curElem, listener);
     }
   };

   // Some drag events must call preventDefault to prevent native text selection.
   dispatchDragEvent = (dart_html.Event evt) {
     evt.preventDefault();
     dispatchEvent(evt);
   };

   dispatchUnhandledEvent = (dart_html.Event evt) {
     if (evt.target is dart_html.ImageElement) {
       (evt.target as dart_html.ImageElement).dataset[DomImpl.UNHANDLED_EVENT_ATTR] = evt.type;
     }
     dispatchEvent(evt);
   };

   dispatchCapturedMouseEvent = (dart_html.Event evt) {
     Function dispatchCapturedEventFn = dispatchCapturedEvent;
     if (dispatchCapturedEventFn(evt)) {
       dart_html.Element cap = captureElem;
       if (cap != null && _listener[cap] != null) {
         Dom.dispatchEvent(evt, cap, _listener[cap]);
         evt.stopPropagation();
       }
     }
   };

   //dart_html.window.onClick.listen(dispatchCapturedMouseEvent, true);
   dart_html.Element.clickEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.doubleClickEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.mouseDownEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.mouseUpEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.mouseMoveEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.mouseOverEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.mouseOutEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.mouseWheelEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.keyDownEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedEvent);
   dart_html.Element.keyUpEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedEvent);
   dart_html.Element.keyPressEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedEvent);

   // Touch and gesture events are not actually mouse events, but we treat
   // them as such, so that DOM#setCapture() and DOM#releaseCapture() work.
   dart_html.Element.touchStartEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.touchMoveEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.touchEndEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
   dart_html.Element.touchCancelEvent.forTarget(dart_html.window, useCapture:true).listen(dispatchCapturedMouseEvent);
//    dart_html.window.on.gesturestart.add(dispatchCapturedMouseEvent, true);
//    dart_html.window.on.gesturechange.add(dispatchCapturedMouseEvent, true);
//    dart_html.window.on.gesturechange.add(dispatchCapturedMouseEvent, true);
 }

 EventListener getEventListener(dart_html.Element elem) {
   //return elem.__listener;
   return _listener.containsKey(elem) ? _listener[elem] : null;
 }
 void setEventListener(dart_html.Element elem, EventListener listener) {
   //elem.__listener = listener;
   _listener[elem] = listener;
 }

 void sinkBitlessEvent(dart_html.Element elem, String eventTypeName) {
   maybeInitializeEventSystem();
   _sinkBitlessEventImpl(elem, eventTypeName);
 }

 void _sinkBitlessEventImpl(dart_html.Element elem, String eventTypeName) {
   switch(eventTypeName) {
     case "drag": elem.onDrag.listen(dispatchEvent); break;
     case "dragend": elem.onDragEnd.listen(dispatchEvent); break;
     case "dragleave": elem.onDragLeave.listen(dispatchEvent); break;
     case "dragstart": elem.onDragStart.listen(dispatchEvent); break;
     case "drop": elem.onDrop.listen(dispatchEvent); break;

     case "dragenter": elem.onDragEnter.listen(dispatchDragEvent); break;
     case "dragover": elem.onDragOver.listen(dispatchDragEvent); break;

     case "canplaythrough": dart_html.MediaElement.canPlayThroughEvent.forTarget(elem).listen(dispatchEvent); break;
     case "ended": dart_html.MediaElement.endedEvent.forTarget(elem).listen(dispatchEvent); break;
     case "progress": dart_html.MediaElement.progressEvent.forTarget(elem).listen(dispatchEvent); break;
       // First call removeEventListener, so as not to add the same event listener more than once
//        elem.on[eventTypeName].remove(dispatchEvent);
//        elem.on[eventTypeName].add(dispatchEvent);
//        break;
     default:
       // catch missing cases
       throw new Exception("Trying to sink unknown event type $eventTypeName");
   }
 }

 void sinkEvents(dart_html.Element elem, int bits) {
   maybeInitializeEventSystem();
   sinkEventsImpl(elem, bits);
 }

 Map<String, dart_async.StreamSubscription> _subscription = new Map<String, dart_async.StreamSubscription>();

 void sinkEventsImpl(dart_html.Element elem, int bits) {
   int chMask = _getEventBits(elem) ^ bits;
   if (chMask == 0) {
     return;
   }
   _setEventBits(elem, chMask);
   //
   _applyDispatcher(elem, dart_html.Element.clickEvent,  bits, chMask, "click",   0x00001, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.doubleClickEvent, bits, chMask, "dblclick", 0x00002, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.mouseDownEvent, bits, chMask, "mousedown", 0x00004, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.mouseUpEvent, bits, chMask, "mouseup", 0x00008, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.mouseOverEvent, bits, chMask, "mouseover", 0x00010, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.mouseOutEvent, bits, chMask, "mouseout", 0x00020, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.mouseMoveEvent, bits, chMask, "mousemove", 0x00040, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.keyDownEvent, bits, chMask, "keydown", 0x00080, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.keyPressEvent, bits, chMask, "keypress", 0x00100, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.keyUpEvent, bits, chMask, "keyup", 0x00200, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.changeEvent, bits, chMask, "change", 0x00400, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.focusEvent, bits, chMask, "focus", 0x00800, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.blurEvent, bits, chMask, "blur", 0x01000, dispatchEvent);
   //_applyDispatcher(elem, bits, chMask, "losecapture", 0x02000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.scrollEvent, bits, chMask, "scroll", 0x04000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.loadEvent, bits, chMask, "load", 0x08000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.errorEvent, bits, chMask, "error", 0x10000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.mouseWheelEvent, bits, chMask, "mousewheel", 0x20000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.contextMenuEvent, bits, chMask, "contextmenu", 0x40000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.pasteEvent, bits, chMask, "paste", 0x80000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.touchStartEvent, bits, chMask, "touchstart", 0x100000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.touchMoveEvent, bits, chMask, "touchmove", 0x200000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.touchEndEvent, bits, chMask, "touchend", 0x400000, dispatchEvent);
   _applyDispatcher(elem, dart_html.Element.touchCancelEvent, bits, chMask, "touchcancel", 0x800000, dispatchEvent);
//    _applyDispatcher(elem, bits, chMask, "gesturestart", 0x1000000, dispatchEvent);
//    _applyDispatcher(elem, bits, chMask, "gesturechange", 0x2000000, dispatchEvent);
//    _applyDispatcher(elem, bits, chMask, "gestureend", 0x4000000, dispatchEvent);
 }

 void _applyDispatcher(dart_html.Element elem, dart_html.EventStreamProvider provider, int bits, int chMask, String eventName, int mask, dart_html.EventListener handler, [bool useCapture = false]) {
   if ((chMask & 0x00001) != 0) {
     if ((bits & 0x00001) != 0) {
       _subscription["click"] = provider.forTarget(elem, useCapture:useCapture).listen(dispatchEvent);
     } else {
       _subscription["click"].cancel();
     }
   }

 }

 dart_html.Element eventGetToElement(dart_html.Event evt) {
   if (evt.type == BrowserEvents.MOUSEOVER) {
     return evt.target as dart_html.Element;
   }

   if (evt.type == BrowserEvents.MOUSEOUT) {
     return (evt as dart_html.MouseEvent).relatedTarget as dart_html.Element;
   }

   return null;
 }

 dart_html.Event createHtmlEvent(String type, bool canBubble, bool cancelable) {
//    dart_html.CustomEvent evt = new dart_html.CustomEvent('HTMLEvents');
//    evt.$dom_initCustomEvent(type, canBubble, cancelable, null);
//    return evt;
   return new dart_html.CustomEvent('HTMLEvents', 
       canBubble:canBubble, cancelable:cancelable, detail:null);
 }
}