dojo.provide("dojo.window");

dojo.window.getBox = function(){
	// summary:
	//		Returns the dimensions and scroll position of the viewable area of a browser window

	var scrollRoot = (dojo.doc.compatMode == 'BackCompat') ? dojo.body() : dojo.doc.documentElement;

	// get scroll position
	var scroll = dojo._docScroll(); // scrollRoot.scrollTop/Left should work
	return { w: scrollRoot.clientWidth, h: scrollRoot.clientHeight, l: scroll.x, t: scroll.y };
};

dojo.window.get = function(doc){
	// summary:
	// 		Get window object associated with document doc

	// In some IE versions (at least 6.0), document.parentWindow does not return a
	// reference to the real window object (maybe a copy), so we must fix it as well
	// We use IE specific execScript to attach the real window reference to
	// document._parentWindow for later use
	if(dojo.isIE && window !== document.parentWindow){
		/*
		In IE 6, only the variable "window" can be used to connect events (others
		may be only copies).
		*/
		doc.parentWindow.execScript("document._parentWindow = window;", "Javascript");
		//to prevent memory leak, unset it after use
		//another possibility is to add an onUnload handler which seems overkill to me (liucougar)
		var win = doc._parentWindow;
		doc._parentWindow = null;
		return win;	//	Window
	}

	return doc.parentWindow || doc.defaultView;	//	Window
};

dojo.window.scrollIntoView = function(/*DomNode*/ node, /*Object?*/ pos){
	// summary:
	//		Scroll the passed node into view, if it is not already.
	
	// don't rely on node.scrollIntoView working just because the function is there

	try{ // catch unexpected/unrecreatable errors (#7808) since we can recover using a semi-acceptable native method
		node = dojo.byId(node);
		var doc = node.ownerDocument || dojo.doc,
			body = doc.body || dojo.body(),
			html = doc.documentElement || body.parentNode,
			isIE = dojo.isIE, isWK = dojo.isWebKit;
		// if an untested browser, then use the native method
		if((!(dojo.isMoz || isIE || isWK || dojo.isOpera) || node == body || node == html) && (typeof node.scrollIntoView != "undefined")){
			node.scrollIntoView(false); // short-circuit to native if possible
			return;
		}
		var backCompat = doc.compatMode == 'BackCompat',
			clientAreaRoot = backCompat? body : html,
			scrollRoot = isWK ? body : clientAreaRoot,
			rootWidth = clientAreaRoot.clientWidth,
			rootHeight = clientAreaRoot.clientHeight,
			rtl = !dojo._isBodyLtr(),
			nodePos = pos || dojo.position(node),
			el = node.parentNode,
			isFixed = function(el){
				return ((isIE <= 6 || (isIE && backCompat))? false : (dojo.style(el, 'position').toLowerCase() == "fixed"));
			};
		if(isFixed(node)){ return; } // nothing to do

		while(el){
			if(el == body){ el = scrollRoot; }
			var elPos = dojo.position(el),
				fixedPos = isFixed(el);
	
			if(el == scrollRoot){
				elPos.w = rootWidth; elPos.h = rootHeight;
				if(scrollRoot == html && isIE && rtl){ elPos.x += scrollRoot.offsetWidth-elPos.w; } // IE workaround where scrollbar causes negative x
				if(elPos.x < 0 || !isIE){ elPos.x = 0; } // IE can have values > 0
				if(elPos.y < 0 || !isIE){ elPos.y = 0; }
			}else{
				var pb = dojo._getPadBorderExtents(el);
				elPos.w -= pb.w; elPos.h -= pb.h; elPos.x += pb.l; elPos.y += pb.t;
			}
	
			if(el != scrollRoot){ // body, html sizes already have the scrollbar removed
				var clientSize = el.clientWidth,
					scrollBarSize = elPos.w - clientSize;
				if(clientSize > 0 && scrollBarSize > 0){
					elPos.w = clientSize;
					if(isIE && rtl){ elPos.x += scrollBarSize; }
				}
				clientSize = el.clientHeight;
				scrollBarSize = elPos.h - clientSize;
				if(clientSize > 0 && scrollBarSize > 0){
					elPos.h = clientSize;
				}
			}
			if(fixedPos){ // bounded by viewport, not parents
				if(elPos.y < 0){
					elPos.h += elPos.y; elPos.y = 0;
				}
				if(elPos.x < 0){
					elPos.w += elPos.x; elPos.x = 0;
				}
				if(elPos.y + elPos.h > rootHeight){
					elPos.h = rootHeight - elPos.y;
				}
				if(elPos.x + elPos.w > rootWidth){
					elPos.w = rootWidth - elPos.x;
				}
			}
			// calculate overflow in all 4 directions
			var l = nodePos.x - elPos.x, // beyond left: < 0
				t = nodePos.y - Math.max(elPos.y, 0), // beyond top: < 0
				r = l + nodePos.w - elPos.w, // beyond right: > 0
				bot = t + nodePos.h - elPos.h; // beyond bottom: > 0
			if(r * l > 0){
				var s = Math[l < 0? "max" : "min"](l, r);
				nodePos.x += el.scrollLeft;
				el.scrollLeft += (isIE >= 8 && !backCompat && rtl)? -s : s;
				nodePos.x -= el.scrollLeft;
			}
			if(bot * t > 0){
				nodePos.y += el.scrollTop;
				el.scrollTop += Math[t < 0? "max" : "min"](t, bot);
				nodePos.y -= el.scrollTop;
			}
			el = (el != scrollRoot) && !fixedPos && el.parentNode;
		}	
	}catch(error){
		console.error('scrollIntoView: ' + error);
		node.scrollIntoView(false);
	}
};
