if (!dojo._hasResource['dojox.grid._grid.scroller']) { // _hasResource checks
														// added by build. Do
														// not use _hasResource
														// directly in your
														// code.
	dojo._hasResource['dojox.grid._grid.scroller'] = true;
	dojo.provide('dojox.grid._grid.scroller');

	dojo.declare('dojox.grid.scroller.base', null, {
		// summary:
		// virtual scrollbox, abstract class
		// Content must in /rows/
		// Rows are managed in contiguous sets called /pages/
		// There are a fixed # of rows per page
		// The minimum rendered unit is a page
		constructor : function() {
			this.pageHeights = [];
			this.stack = [];
		},
		// specified
		rowCount : 0, // total number of rows to manage
		defaultRowHeight : 10, // default height of a row
		keepRows : 100, // maximum number of rows that should exist at one time
		contentNode : null, // node to contain pages
		scrollboxNode : null, // node that controls scrolling
		// calculated
		defaultPageHeight : 0, // default height of a page
		keepPages : 10, // maximum number of pages that should exists at one
						// time
		pageCount : 0,
		windowHeight : 0,
		firstVisibleRow : 0,
		lastVisibleRow : 0,
		// private
		page : 0,
		pageTop : 0,
		// init
		init : function(inRowCount, inKeepRows, inRowsPerPage) {
			switch (arguments.length) {
				case 3 :
					this.rowsPerPage = inRowsPerPage;
				case 2 :
					this.keepRows = inKeepRows;
				case 1 :
					this.rowCount = inRowCount;
			}
			this.defaultPageHeight = this.defaultRowHeight * this.rowsPerPage;
			// this.defaultPageHeight = this.defaultRowHeight *
			// Math.min(this.rowsPerPage, this.rowCount);
			this.pageCount = Math.ceil(this.rowCount / this.rowsPerPage);
			this.keepPages = Math.max(Math.ceil(this.keepRows
							/ this.rowsPerPage), 2);
			this.invalidate();
			if (this.scrollboxNode) {
				this.scrollboxNode.scrollTop = 0;
				this.scroll(0);
				this.scrollboxNode.onscroll = dojo.hitch(this, 'onscroll');
			}
		},
		// updating
		invalidate : function() {
			this.invalidateNodes();
			this.pageHeights = [];
			this.height = (this.pageCount ? (this.pageCount - 1)
					* this.defaultPageHeight + this.calcLastPageHeight() : 0);
			this.resize();
		},
		updateRowCount : function(inRowCount) {
			this.invalidateNodes();
			this.rowCount = inRowCount;
			// update page count, adjust document height
			oldPageCount = this.pageCount;
			this.pageCount = Math.ceil(this.rowCount / this.rowsPerPage);
			if (this.pageCount < oldPageCount) {
				for (var i = oldPageCount - 1; i >= this.pageCount; i--) {
					this.height -= this.getPageHeight(i);
					delete this.pageHeights[i]
				}
			} else if (this.pageCount > oldPageCount) {
				this.height += this.defaultPageHeight
						* (this.pageCount - oldPageCount - 1)
						+ this.calcLastPageHeight();
			}
			this.resize();
		},
		// abstract interface
		pageExists : function(inPageIndex) {
		},
		measurePage : function(inPageIndex) {
		},
		positionPage : function(inPageIndex, inPos) {
		},
		repositionPages : function(inPageIndex) {
		},
		installPage : function(inPageIndex) {
		},
		preparePage : function(inPageIndex, inPos, inReuseNode) {
		},
		renderPage : function(inPageIndex) {
		},
		removePage : function(inPageIndex) {
		},
		pacify : function(inShouldPacify) {
		},
		// pacification
		pacifying : false,
		pacifyTicks : 200,
		setPacifying : function(inPacifying) {
			if (this.pacifying != inPacifying) {
				this.pacifying = inPacifying;
				this.pacify(this.pacifying);
			}
		},
		startPacify : function() {
			this.startPacifyTicks = allGetServerTime().getTime();
		},
		doPacify : function() {
			var result = (allGetServerTime().getTime() - this.startPacifyTicks) > this.pacifyTicks;
			this.setPacifying(true);
			this.startPacify();
			return result;
		},
		endPacify : function() {
			this.setPacifying(false);
		},
		// default sizing implementation
		resize : function() {
			if (this.scrollboxNode) {
				this.windowHeight = this.scrollboxNode.clientHeight;
			}
			dojox.grid.setStyleHeightPx(this.contentNode, this.height);
		},
		calcLastPageHeight : function() {
			if (!this.pageCount) {
				return 0;
			}
			var lastPage = this.pageCount - 1;
			var lastPageHeight = ((this.rowCount % this.rowsPerPage) || (this.rowsPerPage))
					* this.defaultRowHeight;
			this.pageHeights[lastPage] = lastPageHeight;
			return lastPageHeight;
		},
		updateContentHeight : function(inDh) {
			this.height += inDh;
			this.resize();
		},
		updatePageHeight : function(inPageIndex) {
			if (this.pageExists(inPageIndex)) {
				var oh = this.getPageHeight(inPageIndex);
				var h = (this.measurePage(inPageIndex)) || (oh);
				this.pageHeights[inPageIndex] = h;
				if ((h) && (oh != h)) {
					this.updateContentHeight(h - oh)
					this.repositionPages(inPageIndex);
				}
			}
		},
		rowHeightChanged : function(inRowIndex) {
			this.updatePageHeight(Math.floor(inRowIndex / this.rowsPerPage));
		},
		// scroller core
		invalidateNodes : function() {
			while (this.stack.length) {
				this.destroyPage(this.popPage());
			}
		},
		createPageNode : function() {
			var p = document.createElement('div');
			p.style.position = 'absolute';
			// p.style.width = '100%';
			p.style.left = '0';
			return p;
		},
		getPageHeight : function(inPageIndex) {
			var ph = this.pageHeights[inPageIndex];
			return (ph !== undefined ? ph : this.defaultPageHeight);
		},
		// FIXME: this is not a stack, it's a FIFO list
		pushPage : function(inPageIndex) {
			return this.stack.push(inPageIndex);
		},
		popPage : function() {
			return this.stack.shift();
		},
		findPage : function(inTop) {
			var i = 0, h = 0;
			for (var ph = 0; i < this.pageCount; i++, h += ph) {
				ph = this.getPageHeight(i);
				if (h + ph >= inTop) {
					break;
				}
			}
			this.page = i;
			this.pageTop = h;
		},
		buildPage : function(inPageIndex, inReuseNode, inPos) {
			this.preparePage(inPageIndex, inReuseNode);
			this.positionPage(inPageIndex, inPos);
			// order of operations is key below
			this.installPage(inPageIndex);
			this.renderPage(inPageIndex);
			// order of operations is key above
			this.pushPage(inPageIndex);
		},
		needPage : function(inPageIndex, inPos) {
			var h = this.getPageHeight(inPageIndex), oh = h;
			if (!this.pageExists(inPageIndex)) {
				this
						.buildPage(
								inPageIndex,
								(this.keepPages)
										&& (this.stack.length >= this.keepPages),
								inPos);
				h = this.measurePage(inPageIndex) || h;
				this.pageHeights[inPageIndex] = h;
				if (h && (oh != h)) {
					this.updateContentHeight(h - oh)
				}
			} else {
				this.positionPage(inPageIndex, inPos);
			}
			return h;
		},
		onscroll : function() {
			this.scroll(this.scrollboxNode.scrollTop);
		},
		scroll : function(inTop) {
			this.startPacify();
			this.findPage(inTop);
			var h = this.height;
			var b = this.getScrollBottom(inTop);
			for (var p = this.page, y = this.pageTop; (p < this.pageCount)
					&& ((b < 0) || (y < b)); p++) {
				y += this.needPage(p, y);
			}
			this.firstVisibleRow = this.getFirstVisibleRow(this.page,
					this.pageTop, inTop);
			this.lastVisibleRow = this.getLastVisibleRow(p - 1, y, b);
			// indicates some page size has been updated
			if (h != this.height) {
				this.repositionPages(p - 1);
			}
			this.endPacify();
		},
		getScrollBottom : function(inTop) {
			return (this.windowHeight >= 0 ? inTop + this.windowHeight : -1);
		},
		// events
		processNodeEvent : function(e, inNode) {
			var t = e.target;
			while (t && (t != inNode) && t.parentNode
					&& (t.parentNode.parentNode != inNode)) {
				t = t.parentNode;
			}
			if (!t || !t.parentNode || (t.parentNode.parentNode != inNode)) {
				return false;
			}
			var page = t.parentNode;
			e.topRowIndex = page.pageIndex * this.rowsPerPage;
			e.rowIndex = e.topRowIndex + dojox.grid.indexInParent(t);
			e.rowTarget = t;
			return true;
		},
		processEvent : function(e) {
			return this.processNodeEvent(e, this.contentNode);
		},
		dummy : 0
	});

	dojo.declare('dojox.grid.scroller', dojox.grid.scroller.base, {
		// summary:
		// virtual scroller class, makes no assumption about shape of items
		// being scrolled
		constructor : function() {
			this.pageNodes = [];
		},
		// virtual rendering interface
		renderRow : function(inRowIndex, inPageNode) {
		},
		removeRow : function(inRowIndex) {
		},
		// page node operations
		getDefaultNodes : function() {
			return this.pageNodes;
		},
		getDefaultPageNode : function(inPageIndex) {
			return this.getDefaultNodes()[inPageIndex];
		},
		positionPageNode : function(inNode, inPos) {
			inNode.style.top = inPos + 'px';
		},
		getPageNodePosition : function(inNode) {
			return inNode.offsetTop;
		},
		repositionPageNodes : function(inPageIndex, inNodes) {
			var last = 0;
			for (var i = 0; i < this.stack.length; i++) {
				last = Math.max(this.stack[i], last);
			}
			//
			var n = inNodes[inPageIndex];
			var y = (n ? this.getPageNodePosition(n)
					+ this.getPageHeight(inPageIndex) : 0);
			// console.log('detected height change, repositioning from #%d (%d)
			// @ %d ', inPageIndex + 1, last, y, this.pageHeights[0]);
			//
			for (var p = inPageIndex + 1; p <= last; p++) {
				n = inNodes[p];
				if (n) {
					// console.log('#%d @ %d', inPageIndex, y,
					// this.getPageNodePosition(n));
					if (this.getPageNodePosition(n) == y) {
						return;
					}
					// console.log('placing page %d at %d', p, y);
					this.positionPage(p, y);
				}
				y += this.getPageHeight(p);
			}
		},
		invalidatePageNode : function(inPageIndex, inNodes) {
			var p = inNodes[inPageIndex];
			if (p) {
				delete inNodes[inPageIndex];
				this.removePage(inPageIndex, p);
				dojox.grid.cleanNode(p);
				p.innerHTML = '';
			}
			return p;
		},
		preparePageNode : function(inPageIndex, inReusePageIndex, inNodes) {
			var p = (inReusePageIndex === null ? this.createPageNode() : this
					.invalidatePageNode(inReusePageIndex, inNodes));
			p.pageIndex = inPageIndex;
			p.id = 'page-' + inPageIndex;
			inNodes[inPageIndex] = p;
		},
		// implementation for page manager
		pageExists : function(inPageIndex) {
			return Boolean(this.getDefaultPageNode(inPageIndex));
		},
		measurePage : function(inPageIndex) {
			return this.getDefaultPageNode(inPageIndex).offsetHeight;
		},
		positionPage : function(inPageIndex, inPos) {
			this.positionPageNode(this.getDefaultPageNode(inPageIndex), inPos);
		},
		repositionPages : function(inPageIndex) {
			this.repositionPageNodes(inPageIndex, this.getDefaultNodes());
		},
		preparePage : function(inPageIndex, inReuseNode) {
			this.preparePageNode(inPageIndex, (inReuseNode
							? this.popPage()
							: null), this.getDefaultNodes());
		},
		installPage : function(inPageIndex) {
			this.contentNode.appendChild(this.getDefaultPageNode(inPageIndex));
		},
		destroyPage : function(inPageIndex) {
			var p = this
					.invalidatePageNode(inPageIndex, this.getDefaultNodes());
			dojox.grid.removeNode(p);
		},
		// rendering implementation
		renderPage : function(inPageIndex) {
			var node = this.pageNodes[inPageIndex];
			for (var i = 0, j = inPageIndex * this.rowsPerPage; (i < this.rowsPerPage)
					&& (j < this.rowCount); i++, j++) {
				this.renderRow(j, node);
			}
		},
		removePage : function(inPageIndex) {
			for (var i = 0, j = inPageIndex * this.rowsPerPage; i < this.rowsPerPage; i++, j++) {
				this.removeRow(j);
			}
		},
		// scroll control
		getPageRow : function(inPage) {
			return inPage * this.rowsPerPage;
		},
		getLastPageRow : function(inPage) {
			return Math.min(this.rowCount, this.getPageRow(inPage + 1)) - 1;
		},
		getFirstVisibleRowNodes : function(inPage, inPageTop, inScrollTop,
				inNodes) {
			var row = this.getPageRow(inPage);
			var rows = dojox.grid.divkids(inNodes[inPage]);
			for (var i = 0, l = rows.length; i < l && inPageTop < inScrollTop; i++, row++) {
				inPageTop += rows[i].offsetHeight;
			}
			return (row ? row - 1 : row);
		},
		getFirstVisibleRow : function(inPage, inPageTop, inScrollTop) {
			if (!this.pageExists(inPage)) {
				return 0;
			}
			return this.getFirstVisibleRowNodes(inPage, inPageTop, inScrollTop,
					this.getDefaultNodes());
		},
		getLastVisibleRowNodes : function(inPage, inBottom, inScrollBottom,
				inNodes) {
			var row = this.getLastPageRow(inPage);
			var rows = dojox.grid.divkids(inNodes[inPage]);
			for (var i = rows.length - 1; i >= 0 && inBottom > inScrollBottom; i--, row--) {
				inBottom -= rows[i].offsetHeight;
			}
			return row + 1;
		},
		getLastVisibleRow : function(inPage, inBottom, inScrollBottom) {
			if (!this.pageExists(inPage)) {
				return 0;
			}
			return this.getLastVisibleRowNodes(inPage, inBottom,
					inScrollBottom, this.getDefaultNodes());
		},
		findTopRowForNodes : function(inScrollTop, inNodes) {
			var rows = dojox.grid.divkids(inNodes[this.page]);
			for (var i = 0, l = rows.length, t = this.pageTop, h; i < l; i++) {
				h = rows[i].offsetHeight;
				t += h;
				if (t >= inScrollTop) {
					this.offset = h - (t - inScrollTop);
					return i + this.page * this.rowsPerPage;
				}
			}
			return -1;
		},
		findScrollTopForNodes : function(inRow, inNodes) {
			var rowPage = Math.floor(inRow / this.rowsPerPage);
			var t = 0;
			for (var i = 0; i < rowPage; i++) {
				t += this.getPageHeight(i);
			}
			this.pageTop = t;
			this.needPage(rowPage, this.pageTop);
			var rows = dojox.grid.divkids(inNodes[rowPage]);
			var r = inRow - this.rowsPerPage * rowPage;
			for (var i = 0, l = rows.length; i < l && i < r; i++) {
				t += rows[i].offsetHeight;
			}
			return t;
		},
		findTopRow : function(inScrollTop) {
			return this.findTopRowForNodes(inScrollTop, this.getDefaultNodes());
		},
		findScrollTop : function(inRow) {
			return this.findScrollTopForNodes(inRow, this.getDefaultNodes());
		},
		dummy : 0
	});

	dojo.declare('dojox.grid.scroller.columns', dojox.grid.scroller, {
		// summary:
		// Virtual scroller class that scrolls list of columns. Owned by grid
		// and used internally
		// for virtual scrolling.
		constructor : function(inContentNodes) {
			this.setContentNodes(inContentNodes);
		},
		// nodes
		setContentNodes : function(inNodes) {
			this.contentNodes = inNodes;
			this.colCount = (this.contentNodes ? this.contentNodes.length : 0);
			this.pageNodes = [];
			for (var i = 0; i < this.colCount; i++) {
				this.pageNodes[i] = [];
			}
		},
		getDefaultNodes : function() {
			return this.pageNodes[0] || [];
		},
		scroll : function(inTop) {
			if (this.colCount) {
				dojox.grid.scroller.prototype.scroll.call(this, inTop);
			}
		},
		// resize
		resize : function() {
			if (this.scrollboxNode) {
				this.windowHeight = this.scrollboxNode.clientHeight;
			}
			for (var i = 0; i < this.colCount; i++) {
				dojox.grid.setStyleHeightPx(this.contentNodes[i], this.height);
			}
		},
		// implementation for page manager
		positionPage : function(inPageIndex, inPos) {
			for (var i = 0; i < this.colCount; i++) {
				this.positionPageNode(this.pageNodes[i][inPageIndex], inPos);
			}
		},
		preparePage : function(inPageIndex, inReuseNode) {
			var p = (inReuseNode ? this.popPage() : null);
			for (var i = 0; i < this.colCount; i++) {
				this.preparePageNode(inPageIndex, p, this.pageNodes[i]);
			}
		},
		installPage : function(inPageIndex) {
			for (var i = 0; i < this.colCount; i++) {
				this.contentNodes[i]
						.appendChild(this.pageNodes[i][inPageIndex]);
			}
		},
		destroyPage : function(inPageIndex) {
			for (var i = 0; i < this.colCount; i++) {
				dojox.grid.removeNode(this.invalidatePageNode(inPageIndex,
						this.pageNodes[i]));
			}
		},
		// rendering implementation
		renderPage : function(inPageIndex) {
			var nodes = [];
			for (var i = 0; i < this.colCount; i++) {
				nodes[i] = this.pageNodes[i][inPageIndex];
			}
			// this.renderRows(inPageIndex*this.rowsPerPage, this.rowsPerPage,
			// nodes);
			for (var i = 0, j = inPageIndex * this.rowsPerPage; (i < this.rowsPerPage)
					&& (j < this.rowCount); i++, j++) {
				this.renderRow(j, nodes);
			}
		}
	});

}