function ResourceEventRenderer() {
	var t = this;
	
	
	// exports
	t.renderEvents = renderEvents;
	t.clearEvents = clearEvents;
	t.slotSegHtml = slotSegHtml;
	
	
	// imports
	DayEventRenderer.call(t);
	var opt = t.opt;
	var trigger = t.trigger;
	var isEventDraggable = t.isEventDraggable;
	var isEventResizable = t.isEventResizable;
	var eventEnd = t.eventEnd;
	var eventElementHandlers = t.eventElementHandlers;
	var setHeight = t.setHeight;
	var getDaySegmentContainer = t.getDaySegmentContainer;
	var getSlotSegmentContainer = t.getSlotSegmentContainer;
	var getHoverListener = t.getHoverListener;
	var getMaxMinute = t.getMaxMinute;
	var getMinMinute = t.getMinMinute;
	var timePosition = t.timePosition;
	var getIsCellAllDay = t.getIsCellAllDay;
	var colContentLeft = t.colContentLeft;
	var colContentRight = t.colContentRight;
	var cellToDate = t.cellToDate;
	var segmentCompare = t.segmentCompare;
	var getColCnt = t.getColCnt;
	var getColWidth = t.getColWidth;
	var getSnapHeight = t.getSnapHeight;
	var getSnapMinutes = t.getSnapMinutes;
	var getSlotContainer = t.getSlotContainer;
	var reportEventElement = t.reportEventElement;
	var showEvents = t.showEvents;
	var hideEvents = t.hideEvents;
	var eventDrop = t.eventDrop;
	var eventResize = t.eventResize;
	var renderDayOverlay = t.renderDayOverlay;
	var clearOverlays = t.clearOverlays;
	var renderDayEvents = t.renderDayEvents;
	var calendar = t.calendar;
	var formatDate = calendar.formatDate;
	var formatDates = calendar.formatDates;
	var resources = t.getResources;


	// overrides
	t.draggableDayEvent = draggableDayEvent;

	
	
	/* Rendering
	----------------------------------------------------------------------------*/
	

	function renderEvents(events, modifiedEventId) {
		var i, len=events.length,
			dayEvents=[],
			slotEvents=[];
		for (i=0; i<len; i++) {
			if (events[i].allDay) {
				dayEvents.push(events[i]);
			}else{
				slotEvents.push(events[i]);
			}
		}

		if (opt('allDaySlot')) {
			renderDayEvents(dayEvents, modifiedEventId);
			setHeight(); // no params means set to viewHeight
		}

		renderSlotSegs(compileSlotSegs(slotEvents), modifiedEventId);
	}
	
	
	function clearEvents() {
		getDaySegmentContainer().empty();
		getSlotSegmentContainer().empty();
	}

	
	function compileSlotSegs(events) {
		var colCnt = getColCnt(),
			minMinute = getMinMinute(),
			maxMinute = getMaxMinute(),
			d,
			visEventEnds,
			i, col,
			j, level,
			k, seg,
			segs = [];
		for (i=0; i<colCnt; i++) {

			d = cloneDate(t.visStart);
			addMinutes(d, minMinute);

			var resourceEvents = eventsForResource(resources[i], events);
			visEventEnds = $.map(resourceEvents, slotEventEnd);
			col = stackAgendaSegs(
				sliceSegs(
					resourceEvents,
					visEventEnds,
					d,
					addMinutes(cloneDate(d), maxMinute-minMinute)
				)
			);
			countForwardSegs(col);

			for (j=0; j<col.length; j++) {
				level = col[j];
				for (k=0; k<level.length; k++) {
					seg = level[k];
					seg.col = i;
					seg.level = j;
					segs.push(seg);
				}
			}
		}
		return segs;
	}


	function sliceSegs(events, visEventEnds, start, end) {
		var segs = [],
			i, len=events.length, event,
			eventStart, eventEnd,
			segStart, segEnd,
			isStart, isEnd;
		for (i=0; i<len; i++) {
			event = events[i];
			eventStart = event.start;
			eventEnd = visEventEnds[i];
			if (eventEnd > start && eventStart < end) {
				if (eventStart < start) {
					segStart = cloneDate(start);
					isStart = false;
				}else{
					segStart = eventStart;
					isStart = true;
				}
				if (eventEnd > end) {
					segEnd = cloneDate(end);
					isEnd = false;
				}else{
					segEnd = eventEnd;
					isEnd = true;
				}
				segs.push({
					event: event,
					start: segStart,
					end: segEnd,
					isStart: isStart,
					isEnd: isEnd,
					msLength: segEnd - segStart
				});
			}
		}
		return segs.sort(segmentCompare);
	}

	function eventsForResource(resource, events) {
	var resourceEvents = [];
	for (var i = 0; i < events.length; i++) {
	    if (events[i].resources && $.inArray(resource.id, events[i].resources) >= 0) {
	        resourceEvents.push(events[i])
	    }
	}
	return resourceEvents;
	}

	function slotEventEnd(event) {
		if (event.end) {
			return cloneDate(event.end);
		}else{
			return addMinutes(cloneDate(event.start), opt('defaultEventMinutes'));
		}
	}
	
	
	// renders events in the 'time slots' at the bottom
	// TODO: when we refactor this, when user returns `false` eventRender, don't have empty space
	// TODO: refactor will include using pixels to detect collisions instead of dates (handy for seg cmp)
	
	function renderSlotSegs(segs, modifiedEventId) {
	
		var i, segCnt=segs.length, seg,
			event,
			classes,
			top, bottom,
			colI, levelI, forward,
			leftmost,
			availWidth,
			outerWidth,
			left,
			html='',
			eventElements,
			eventElement,
			triggerRes,
			titleElement,
			height,
			slotSegmentContainer = getSlotSegmentContainer(),
			rtl, dis;
			
		if (rtl = opt('isRTL')) {
			dis = -1;
		}else{
			dis = 1;
		}
			
		// calculate position/dimensions, create html
		for (i=0; i<segCnt; i++) {
			seg = segs[i];
			event = seg.event;
			top = timePosition(seg.start, seg.start);
			bottom = timePosition(seg.start, seg.end);
			colI = seg.col;
			levelI = seg.level;
			forward = seg.forward || 0;
			leftmost = colContentLeft(colI);
			availWidth = colContentRight(colI) - leftmost;
			availWidth = Math.min(availWidth-6, availWidth*.95); // TODO: move this to CSS
			if (levelI) {
				// indented and thin
				outerWidth = availWidth / (levelI + forward + 1);
			}else{
				if (forward) {
					// moderately wide, aligned left still
					outerWidth = ((availWidth / (forward + 1)) - (12/2)) * 2; // 12 is the predicted width of resizer =
				}else{
					// can be entire width, aligned left
					outerWidth = availWidth;
				}
			}
			left = leftmost +                                  // leftmost possible
				(availWidth / (levelI + forward + 1) * levelI) // indentation
				* dis + (rtl ? availWidth - outerWidth : 0);   // rtl
			seg.top = top;
			seg.left = left;
			seg.outerWidth = outerWidth;
			seg.outerHeight = bottom - top;
			html += slotSegHtml(event, seg);
		}
		slotSegmentContainer[0].innerHTML = html; // faster than html()
		eventElements = slotSegmentContainer.children();
		
		// retrieve elements, run through eventRender callback, bind event handlers
		for (i=0; i<segCnt; i++) {
			seg = segs[i];
			event = seg.event;
			eventElement = $(eventElements[i]); // faster than eq()
			triggerRes = trigger('eventRender', event, event, eventElement);
			if (triggerRes === false) {
				eventElement.remove();
			}else{
				if (triggerRes && triggerRes !== true) {
					eventElement.remove();
					eventElement = $(triggerRes)
						.css({
							position: 'absolute',
							top: seg.top,
							left: seg.left
						})
						.appendTo(slotSegmentContainer);
				}
				seg.element = eventElement;
				if (event._id === modifiedEventId) {
					bindSlotSeg(event, eventElement, seg);
				}else{
					eventElement[0]._fci = i; // for lazySegBind
				}
				reportEventElement(event, eventElement);
			}
		}
		
		lazySegBind(slotSegmentContainer, segs, bindSlotSeg);
		
		// record event sides and title positions
		for (i=0; i<segCnt; i++) {
			seg = segs[i];
			if (eventElement = seg.element) {
				seg.vsides = vsides(eventElement, true);
				seg.hsides = hsides(eventElement, true);
				titleElement = eventElement.find('.fc-event-title');
				if (titleElement.length) {
					seg.contentTop = titleElement[0].offsetTop;
				}
			}
		}
		
		// set all positions/dimensions at once
		for (i=0; i<segCnt; i++) {
			seg = segs[i];
			if (eventElement = seg.element) {
				eventElement[0].style.width = Math.max(0, seg.outerWidth - seg.hsides) + 'px';
				height = Math.max(0, seg.outerHeight - seg.vsides);
				eventElement[0].style.height = height + 'px';
				event = seg.event;
				if (seg.contentTop !== undefined && height - seg.contentTop < 10) {
					// not enough room for title, put it in the time (TODO: maybe make both display:inline instead)
					eventElement.find('div.fc-event-time')
						.text(formatDate(event.start, opt('timeFormat')) + ' - ' + event.title);
					eventElement.find('div.fc-event-title')
						.remove();
				}
				trigger('eventAfterRender', event, event, eventElement);
			}
		}
					
	}
	
	
	function slotSegHtml(event, seg) {
		var html = "<";
		var url = event.url;
		var skinCss = getSkinCss(event, opt);
		var classes = ['fc-event', 'fc-event-vert'];
		if (isEventDraggable(event)) {
			classes.push('fc-event-draggable');
		}
		if (seg.isStart) {
			classes.push('fc-event-start');
		}
		if (seg.isEnd) {
			classes.push('fc-event-end');
		}
		classes = classes.concat(event.className);
		if (event.source) {
			classes = classes.concat(event.source.className || []);
		}
		if (url) {
			html += "a href='" + htmlEscape(event.url) + "'";
		}else{
			html += "div";
		}
		html +=
			" class='" + classes.join(' ') + "'" +
			" style=" +
				"'" +
				"position:absolute;" +
				"top:" + seg.top + "px;" +
				"left:" + seg.left + "px;" +
				skinCss +
				"'" +
			">" +
			"<div class='fc-event-inner'>" +
			"<div class='fc-event-time'>" +
			htmlEscape(formatDates(event.start, event.end, opt('timeFormat'))) +
			"</div>" +
			"<div class='fc-event-title'>" +
			htmlEscape(event.title || '') +
			"</div>" +
			"</div>" +
			"<div class='fc-event-bg'></div>";
		if (seg.isEnd && isEventResizable(event)) {
			html +=
				"<div class='ui-resizable-handle ui-resizable-s'>=</div>";
		}
		html +=
			"</" + (url ? "a" : "div") + ">";
		return html;
	}
	
	
	function bindSlotSeg(event, eventElement, seg) {
		var timeElement = eventElement.find('div.fc-event-time');
		if (isEventDraggable(event)) {
			draggableSlotEvent(event, eventElement, timeElement);
		}
		if (seg.isEnd && isEventResizable(event)) {
			resizableSlotEvent(event, eventElement, timeElement);
		}
		eventElementHandlers(event, eventElement);
	}
	
	
	
	/* Dragging
	-----------------------------------------------------------------------------------*/
	
	
	// when event starts out FULL-DAY
	// overrides DayEventRenderer's version because it needs to account for dragging elements
	// to and from the slot area.
	
	function draggableDayEvent(event, eventElement, seg) {
		var isStart = seg.isStart;
		var origWidth;
		var revert;
		var allDay = true;
		var dayDelta;
		var hoverListener = getHoverListener();
		var colWidth = getColWidth();
		var snapHeight = getSnapHeight();
		var snapMinutes = getSnapMinutes();
		var minMinute = getMinMinute();
		eventElement.draggable({
			opacity: opt('dragOpacity', 'month'), // use whatever the month view was using
			revertDuration: opt('dragRevertDuration'),
			start: function(ev, ui) {
				trigger('eventDragStart', eventElement, event, ev, ui);
				hideEvents(event, eventElement);
				origWidth = eventElement.width();
				hoverListener.start(function(cell, origCell) {
					clearOverlays();
					if (cell) {
						revert = false;
						var origDate = cellToDate(0, origCell.col);
						var date = cellToDate(0, cell.col);
						dayDelta = dayDiff(date, origDate);
						if (!cell.row) {
							// on full-days
							renderDayOverlay(
								addDays(cloneDate(event.start), dayDelta),
								addDays(exclEndDay(event), dayDelta)
							);
							resetElement();
						}else{
							// mouse is over bottom slots
							if (isStart) {
								if (allDay) {
									// convert event to temporary slot-event
									eventElement.width(colWidth - 10); // don't use entire width
									setOuterHeight(
										eventElement,
										snapHeight * Math.round(
											(event.end ? ((event.end - event.start) / MINUTE_MS) : opt('defaultEventMinutes')) /
												snapMinutes
										)
									);
									eventElement.draggable('option', 'grid', [colWidth, 1]);
									allDay = false;
								}
							}else{
								revert = true;
							}
						}
						revert = revert || (allDay && !dayDelta);
					}else{
						resetElement();
						revert = true;
					}
					eventElement.draggable('option', 'revert', revert);
				}, ev, 'drag');
			},
			stop: function(ev, ui) {
				hoverListener.stop();
				clearOverlays();
				trigger('eventDragStop', eventElement, event, ev, ui);
				if (revert) {
					// hasn't moved or is out of bounds (draggable has already reverted)
					resetElement();
					eventElement.css('filter', ''); // clear IE opacity side-effects
					showEvents(event, eventElement);
				}else{
					// changed!
					var minuteDelta = 0;
					if (!allDay) {
						minuteDelta = Math.round((eventElement.offset().top - getSlotContainer().offset().top) / snapHeight)
							* snapMinutes
							+ minMinute
							- (event.start.getHours() * 60 + event.start.getMinutes());
					}
					eventDrop(this, event, dayDelta, minuteDelta, allDay, ev, ui);
				}
			}
		});
		function resetElement() {
			if (!allDay) {
				eventElement
					.width(origWidth)
					.height('')
					.draggable('option', 'grid', null);
				allDay = true;
			}
		}
	}
	
	
	// when event starts out IN TIMESLOTS
	
	function draggableSlotEvent(event, eventElement, timeElement) {
		var coordinateGrid = t.getCoordinateGrid();
		var colCnt = getColCnt();
		var colWidth = getColWidth();
		var snapHeight = getSnapHeight();
		var snapMinutes = getSnapMinutes();

		// states
		var origPosition; // original position of the element, not the mouse
		var origCell;
		var isInBounds, prevIsInBounds;
		var isAllDay, prevIsAllDay;
		var colDelta, prevColDelta;
		var dayDelta; // derived from colDelta
		var minuteDelta, prevMinuteDelta;

		eventElement.draggable({
			scroll: false,
			grid: [ colWidth, snapHeight ],
			axis: colCnt==1 ? 'y' : false,
			opacity: opt('dragOpacity'),
			revertDuration: opt('dragRevertDuration'),
			start: function(ev, ui) {

				trigger('eventDragStart', eventElement, event, ev, ui);
				hideEvents(event, eventElement);

				coordinateGrid.build();

				// initialize states
				origPosition = eventElement.position();
				origCell = coordinateGrid.cell(ev.pageX, ev.pageY);
				isInBounds = prevIsInBounds = true;
				isAllDay = prevIsAllDay = getIsCellAllDay(origCell);
				colDelta = prevColDelta = 0;
				dayDelta = 0;
				minuteDelta = prevMinuteDelta = 0;

			},
			drag: function(ev, ui) {

				// NOTE: this `cell` value is only useful for determining in-bounds and all-day.
				// Bad for anything else due to the discrepancy between the mouse position and the
				// element position while snapping. (problem revealed in PR #55)
				//
				// PS- the problem exists for draggableDayEvent() when dragging an all-day event to a slot event.
				// We should overhaul the dragging system and stop relying on jQuery UI.
				var cell = coordinateGrid.cell(ev.pageX, ev.pageY);

				// update states
				isInBounds = !!cell;
				if (isInBounds) {
					isAllDay = getIsCellAllDay(cell);

					// calculate column delta
					colDelta = Math.round((ui.position.left - origPosition.left) / colWidth);
					if (colDelta != prevColDelta) {
						// calculate the day delta based off of the original clicked column and the column delta
						var origDate = cellToDate(0, origCell.col);
						var col = origCell.col + colDelta;
						col = Math.max(0, col);
						col = Math.min(colCnt-1, col);
						var date = cellToDate(0, col);
						dayDelta = dayDiff(date, origDate);
					}

					// calculate minute delta (only if over slots)
					if (!isAllDay) {
						minuteDelta = Math.round((ui.position.top - origPosition.top) / snapHeight) * snapMinutes;
					}
				}

				// any state changes?
				if (
					isInBounds != prevIsInBounds ||
					isAllDay != prevIsAllDay ||
					colDelta != prevColDelta ||
					minuteDelta != prevMinuteDelta
				) {

					updateUI();

					// update previous states for next time
					prevIsInBounds = isInBounds;
					prevIsAllDay = isAllDay;
					prevColDelta = colDelta;
					prevMinuteDelta = minuteDelta;
				}

				// if out-of-bounds, revert when done, and vice versa.
				eventElement.draggable('option', 'revert', !isInBounds);

			},
			stop: function(ev, ui) {

				clearOverlays();
				trigger('eventDragStop', eventElement, event, ev, ui);

				if (isInBounds && (isAllDay || dayDelta || minuteDelta)) { // changed!
					eventDrop(this, event, dayDelta, isAllDay ? 0 : minuteDelta, isAllDay, ev, ui);
				}
				else { // either no change or out-of-bounds (draggable has already reverted)

					// reset states for next time, and for updateUI()
					isInBounds = true;
					isAllDay = false;
					colDelta = 0;
					dayDelta = 0;
					minuteDelta = 0;

					updateUI();
					eventElement.css('filter', ''); // clear IE opacity side-effects

					// sometimes fast drags make event revert to wrong position, so reset.
					// also, if we dragged the element out of the area because of snapping,
					// but the *mouse* is still in bounds, we need to reset the position.
					eventElement.css(origPosition);

					showEvents(event, eventElement);
				}
			}
		});

		function updateUI() {
			clearOverlays();
			if (isInBounds) {
				if (isAllDay) {
					timeElement.hide();
					eventElement.draggable('option', 'grid', null); // disable grid snapping
					renderDayOverlay(
						addDays(cloneDate(event.start), dayDelta),
						addDays(exclEndDay(event), dayDelta)
					);
				}
				else {
					updateTimeText(minuteDelta);
					timeElement.css('display', ''); // show() was causing display=inline
					eventElement.draggable('option', 'grid', [colWidth, snapHeight]); // re-enable grid snapping
				}
			}
		}

		function updateTimeText(minuteDelta) {
			var newStart = addMinutes(cloneDate(event.start), minuteDelta);
			var newEnd;
			if (event.end) {
				newEnd = addMinutes(cloneDate(event.end), minuteDelta);
			}
			timeElement.text(formatDates(newStart, newEnd, opt('timeFormat')));
		}

	}
	
	
	
	/* Resizing
	--------------------------------------------------------------------------------------*/
	
	
	function resizableSlotEvent(event, eventElement, timeElement) {
		var snapDelta, prevSnapDelta;
		var snapHeight = getSnapHeight();
		var snapMinutes = getSnapMinutes();
		eventElement.resizable({
			handles: {
				s: '.ui-resizable-handle'
			},
			grid: snapHeight,
			start: function(ev, ui) {
				snapDelta = prevSnapDelta = 0;
				hideEvents(event, eventElement);
				trigger('eventResizeStart', this, event, ev, ui);
			},
			resize: function(ev, ui) {
				// don't rely on ui.size.height, doesn't take grid into account
				snapDelta = Math.round((Math.max(snapHeight, eventElement.height()) - ui.originalSize.height) / snapHeight);
				if (snapDelta != prevSnapDelta) {
					timeElement.text(
						formatDates(
							event.start,
							(!snapDelta && !event.end) ? null : // no change, so don't display time range
								addMinutes(eventEnd(event), snapMinutes*snapDelta),
							opt('timeFormat')
						)
					);
					prevSnapDelta = snapDelta;
				}
			},
			stop: function(ev, ui) {
				trigger('eventResizeStop', this, event, ev, ui);
				if (snapDelta) {
					eventResize(this, event, 0, snapMinutes*snapDelta, ev, ui);
				}else{
					showEvents(event, eventElement);
					// BUG: if event was really short, need to put title back in span
				}
			}
		});
	}
	

}



/* Agenda Event Segment Utilities
-----------------------------------------------------------------------------*/
// TODO: maybe somehow consolidate this with DayEventRenderer's segment system


function stackAgendaSegs(segs) {
	var levels = [],
		i, len = segs.length, seg,
		j, collide, k;
	for (i=0; i<len; i++) {
		seg = segs[i];
		j = 0; // the level index where seg should belong
		while (true) {
			collide = false;
			if (levels[j]) {
				for (k=0; k<levels[j].length; k++) {
					if (agendaSegsCollide(levels[j][k], seg)) {
						collide = true;
						break;
					}
				}
			}
			if (collide) {
				j++;
			}else{
				break;
			}
		}
		if (levels[j]) {
			levels[j].push(seg);
		}else{
			levels[j] = [seg];
		}
	}
	return levels;
}


function countForwardSegs(levels) {
	var i, j, k, level, segForward, segBack;
	for (i=levels.length-1; i>0; i--) {
		level = levels[i];
		for (j=0; j<level.length; j++) {
			segForward = level[j];
			for (k=0; k<levels[i-1].length; k++) {
				segBack = levels[i-1][k];
				if (agendaSegsCollide(segForward, segBack)) {
					segBack.forward = Math.max(segBack.forward||0, (segForward.forward||0)+1);
				}
			}
		}
	}
}


function agendaSegsCollide(seg1, seg2) {
	return seg1.end > seg2.start && seg1.start < seg2.end;
}