implement slotLabelInterval for agenda view

src/agenda/config.js

@@ -1,6 +1,16 @@
 
 var AGENDA_ALL_DAY_EVENT_LIMIT = 5;
 
+// potential nice values for the slot-duration and interval-duration
+// from largest to smallest
+var AGENDA_STOCK_SUB_DURATIONS = [
+	{ hours: 1 },
+	{ minutes: 30 },
+	{ minutes: 15 },
+	{ seconds: 30 },
+	{ seconds: 15 }
+];
+
 fcViews.agenda = {
 	'class': AgendaView,
 	defaults: {

src/common/TimeGrid.js

@@ -10,6 +10,7 @@ var TimeGrid = Grid.extend({
 	maxTime: null, // Duration object that denotes the exclusive visible end time of any given day
 	colDates: null, // whole-day dates for each column. left to right
 	labelFormat: null, // formatting string for times running along vertical axis
+	labelInterval: null, // duration of how often a label should be displayed for a slot
 
 	dayEls: null, // cells elements in the day-row background
 	slatEls: null, // elements running horizontally across all columns
@@ -70,20 +71,19 @@ var TimeGrid = Grid.extend({
 		var view = this.view;
 		var isRTL = this.isRTL;
 		var html = '';
-		var slotNormal = this.slotDuration.asMinutes() % 15 === 0;
 		var slotTime = moment.duration(+this.minTime); // wish there was .clone() for durations
 		var slotDate; // will be on the view's first day, but we only care about its time
-		var minutes;
+		var isLabeled;
 		var axisHtml;
 
 		// Calculate the time for each slot
 		while (slotTime < this.maxTime) {
-			slotDate = this.start.clone().time(slotTime); // will be in UTC but that's good. to avoid DST issues
-			minutes = slotDate.minutes();
+			slotDate = this.start.clone().time(slotTime); // after .time() will be in UTC. but that's good, avoids DST issues
+			isLabeled = isInt(divideDurationByDuration(slotTime, this.labelInterval));
 
 			axisHtml =
 				'<td class="fc-axis fc-time ' + view.widgetContentClass + '" ' + view.axisStyleAttr() + '>' +
-					((!slotNormal || !minutes) ? // if irregular slot duration, or on the hour, then display the time
+					(isLabeled ?
 						'<span>' + // for matchCellWidths
 							htmlEscape(slotDate.format(this.labelFormat)) +
 						'</span>' :
@@ -92,7 +92,7 @@ var TimeGrid = Grid.extend({
 				'</td>';
 
 			html +=
-				'<tr ' + (!minutes ? '' : 'class="fc-minor"') + '>' +
+				'<tr ' + (isLabeled ? '' : 'class="fc-minor"') + '>' +
 					(!isRTL ? axisHtml : '') +
 					'<td class="' + view.widgetContentClass + '"/>' +
 					(isRTL ? axisHtml : '') +
@@ -114,6 +114,7 @@ var TimeGrid = Grid.extend({
 		var view = this.view;
 		var slotDuration = view.opt('slotDuration');
 		var snapDuration = view.opt('snapDuration');
+		var input;
 
 		slotDuration = moment.duration(slotDuration);
 		snapDuration = snapDuration ? moment.duration(snapDuration) : slotDuration;
@@ -129,6 +130,30 @@ var TimeGrid = Grid.extend({
 			view.opt('slotLabelFormat') ||
 			view.opt('axisFormat') || // deprecated
 			view.opt('smallTimeFormat'); // the computed default
+
+		input = view.opt('slotLabelInterval');
+		this.labelInterval = input ?
+			moment.duration(input) :
+			this.computeLabelInterval(slotDuration);
+	},
+
+
+	// Computes an automatic value for slotLabelInterval
+	computeLabelInterval: function(slotDuration) {
+		var i;
+		var labelInterval;
+		var slotsPerLabel;
+
+		// find the smallest stock label interval that results in more than one slots-per-label
+		for (i = AGENDA_STOCK_SUB_DURATIONS.length - 1; i >= 0; i--) {
+			labelInterval = moment.duration(AGENDA_STOCK_SUB_DURATIONS[i]);
+			slotsPerLabel = divideDurationByDuration(labelInterval, slotDuration);
+			if (isInt(slotsPerLabel) && slotsPerLabel > 1) {
+				return labelInterval;
+			}
+		}
+
+		return moment.duration(slotDuration); // fall back. clone
 	},