Allow Speed scheduler to accept an initial time

Adds an additional optional time argument to Scheduler.Speed.add(), which
defines an initial time to schedule the item. If the item is repeated then
subsequent scheduling will use 1/item.getSpeed() as before.

Also exposes an item's time through a Scheduler.getTimeOf(item) method. In
combination, these two changes allow clients to completely recreate the
state of the speed scheduler at a given point, useful when saving and
restoring a game state.

Author: Travis Scholtens

src/eventqueue.js

@@ -56,6 +56,17 @@ ROT.EventQueue.prototype.get = function() {
 	return this._events.splice(0, 1)[0];
 }
 
+/**
+ * Get the time associated with the given event
+ * @param {?} event
+ * @returns {number} time
+ */
+ROT.EventQueue.prototype.getEventTime = function(event) {
+	var index = this._events.indexOf(event);
+	if (index == -1) { return undefined }
+	return this._eventTimes[index];
+}
+
 /**
  * Remove an event from the queue
  * @param {?} event

src/scheduler/scheduler-speed.js

@@ -10,10 +10,11 @@ ROT.Scheduler.Speed.extend(ROT.Scheduler);
 /**
  * @param {object} item anything with "getSpeed" method
  * @param {bool} repeat
+ * @param {number} [time=1/item.getSpeed()]
  * @see ROT.Scheduler#add
  */
-ROT.Scheduler.Speed.prototype.add = function(item, repeat) {
-	this._queue.add(item, 1/item.getSpeed());
+ROT.Scheduler.Speed.prototype.add = function(item, repeat, time) {
+	this._queue.add(item, time !== undefined ? time : 1/item.getSpeed());
 	return ROT.Scheduler.prototype.add.call(this, item, repeat);
 }
 

src/scheduler/scheduler.js

@@ -23,6 +23,15 @@ ROT.Scheduler.prototype.add = function(item, repeat) {
 	return this;
 }
 
+/**
+ * Get the time the given item is scheduled for
+ * @param {?} item
+ * @returns {number} time
+ */
+ROT.Scheduler.prototype.getTimeOf = function(item) {
+	return this._queue.getEventTime(item);
+}
+
 /**
  * Clear all items
  */

tests/spec/eventqueue.js

@@ -17,6 +17,25 @@ describe("EventQueue", function() {
 		expect(q.get()).toEqual(null);
 	});
 
+	it("should look up time of events", function() {
+		var q = new ROT.EventQueue();
+		q.add(123, 187);
+		q.add(456, 42);
+		expect(q.getEventTime(123)).toEqual(187);
+		expect(q.getEventTime(456)).toEqual(42);
+	});
+
+	it("should look up correct times after events removed", function() {
+		var q = new ROT.EventQueue();
+		q.add(123, 187);
+		q.add(456, 42);
+		q.add(789, 411);
+                q.get();
+		expect(q.getEventTime(456)).toBeUndefined();
+		expect(q.getEventTime(123)).toEqual(187 - 42);
+		expect(q.getEventTime(789)).toEqual(411 - 42);
+	});
+
 	it("should remove events", function() {
 		var q = new ROT.EventQueue();
 		q.add(123, 0);

tests/spec/scheduler.js

@@ -89,6 +89,23 @@ describe("Scheduler", function() {
 			for (var i=0;i<7;i++) { result.push(S.next()); }
 			expect(result).toSchedule([A200, A100a, A200, A200, A50, A100a, A200]);
 		});
+
+		it("should schedule with initial offsets", function() {
+			S.add(A50, true, 1/300);
+			S.add(A100a, true, 0);
+			S.add(A200, true);
+			var result = [];
+			for (var i=0;i<9;i++) { result.push(S.next()); }
+			expect(result).toSchedule([A100a, A50, A200, A100a, A200, A200, A100a, A200, A50]);
+		});
+
+		it("should look up the time of an event", function() {
+			S.add(A100a, true);
+			S.add(A50, true, 1/200);
+			expect(S.getTimeOf(A50)).toEqual(1/200);
+			expect(S.getTimeOf(A100a)).toEqual(1/100);
+		});
+
 	});
 
 	describe("Action", function() {