timer that triggers events

exec/load/event-timer.js

+/*     
+	Event Timer  - for Synchronet 3.15a+ (2011)
+	
+	-	code by mcmlxxix
+	
+	methods:
+	
+	-	Timer.cycle()
+	-	Timer.addEvent()
+	
+	sample usage: 
+	
+		load(event-timer.js);
+		var timer=new Timer();
+		
+		function event() {
+			print("hello\r\n");
+		}
+		timer.addEvent(10,10,event);
+		
+		//will print "hello" 10 times at 10 second intervals
+		
+		while(timer.events.length > 0) {
+			timer.cycle();
+			mswait(1000);
+		}
+		
+		//script will end when the event runs its course
+*/
+function Timer() {
+	this.events = [];
+	
+	/* called by parent script, generally in a loop, and generally with a pause or timeout to minimize cpu usage */
+	this.cycle = function() {
+		var now = time();
+		var count = 0;
+		/* scan all events and run any that are due */
+		for(var e = 0; e<this.events.length; e++) {
+			var event = this.events[e];
+			if(now - event.lastrun >= event.interval) {
+				/* run event */
+				event.run();
+				count++;
+				/* an event with a repeat set to TRUE will never expire */
+				if(event.repeat === true)
+					continue;
+				/* decrement event repeat counter */
+				if(event.repeat > 0)
+					event.repeat--;
+				/* if event has expired, or is set to run only once, delete it */
+				if(!event.repeat) 
+					this.events.splice(e--,1);
+			}
+		}
+		/* return the number of events run this cycle */
+		return count;
+	}
+	
+	/* create a new event, do not include () on action parameter */
+	this.addEvent = function(interval,repeat,action) {
+		var event=new Event(interval,repeat,action);
+		this.events.push(event);
+	}
+	
+	/* event object created by addEvent */
+	function Event(interval,repeat,action) {
+		/* last time_t at which event was executed */
+		this.lastrun = time();
+		/* seconds between event occurance */
+		this.interval=interval;
+		/* number of times to repeat, true to repeat indefinitely, false to run only once */
+		this.repeat=repeat;
+		/* function called when event is run */
+		this.action=action;
+		/* run event */
+		this.run = function() {
+			this.action();
+			this.lastrun = time();
+		}
+	}
+};
+
+
+