Merge pull request #2 from BinaryMuse/mkt-allow-setting-timer-rate

Add API for setting timer rate

README.md

@@ -42,6 +42,14 @@ Pauses the timer.
 
 Sets the timer's current time (in milliseconds).
 
+**`Timex#getRate()`**
+
+Returns the timer's current rate. Defaults to `1  `.
+
+**`Timex#setRate(rate)`**
+
+Sets the timer's rate. The rate affects how the time is calculated, not how often the timer ticks. For example, setting `rate` to `0.5` makes the timer increment time twice as slowly, but the ticks will occur just as often as before.
+
 **`Timex#register(function(time){})`**
 
 Registers a callback that gets called each time the timer ticks. The callback receives the current time of the timer as its only argument.

index.js

@@ -6,6 +6,7 @@ function Timer() {
   this.currentTime = 0;
   this.lastTick = null;
   this.callbacks = [];
+  this._rate = 1;
 
   this._tick = this._tick.bind(this);
 }
@@ -32,6 +33,14 @@ Timer.prototype.pause = function() {
   this.running = false;
 };
 
+Timer.prototype.setRate = function(rate) {
+  this._rate = rate;
+};
+
+Timer.prototype.getRate = function() {
+  return this._rate;
+};
+
 Timer.prototype._startTimer = function() {
   this._tick();
 };
@@ -44,7 +53,7 @@ Timer.prototype._tick = function() {
   } else {
     var thisTick = now(),
         delta = thisTick - this.lastTick;
-    this.currentTime = this.currentTime + delta;
+    this.currentTime = this.currentTime + delta * this._rate;
     this.lastTick = thisTick;
   }
 

test/browser.js

@@ -1,11 +1,14 @@
 var Timex = require("../");
 var timer = new Timex();
+var timer2 = new Timex();
 
 var div1 = document.createElement("div");
 var div2 = document.createElement("div");
+var div3 = document.createElement("div");
 
 document.documentElement.appendChild(div1);
 document.documentElement.appendChild(div2);
+document.documentElement.appendChild(div3);
 
 var updateDoc1 = function(time) {
   div1.textContent = "" + time;
@@ -15,11 +18,20 @@ var updateDoc2 = function(time) {
   div2.textContent = "" + time;
 };
 
+var updateDoc3 = function(time) {
+  div3.textContent = "" + time;
+};
+
 timer.register(updateDoc1)
 timer.register(updateDoc2)
 
+timer2.register(updateDoc3)
+
 setTimeout(function() {
   timer.unregister(updateDoc2);
 }, 2000);
 
+timer2.setRate(0.5);
+
 timer.start();
+timer2.start();

test/node.js

@@ -1,5 +1,6 @@
 var Timex = require("../");
 var timer = new Timex();
+var timer2 = new Timex();
 
 var log1 = function(time) {
   console.log("Timer 1: " + time);
@@ -9,11 +10,20 @@ var log2 = function(time) {
   console.log("Timer 2: " + time);
 };
 
+var log3 = function(time) {
+  console.log("Timer 3: " + time);
+};
+
 timer.register(log1);
 timer.register(log2);
 
+timer2.register(log3);
+
 setTimeout(function() {
   timer.unregister(log2);
 }, 2000);
 
+timer2.setRate(0.5);
+
 timer.start();
+timer2.start();