1 files changed, 89 insertions, 0 deletions
diff --git a/src/animator.js b/src/animator.js
new file mode 100644
index 0000000..4d37008
--- /dev/null
+++ b/src/animator.js
@@ -0,0 +1,89 @@
+/* global requestAnimationFrame */
+
+SVG.Animator = {
+  nextDraw: null,
+  frames: new SVG.Queue(),
+  timeouts: new SVG.Queue(),
+  frameCount: 0,
+  timeoutCount: 0,
+  timer: window.performance || window.Date,
+
+  frame: function (fn) {
+    SVG.Animator.frames.push({
+      id: SVG.Animator.frameCount,
+      run: fn
+    })
+
+    if (SVG.Animator.nextDraw === null) {
+      SVG.Animator.nextDraw = requestAnimationFrame(SVG.Animator._draw)
+    }
+
+    return ++SVG.Animator.frameCount
+  },
+
+  timeout: function (fn, delay) {
+    delay = delay || 0
+
+    // Work out when the event should fire
+    var time = SVG.Animator.timer.now() + delay
+
+    // Add the timeout to the end of the queue
+    var thisId = SVG.Animator.timeoutCount++
+    SVG.Animator.timeouts.push({
+      id: thisId,
+      run: fn,
+      time: time
+    })
+
+    // Request another animation frame if we need one
+    if (SVG.Animator.nextDraw === null) {
+      SVG.Animator.nextDraw = requestAnimationFrame(SVG.Animator._draw)
+    }
+
+    return thisId
+  },
+
+  cancelTimeout: function (id) {
+    // Find the index of the timeout to cancel and remove it
+    var index = SVG.Animator.timeouts.remove(
+      function (t) {
+        return t.id === id
+      }
+    )
+    return index
+  },
+
+  _draw: function (now) {
+
+    // Run all the timeouts we can run, if they are not ready yet, add them
+    // to the end of the queue immediately! (bad timeouts!!! [sarcasm])
+    var tracking = true
+    var nextTimeout = null
+    var lastTimeout = SVG.Animator.timeouts.last()
+    while ((nextTimeout = SVG.Animator.timeouts.shift())) {
+
+      // Run the timeout if its time, or push it to the end
+      if (now > nextTimeout.time) {
+        nextTimeout.run()
+      } else {
+        SVG.Animator.timeouts.push(nextTimeout)
+      }
+
+        // If we hit the last item, we should stop shifting out more items
+      if (nextTimeout === lastTimeout) break
+    }
+
+    // Run all of the frames available up until this point
+    var lastFrame = SVG.Animator.frames.last()
+    var lastFrameId = SVG.Animator.frameCount
+    while (SVG.Animator.frames.first() && SVG.Animator.frames.first().id < lastFrameId) {
+      var nextFrame = SVG.Animator.frames.shift()
+      nextFrame.run(now)
+    }
+
+    // If we have remaining timeouts or frames, draw until we don't anymore
+    SVG.Animator.nextDraw = SVG.Animator.timeouts.length > 0 || SVG.Animator.frames.length > 0
+        ? requestAnimationFrame(SVG.Animator._draw)
+        : null
+  }
+}