--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/core/timer.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,104 @@
+var d3_timer_queue = null,
+    d3_timer_interval, // is an interval (or frame) active?
+    d3_timer_timeout; // is a timeout active?
+
+// The timer will continue to fire until callback returns true.
+d3.timer = function(callback, delay, then) {
+  var found = false,
+      t0,
+      t1 = d3_timer_queue;
+
+  if (arguments.length < 3) {
+    if (arguments.length < 2) delay = 0;
+    else if (!isFinite(delay)) return;
+    then = Date.now();
+  }
+
+  // See if the callback's already in the queue.
+  while (t1) {
+    if (t1.callback === callback) {
+      t1.then = then;
+      t1.delay = delay;
+      found = true;
+      break;
+    }
+    t0 = t1;
+    t1 = t1.next;
+  }
+
+  // Otherwise, add the callback to the queue.
+  if (!found) d3_timer_queue = {
+    callback: callback,
+    then: then,
+    delay: delay,
+    next: d3_timer_queue
+  };
+
+  // Start animatin'!
+  if (!d3_timer_interval) {
+    d3_timer_timeout = clearTimeout(d3_timer_timeout);
+    d3_timer_interval = 1;
+    d3_timer_frame(d3_timer_step);
+  }
+}
+
+function d3_timer_step() {
+  var elapsed,
+      now = Date.now(),
+      t1 = d3_timer_queue;
+
+  while (t1) {
+    elapsed = now - t1.then;
+    if (elapsed >= t1.delay) t1.flush = t1.callback(elapsed);
+    t1 = t1.next;
+  }
+
+  var delay = d3_timer_flush() - now;
+  if (delay > 24) {
+    if (isFinite(delay)) {
+      clearTimeout(d3_timer_timeout);
+      d3_timer_timeout = setTimeout(d3_timer_step, delay);
+    }
+    d3_timer_interval = 0;
+  } else {
+    d3_timer_interval = 1;
+    d3_timer_frame(d3_timer_step);
+  }
+}
+
+d3.timer.flush = function() {
+  var elapsed,
+      now = Date.now(),
+      t1 = d3_timer_queue;
+
+  while (t1) {
+    elapsed = now - t1.then;
+    if (!t1.delay) t1.flush = t1.callback(elapsed);
+    t1 = t1.next;
+  }
+
+  d3_timer_flush();
+};
+
+// Flush after callbacks, to avoid concurrent queue modification.
+function d3_timer_flush() {
+  var t0 = null,
+      t1 = d3_timer_queue,
+      then = Infinity;
+  while (t1) {
+    if (t1.flush) {
+      t1 = t0 ? t0.next = t1.next : d3_timer_queue = t1.next;
+    } else {
+      then = Math.min(then, t1.then + t1.delay);
+      t1 = (t0 = t1).next;
+    }
+  }
+  return then;
+}
+
+var d3_timer_frame = window.requestAnimationFrame
+    || window.webkitRequestAnimationFrame
+    || window.mozRequestAnimationFrame
+    || window.oRequestAnimationFrame
+    || window.msRequestAnimationFrame
+    || function(callback) { setTimeout(callback, 17); };