+ * Call a function N times at a given interval, then call a cleanup function
+ * once. repeat_fn is called once immediately, then (times - 1) times
+ * asynchronously. If times=1, then cleanup_fn() is also called synchronously.
+ * @param repeat_fn {Function} Called repeatedly -- takes the number of calls
+ * (from 0 to times-1) as an argument.
+ * @param times {number} The number of times to call repeat_fn
+ * @param every_ms {number} Milliseconds between calls
+ * @param cleanup_fn {Function} A function to call after all repeat_fn calls.
+ * @private
+ */
+Dygraph.repeatAndCleanup = function(repeat_fn, times, every_ms, cleanup_fn) {
+ var count = 0;
+ var start_time = new Date().getTime();
+ repeat_fn(count);
+ if (times == 1) {
+ cleanup_fn();
+ return;
+ }
+
+ (function loop() {
+ if (count >= times) return;
+ var target_time = start_time + (1 + count) * every_ms;
+ setTimeout(function() {
+ count++;
+ repeat_fn(count)
+ if (count >= times - 1) {
+ cleanup_fn();
+ } else {
+ loop();
+ }
+ }, target_time - new Date().getTime());
+ // TODO(danvk): adjust every_ms to produce evenly-timed function calls.
+ })();
+};
+
+/**
+ * @private