Update fast-forward and rewind to work with play/pause.

Closes #130.

Change-Id: I33ed2e2ac0014eb3b271f72904996d669b0f13ee

controls.js

@@ -65,6 +65,7 @@ playerControls.init = function(video) {
   // play
   playButton.addEventListener('click', function() {
     if (!video.src) return;
+    playerControls.player_.setPlaybackRate(1);
     video.play();
   });
   video.addEventListener('play', function() {
@@ -247,6 +248,7 @@ playerControls.onRewind = function() {
   var rate = playerControls.player_.getPlaybackRate();
   playerControls.player_.setPlaybackRate(
       rate > 0 || rate < -4 ? -1.0 : rate * 2);
+  playerControls.video_.play();
 };
 
 
@@ -258,6 +260,7 @@ playerControls.onFastForward = function() {
   if (!playerControls.player_) return;
   var rate = playerControls.player_.getPlaybackRate();
   playerControls.player_.setPlaybackRate(rate < 0 || rate > 4 ? 1.0 : rate * 2);
+  playerControls.video_.play();
 };
 
 

lib/player/player.js

@@ -409,6 +409,7 @@ shaka.player.Player.prototype.onPause_ = function(event) {
   if (!isNaN(elapsed)) {
     this.stats_.logPlayTime(elapsed);
   }
+  this.cancelRewindTimer_();
 };
 
 
@@ -872,12 +873,20 @@ shaka.player.Player.prototype.cancelWatchdogTimer_ = function() {
 shaka.player.Player.prototype.onRewindTimer_ =
     function(startVideoTime, startWallTime, rate) {
   shaka.asserts.assert(rate < 0);
-  var offset = ((Date.now() - startWallTime) / 1000) * rate;
-  this.video_.currentTime = startVideoTime + offset;
-
-  var callback = this.onRewindTimer_.bind(
-      this, startVideoTime, startWallTime, rate);
-  this.rewindTimer_ = window.setTimeout(callback, 100);
+  var rewindOffset =
+      shaka.player.Player.REWIND_UPDATE_INTERVAL_ * Math.abs(rate);
+  if (this.video_.buffered.length &&
+      this.video_.buffered.start(0) + rewindOffset < this.video_.currentTime) {
+    var offset = ((Date.now() - startWallTime) / 1000) * rate;
+    this.video_.currentTime = startVideoTime + offset;
+
+    var callback = this.onRewindTimer_.bind(
+        this, startVideoTime, startWallTime, rate);
+    this.rewindTimer_ = window.setTimeout(
+        callback, shaka.player.Player.REWIND_UPDATE_INTERVAL_ * 1000);
+  } else {
+    this.video_.pause();
+  }
 };
 
 
@@ -968,6 +977,15 @@ shaka.player.Player.UNDERFLOW_THRESHOLD_ = 0.1;
 shaka.player.Player.BUFFERED_FUDGE_FACTOR_ = 0.05;
 
 
+/**
+ * The number of seconds for each rewind update interval.
+ *
+ * @private {number}
+ * @const
+ */
+shaka.player.Player.REWIND_UPDATE_INTERVAL_ = 0.1;
+
+
 /**
  * A map of MediaError codes to error messages.  The JS interpreter won't take
  * a symbolic name as a key, so the symbolic names for these error codes appear