1 files changed, 57 insertions, 0 deletions
diff --git a/catapult/telemetry/telemetry/internal/actions/seek.js b/catapult/telemetry/telemetry/internal/actions/seek.js
new file mode 100644
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--- /dev/null
+++ b/catapult/telemetry/telemetry/internal/actions/seek.js
@@ -0,0 +1,57 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file performs actions on media elements.
+(function() {
+  function seekMedia(selector, seekTime, logSeekTime, seekLabel) {
+    // Performs the "Seek" action on media satisfying selector.
+    var mediaElements = window.__findMediaElements(selector);
+    for (var i = 0; i < mediaElements.length; i++) {
+      if (mediaElements[i] instanceof HTMLMediaElement)
+        seekHTML5Element(mediaElements[i], seekTime, logSeekTime, seekLabel);
+      else
+        throw new Error('Can not seek non HTML5 media elements.');
+    }
+  }
+
+  function seekHTML5Element(element, seekTime, logSeekTime, seekLabel) {
+    function readyForSeek() {
+      seekHTML5ElementPostLoad(element, seekTime, logSeekTime, seekLabel);
+    }
+    if (element.readyState == element.HAVE_NOTHING) {
+      var onLoadedMetaData = function(e) {
+        element.removeEventListener('loadedmetadata', onLoadedMetaData);
+        readyForSeek();
+      };
+      element.addEventListener('loadedmetadata', onLoadedMetaData);
+      element.load();
+    } else {
+      readyForSeek();
+    }
+  }
+
+  function seekHTML5ElementPostLoad(element, seekTime, logSeekTime, seekLabel) {
+    // Reset seek completion since multiple seeks can run on same media element.
+    element['seeked_completed'] = false;
+    window.__registerHTML5ErrorEvents(element);
+    window.__registerHTML5EventCompleted(element, 'seeked');
+
+    if (logSeekTime) {
+      var willSeekEvent = document.createEvent('Event');
+      willSeekEvent.initEvent('willSeek', false, false);
+      if (seekLabel)
+        willSeekEvent.seekLabel = seekLabel;
+      else
+        willSeekEvent.seekLabel = seekTime;
+      element.dispatchEvent(willSeekEvent);
+    }
+    try {
+      element.currentTime = seekTime;
+    } catch (err) {
+      throw new Error('Cannot seek in network state: ' + element.networkState);
+    }
+  }
+
+  window.__seekMedia = seekMedia;
+})();