move src -> lib

lib/utils/render-status.html

@@ -0,0 +1,120 @@
+<!--
+@license
+Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+<link rel="import" href="boot.html">
+
+<script>
+(function() {
+
+  'use strict';
+
+  let scheduled = false;
+  let beforeRenderQueue = [];
+  let afterRenderQueue = [];
+
+  function schedule() {
+    scheduled = true;
+    // before next render
+    requestAnimationFrame(function() {
+      scheduled = false;
+      flushQueue(beforeRenderQueue);
+      // after the render
+      setTimeout(function() {
+        flushQueue(afterRenderQueue);
+      });
+    });
+  }
+
+  function flushQueue(queue) {
+    while (queue.length) {
+      const q = queue.shift();
+      const context = q[0];
+      const callback = q[1];
+      const args = q[2];
+      try {
+        callback.apply(context, args);
+      } catch(e) {
+        setTimeout(() => {
+          throw e;
+        })
+      }
+    }
+  }
+
+  function flush() {
+    while (beforeRenderQueue.length || afterRenderQueue.length) {
+      flushQueue(beforeRenderQueue);
+      flushQueue(afterRenderQueue);
+    }
+  }
+
+  /**
+   * Module for scheduling flushable pre-render and post-render tasks.
+   *
+   * @namespace
+   * @memberof Polymer
+   * @summary Module for scheduling flushable pre-render and post-render tasks.
+   */
+  Polymer.RenderStatus = {
+
+    /**
+     * Enqueues a callback which will be run before the next render, at
+     * `requestAnimationFrame` timing.
+     *
+     * This method is useful for enqueuing work that requires DOM measurement,
+     * since measurement may not be reliable in custom element callbacks before
+     * the first render, as well as for batching measurement tasks in general.
+     *
+     * Tasks in this queue may be flushed by calling `Polymer.RenderStatus.flush()`.
+     *
+     * @memberof Polymer.RenderStatus
+     * @param {*} context Context object the callback function will be bound to
+     * @param {function} callback Callback function
+     * @param {Array} args An array of arguments to call the callback function with
+     */
+    beforeNextRender: function(context, callback, args) {
+      if (!scheduled) {
+        schedule();
+      }
+      beforeRenderQueue.push([context, callback, args]);
+    },
+
+    /**
+     * Enqueues a callback which will be run after the next render, equivalent
+     * to one task (`setTimeout`) after the next `requestAnimationFrame`.
+     *
+     * This method is useful for tuning the first-render performance of an
+     * element or application by deferring non-critical work until after the
+     * first paint.  Typical non-render-critical work may include adding UI
+     * event listeners and aria attributes.
+     *
+     * @memberof Polymer.RenderStatus
+     * @param {*} context Context object the callback function will be bound to
+     * @param {function} callback Callback function
+     * @param {Array} args An array of arguments to call the callback function with
+     */
+    afterNextRender: function(context, callback, args) {
+      if (!scheduled) {
+        schedule();
+      }
+      afterRenderQueue.push([context, callback, args]);
+    },
+
+    /**
+     * Flushes all `beforeNextRender` tasks, followed by all `afterNextRender`
+     * tasks.
+     *
+     * @memberof Polymer.RenderStatus
+     */
+    flush: flush
+
+  };
+
+})();
+</script>