VrShell: Split HTML UI Javascript into UI and support portions.

chrome/browser/resources/vr_shell/vr_shell_ui_scene.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js b/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
new file mode 100644
index 0000000000000000000000000000000000000000..f26e71b54c0bf5dac68d4ec6b4e1cd4bd2d78dd4
--- /dev/null
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui_scene.js
@@ -0,0 +1,145 @@
+// Copyright 2016 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.
+
+var ui = (function() {
+  'use strict';
+
+  /**
+   * The scene class assists in managing element and animations in the scene.
+   * It allows scene update commands to be queued in batches, and manages
+   * allocation of element and animation IDs.
+   *
+   * Examples:
+   *
+   * var scene = new ui.Scene();
+   *
+   * // Add an element.
+   * var el = new api.UiElement(100, 200, 50, 50);
+   * el.setSize(buttonWidth, buttonHeight);
+   *
+   * // Anchor it to the bottom of the content quad.
+   * el.setParentId(api.getContentElementId());
+   * el.setAnchoring(api.XAnchoring.XNONE, api.YAnchoring.YBOTTOM);
+   *
+   * // Place it just below the content quad edge.
+   * el.setTranslation(0, -0.2, 0.0);
+   *
+   * // Add it to the scene.
+   * var buttonId = scene.addElement(el);
+   * scene.flush();
+   *
+   * // Make the button twice as big.
+   * var update = new api.UiElementUpdate();
+   * update.setSize(bunttonWidth * 2, buttonHeight * 2);
+   * scene.updateElement(buttonId, update);
+   * scene.flush();
+   *
+   * // Animate the button size back to its original size, over 250 ms.
+   * var resize = new api.Animation(buttonId, 250);
+   * resize.setSize(buttonWidth, buttonHeight);
+   * scene.addAnimation(resize);
+   * scene.flush();
+   */
+  class Scene {
+
+    constructor() {
+      this.idIndex = api.getContentElementId() + 1;
+      this.commands = [];
+      this.elements = new Set();
+      this.animations = {};
+    }
+
+    /**
+     * Flush all queued commands to native.
+     */
+    flush() {
+      api.sendCommands(this.commands);
+      this.commands = [];
+    }
+
+    /**
+     * Add a new UiElement to the scene, returning the ID assigned.
+     */
+    addElement(element) {
+      var id = this.idIndex++;
+      element.id = id;
+      this.commands.push({
+        'type': api.Command.ADD_ELEMENT,
+        'data': element
+      });
+      this.elements.add(id);
+      return id;
+    }
+
+    /**
+     * Update an existing element, according to a UiElementUpdate object.
+     */
+    updateElement(id, update) {
+      // To-do:  Make sure ID exists.
+      update.id = id;
+      this.commands.push({
+        'type': api.Command.UPDATE_ELEMENT,
+        'data': update
+      });
+    }
+
+    /*
+     * Remove an element from the scene.
+     */
+    removeElement(id) {
+      // To-do: Make sure ID exists.
+      this.commands.push({
+        'type': api.Command.REMOVE_ELEMENT,
+        'data': {'id': id}
+      });
+      this.elements.delete(id);
+    }
+
+    /**
+     * Add a new Animation to the scene, returning the ID assigned.
+     */
+    addAnimation(animation) {
+      var id = this.idIndex++;
+      animation.id = id;
+      this.commands.push({
+        'type': api.Command.ADD_ANIMATION,
+        'data': animation
+      });
+      this.animations[id] = animation.meshId;
+      return id;
+    }
+
+    /*
+     * Remove an animation from the scene.
+     */
+    removeAnimation(id) {
+      // To-do: Make sure ID exists.
+      this.commands.push({
+        'type': api.Command.REMOVE_ANIMATION,
+        'data': {'id': id, 'meshId': this.animations[id]}
+      });
+      delete this.animations[id];
+    }
+
+    /*
+     * Purge all elements in the scene.
+     */
+    purge() {
+      var ids = Object.keys(this.animations);
+      for (let id_key of ids) {
+        var id = parseInt(id_key);
+        this.removeAnimation(id);
+      }
+      var ids = this.elements.values();
+      for (let id of ids) {
+        this.removeElement(id);
+      }
+      this.flush();
+    }
+  };
+
+  return {
+    Scene: Scene,
+  };
+})();