CRD Viewport Management refactor

remoting/webapp/crd/js/client_plugin_host_desktop_impl.js

Index: remoting/webapp/crd/js/client_plugin_host_desktop_impl.js
diff --git a/remoting/webapp/crd/js/client_plugin_host_desktop_impl.js b/remoting/webapp/crd/js/client_plugin_host_desktop_impl.js
new file mode 100644
index 0000000000000000000000000000000000000000..d47a6fb296f5b5eb84375ebe6b7d08e92e8cc01a
--- /dev/null
+++ b/remoting/webapp/crd/js/client_plugin_host_desktop_impl.js
@@ -0,0 +1,138 @@
+// Copyright 2014 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.
+
+/**
+ * @fileoverview
+ * Provides an interface to manage the Host Desktop of a remoting session.
+ */
+
+/** @suppress {duplicate} */
+var remoting = remoting || {};
+remoting.ClientPlugin = remoting.ClientPlugin || {};
+
+(function() {
+
+'use strict';
+
+var HostDesktopEvents = remoting.ClientPlugin.HostDesktop.Events;
+
+/**
+ * @param {remoting.ClientPluginImpl} plugin
+ * @param {function(Object):void} postMessageCallback Callback to post a message
+ *   to the Client Plugin.
+ *
+ * @implements {remoting.ClientPlugin.HostDesktop}
+ * @extends {base.EventSourceImpl}
+ * @constructor
+ */
+remoting.ClientPlugin.HostDesktopImpl = function(plugin, postMessageCallback) {

[Jamie, 2015/02/12 21:07:29]

I think it's confusing to have a nested type declared in a different file to its
parent. I think this can just be remoting.HostDesktop. You should also consider
moving HostDesktop out of ClientPlugin. As a rule-of-thumb, nested types make
sense when the nested name would be too generic out-of-context (such as
Application.Delegate) or if the nested type only makes sense in the context of
its container. The host desktop is a concept that exists independently of the
client plugin, so I don't think a nested type is the right model.

[kelvinp, 2015/02/12 23:26:41]

I removed ClientPlugin from the interface.  But the implementation of the
HostDesktop is heavily dependent on the clientPlugin. So I will leave the
implementation inside ClientPlugin

+  /** @private */
+  this.plugin_ = plugin;
+  /** @private */
+  this.width_ = 0;
+  /** @private */
+  this.height_ = 0;
+  /** @private */
+  this.xDpi_ = 96;
+  /** @private */
+  this.yDpi_ = 96;
+  /** @private */
+  this.hasResizeRateLimit_ = false;
+  /** @private */
+  this.postMessageCallback_ = postMessageCallback;
+
+  this.defineEvents(Object.keys(HostDesktopEvents));
+};
+base.extend(remoting.ClientPlugin.HostDesktopImpl, base.EventSourceImpl);
+
+/** @return {boolean} */
+remoting.ClientPlugin.HostDesktopImpl.prototype.hasResizeRateLimit =
+    function() {
+  return this.hasResizeRateLimit_;
+};
+
+/** @return {boolean} Whether the host supports desktop resizing. */
+remoting.ClientPlugin.HostDesktopImpl.prototype.isResizable = function() {
+  return this.plugin_.hasFeature(
+      remoting.ClientPlugin.Feature.NOTIFY_CLIENT_RESOLUTION);
+};
+
+/** @return {{width:number, height:number, xDpi:number, yDpi:number}} */
+remoting.ClientPlugin.HostDesktopImpl.prototype.getDimensions = function() {
+  return {
+    width: this.width_,
+    height: this.height_,
+    xDpi: this.xDpi_,
+    yDpi: this.yDpi_
+  };
+};
+
+/**
+ * @param {number} width
+ * @param {number} height
+ * @param {number} device_scale
+ */
+remoting.ClientPlugin.HostDesktopImpl.prototype.resize = function(
+    width, height, device_scale) {
+  if (this.isResizable()) {
+    var dpi = Math.floor(device_scale * 96);
+    this.postMessageCallback_({
+      method: 'notifyClientResolution',
+      data: {
+        width: Math.floor(width * device_scale),
+        height: Math.floor(height * device_scale),
+        x_dpi: dpi,
+        y_dpi: dpi
+      }
+    });
+  }
+};
+
+/**
+ * @param {Array.<string>} capabilities
+ */
+remoting.ClientPlugin.HostDesktopImpl.prototype.onSetCapabilities = function(
+    capabilities) {
+  this.hasResizeRateLimit_ =
+      capabilities.indexOf(
+          remoting.ClientSession.Capability.RATE_LIMIT_RESIZE_REQUESTS) !== -1;
+};
+
+/**
+ * This function is called by |this.plugin_| when the size of the host
+ * desktop is changed.
+ *
+ * @param {remoting.ClientPluginMessage} message
+ */
+remoting.ClientPlugin.HostDesktopImpl.prototype.onSizeUpdated = function(
+    message) {
+  this.width_ = getNumberAttr(message.data, 'width');
+  this.height_ = getNumberAttr(message.data, 'height');
+  this.xDpi_ = getNumberAttr(message.data, 'x_dpi', 96);
+  this.yDpi_ = getNumberAttr(message.data, 'y_dpi', 96);
+  this.raiseEvent(HostDesktopEvents.sizeChanged);
+};
+
+/**
+ * This function is called by |this.plugin_| when the shape of the host
+ * desktop is changed.
+ *
+ * @param {remoting.ClientPluginMessage} message
+ * @return {Array.<Array.<number>>} rectangles of the desktop shape.
+ */
+remoting.ClientPlugin.HostDesktopImpl.prototype.onShapeUpdated =
+    function(message) {
+  var rects = getArrayAttr(message.data, 'rects');
+  for (var i = 0; i < rects.length; ++i) {
+    /** @type {Array.<number>} */
+    var rect = rects[i];
+    if (typeof rect != 'object' || rect.length != 4) {
+      throw 'Received invalid onDesktopShape message';
+    }
+  }
+  this.raiseEvent(HostDesktopEvents.shapeChanged, rects);
+  return rects;
+};
+
+}());