Separate host desktop related functionality into remoting.HostDesktop

remoting/webapp/crd/js/host_desktop.js

+// Copyright 2015 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
+ * Interface abstracting the functionality of the HostDesktop.
+ */
+
+var remoting = remoting || {};
+
+(function() {
+
+'use strict';
+
+/**
+ * @interface
+ * @extends {base.EventSource}
+ */
+remoting.HostDesktop = function() {};
+
+/** @return {boolean} Whether the host rate limits desktop-resize requests. */
+remoting.HostDesktop.prototype.hasResizeRateLimit = function() {};

[Jamie, 2015/02/18 23:06:19]

I don't think you need this. It was important to avoid sending too many resize
events to hosts when the user drags the window to resize it, but all hosts have
supported this since M29 (https://chromiumcodereview.appspot.com/15927033), so I
think we can retire it and simplify this interface.

[kelvinp, 2015/02/19 20:58:15]

Done.

+
+/** @return {boolean} Whether the host supports desktop resizing. */
+remoting.HostDesktop.prototype.isResizable = function() {};

[Jamie, 2015/02/18 23:06:19]

I'm not sure you need this either. Some Linux hosts don't support resize, but I
think they just ignore the message. The only reason for having it exposed at the
API level is if we wanted to customize the UI for this case, but I don't think
we do that.

[kelvinp, 2015/02/19 20:58:15]

Yes, I think it would be nice if we can expose that functionality in the UI in
the future.

+
+/** @enum {string} */
+remoting.HostDesktop.Events = {
+  // Fired when the size of the host desktop changes with no event data.
+  sizeChanged: 'sizeChanged',
+  // Fired when the shape of the host desktop changes with an array of
+  // rectangles of desktop shapes as the event data.
+  //   Array<{left:number, top:number, width:number, height:number}>
+  shapeChanged: 'shapeChanged'
+};
+
+/**
+ * @return {{width:number, height:number, xDpi:number, yDpi:number}}
+ *  The dimensions and DPI settings of the host desktop.
+ */
+remoting.HostDesktop.prototype.getDimensions = function() {};
+
+/**
+ * Resize the desktop of the host to |width|, |height| and |dpi|.
+ *
+ * @param {number} width

[Jamie, 2015/02/18 23:06:19]

I think |width| and |height| are in DIPs, correct? The interface should make
that explicit.

[kelvinp, 2015/02/19 20:58:15]

Yes.  Comments updated.

+ * @param {number} height
+ * @param {number} dpi
+ */
+remoting.HostDesktop.prototype.resize = function(width, height, dpi) {};
+
+})();