// 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.

#include "ui/base/cocoa/remote_layer_api.h"

#include "base/command_line.h"
#include "base/mac/mac_util.h"
#include "ui/base/ui_base_switches.h"

#include <objc/runtime.h>

namespace ui {

bool RemoteLayerAPISupported() {
  // This API only works on Mac OS 10.9 and later.
  if (!base::mac::IsOSMavericksOrLater())
    return false;

  bool disabled_at_command_line =
      base::CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kDisableRemoteCoreAnimation);
  if (disabled_at_command_line)
    return false;

  // Verify the GPU process interfaces are present.
  static Class caContextClass = NSClassFromString(@"CAContext");
  if (!caContextClass)
    return false;

  // Note that because the contextId and layer properties are dynamic,
  // instancesRespondToSelector will return NO for them.
  static bool caContextClassValid =
      [caContextClass respondsToSelector:
          @selector(contextWithCGSConnection:options:)] &&
      class_getProperty(caContextClass, "contextId") &&
      class_getProperty(caContextClass, "layer");
  if (!caContextClassValid)
    return false;

  // Verify the browser process interfaces are present.
  static Class caLayerHostClass = NSClassFromString(@"CALayerHost");
  if (!caLayerHostClass)
    return false;

  static bool caLayerHostClassValid =
      [caLayerHostClass instancesRespondToSelector:@selector(contextId)] &&
      [caLayerHostClass instancesRespondToSelector:@selector(setContextId:)];
  if (!caLayerHostClassValid)
    return false;

  // If everything is there, we should be able to use the API.
  return true;
}

}  // namespace