content/browser/renderer_host/render_widget_helper.h

// Copyright (c) 2012 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.

#ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_
#define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_

#include <stdint.h>

#include <map>

#include "base/atomic_sequence_num.h"
#include "base/containers/hash_tables.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/process/process.h"
#include "content/common/render_message_filter.mojom.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/global_request_id.h"
#include "content/public/common/widget_type.h"
#include "ui/gfx/native_widget_types.h"

namespace content {

class ResourceDispatcherHostImpl;

// Instantiated per RenderProcessHost to provide various optimizations on
// behalf of a RenderWidgetHost.  This class bridges between the IO thread
// where the RenderProcessHost's MessageFilter lives and the UI thread where
// the RenderWidgetHost lives.
class RenderWidgetHelper
    : public base::RefCountedThreadSafe<RenderWidgetHelper,
                                        BrowserThread::DeleteOnIOThread> {
 public:
  RenderWidgetHelper();

  void Init(int render_process_id,
            ResourceDispatcherHostImpl* resource_dispatcher_host);

  // Gets the next available routing id.  This is thread safe.
  int GetNextRoutingID();

  // IO THREAD ONLY -----------------------------------------------------------

  // Lookup the RenderWidgetHelper from the render_process_host_id. Returns NULL
  // if not found. NOTE: The raw pointer is for temporary use only. To retain,
  // store in a scoped_refptr.
  static RenderWidgetHelper* FromProcessHostID(int render_process_host_id);

  // IO THREAD ONLY -----------------------------------------------------------
  void CreateNewWidget(int opener_id,
                       mojom::WidgetPtr,
                       int* route_id);
  void CreateNewFullscreenWidget(int opener_id,
                                 mojom::WidgetPtr,
                                 int* route_id);

 private:
  friend class base::RefCountedThreadSafe<RenderWidgetHelper>;
  friend struct BrowserThread::DeleteOnThread<BrowserThread::IO>;
  friend class base::DeleteHelper<RenderWidgetHelper>;

  ~RenderWidgetHelper();

  // Called on the UI thread to finish creating a widget.
  void OnCreateWidgetOnUI(int32_t opener_id,
                          int32_t route_id,
                          mojom::WidgetPtrInfo widget);

  // Called on the UI thread to create a fullscreen widget.
  void OnCreateFullscreenWidgetOnUI(int32_t opener_id,
                                    int32_t route_id,
                                    mojom::WidgetPtrInfo widget);

  int render_process_id_;

  // The next routing id to use.
  base::AtomicSequenceNumber next_routing_id_;

  ResourceDispatcherHostImpl* resource_dispatcher_host_;

  DISALLOW_COPY_AND_ASSIGN(RenderWidgetHelper);
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HELPER_H_