content/browser/renderer_host/render_widget_host_factory.h

// Copyright 2017 The Chromium Authors
// 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_HOST_FACTORY_H_
#define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_FACTORY_H_

#include <stdint.h>
#include <memory>

#include "base/memory/safe_ref.h"
#include "components/viz/common/surfaces/frame_sink_id.h"
#include "content/common/content_export.h"
#include "mojo/public/cpp/bindings/pending_remote.h"

namespace content {
class FrameTree;
class RenderWidgetHostDelegate;
class RenderWidgetHostImpl;
class SiteInstanceGroup;

// A factory for creating RenderWidgetHostImpls. There is a global factory
// function that can be installed for the purposes of testing to provide a
// specialized RenderWidgetHostImpl class.
class CONTENT_EXPORT RenderWidgetHostFactory {
 public:
  RenderWidgetHostFactory(const RenderWidgetHostFactory&) = delete;
  RenderWidgetHostFactory& operator=(const RenderWidgetHostFactory&) = delete;

  // Creates a RenderWidgetHostImpl using the currently registered factory, or
  // the default one if no factory is registered. Ownership of the returned
  // pointer will be passed to the caller.
  static std::unique_ptr<RenderWidgetHostImpl> Create(
      FrameTree* frame_tree,
      RenderWidgetHostDelegate* delegate,
      viz::FrameSinkId frame_sink_id,
      base::SafeRef<SiteInstanceGroup> site_instance_group,
      int32_t routing_id,
      bool hidden,
      bool renderer_initiated_creation);

  // Similar to the above but creates a self-owned `RenderWidgetHostImpl`.
  static RenderWidgetHostImpl* CreateSelfOwned(
      FrameTree* frame_tree,
      RenderWidgetHostDelegate* delegate,
      base::SafeRef<SiteInstanceGroup> site_instance_group,
      int32_t routing_id,
      bool hidden);

 protected:
  RenderWidgetHostFactory() = default;
  virtual ~RenderWidgetHostFactory() = default;

  // Subclasses can override this method to hook RenderWidgetHostImpl creation
  // as needed, e.g. to create a different subclass of RenderWidgetHostImpl. The
  // base implementation forwards to `RenderWidgetHostImpl::Create()`.
  virtual std::unique_ptr<RenderWidgetHostImpl> CreateRenderWidgetHost(
      FrameTree* frame_tree,
      RenderWidgetHostDelegate* delegate,
      viz::FrameSinkId frame_sink_id,
      base::SafeRef<SiteInstanceGroup> site_instance_group,
      int32_t routing_id,
      bool hidden,
      bool renderer_initiated_creation);

  // Similar to `CreateRenderWidgetHost()`, but for self-owned widgets. The
  // base implementation forwards to `RenderWidgetHostImpl::CreateSelfOwned()`.
  virtual RenderWidgetHostImpl* CreateSelfOwnedRenderWidgetHost(
      FrameTree* frame_tree,
      RenderWidgetHostDelegate* delegate,
      base::SafeRef<SiteInstanceGroup> site_instance_group,
      int32_t routing_id,
      bool hidden);

  // Registers your factory to be called when new RenderWidgetHostImpls are
  // created. We have only one global factory, so there must be no factory
  // registered before the call. This class does NOT take ownership of the
  // pointer.
  static void RegisterFactory(RenderWidgetHostFactory* factory);

  // Unregister the previously registered factory. With no factory registered,
  // the default RenderWidgetHostImpls will be created.
  static void UnregisterFactory();

 private:
  // The current globally registered factory. This is NULL when we should
  // create the default RenderWidgetHostImpls.
  static RenderWidgetHostFactory* factory_;
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_FACTORY_H_