content/browser/frame_host/render_frame_proxy_host.h

// 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.

#ifndef CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_
#define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_

#include <stdint.h>

#include <memory>

#include "base/callback_forward.h"
#include "base/macros.h"
#include "content/browser/site_instance_impl.h"
#include "content/common/frame.mojom.h"
#include "content/common/frame_proxy.mojom.h"
#include "ipc/ipc_listener.h"
#include "ipc/ipc_sender.h"
#include "mojo/public/cpp/bindings/associated_receiver.h"
#include "third_party/blink/public/mojom/frame/frame.mojom.h"
#include "third_party/blink/public/mojom/input/focus_type.mojom-forward.h"
#include "third_party/blink/public/mojom/messaging/transferable_message.mojom-forward.h"
#include "third_party/blink/public/mojom/scroll/scroll_into_view_params.mojom-forward.h"

namespace blink {
class AssociatedInterfaceProvider;
}

namespace gfx {
class Rect;
}

namespace content {

class CrossProcessFrameConnector;
class FrameTreeNode;
class RenderProcessHost;
class RenderViewHostImpl;
class RenderWidgetHostView;

// When a page's frames are rendered by multiple processes, each renderer has a
// full copy of the frame tree. It has full RenderFrames for the frames it is
// responsible for rendering and placeholder objects (i.e., RenderFrameProxies)
// for frames rendered by other processes.
//
// This class is the browser-side host object for the placeholder. Each node in
// the frame tree has a RenderFrameHost for the active SiteInstance and a set
// of RenderFrameProxyHost objects - one for all other SiteInstances with
// references to this frame. The proxies allow us to keep existing window
// references valid over cross-process navigations and route cross-site
// asynchronous JavaScript calls, such as postMessage.
//
// RenderFrameProxyHost is created whenever a cross-site
// navigation occurs and a reference to the frame navigating needs to be kept
// alive. A RenderFrameProxyHost and a RenderFrameHost for the same SiteInstance
// can exist at the same time, but only one will be "active" at a time.
// There are two cases where the two objects will coexist:
// * When navigating cross-process and there is already a RenderFrameProxyHost
// for the new SiteInstance. A pending RenderFrameHost is created, but it is
// not used until it commits. At that point, RenderFrameHostManager transitions
// the pending RenderFrameHost to the active one and deletes the proxy.
// * When navigating cross-process and the existing document has an unload
// event handler. When the new navigation commits, RenderFrameHostManager
// creates a RenderFrameProxyHost for the old SiteInstance and uses it going
// forward. It also instructs the RenderFrameHost to run the unload event
// handler and is kept alive for the duration. Once the event handling is
// complete, the RenderFrameHost is deleted.
class CONTENT_EXPORT RenderFrameProxyHost
    : public IPC::Listener,
      public IPC::Sender,
      public mojom::RenderFrameProxyHost,
      public blink::mojom::RemoteFrameHost,
      public blink::mojom::RemoteMainFrameHost {
 public:
  using CreatedCallback = base::RepeatingCallback<void(RenderFrameProxyHost*)>;

  static RenderFrameProxyHost* FromID(int process_id, int routing_id);
  static RenderFrameProxyHost* FromFrameToken(
      int process_id,
      const base::UnguessableToken& frame_token);

  // Sets a callback to be called whenever any RenderFrameProxyHost is created.
  static void SetCreatedCallbackForTesting(
      const CreatedCallback& created_callback);

  RenderFrameProxyHost(SiteInstance* site_instance,
                       scoped_refptr<RenderViewHostImpl> render_view_host,
                       FrameTreeNode* frame_tree_node);
  ~RenderFrameProxyHost() override;

  RenderProcessHost* GetProcess() { return process_; }

  // Initializes the object and creates the RenderFrameProxy in the process
  // for the SiteInstance.
  bool InitRenderFrameProxy();

  int GetRoutingID() { return routing_id_; }

  SiteInstance* GetSiteInstance() { return site_instance_.get(); }

  FrameTreeNode* frame_tree_node() const { return frame_tree_node_; }

  // Associates the RenderWidgetHostViewChildFrame |view| with this
  // RenderFrameProxyHost. If |initial_frame_size| isn't specified at this time,
  // the child frame will wait until the CrossProcessFrameConnector
  // receives its size from the parent via FrameHostMsg_UpdateResizeParams
  // before it begins parsing the content.
  void SetChildRWHView(RenderWidgetHostView* view,
                       const gfx::Size* initial_frame_size);

  RenderViewHostImpl* GetRenderViewHost();
  RenderWidgetHostView* GetRenderWidgetHostView();

  // IPC::Sender
  bool Send(IPC::Message* msg) override;

  // IPC::Listener
  bool OnMessageReceived(const IPC::Message& msg) override;

  CrossProcessFrameConnector* cross_process_frame_connector() {
    return cross_process_frame_connector_.get();
  }

  // Update the frame's opener in the renderer process in response to the
  // opener being modified (e.g., with window.open or being set to null) in
  // another renderer process.
  void UpdateOpener();

  // Set this proxy as the focused frame in the renderer process.  This is
  // called to replicate the focused frame when a frame in a different process
  // becomes focused.
  void SetFocusedFrame();

  // Scroll |rect_to_scroll| into view, starting from this proxy's FrameOwner
  // element in the frame's parent. Calling this continues a scroll started in
  // the frame's current process. |rect_to_scroll| is with respect to the
  // coordinates of the originating frame in OOPIF process.
  void ScrollRectToVisible(const gfx::Rect& rect_to_scroll,
                           blink::mojom::ScrollIntoViewParamsPtr params);

  // Sets render frame proxy created state. If |created| is false, any existing
  // mojo connections to RenderFrameProxyHost will be closed.
  void SetRenderFrameProxyCreated(bool created);

  // Returns if the RenderFrameProxy for this host is alive.
  bool is_render_frame_proxy_live() { return render_frame_proxy_created_; }

  // Returns associated remote for the blink::mojom::RemoteFrame Mojo interface.
  const mojo::AssociatedRemote<blink::mojom::RemoteFrame>&
  GetAssociatedRemoteFrame();

  // blink::mojom::RemoteFrameHost
  void SetInheritedEffectiveTouchAction(cc::TouchAction touch_action) override;
  void UpdateRenderThrottlingStatus(bool is_throttled,
                                    bool subtree_throttled) override;
  void VisibilityChanged(blink::mojom::FrameVisibility visibility) override;
  void DidFocusFrame() override;
  void CheckCompleted() override;
  void CapturePaintPreviewOfCrossProcessSubframe(
      const gfx::Rect& clip_rect,
      const base::UnguessableToken& guid) override;
  void SetIsInert(bool inert) override;
  void DidChangeOpener(const base::Optional<base::UnguessableToken>&
                           opener_frame_token) override;
  void AdvanceFocus(blink::mojom::FocusType focus_type,
                    const base::UnguessableToken& source_frame_token) override;
  void RouteMessageEvent(
      const base::Optional<base::UnguessableToken>& source_frame_token,
      const base::string16& source_origin,
      const base::string16& target_origin,
      blink::TransferableMessage message) override;

  // blink::mojom::RemoteMainFrameHost overrides:
  void FocusPage() override;

  // mojom::RenderFrameProxyHost:
  void OpenURL(mojom::OpenURLParamsPtr params) override;

  // Returns associated remote for the content::mojom::RenderFrameProxy Mojo
  // interface.
  const mojo::AssociatedRemote<mojom::RenderFrameProxy>&
  GetAssociatedRenderFrameProxy();
  // Requests a viz::LocalSurfaceId to enable auto-resize mode from the parent
  // renderer.
  void EnableAutoResize(const gfx::Size& min_size, const gfx::Size& max_size);
  // Requests a viz::LocalSurfaceId to disable auto-resize mode from the parent
  // renderer.
  void DisableAutoResize();
  void DidUpdateVisualProperties(const cc::RenderFrameMetadata& metadata);
  void ChildProcessGone();

  blink::AssociatedInterfaceProvider* GetRemoteAssociatedInterfacesTesting();
  bool IsInertForTesting();

  const base::UnguessableToken& GetFrameToken() const { return frame_token_; }

 private:
  // The interceptor needs access to frame_host_receiver_for_testing().
  friend class RouteMessageEventInterceptor;

  // IPC Message handlers.
  void OnDetach();
  void OnPrintCrossProcessSubframe(const gfx::Rect& rect, int document_cookie);

  // IPC::Listener
  void OnAssociatedInterfaceRequest(
      const std::string& interface_name,
      mojo::ScopedInterfaceEndpointHandle handle) override;

  blink::AssociatedInterfaceProvider* GetRemoteAssociatedInterfaces();

  // Needed for tests to be able to swap the implementation and intercept calls.
  mojo::AssociatedReceiver<blink::mojom::RemoteFrameHost>&
  frame_host_receiver_for_testing() {
    return remote_frame_host_receiver_;
  }

  // This RenderFrameProxyHost's routing id.
  int routing_id_;

  // The SiteInstance this proxy is associated with.
  scoped_refptr<SiteInstance> site_instance_;

  // The renderer process this RenderFrameHostProxy is associated with. It is
  // equivalent to the result of site_instance_->GetProcess(), but that
  // method has the side effect of creating the process if it doesn't exist.
  // Cache a pointer to avoid unnecessary process creation.
  RenderProcessHost* process_;

  // The node in the frame tree where this proxy is located.
  FrameTreeNode* frame_tree_node_;

  // True if we have a live RenderFrameProxy for this host.
  bool render_frame_proxy_created_;

  // When a RenderFrameHost is in a different process from its parent in the
  // frame tree, this class connects its associated RenderWidgetHostView
  // to this RenderFrameProxyHost, which corresponds to the same frame in the
  // parent's renderer process.
  std::unique_ptr<CrossProcessFrameConnector> cross_process_frame_connector_;

  // The RenderViewHost that this RenderFrameProxyHost is associated with.
  //
  // It is kept alive as long as any RenderFrameHosts or RenderFrameProxyHosts
  // are using it.
  //
  // TODO(creis): RenderViewHost will eventually go away and be replaced with
  // some form of page context.
  scoped_refptr<RenderViewHostImpl> render_view_host_;

  std::unique_ptr<blink::AssociatedInterfaceProvider>
      remote_associated_interfaces_;

  // Mojo receiver to this RenderFrameProxyHost.
  mojo::AssociatedReceiver<mojom::RenderFrameProxyHost>
      frame_proxy_host_associated_receiver_{this};

  // Holder of Mojo connection with the Frame service in Blink.
  mojo::AssociatedRemote<blink::mojom::RemoteFrame> remote_frame_;

  // Holder of Mojo connection with the content::mojom::RenderFrameProxy.
  mojo::AssociatedRemote<mojom::RenderFrameProxy> render_frame_proxy_;

  mojo::AssociatedReceiver<blink::mojom::RemoteFrameHost>
      remote_frame_host_receiver_{this};

  mojo::AssociatedReceiver<blink::mojom::RemoteMainFrameHost>
      remote_main_frame_host_receiver_{this};

  base::UnguessableToken frame_token_ = base::UnguessableToken::Create();

  DISALLOW_COPY_AND_ASSIGN(RenderFrameProxyHost);
};

}  // namespace content

#endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_