src/include/cef_frame_handler.h

// Copyright (c) 2021 Marshall A. Greenblatt. All rights reserved.
//
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// ---------------------------------------------------------------------------
//
// The contents of this file must follow a specific format in order to
// support the CEF translator tool. See the translator.README.txt file in the
// tools directory for more information.
//

#ifndef CEF_INCLUDE_CEF_FRAME_HANDLER_H_
#define CEF_INCLUDE_CEF_FRAME_HANDLER_H_
#pragma once

#include "include/cef_base.h"
#include "include/cef_browser.h"
#include "include/cef_frame.h"

///
/// Implement this interface to handle events related to CefFrame life span. The
/// order of callbacks is:
///
/// (1) During initial CefBrowserHost creation and navigation of the main frame:
/// - CefFrameHandler::OnFrameCreated => The initial main frame object has been
///   created. Any commands will be queued until the frame is attached.
/// - CefFrameHandler::OnMainFrameChanged => The initial main frame object has
///   been assigned to the browser.
/// - CefLifeSpanHandler::OnAfterCreated => The browser is now valid and can be
///   used.
/// - CefFrameHandler::OnFrameAttached => The initial main frame object is now
///   connected to its peer in the renderer process. Commands can be routed.
///
/// (2) During further CefBrowserHost navigation/loading of the main frame
///     and/or sub-frames:
/// - CefFrameHandler::OnFrameCreated => A new main frame or sub-frame object
///   has been created. Any commands will be queued until the frame is attached.
/// - CefFrameHandler::OnFrameAttached => A new main frame or sub-frame object
///   is now connected to its peer in the renderer process. Commands can be
///   routed.
/// - CefFrameHandler::OnFrameDetached => An existing main frame or sub-frame
///   object has lost its connection to the renderer process. If multiple
///   objects are detached at the same time then notifications will be sent for
///   any sub-frame objects before the main frame object. Commands can no longer
///   be routed and will be discarded.
/// - CefFrameHandler::OnMainFrameChanged => A new main frame object has been
///   assigned to the browser. This will only occur with cross-origin navigation
///   or re-navigation after renderer process termination (due to crashes, etc).
///
/// (3) During final CefBrowserHost destruction of the main frame:
/// - CefFrameHandler::OnFrameDetached => Any sub-frame objects have lost their
///   connection to the renderer process. Commands can no longer be routed and
///   will be discarded.
/// - CefLifeSpanHandler::OnBeforeClose => The browser has been destroyed.
/// - CefFrameHandler::OnFrameDetached => The main frame object have lost its
///   connection to the renderer process. Notifications will be sent for any
///   sub-frame objects before the main frame object. Commands can no longer be
///   routed and will be discarded.
/// - CefFrameHandler::OnMainFrameChanged => The final main frame object has
///   been removed from the browser.
///
/// Cross-origin navigation and/or loading receives special handling.
///
/// When the main frame navigates to a different origin the OnMainFrameChanged
/// callback (2) will be executed with the old and new main frame objects.
///
/// When a new sub-frame is loaded in, or an existing sub-frame is navigated to,
/// a different origin from the parent frame, a temporary sub-frame object will
/// first be created in the parent's renderer process. That temporary sub-frame
/// will then be discarded after the real cross-origin sub-frame is created in
/// the new/target renderer process. The client will receive cross-origin
/// navigation callbacks (2) for the transition from the temporary sub-frame to
/// the real sub-frame. The temporary sub-frame will not recieve or execute
/// commands during this transitional period (any sent commands will be
/// discarded).
///
/// When a new popup browser is created in a different origin from the parent
/// browser, a temporary main frame object for the popup will first be created
/// in the parent's renderer process. That temporary main frame will then be
/// discarded after the real cross-origin main frame is created in the
/// new/target renderer process. The client will recieve creation and initial
/// navigation callbacks (1) for the temporary main frame, followed by
/// cross-origin navigation callbacks (2) for the transition from the temporary
/// main frame to the real main frame. The temporary main frame may receive and
/// execute commands during this transitional period (any sent commands may be
/// executed, but the behavior is potentially undesirable since they execute in
/// the parent browser's renderer process and not the new/target renderer
/// process).
///
/// Callbacks will not be executed for placeholders that may be created during
/// pre-commit navigation for sub-frames that do not yet exist in the renderer
/// process. Placeholders will have CefFrame::GetIdentifier() == -4.
///
/// The methods of this class will be called on the UI thread unless otherwise
/// indicated.
///
/*--cef(source=client)--*/
class CefFrameHandler : public virtual CefBaseRefCounted {
 public:
  ///
  /// Called when a new frame is created. This will be the first notification
  /// that references |frame|. Any commands that require transport to the
  /// associated renderer process (LoadRequest, SendProcessMessage, GetSource,
  /// etc.) will be queued until OnFrameAttached is called for |frame|.
  ///
  /*--cef()--*/
  virtual void OnFrameCreated(CefRefPtr<CefBrowser> browser,
                              CefRefPtr<CefFrame> frame) {}

  ///
  /// Called when a frame can begin routing commands to/from the associated
  /// renderer process. |reattached| will be true if the frame was re-attached
  /// after exiting the BackForwardCache. Any commands that were queued have now
  /// been dispatched.
  ///
  /*--cef()--*/
  virtual void OnFrameAttached(CefRefPtr<CefBrowser> browser,
                               CefRefPtr<CefFrame> frame,
                               bool reattached) {}

  ///
  /// Called when a frame loses its connection to the renderer process and will
  /// be destroyed. Any pending or future commands will be discarded and
  /// CefFrame::IsValid() will now return false for |frame|. If called after
  /// CefLifeSpanHandler::OnBeforeClose() during browser destruction then
  /// CefBrowser::IsValid() will return false for |browser|.
  ///
  /*--cef()--*/
  virtual void OnFrameDetached(CefRefPtr<CefBrowser> browser,
                               CefRefPtr<CefFrame> frame) {}

  ///
  /// Called when the main frame changes due to (a) initial browser creation,
  /// (b) final browser destruction, (c) cross-origin navigation or (d)
  /// re-navigation after renderer process termination (due to crashes, etc).
  /// |old_frame| will be NULL and |new_frame| will be non-NULL when a main
  /// frame is assigned to |browser| for the first time. |old_frame| will be
  /// non-NULL and |new_frame| will be NULL and  when a main frame is removed
  /// from |browser| for the last time. Both |old_frame| and |new_frame| will be
  /// non-NULL for cross-origin navigations or re-navigation after renderer
  /// process termination. This method will be called after OnFrameCreated() for
  /// |new_frame| and/or after OnFrameDetached() for |old_frame|. If called
  /// after CefLifeSpanHandler::OnBeforeClose() during browser destruction then
  /// CefBrowser::IsValid() will return false for |browser|.
  ///
  /*--cef(optional_param=old_frame,optional_param=new_frame)--*/
  virtual void OnMainFrameChanged(CefRefPtr<CefBrowser> browser,
                                  CefRefPtr<CefFrame> old_frame,
                                  CefRefPtr<CefFrame> new_frame) {}
};

#endif  // CEF_INCLUDE_CEF_FRAME_HANDLER_H_