content/common/swapped_out_messages.cc

// Copyright (c) 2011 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 "content/common/swapped_out_messages.h"

#include "content/common/content_client.h"
#include "content/common/view_messages.h"

namespace content {

bool SwappedOutMessages::CanSendWhileSwappedOut(const IPC::Message* msg) {
  // We filter out most IPC messages when swapped out.  However, some are
  // important (e.g., ACKs) for keeping the browser and renderer state
  // consistent in case we later return to the same renderer.
  switch (msg->type()) {
    // Handled by RenderWidget.
    case ViewHostMsg_HandleInputEvent_ACK::ID:
    case ViewHostMsg_PaintAtSize_ACK::ID:
    case ViewHostMsg_UpdateRect::ID:
    // Handled by RenderView.
    case ViewHostMsg_RenderViewGone::ID:
    case ViewHostMsg_ShouldClose_ACK::ID:
    case ViewHostMsg_SwapOut_ACK::ID:
    case ViewHostMsg_ClosePage_ACK::ID:
      return true;
    default:
      break;
  }

  // Check with the embedder as well.
  ContentClient* client = GetContentClient();
  return client->CanSendWhileSwappedOut(msg);
}

bool SwappedOutMessages::CanHandleWhileSwappedOut(
    const IPC::Message& msg) {
  // Any message the renderer is allowed to send while swapped out should
  // be handled by the browser.
  if (CanSendWhileSwappedOut(&msg))
    return true;

  // We drop most other messages that arrive from a swapped out renderer.
  // However, some are important (e.g., ACKs) for keeping the browser and
  // renderer state consistent in case we later return to the renderer.
  switch (msg.type()) {
    // Sends an ACK.
    case ViewHostMsg_ShowView::ID:
    // Sends an ACK.
    case ViewHostMsg_ShowWidget::ID:
    // Sends an ACK.
    case ViewHostMsg_ShowFullscreenWidget::ID:
    // Updates browser state.
    case ViewHostMsg_RenderViewReady::ID:
    // Updates the previous navigation entry.
    case ViewHostMsg_UpdateState::ID:
    // Sends an ACK.
    case ViewHostMsg_UpdateTargetURL::ID:
    // We allow closing even if we are in the process of swapping out.
    case ViewHostMsg_Close::ID:
    // Sends an ACK.
    case ViewHostMsg_RequestMove::ID:
    // Suppresses dialog and sends an ACK.
    case ViewHostMsg_RunJavaScriptMessage::ID:
    // Suppresses dialog and sends an ACK.
    case ViewHostMsg_RunBeforeUnloadConfirm::ID:
    // Sends an ACK.
    case ViewHostMsg_AccessibilityNotifications::ID:
#if defined(USE_X11)
    // Synchronous message when leaving a page with plugin.
    case ViewHostMsg_DestroyPluginContainer::ID:
#endif
      return true;
    default:
      break;
  }

  // Check with the embedder as well.
  ContentClient* client = GetContentClient();
  return client->CanHandleWhileSwappedOut(msg);
}

}  // namespace content