dom/base/mozAutoDocUpdate.h
author Sylvestre Ledru <sledru@mozilla.com>
Fri, 30 Nov 2018 11:46:48 +0100
changeset 508163 6f3709b3878117466168c40affa7bca0b60cf75b
parent 477194 f7a6b594d8000c12e44a7df96e2b962cd31f7df4
child 512431 f0a91d36587266d7454a450c6044d573664fbed5
permissions -rw-r--r--
Bug 1511181 - Reformat everything to the Google coding style r=ehsan a=clang-format # ignore-this-changeset

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozAutoDocUpdate_h_
#define mozAutoDocUpdate_h_

#include "nsContentUtils.h"  // For AddScriptBlocker() and RemoveScriptBlocker().
#include "nsIDocument.h"
#include "nsIDocumentObserver.h"

/**
 * Helper class to automatically handle batching of document updates.  This
 * class will call BeginUpdate on construction and EndUpdate on destruction on
 * the given document with the given update type.  The document could be null,
 * in which case no updates will be called.  The constructor also takes a
 * boolean that can be set to false to prevent notifications.
 */
class MOZ_STACK_CLASS mozAutoDocUpdate {
 public:
  mozAutoDocUpdate(nsIDocument* aDocument, bool aNotify)
      : mDocument(aNotify ? aDocument : nullptr) {
    if (mDocument) {
      mDocument->BeginUpdate();
    } else {
      nsContentUtils::AddScriptBlocker();
    }
  }

  ~mozAutoDocUpdate() {
    if (mDocument) {
      mDocument->EndUpdate();
    } else {
      nsContentUtils::RemoveScriptBlocker();
    }
  }

 private:
  nsCOMPtr<nsIDocument> mDocument;
};

#define MOZ_AUTO_DOC_UPDATE_PASTE2(tok, line) tok##line
#define MOZ_AUTO_DOC_UPDATE_PASTE(tok, line) \
  MOZ_AUTO_DOC_UPDATE_PASTE2(tok, line)
#define MOZ_AUTO_DOC_UPDATE(doc, notify)                                  \
  mozAutoDocUpdate MOZ_AUTO_DOC_UPDATE_PASTE(_autoDocUpdater_, __LINE__)( \
      doc, notify)

#endif