dom/base/mozAutoDocUpdate.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozAutoDocUpdate_h_
   8 #define mozAutoDocUpdate_h_
   9
  10 #include "nsContentUtils.h"  // For AddScriptBlocker() and RemoveScriptBlocker().
  11 #include "mozilla/dom/Document.h"
  12 #include "nsIDocumentObserver.h"
  13
  14 /**
  15  * Helper class to automatically handle batching of document updates.  This
  16  * class will call BeginUpdate on construction and EndUpdate on destruction on
  17  * the given document with the given update type.  The document could be null,
  18  * in which case no updates will be called.  The constructor also takes a
  19  * boolean that can be set to false to prevent notifications.
  20  */
  21 class MOZ_STACK_CLASS mozAutoDocUpdate {
  22  public:
  23   mozAutoDocUpdate(mozilla::dom::Document* aDocument, bool aNotify)
  24       : mDocument(aNotify ? aDocument : nullptr) {
  25     if (mDocument) {
  26       mDocument->BeginUpdate();
  27     } else {
  28       nsContentUtils::AddScriptBlocker();
  29     }
  30   }
  31
  32   ~mozAutoDocUpdate() {
  33     if (mDocument) {
  34       mDocument->EndUpdate();
  35     } else {
  36       nsContentUtils::RemoveScriptBlocker();
  37     }
  38   }
  39
  40  private:
  41   RefPtr<mozilla::dom::Document> mDocument;
  42 };
  43
  44 #define MOZ_AUTO_DOC_UPDATE_PASTE2(tok, line) tok##line
  45 #define MOZ_AUTO_DOC_UPDATE_PASTE(tok, line) \
  46   MOZ_AUTO_DOC_UPDATE_PASTE2(tok, line)
  47 #define MOZ_AUTO_DOC_UPDATE(doc, notify)                                  \
  48   mozAutoDocUpdate MOZ_AUTO_DOC_UPDATE_PASTE(_autoDocUpdater_, __LINE__)( \
  49       doc, notify)
  50
  51 #endif