gecko-dev/dom/base/mozAutoDocUpdate.h

90 строки
2.5 KiB
C++

/* 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, nsUpdateType aUpdateType,
bool aNotify) :
mDocument(aNotify ? aDocument : nullptr),
mUpdateType(aUpdateType)
{
if (mDocument) {
mDocument->BeginUpdate(mUpdateType);
}
else {
nsContentUtils::AddScriptBlocker();
}
}
~mozAutoDocUpdate()
{
if (mDocument) {
mDocument->EndUpdate(mUpdateType);
}
else {
nsContentUtils::RemoveScriptBlocker();
}
}
private:
nsCOMPtr<nsIDocument> mDocument;
nsUpdateType mUpdateType;
};
#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,type,notify) \
mozAutoDocUpdate MOZ_AUTO_DOC_UPDATE_PASTE(_autoDocUpdater_, __LINE__) \
(doc,type,notify)
/**
* Creates an update batch only under certain conditions.
* Use this rather than mozAutoDocUpdate when you expect inner updates
* to notify but you don't always want to spec cycles creating a batch.
* This is needed to avoid having this batch always create a blocker,
* but then have inner mozAutoDocUpdate call the last EndUpdate before.
* we remove that blocker. See bug 423269.
*/
class MOZ_STACK_CLASS mozAutoDocConditionalContentUpdateBatch
{
public:
mozAutoDocConditionalContentUpdateBatch(nsIDocument* aDocument,
bool aNotify) :
mDocument(aNotify ? aDocument : nullptr)
{
if (mDocument) {
mDocument->BeginUpdate(UPDATE_CONTENT_MODEL);
}
}
~mozAutoDocConditionalContentUpdateBatch()
{
if (mDocument) {
mDocument->EndUpdate(UPDATE_CONTENT_MODEL);
}
}
private:
nsCOMPtr<nsIDocument> mDocument;
};
#endif