зеркало из https://github.com/mozilla/gecko-dev.git
54 строки
1.7 KiB
C++
54 строки
1.7 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_PrintPreviewUserEventSuppressor_h
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#define mozilla_PrintPreviewUserEventSuppressor_h
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#include "nsCOMPtr.h"
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#include "nsIDOMEventListener.h"
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#include "mozilla/Attributes.h"
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namespace mozilla {
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namespace dom {
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class EventTarget;
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} // namespace dom
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/**
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* A class that filters out certain user events targeted at the given event
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* target (a document). Intended for use with the Print Preview document to
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* stop users from doing anything that would break printing invariants. (For
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* example, blocks opening of the context menu, interaction with form controls,
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* content selection, etc.)
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*/
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class PrintPreviewUserEventSuppressor final : public nsIDOMEventListener {
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public:
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NS_DECL_ISUPPORTS
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NS_DECL_NSIDOMEVENTLISTENER
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explicit PrintPreviewUserEventSuppressor(dom::EventTarget* aTarget);
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/**
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* Must be called before releasing this object in order to break the strong
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* reference cycle between ourselves and the document we're listening to,
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* or else the objects in the cylce will be leaked (since this class does
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* not participate in cycle collection).
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*/
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void StopSuppressing() { RemoveListeners(); }
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private:
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~PrintPreviewUserEventSuppressor() { RemoveListeners(); }
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void AddListeners();
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void RemoveListeners();
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nsCOMPtr<mozilla::dom::EventTarget> mEventTarget;
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};
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} // namespace mozilla
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#endif // mozilla_PrintPreviewUserEventSuppressor_h
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