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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 nsAutoRollup_h__
#define nsAutoRollup_h__
#include "mozilla/Attributes.h" // for MOZ_RAII
#include "mozilla/StaticPtr.h" // for StaticRefPtr
#include "nsIContent.h"
namespace mozilla {
namespace widget {
// A situation can occur when a mouse event occurs over a menu label while the
// menu popup is already open. The expected behaviour is to close the popup.
// This happens by calling nsIRollupListener::Rollup before the mouse event is
// processed. However, in cases where the mouse event is not consumed, this
// event will then get targeted at the menu label causing the menu to open
// again. To prevent this, we store in sLastRollup a reference to the popup
// that was closed during the Rollup call, and prevent this popup from
// reopening while processing the mouse event.
// sLastRollup can only be set while an nsAutoRollup is in scope;
// when it goes out of scope sLastRollup is cleared automatically.
// As sLastRollup is static, it can be retrieved by calling
// nsAutoRollup::GetLastRollup.
class MOZ_RAII nsAutoRollup {
public:
nsAutoRollup();
~nsAutoRollup();
// Convenience constructor that creates a nsAutoRollup and also sets
// the last rollup.
explicit nsAutoRollup(nsIContent* aRollup);
static void SetLastRollup(nsIContent* aLastRollup);
// Return the popup that was last rolled up, or null if there isn't one.
static nsIContent* GetLastRollup();
private:
// Whether sLastRollup was clear when this nsAutoRollup
// was created.
bool mWasClear;
// The number of nsAutoRollup instances active.
static uint32_t sCount;
// The last rolled up popup.
static StaticRefPtr<nsIContent> sLastRollup;
};
} // namespace widget
} // namespace mozilla
#endif // nsAutoRollup_h__