gecko-dev/widget/nsAutoRollup.h
Kartikaya Gupta 0525357947 Bug 1343977 - Ensure that synthetic mouseclicks generated from touch gestures don't reopen rollups. r=botond,enndeakin+6102
Synthetic mouseevents generated from touch gestures are dispatched asynchronously
from the touch events. This means that the nsAutoRollup that the widget puts on
the stack during the dispatching of the touch events is no longer in scope when
we get around to firing the mouse events. As a result, the mouse events can end
up reopening rollups that got closed by the touch events and that shouldn't be
reopened. We fix this by stashing the rollup that was in scope while the touch
events were being dispatched, and make sure we keep that in scope for the
synthetic mouse events.

MozReview-Commit-ID: HjteKHfAqvD

--HG--
extra : rebase_source : 46217b1ba610ef193963ccab454a6f584af61a2b
2017-03-13 10:44:59 -04:00

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2.0 KiB
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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
class nsIContent;
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__