From 3edce263fb92ca96f6d7b5f90baf000bb2e0d74a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tor=20Arne=20Vestb=C3=B8?= Date: Mon, 13 Oct 2014 13:57:35 +0200 Subject: [PATCH] Prevent 'recursive' update events when calling QToolButton::setMenu() Commit bb3d2ca9f18 (QToolButton: properly reset the size hint when a menu is set on it) didn't take the case of re-setting the same menu into account, and the result was that we would unconditionally cause an update, resulting in the following backtrace again and again, as each posted update event was processed by the event loop: frame #0: QToolButton::setMenu(this=0x7af59500, menu=0x00000000) frame #1: QToolBarLayout::setUsePopupMenu(this=0x7ae65a30, set=false) frame #2: QToolBarLayout::checkUsePopupMenu(this=0x7ae65a30) frame #3: QToolBarAreaLayoutLine::fitLayout(this=0x78e5f870) frame #4: QToolBarAreaLayoutInfo::fitLayout(this=0x790be278) ... Besides consuming needless CPU time this also uncovered a case on iOS where Qt would starve native events and animations from being processed, preventing eg. rotation animations from running. Change-Id: Ib6bd4ba21d8e84ca73fb0a75b598016dbd9ae0fd Reviewed-by: Richard Moe Gustavsen --- src/widgets/widgets/qtoolbutton.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/widgets/widgets/qtoolbutton.cpp b/src/widgets/widgets/qtoolbutton.cpp index 3d3f42605e..bb3f2d74a8 100644 --- a/src/widgets/widgets/qtoolbutton.cpp +++ b/src/widgets/widgets/qtoolbutton.cpp @@ -636,6 +636,9 @@ void QToolButton::setMenu(QMenu* menu) { Q_D(QToolButton); + if (d->menuAction == (menu ? menu->menuAction() : 0)) + return; + if (d->menuAction) removeAction(d->menuAction);