ScrollLinkedEffectDetector.cpp (1434B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #include "ScrollLinkedEffectDetector.h" 8 9 #include "mozilla/dom/Document.h" 10 #include "nsThreadUtils.h" 11 12 namespace mozilla { 13 namespace layers { 14 15 uint32_t ScrollLinkedEffectDetector::sDepth = 0; 16 bool ScrollLinkedEffectDetector::sFoundScrollLinkedEffect = false; 17 18 /* static */ 19 void ScrollLinkedEffectDetector::PositioningPropertyMutated() { 20 MOZ_ASSERT(NS_IsMainThread()); 21 22 if (sDepth > 0) { 23 // We are inside a scroll event dispatch 24 sFoundScrollLinkedEffect = true; 25 } 26 } 27 28 ScrollLinkedEffectDetector::ScrollLinkedEffectDetector( 29 dom::Document* aDoc, const TimeStamp& aTimeStamp) 30 : mDocument(aDoc), mTimeStamp(aTimeStamp) { 31 MOZ_ASSERT(NS_IsMainThread()); 32 sDepth++; 33 } 34 35 ScrollLinkedEffectDetector::~ScrollLinkedEffectDetector() { 36 sDepth--; 37 if (sDepth == 0) { 38 // We have exited all (possibly-nested) scroll event dispatches, 39 // record whether or not we found an effect, and reset state 40 if (sFoundScrollLinkedEffect) { 41 mDocument->ReportHasScrollLinkedEffect(mTimeStamp); 42 sFoundScrollLinkedEffect = false; 43 } 44 } 45 } 46 47 } // namespace layers 48 } // namespace mozilla