| /* |
| * Copyright (C) 2020 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
| * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| * THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "WebWheelEventCoalescer.h" |
| |
| #include "Logging.h" |
| #include "NativeWebWheelEvent.h" |
| #include "WebEventConversion.h" |
| #include <wtf/text/TextStream.h> |
| |
| namespace WebKit { |
| |
| // Represents the number of wheel events we can hold in the queue before we start pushing them preemptively. |
| constexpr unsigned wheelEventQueueSizeThreshold = 10; |
| |
| #if !LOG_DISABLED |
| static WTF::TextStream& operator<<(WTF::TextStream& ts, const WebWheelEvent& wheelEvent) |
| { |
| ts << platform(wheelEvent); |
| return ts; |
| } |
| #endif |
| |
| bool WebWheelEventCoalescer::canCoalesce(const WebWheelEvent& a, const WebWheelEvent& b) |
| { |
| if (a.position() != b.position()) |
| return false; |
| if (a.globalPosition() != b.globalPosition()) |
| return false; |
| if (a.modifiers() != b.modifiers()) |
| return false; |
| if (a.granularity() != b.granularity()) |
| return false; |
| #if PLATFORM(COCOA) |
| if (a.phase() != b.phase()) |
| return false; |
| if (a.momentumPhase() != b.momentumPhase()) |
| return false; |
| #endif |
| #if PLATFORM(COCOA) || PLATFORM(GTK) || USE(LIBWPE) |
| if (a.hasPreciseScrollingDeltas() != b.hasPreciseScrollingDeltas()) |
| return false; |
| #endif |
| |
| return true; |
| } |
| |
| WebWheelEvent WebWheelEventCoalescer::coalesce(const WebWheelEvent& a, const WebWheelEvent& b) |
| { |
| ASSERT(canCoalesce(a, b)); |
| |
| auto mergedDelta = a.delta() + b.delta(); |
| auto mergedWheelTicks = a.wheelTicks() + b.wheelTicks(); |
| |
| #if PLATFORM(COCOA) |
| auto mergedUnacceleratedScrollingDelta = a.unacceleratedScrollingDelta() + b.unacceleratedScrollingDelta(); |
| std::optional<WebCore::FloatSize> mergedRawPlatformScrollingDelta; |
| if (a.rawPlatformDelta() && b.rawPlatformDelta()) |
| mergedRawPlatformScrollingDelta = a.rawPlatformDelta().value() + b.rawPlatformDelta().value(); |
| |
| return WebWheelEvent(WebEvent::Wheel, b.position(), b.globalPosition(), mergedDelta, mergedWheelTicks, b.granularity(), b.directionInvertedFromDevice(), b.phase(), b.momentumPhase(), b.hasPreciseScrollingDeltas(), b.scrollCount(), mergedUnacceleratedScrollingDelta, b.modifiers(), b.timestamp(), b.ioHIDEventTimestamp(), mergedRawPlatformScrollingDelta, b.momentumEndType()); |
| #elif PLATFORM(GTK) || USE(LIBWPE) |
| return WebWheelEvent(WebEvent::Wheel, b.position(), b.globalPosition(), mergedDelta, mergedWheelTicks, b.phase(), b.momentumPhase(), b.granularity(), b.hasPreciseScrollingDeltas(), b.modifiers(), b.timestamp()); |
| #else |
| return WebWheelEvent(WebEvent::Wheel, b.position(), b.globalPosition(), mergedDelta, mergedWheelTicks, b.granularity(), b.modifiers(), b.timestamp()); |
| #endif |
| } |
| |
| bool WebWheelEventCoalescer::shouldDispatchEventNow(const WebWheelEvent& event) const |
| { |
| #if PLATFORM(GTK) |
| // Don't queue events representing a non-trivial scrolling phase to |
| // avoid having them trapped in the queue, potentially preventing a |
| // scrolling session to beginning or end correctly. |
| // This is only needed by platforms whose WebWheelEvent has this phase |
| // information (Cocoa and GTK+) but Cocoa was fine without it. |
| if (event.phase() == WebWheelEvent::Phase::PhaseNone |
| || event.phase() == WebWheelEvent::Phase::PhaseChanged |
| || event.momentumPhase() == WebWheelEvent::Phase::PhaseNone |
| || event.momentumPhase() == WebWheelEvent::Phase::PhaseChanged) |
| return true; |
| #else |
| UNUSED_PARAM(event); |
| #endif |
| |
| return m_wheelEventQueue.size() >= wheelEventQueueSizeThreshold; |
| } |
| |
| std::optional<WebWheelEvent> WebWheelEventCoalescer::nextEventToDispatch() |
| { |
| if (m_wheelEventQueue.isEmpty()) |
| return std::nullopt; |
| |
| auto coalescedEvent = m_wheelEventQueue.takeFirst(); |
| |
| auto coalescedSequence = makeUnique<CoalescedEventSequence>(); |
| coalescedSequence->append(coalescedEvent); |
| |
| WebWheelEvent coalescedWebEvent = coalescedEvent; |
| |
| while (!m_wheelEventQueue.isEmpty() && canCoalesce(coalescedWebEvent, m_wheelEventQueue.first())) { |
| auto firstEvent = m_wheelEventQueue.takeFirst(); |
| coalescedSequence->append(firstEvent); |
| coalescedWebEvent = coalesce(coalescedWebEvent, firstEvent); |
| } |
| |
| #if !LOG_DISABLED |
| if (coalescedSequence->size() > 1) |
| LOG_WITH_STREAM(WheelEvents, stream << "WebWheelEventCoalescer::wheelEventWithCoalescing coalesced " << *coalescedSequence << " into " << coalescedWebEvent); |
| #endif |
| |
| m_eventsBeingProcessed.append(WTFMove(coalescedSequence)); |
| return coalescedWebEvent; |
| } |
| |
| bool WebWheelEventCoalescer::shouldDispatchEvent(const NativeWebWheelEvent& event) |
| { |
| LOG_WITH_STREAM(WheelEvents, stream << "WebWheelEventCoalescer::shouldDispatchEvent " << event << " (" << m_wheelEventQueue.size() << " events in the queue, " << m_eventsBeingProcessed.size() << " event sequences being processed)"); |
| |
| m_wheelEventQueue.append(event); |
| |
| if (!m_eventsBeingProcessed.isEmpty()) { |
| if (!shouldDispatchEventNow(m_wheelEventQueue.last())) { |
| LOG_WITH_STREAM(WheelEvents, stream << "WebWheelEventCoalescer::shouldDispatchEvent - " << m_wheelEventQueue.size() << " events queued; not dispatching"); |
| return false; |
| } |
| // The queue has too many wheel events, so push a new event. |
| // FIXME: This logic is confusing, and possibly not necessary. |
| } |
| |
| return true; |
| } |
| |
| NativeWebWheelEvent WebWheelEventCoalescer::takeOldestEventBeingProcessed() |
| { |
| ASSERT(hasEventsBeingProcessed()); |
| auto oldestSequence = m_eventsBeingProcessed.takeFirst(); |
| return oldestSequence->last(); |
| } |
| |
| void WebWheelEventCoalescer::clear() |
| { |
| m_wheelEventQueue.clear(); |
| m_eventsBeingProcessed.clear(); |
| } |
| |
| } // namespace WebKit |