dom/ipc/CoalescedTouchData.cpp

   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 "CoalescedTouchData.h"
   8 #include "BrowserChild.h"
   9 #include "mozilla/dom/PointerEventHandler.h"
  10
  11 using namespace mozilla;
  12 using namespace mozilla::dom;
  13
  14 static const uint32_t sMaxTouchMoveIdentifiers = 10;
  15
  16 void CoalescedTouchData::CreateCoalescedTouchEvent(
  17     const WidgetTouchEvent& aEvent) {
  18   MOZ_ASSERT(IsEmpty());
  19   mCoalescedInputEvent = MakeUnique<WidgetTouchEvent>(aEvent);
  20   for (size_t i = 0; i < mCoalescedInputEvent->mTouches.Length(); i++) {
  21     const RefPtr<Touch>& touch = mCoalescedInputEvent->mTouches[i];
  22     touch->mCoalescedWidgetEvents = MakeAndAddRef<WidgetPointerEventHolder>();
  23     // Add an initial event into coalesced events, so
  24     // the relevant pointer event would at least contain one coalesced event.
  25     WidgetPointerEvent* event =
  26         touch->mCoalescedWidgetEvents->mEvents.AppendElement(WidgetPointerEvent(
  27             aEvent.IsTrusted(), ePointerMove, aEvent.mWidget));
  28     PointerEventHandler::InitPointerEventFromTouch(*event, aEvent, *touch,
  29                                                    i == 0);
  30     event->mFlags.mBubbles = false;
  31     event->mFlags.mCancelable = false;
  32   }
  33 }
  34
  35 void CoalescedTouchData::Coalesce(const WidgetTouchEvent& aEvent,
  36                                   const ScrollableLayerGuid& aGuid,
  37                                   const uint64_t& aInputBlockId,
  38                                   const nsEventStatus& aApzResponse) {
  39   MOZ_ASSERT(aEvent.mMessage == eTouchMove);
  40   if (IsEmpty()) {
  41     CreateCoalescedTouchEvent(aEvent);
  42     mGuid = aGuid;
  43     mInputBlockId = aInputBlockId;
  44     mApzResponse = aApzResponse;
  45   } else {
  46     MOZ_ASSERT(mGuid == aGuid);
  47     MOZ_ASSERT(mInputBlockId == aInputBlockId);
  48     MOZ_ASSERT(mCoalescedInputEvent->mModifiers == aEvent.mModifiers);
  49     MOZ_ASSERT(mCoalescedInputEvent->mInputSource == aEvent.mInputSource);
  50
  51     for (size_t i = 0; i < aEvent.mTouches.Length(); i++) {
  52       const RefPtr<Touch>& touch = aEvent.mTouches[i];
  53       // Get the same touch in the original event
  54       RefPtr<Touch> sameTouch = GetTouch(touch->Identifier());
  55       // The checks in CoalescedTouchData::CanCoalesce ensure it should never
  56       // be null.
  57       MOZ_ASSERT(sameTouch);
  58       MOZ_ASSERT(sameTouch->mCoalescedWidgetEvents);
  59       MOZ_ASSERT(!sameTouch->mCoalescedWidgetEvents->mEvents.IsEmpty());
  60       if (!sameTouch->Equals(touch)) {
  61         sameTouch->SetSameAs(touch);
  62         WidgetPointerEvent* event =
  63             sameTouch->mCoalescedWidgetEvents->mEvents.AppendElement(
  64                 WidgetPointerEvent(aEvent.IsTrusted(), ePointerMove,
  65                                    aEvent.mWidget));
  66         PointerEventHandler::InitPointerEventFromTouch(*event, aEvent, *touch,
  67                                                        i == 0);
  68         event->mFlags.mBubbles = false;
  69         event->mFlags.mCancelable = false;
  70       }
  71     }
  72
  73     mCoalescedInputEvent->mTimeStamp = aEvent.mTimeStamp;
  74   }
  75 }
  76
  77 bool CoalescedTouchData::CanCoalesce(const WidgetTouchEvent& aEvent,
  78                                      const ScrollableLayerGuid& aGuid,
  79                                      const uint64_t& aInputBlockId,
  80                                      const nsEventStatus& aApzResponse) {
  81   MOZ_ASSERT(!IsEmpty());
  82   if (mGuid != aGuid || mInputBlockId != aInputBlockId ||
  83       mCoalescedInputEvent->mModifiers != aEvent.mModifiers ||
  84       mCoalescedInputEvent->mInputSource != aEvent.mInputSource ||
  85       aEvent.mTouches.Length() > sMaxTouchMoveIdentifiers) {
  86     return false;
  87   }
  88
  89   // Ensures both touchmove events have the same touches
  90   if (aEvent.mTouches.Length() != mCoalescedInputEvent->mTouches.Length()) {
  91     return false;
  92   }
  93   for (const RefPtr<Touch>& touch : aEvent.mTouches) {
  94     if (!GetTouch(touch->Identifier())) {
  95       return false;
  96     }
  97   }
  98
  99   // If one of them is eIgnore and the other one is eConsumeDoDefault,
 100   // we always coalesce them to eConsumeDoDefault.
 101   if (mApzResponse != aApzResponse) {
 102     if (mApzResponse == nsEventStatus::nsEventStatus_eIgnore &&
 103         aApzResponse == nsEventStatus::nsEventStatus_eConsumeDoDefault) {
 104       mApzResponse = aApzResponse;
 105     } else if (mApzResponse != nsEventStatus::nsEventStatus_eConsumeDoDefault ||
 106                aApzResponse != nsEventStatus::nsEventStatus_eIgnore) {
 107       return false;
 108     }
 109   }
 110
 111   return true;
 112 }
 113
 114 Touch* CoalescedTouchData::GetTouch(int32_t aIdentifier) {
 115   for (const RefPtr<Touch>& touch : mCoalescedInputEvent->mTouches) {
 116     if (touch->Identifier() == aIdentifier) {
 117       return touch;
 118     }
 119   }
 120   return nullptr;
 121 }
 122
 123 void CoalescedTouchMoveFlusher::WillRefresh(mozilla::TimeStamp aTime) {
 124   MOZ_ASSERT(mRefreshDriver);
 125   mBrowserChild->ProcessPendingCoalescedTouchData();
 126 }
 127
 128 CoalescedTouchMoveFlusher::CoalescedTouchMoveFlusher(
 129     BrowserChild* aBrowserChild)
 130     : CoalescedInputFlusher(aBrowserChild) {}
 131
 132 CoalescedTouchMoveFlusher::~CoalescedTouchMoveFlusher() { RemoveObserver(); }