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