layout/generic/ScrollPositionUpdate.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "ScrollPositionUpdate.h"
   6
   7 #include <ostream>
   8
   9 #include "mozilla/Assertions.h"
  10
  11 namespace mozilla {
  12
  13 static ScrollGenerationCounter sGenerationCounter;
  14
  15 ScrollPositionUpdate::ScrollPositionUpdate()
  16     : mType(ScrollUpdateType::Absolute),
  17       mScrollMode(ScrollMode::Normal),
  18       mScrollOrigin(ScrollOrigin::None),
  19       mTriggeredByScript(ScrollTriggeredByScript::No) {}
  20
  21 /*static*/
  22 ScrollPositionUpdate ScrollPositionUpdate::NewScrollframe(
  23     nsPoint aInitialPosition) {
  24   ScrollPositionUpdate ret;
  25   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  26   ret.mScrollMode = ScrollMode::Instant;
  27   ret.mDestination = CSSPoint::FromAppUnits(aInitialPosition);
  28   return ret;
  29 }
  30
  31 /*static*/
  32 ScrollPositionUpdate ScrollPositionUpdate::NewScroll(ScrollOrigin aOrigin,
  33                                                      nsPoint aDestination) {
  34   MOZ_ASSERT(aOrigin != ScrollOrigin::NotSpecified);
  35   MOZ_ASSERT(aOrigin != ScrollOrigin::None);
  36
  37   ScrollPositionUpdate ret;
  38   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  39   ret.mType = ScrollUpdateType::Absolute;
  40   ret.mScrollMode = ScrollMode::Instant;
  41   ret.mScrollOrigin = aOrigin;
  42   ret.mDestination = CSSPoint::FromAppUnits(aDestination);
  43   return ret;
  44 }
  45
  46 /*static*/
  47 ScrollPositionUpdate ScrollPositionUpdate::NewRelativeScroll(
  48     nsPoint aSource, nsPoint aDestination) {
  49   ScrollPositionUpdate ret;
  50   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  51   ret.mType = ScrollUpdateType::Relative;
  52   ret.mScrollMode = ScrollMode::Instant;
  53   ret.mScrollOrigin = ScrollOrigin::Relative;
  54   ret.mDestination = CSSPoint::FromAppUnits(aDestination);
  55   ret.mSource = CSSPoint::FromAppUnits(aSource);
  56   return ret;
  57 }
  58
  59 /*static*/
  60 ScrollPositionUpdate ScrollPositionUpdate::NewSmoothScroll(
  61     ScrollMode aMode, ScrollOrigin aOrigin, nsPoint aDestination,
  62     ScrollTriggeredByScript aTriggeredByScript,
  63     UniquePtr<ScrollSnapTargetIds> aSnapTargetIds) {
  64   MOZ_ASSERT(aOrigin != ScrollOrigin::NotSpecified);
  65   MOZ_ASSERT(aOrigin != ScrollOrigin::None);
  66   MOZ_ASSERT(aMode == ScrollMode::Smooth || aMode == ScrollMode::SmoothMsd);
  67
  68   ScrollPositionUpdate ret;
  69   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  70   ret.mType = ScrollUpdateType::Absolute;
  71   ret.mScrollMode = aMode;
  72   ret.mScrollOrigin = aOrigin;
  73   ret.mDestination = CSSPoint::FromAppUnits(aDestination);
  74   ret.mTriggeredByScript = aTriggeredByScript;
  75   if (aSnapTargetIds) {
  76     ret.mSnapTargetIds = *aSnapTargetIds;
  77   }
  78   return ret;
  79 }
  80
  81 /*static*/
  82 ScrollPositionUpdate ScrollPositionUpdate::NewPureRelativeScroll(
  83     ScrollOrigin aOrigin, ScrollMode aMode, const nsPoint& aDelta) {
  84   MOZ_ASSERT(aOrigin != ScrollOrigin::NotSpecified);
  85   MOZ_ASSERT(aOrigin != ScrollOrigin::None);
  86
  87   ScrollPositionUpdate ret;
  88   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  89   ret.mType = ScrollUpdateType::PureRelative;
  90   ret.mScrollMode = aMode;
  91   ret.mScrollOrigin = aOrigin;
  92   ret.mDelta = CSSPoint::FromAppUnits(aDelta);
  93   return ret;
  94 }
  95
  96 /*static*/
  97 ScrollPositionUpdate ScrollPositionUpdate::NewMergeableScroll(
  98     ScrollOrigin aOrigin, nsPoint aDestination) {
  99   MOZ_ASSERT(aOrigin == ScrollOrigin::AnchorAdjustment);
 100
 101   ScrollPositionUpdate ret;
 102   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
 103   ret.mType = ScrollUpdateType::MergeableAbsolute;
 104   ret.mScrollMode = ScrollMode::Instant;
 105   ret.mScrollOrigin = aOrigin;
 106   ret.mDestination = CSSPoint::FromAppUnits(aDestination);
 107   return ret;
 108 }
 109
 110 bool ScrollPositionUpdate::operator==(
 111     const ScrollPositionUpdate& aOther) const {
 112   // instances are immutable, and all the fields are set when the generation
 113   // is set. So if the generation matches, these instances are identical.
 114   return mScrollGeneration == aOther.mScrollGeneration;
 115 }
 116
 117 MainThreadScrollGeneration ScrollPositionUpdate::GetGeneration() const {
 118   return mScrollGeneration;
 119 }
 120
 121 ScrollUpdateType ScrollPositionUpdate::GetType() const { return mType; }
 122
 123 ScrollMode ScrollPositionUpdate::GetMode() const { return mScrollMode; }
 124
 125 ScrollOrigin ScrollPositionUpdate::GetOrigin() const { return mScrollOrigin; }
 126
 127 CSSPoint ScrollPositionUpdate::GetDestination() const {
 128   MOZ_ASSERT(mType == ScrollUpdateType::Absolute ||
 129              mType == ScrollUpdateType::MergeableAbsolute ||
 130              mType == ScrollUpdateType::Relative);
 131   return mDestination;
 132 }
 133
 134 CSSPoint ScrollPositionUpdate::GetSource() const {
 135   MOZ_ASSERT(mType == ScrollUpdateType::Relative);
 136   return mSource;
 137 }
 138
 139 CSSPoint ScrollPositionUpdate::GetDelta() const {
 140   MOZ_ASSERT(mType == ScrollUpdateType::PureRelative);
 141   return mDelta;
 142 }
 143
 144 std::ostream& operator<<(std::ostream& aStream,
 145                          const ScrollPositionUpdate& aUpdate) {
 146   aStream << "{ gen=" << aUpdate.mScrollGeneration
 147           << ", type=" << (int)aUpdate.mType
 148           << ", mode=" << (int)aUpdate.mScrollMode
 149           << ", origin=" << (int)aUpdate.mScrollOrigin
 150           << ", dst=" << aUpdate.mDestination << ", src=" << aUpdate.mSource
 151           << ", delta=" << aUpdate.mDelta
 152           << ", triggered by script=" << aUpdate.WasTriggeredByScript() << " }";
 153   return aStream;
 154 }
 155
 156 }  // namespace mozilla