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     ScrollOrigin aOrigin, nsPoint aDestination,
  62     ScrollTriggeredByScript aTriggeredByScript) {
  63   MOZ_ASSERT(aOrigin != ScrollOrigin::NotSpecified);
  64   MOZ_ASSERT(aOrigin != ScrollOrigin::None);
  65
  66   ScrollPositionUpdate ret;
  67   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  68   ret.mType = ScrollUpdateType::Absolute;
  69   ret.mScrollMode = ScrollMode::SmoothMsd;
  70   ret.mScrollOrigin = aOrigin;
  71   ret.mDestination = CSSPoint::FromAppUnits(aDestination);
  72   ret.mTriggeredByScript = aTriggeredByScript;
  73   return ret;
  74 }
  75
  76 /*static*/
  77 ScrollPositionUpdate ScrollPositionUpdate::NewPureRelativeScroll(
  78     ScrollOrigin aOrigin, ScrollMode aMode, const nsPoint& aDelta) {
  79   MOZ_ASSERT(aOrigin != ScrollOrigin::NotSpecified);
  80   MOZ_ASSERT(aOrigin != ScrollOrigin::None);
  81
  82   ScrollPositionUpdate ret;
  83   ret.mScrollGeneration = sGenerationCounter.NewMainThreadGeneration();
  84   ret.mType = ScrollUpdateType::PureRelative;
  85   ret.mScrollMode = aMode;
  86   ret.mScrollOrigin = aOrigin;
  87   ret.mDelta = CSSPoint::FromAppUnits(aDelta);
  88   return ret;
  89 }
  90
  91 bool ScrollPositionUpdate::operator==(
  92     const ScrollPositionUpdate& aOther) const {
  93   // instances are immutable, and all the fields are set when the generation
  94   // is set. So if the generation matches, these instances are identical.
  95   return mScrollGeneration == aOther.mScrollGeneration;
  96 }
  97
  98 MainThreadScrollGeneration ScrollPositionUpdate::GetGeneration() const {
  99   return mScrollGeneration;
 100 }
 101
 102 ScrollUpdateType ScrollPositionUpdate::GetType() const { return mType; }
 103
 104 ScrollMode ScrollPositionUpdate::GetMode() const { return mScrollMode; }
 105
 106 ScrollOrigin ScrollPositionUpdate::GetOrigin() const { return mScrollOrigin; }
 107
 108 CSSPoint ScrollPositionUpdate::GetDestination() const {
 109   MOZ_ASSERT(mType == ScrollUpdateType::Absolute ||
 110              mType == ScrollUpdateType::Relative);
 111   return mDestination;
 112 }
 113
 114 CSSPoint ScrollPositionUpdate::GetSource() const {
 115   MOZ_ASSERT(mType == ScrollUpdateType::Relative);
 116   return mSource;
 117 }
 118
 119 CSSPoint ScrollPositionUpdate::GetDelta() const {
 120   MOZ_ASSERT(mType == ScrollUpdateType::PureRelative);
 121   return mDelta;
 122 }
 123
 124 std::ostream& operator<<(std::ostream& aStream,
 125                          const ScrollPositionUpdate& aUpdate) {
 126   aStream << "{ gen=" << aUpdate.mScrollGeneration
 127           << ", type=" << (int)aUpdate.mType
 128           << ", mode=" << (int)aUpdate.mScrollMode
 129           << ", origin=" << (int)aUpdate.mScrollOrigin
 130           << ", dst=" << aUpdate.mDestination << ", src=" << aUpdate.mSource
 131           << ", delta=" << aUpdate.mDelta
 132           << ", triggered by script=" << aUpdate.WasTriggeredByScript() << " }";
 133   return aStream;
 134 }
 135
 136 }  // namespace mozilla