dom/grid/GridTracks.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 "GridTracks.h"
   8
   9 #include "GridDimension.h"
  10 #include "GridTrack.h"
  11 #include "mozilla/dom/GridBinding.h"
  12 #include "nsGridContainerFrame.h"
  13
  14 namespace mozilla {
  15 namespace dom {
  16
  17 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GridTracks, mParent, mTracks)
  18 NS_IMPL_CYCLE_COLLECTING_ADDREF(GridTracks)
  19 NS_IMPL_CYCLE_COLLECTING_RELEASE(GridTracks)
  20 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GridTracks)
  21   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  22   NS_INTERFACE_MAP_ENTRY(nsISupports)
  23 NS_INTERFACE_MAP_END
  24
  25 GridTracks::GridTracks(GridDimension* aParent) : mParent(aParent) {
  26   MOZ_ASSERT(aParent, "Should never be instantiated with a null GridDimension");
  27 }
  28
  29 GridTracks::~GridTracks() = default;
  30
  31 JSObject* GridTracks::WrapObject(JSContext* aCx,
  32                                  JS::Handle<JSObject*> aGivenProto) {
  33   return GridTracks_Binding::Wrap(aCx, this, aGivenProto);
  34 }
  35
  36 uint32_t GridTracks::Length() const { return mTracks.Length(); }
  37
  38 GridTrack* GridTracks::Item(uint32_t aIndex) {
  39   return mTracks.SafeElementAt(aIndex);
  40 }
  41
  42 GridTrack* GridTracks::IndexedGetter(uint32_t aIndex, bool& aFound) {
  43   aFound = aIndex < mTracks.Length();
  44   if (!aFound) {
  45     return nullptr;
  46   }
  47   return mTracks[aIndex];
  48 }
  49
  50 void GridTracks::SetTrackInfo(const ComputedGridTrackInfo* aTrackInfo) {
  51   // rebuild the tracks based on aTrackInfo
  52   mTracks.Clear();
  53
  54   if (!aTrackInfo) {
  55     return;
  56   }
  57
  58   nscoord lastTrackEdge = 0;
  59   uint32_t repeatIndex = 0;
  60   auto AppendRemovedAutoFits = [this, &aTrackInfo, &lastTrackEdge,
  61                                 &repeatIndex]() {
  62     uint32_t numRepeatTracks = aTrackInfo->mRemovedRepeatTracks.Length();
  63     // Add in removed auto-fit tracks
  64     while (repeatIndex < numRepeatTracks &&
  65            aTrackInfo->mRemovedRepeatTracks[repeatIndex]) {
  66       RefPtr<GridTrack> track = new GridTrack(this);
  67       mTracks.AppendElement(track);
  68       track->SetTrackValues(
  69           nsPresContext::AppUnitsToDoubleCSSPixels(lastTrackEdge),
  70           nsPresContext::AppUnitsToDoubleCSSPixels(0),
  71           GridDeclaration::Explicit, GridTrackState::Removed);
  72       repeatIndex++;
  73     }
  74     repeatIndex++;
  75   };
  76
  77   for (size_t i = aTrackInfo->mStartFragmentTrack;
  78        i < aTrackInfo->mEndFragmentTrack; i++) {
  79     if (i >= aTrackInfo->mRepeatFirstTrack) {
  80       // Append removed auto-fit tracks, if appropriate. The
  81       // AppendRemovedAutoFits function exits early once it has been called
  82       // aTrackInfo->mRemovedRepeatTracks.Length() times -- a check we don't
  83       // replicate here or at subsequent calling sites.
  84       AppendRemovedAutoFits();
  85     }
  86
  87     RefPtr<GridTrack> track = new GridTrack(this);
  88     mTracks.AppendElement(track);
  89     track->SetTrackValues(
  90         nsPresContext::AppUnitsToDoubleCSSPixels(aTrackInfo->mPositions[i]),
  91         nsPresContext::AppUnitsToDoubleCSSPixels(aTrackInfo->mSizes[i]),
  92         (
  93             // Implicit if index is before the first explicit track, or after
  94             // the last explicit track.
  95             (i < aTrackInfo->mNumLeadingImplicitTracks) ||
  96                     (i >= aTrackInfo->mNumLeadingImplicitTracks +
  97                               aTrackInfo->mNumExplicitTracks)
  98                 ? GridDeclaration::Implicit
  99                 : GridDeclaration::Explicit),
 100         GridTrackState(aTrackInfo->mStates[i]));
 101
 102     lastTrackEdge = aTrackInfo->mPositions[i] + aTrackInfo->mSizes[i];
 103   }
 104
 105   // Append any trailing removed auto-fit tracks.
 106   AppendRemovedAutoFits();
 107 }
 108
 109 }  // namespace dom
 110 }  // namespace mozilla