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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at */
/* rendering object for CSS "display: grid | inline-grid" */
#ifndef nsGridContainerFrame_h___
#define nsGridContainerFrame_h___
#include "mozilla/CSSOrderAwareFrameIterator.h"
#include "mozilla/Maybe.h"
#include "mozilla/HashTable.h"
#include "nsContainerFrame.h"
namespace mozilla {
class PresShell;
} // namespace mozilla
* Factory function.
* @return a newly allocated nsGridContainerFrame (infallible)
nsContainerFrame* NS_NewGridContainerFrame(mozilla::PresShell* aPresShell,
mozilla::ComputedStyle* aStyle);
namespace mozilla {
* The number of implicit / explicit tracks and their sizes.
struct ComputedGridTrackInfo {
uint32_t aNumLeadingImplicitTracks, uint32_t aNumExplicitTracks,
uint32_t aStartFragmentTrack, uint32_t aEndFragmentTrack,
nsTArray<nscoord>&& aPositions, nsTArray<nscoord>&& aSizes,
nsTArray<uint32_t>&& aStates, nsTArray<bool>&& aRemovedRepeatTracks,
uint32_t aRepeatFirstTrack,
nsTArray<nsTArray<StyleCustomIdent>>&& aResolvedLineNames,
bool aIsSubgrid, bool aIsMasonry)
: mNumLeadingImplicitTracks(aNumLeadingImplicitTracks),
mIsMasonry(aIsMasonry) {}
uint32_t mNumLeadingImplicitTracks;
uint32_t mNumExplicitTracks;
uint32_t mStartFragmentTrack;
uint32_t mEndFragmentTrack;
nsTArray<nscoord> mPositions;
nsTArray<nscoord> mSizes;
nsTArray<uint32_t> mStates;
// Indicates if a track has been collapsed. This will be populated for each
// track in the repeat(auto-fit) and repeat(auto-fill), even if there are no
// collapsed tracks.
nsTArray<bool> mRemovedRepeatTracks;
// Contains lists of all line name lists, including the name lists inside
// repeats. When a repeat(auto) track exists, the internal track names will
// appear once each in this array.
nsTArray<nsTArray<StyleCustomIdent>> mResolvedLineNames;
uint32_t mRepeatFirstTrack;
bool mIsSubgrid;
bool mIsMasonry;
struct ComputedGridLineInfo {
explicit ComputedGridLineInfo(
nsTArray<nsTArray<RefPtr<nsAtom>>>&& aNames,
const nsTArray<RefPtr<nsAtom>>& aNamesBefore,
const nsTArray<RefPtr<nsAtom>>& aNamesAfter,
nsTArray<RefPtr<nsAtom>>&& aNamesFollowingRepeat)
: mNames(std::move(aNames)),
mNamesFollowingRepeat(std::move(aNamesFollowingRepeat)) {}
nsTArray<nsTArray<RefPtr<nsAtom>>> mNames;
nsTArray<RefPtr<nsAtom>> mNamesBefore;
nsTArray<RefPtr<nsAtom>> mNamesAfter;
nsTArray<RefPtr<nsAtom>> mNamesFollowingRepeat;
} // namespace mozilla
class nsGridContainerFrame final : public nsContainerFrame {
using ComputedGridTrackInfo = mozilla::ComputedGridTrackInfo;
using ComputedGridLineInfo = mozilla::ComputedGridLineInfo;
using LogicalAxis = mozilla::LogicalAxis;
using BaselineSharingGroup = mozilla::BaselineSharingGroup;
using NamedArea = mozilla::StyleNamedArea;
template <typename T>
using PerBaseline = mozilla::EnumeratedArray<BaselineSharingGroup,
BaselineSharingGroup(2), T>;
template <typename T>
using PerLogicalAxis =
mozilla::EnumeratedArray<LogicalAxis, LogicalAxis(2), T>;
// nsIFrame overrides
void Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) override;
void Init(nsIContent* aContent, nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) override;
void DidSetComputedStyle(ComputedStyle* aOldStyle) override;
nscoord GetMinISize(gfxContext* aRenderingContext) override;
nscoord GetPrefISize(gfxContext* aRenderingContext) override;
void MarkIntrinsicISizesDirty() override;
bool IsFrameOfType(uint32_t aFlags) const override {
return nsContainerFrame::IsFrameOfType(
aFlags & ~nsIFrame::eCanContainOverflowContainers);
void BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists) override;
nscoord GetLogicalBaseline(mozilla::WritingMode aWM) const override {
// Return a baseline synthesized from our margin-box.
return nsContainerFrame::GetLogicalBaseline(aWM);
nscoord b;
GetBBaseline(BaselineSharingGroup::First, &b);
return b;
bool GetVerticalAlignBaseline(mozilla::WritingMode aWM,
nscoord* aBaseline) const override {
return GetNaturalBaselineBOffset(aWM, BaselineSharingGroup::First,
bool GetNaturalBaselineBOffset(mozilla::WritingMode aWM,
BaselineSharingGroup aBaselineGroup,
nscoord* aBaseline) const override {
return false;
return GetBBaseline(aBaselineGroup, aBaseline);
nsresult GetFrameName(nsAString& aResult) const override;
void ExtraContainerFrameInfo(nsACString& aTo) const override;
// nsContainerFrame overrides
bool DrainSelfOverflowList() override;
void AppendFrames(ChildListID aListID, nsFrameList& aFrameList) override;
void InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
const nsLineList::iterator* aPrevFrameLine,
nsFrameList& aFrameList) override;
void RemoveFrame(ChildListID aListID, nsIFrame* aOldFrame) override;
mozilla::StyleAlignFlags CSSAlignmentForAbsPosChild(
const ReflowInput& aChildRI, LogicalAxis aLogicalAxis) const override;
#ifdef DEBUG
void SetInitialChildList(ChildListID aListID,
nsFrameList& aChildList) override;
* Return the containing block for aChild which MUST be an abs.pos. child
* of a grid container and that container must have been reflowed.
static const nsRect& GridItemCB(nsIFrame* aChild);
* These properties are created by a call to
* nsGridContainerFrame::GetGridFrameWithComputedInfo, typically from
* Element::GetGridFragments.
const ComputedGridTrackInfo* GetComputedTemplateColumns() {
const ComputedGridTrackInfo* info = GetProperty(GridColTrackInfo());
MOZ_ASSERT(info, "Property generation wasn't requested.");
return info;
const ComputedGridTrackInfo* GetComputedTemplateRows() {
const ComputedGridTrackInfo* info = GetProperty(GridRowTrackInfo());
MOZ_ASSERT(info, "Property generation wasn't requested.");
return info;
const ComputedGridLineInfo* GetComputedTemplateColumnLines() {
const ComputedGridLineInfo* info = GetProperty(GridColumnLineInfo());
MOZ_ASSERT(info, "Property generation wasn't requested.");
return info;
const ComputedGridLineInfo* GetComputedTemplateRowLines() {
const ComputedGridLineInfo* info = GetProperty(GridRowLineInfo());
MOZ_ASSERT(info, "Property generation wasn't requested.");
return info;
struct AtomKey {
RefPtr<nsAtom> mKey;
explicit AtomKey(nsAtom* aAtom) : mKey(aAtom) {}
using Lookup = nsAtom*;
static mozilla::HashNumber hash(const Lookup& aKey) { return aKey->hash(); }
static bool match(const AtomKey& aFirst, const Lookup& aSecond) {
return aFirst.mKey == aSecond;
using ImplicitNamedAreas = mozilla::HashMap<AtomKey, NamedArea, AtomKey>;
ImplicitNamedAreas* GetImplicitNamedAreas() const {
return GetProperty(ImplicitNamedAreasProperty());
using ExplicitNamedAreas = mozilla::StyleOwnedSlice<NamedArea>;
ExplicitNamedAreas* GetExplicitNamedAreas() const {
return GetProperty(ExplicitNamedAreasProperty());
using nsContainerFrame::IsMasonry;
/** Return true if this frame has masonry layout in any axis. */
bool IsMasonry() const {
/** Return true if this frame is subgridded in its aAxis. */
bool IsSubgrid(LogicalAxis aAxis) const {
return HasAnyStateBits(aAxis == mozilla::eLogicalAxisBlock
bool IsColSubgrid() const { return IsSubgrid(mozilla::eLogicalAxisInline); }
bool IsRowSubgrid() const { return IsSubgrid(mozilla::eLogicalAxisBlock); }
/** Return true if this frame is subgridded in any axis. */
bool IsSubgrid() const {
/** Return true if this frame has an item that is subgridded in our aAxis. */
bool HasSubgridItems(LogicalAxis aAxis) const {
return HasAnyStateBits(aAxis == mozilla::eLogicalAxisBlock
/** Return true if this frame has any subgrid items. */
bool HasSubgridItems() const {
* Return a container grid frame for the supplied frame, if available.
* @return nullptr if aFrame has no grid container.
static nsGridContainerFrame* GetGridContainerFrame(nsIFrame* aFrame);
* Return a container grid frame, and ensure it has computed grid info
* @return nullptr if aFrame has no grid container, or frame was destroyed
* @note this might destroy layout/style data since it may flush layout
static nsGridContainerFrame* GetGridFrameWithComputedInfo(nsIFrame* aFrame);
struct Subgrid;
struct UsedTrackSizes;
struct TrackSize;
struct GridItemInfo;
struct GridReflowInput;
struct FindItemInGridOrderResult {
// The first(last) item in (reverse) grid order.
const GridItemInfo* mItem;
// Does the above item span the first(last) track?
bool mIsInEdgeTrack;
/** Return our parent grid container; |this| MUST be a subgrid. */
nsGridContainerFrame* ParentGridContainerForSubgrid() const;
enum class SizingConstraint {
MinContent, // sizing under min-content constraint
MaxContent, // sizing under max-content constraint
NoConstraint // no constraint, used during Reflow
typedef mozilla::LogicalPoint LogicalPoint;
typedef mozilla::LogicalRect LogicalRect;
typedef mozilla::LogicalSize LogicalSize;
typedef mozilla::WritingMode WritingMode;
struct Grid;
struct GridArea;
class LineNameMap;
struct LineRange;
struct SharedGridData;
struct SubgridFallbackTrackSizingFunctions;
struct TrackSizingFunctions;
struct Tracks;
struct TranslatedLineRange;
friend nsContainerFrame* NS_NewGridContainerFrame(
mozilla::PresShell* aPresShell, ComputedStyle* aStyle);
explicit nsGridContainerFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext)
: nsContainerFrame(aStyle, aPresContext, kClassID),
for (auto& perAxisBaseline : mBaseline) {
for (auto& baseline : perAxisBaseline) {
* XXX temporary - move the ImplicitNamedAreas stuff to the style system.
* The implicit area names that come from x-start .. x-end lines in
* grid-template-columns / grid-template-rows are stored in this frame
* property when needed, as a ImplicitNamedAreas* value.
void InitImplicitNamedAreas(const nsStylePosition* aStyle);
using LineNameList =
const mozilla::StyleOwnedSlice<mozilla::StyleCustomIdent>;
void AddImplicitNamedAreas(mozilla::Span<LineNameList>);
* Reflow and place our children.
* @return the consumed size of all of this grid container's continuations
* so far including this frame
nscoord ReflowChildren(GridReflowInput& aState,
const LogicalRect& aContentArea,
const nsSize& aContainerSize,
ReflowOutput& aDesiredSize, nsReflowStatus& aStatus);
* Helper for GetMinISize / GetPrefISize.
nscoord IntrinsicISize(gfxContext* aRenderingContext,
mozilla::IntrinsicISizeType aConstraint);
bool GetBBaseline(BaselineSharingGroup aBaselineGroup,
nscoord* aResult) const {
*aResult = mBaseline[mozilla::eLogicalAxisBlock][aBaselineGroup];
return true;
bool GetIBaseline(BaselineSharingGroup aBaselineGroup,
nscoord* aResult) const {
*aResult = mBaseline[mozilla::eLogicalAxisInline][aBaselineGroup];
return true;
* Calculate this grid container's baselines.
* @param aBaselineSet which baseline(s) to derive from a baseline-group or
* items; a baseline not included is synthesized from the border-box instead.
* @param aFragmentStartTrack is the first track in this fragment in the same
* axis as aMajor. Pass zero if that's not the axis we're fragmenting in.
* @param aFirstExcludedTrack should be the first track in the next fragment
* or one beyond the final track in the last fragment, in aMajor's axis.
* Pass the number of tracks if that's not the axis we're fragmenting in.
enum BaselineSet : uint32_t {
eNone = 0x0,
eFirst = 0x1,
eLast = 0x2,
eBoth = eFirst | eLast,
void CalculateBaselines(BaselineSet aBaselineSet,
mozilla::CSSOrderAwareFrameIterator* aIter,
const nsTArray<GridItemInfo>* aGridItems,
const Tracks& aTracks, uint32_t aFragmentStartTrack,
uint32_t aFirstExcludedTrack, WritingMode aWM,
const nsSize& aCBPhysicalSize,
nscoord aCBBorderPaddingStart,
nscoord aCBBorderPaddingStartEnd, nscoord aCBSize);
* Synthesize a Grid container baseline for aGroup.
nscoord SynthesizeBaseline(const FindItemInGridOrderResult& aItem,
LogicalAxis aAxis, BaselineSharingGroup aGroup,
const nsSize& aCBPhysicalSize, nscoord aCBSize,
WritingMode aCBWM);
* Find the first item in Grid Order in this fragment.
* @param aFragmentStartTrack is the first track in this fragment in the same
* axis as aMajor. Pass zero if that's not the axis we're fragmenting in.
static FindItemInGridOrderResult FindFirstItemInGridOrder(
mozilla::CSSOrderAwareFrameIterator& aIter,
const nsTArray<GridItemInfo>& aGridItems, LineRange GridArea::*aMajor,
LineRange GridArea::*aMinor, uint32_t aFragmentStartTrack);
* Find the last item in Grid Order in this fragment.
* @param aFragmentStartTrack is the first track in this fragment in the same
* axis as aMajor. Pass zero if that's not the axis we're fragmenting in.
* @param aFirstExcludedTrack should be the first track in the next fragment
* or one beyond the final track in the last fragment, in aMajor's axis.
* Pass the number of tracks if that's not the axis we're fragmenting in.
static FindItemInGridOrderResult FindLastItemInGridOrder(
mozilla::ReverseCSSOrderAwareFrameIterator& aIter,
const nsTArray<GridItemInfo>& aGridItems, LineRange GridArea::*aMajor,
LineRange GridArea::*aMinor, uint32_t aFragmentStartTrack,
uint32_t aFirstExcludedTrack);
* Update our NS_STATE_GRID_IS_COL/ROW_SUBGRID bits and related subgrid state
* on our entire continuation chain based on the current style.
* This is needed because grid-template-columns/rows style changes only
* trigger a reflow so we need to update this dynamically.
void UpdateSubgridFrameState();
* NS_STATE_GRID_IS_ROW/COL_MASONRY bits we ought to have.
nsFrameState ComputeSelfSubgridMasonryBits() const;
/** Helper for ComputeSelfSubgridMasonryBits(). */
bool WillHaveAtLeastOneTrackInAxis(LogicalAxis aAxis) const;
// Helpers for ReflowChildren
struct Fragmentainer {
* The distance from the first grid container fragment's block-axis content
* edge to the fragmentainer end.
nscoord mToFragmentainerEnd;
* True if the current fragment is at the start of the fragmentainer.
bool mIsTopOfPage;
* Is there a Class C break opportunity at the start content edge?
bool mCanBreakAtStart;
* Is there a Class C break opportunity at the end content edge?
bool mCanBreakAtEnd;
* Is the grid container's block-size unconstrained?
bool mIsAutoBSize;
mozilla::Maybe<nsGridContainerFrame::Fragmentainer> GetNearestFragmentainer(
const GridReflowInput& aState) const;
// @return the consumed size of all continuations so far including this frame
nscoord ReflowInFragmentainer(GridReflowInput& aState,
const LogicalRect& aContentArea,
ReflowOutput& aDesiredSize,
nsReflowStatus& aStatus,
Fragmentainer& aFragmentainer,
const nsSize& aContainerSize);
// Helper for ReflowInFragmentainer
// @return the consumed size of all continuations so far including this frame
nscoord ReflowRowsInFragmentainer(
GridReflowInput& aState, const LogicalRect& aContentArea,
ReflowOutput& aDesiredSize, nsReflowStatus& aStatus,
Fragmentainer& aFragmentainer, const nsSize& aContainerSize,
const nsTArray<const GridItemInfo*>& aItems, uint32_t aStartRow,
uint32_t aEndRow, nscoord aBSize, nscoord aAvailableSize);
// Helper for ReflowChildren / ReflowInFragmentainer
void ReflowInFlowChild(nsIFrame* aChild, const GridItemInfo* aGridItemInfo,
nsSize aContainerSize,
const mozilla::Maybe<nscoord>& aStretchBSize,
const Fragmentainer* aFragmentainer,
const GridReflowInput& aState,
const LogicalRect& aContentArea,
ReflowOutput& aDesiredSize, nsReflowStatus& aStatus);
* Places and reflows items when we have masonry layout.
* It handles unconstrained reflow and also fragmentation when the row axis
* is the masonry axis. ReflowInFragmentainer handles the case when we're
* fragmenting and our row axis is a grid axis and it handles masonry layout
* in the column axis in that case.
* @return the intrinsic size in the masonry axis
nscoord MasonryLayout(GridReflowInput& aState,
const LogicalRect& aContentArea,
SizingConstraint aConstraint,
ReflowOutput& aDesiredSize, nsReflowStatus& aStatus,
Fragmentainer* aFragmentainer,
const nsSize& aContainerSize);
// Return the stored UsedTrackSizes, if any.
UsedTrackSizes* GetUsedTrackSizes() const;
// Store the given TrackSizes in aAxis on a UsedTrackSizes frame property.
void StoreUsedTrackSizes(LogicalAxis aAxis,
const nsTArray<TrackSize>& aSizes);
* Cached values to optimize GetMinISize/GetPrefISize.
nscoord mCachedMinISize;
nscoord mCachedPrefISize;
// Our baselines, one per BaselineSharingGroup per axis.
PerLogicalAxis<PerBaseline<nscoord>> mBaseline;
#endif /* nsGridContainerFrame_h___ */