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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
#include "GridLines.h"
#include "GridDimension.h"
#include "GridLine.h"
#include "mozilla/dom/GridBinding.h"
#include "mozilla/dom/GridArea.h"
#include "nsGridContainerFrame.h"
namespace mozilla::dom {
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GridLines, mParent, mLines)
NS_IMPL_CYCLE_COLLECTING_ADDREF(GridLines)
NS_IMPL_CYCLE_COLLECTING_RELEASE(GridLines)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GridLines)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
GridLines::GridLines(GridDimension* aParent) : mParent(aParent) {
MOZ_ASSERT(aParent, "Should never be instantiated with a null GridDimension");
}
GridLines::~GridLines() = default;
JSObject* GridLines::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return GridLines_Binding::Wrap(aCx, this, aGivenProto);
}
uint32_t GridLines::Length() const { return mLines.Length(); }
GridLine* GridLines::Item(uint32_t aIndex) {
return mLines.SafeElementAt(aIndex);
}
GridLine* GridLines::IndexedGetter(uint32_t aIndex, bool& aFound) {
aFound = aIndex < mLines.Length();
if (!aFound) {
return nullptr;
}
return mLines[aIndex];
}
static void AddLineNameIfNotPresent(nsTArray<RefPtr<nsAtom>>& aLineNames,
nsAtom* aName) {
if (!aLineNames.Contains(aName)) {
aLineNames.AppendElement(aName);
}
}
static void AddLineNamesIfNotPresent(nsTArray<RefPtr<nsAtom>>& aLineNames,
const nsTArray<RefPtr<nsAtom>>& aNames) {
for (const auto& name : aNames) {
AddLineNameIfNotPresent(aLineNames, name);
}
}
void GridLines::SetLineInfo(const ComputedGridTrackInfo* aTrackInfo,
const ComputedGridLineInfo* aLineInfo,
const nsTArray<RefPtr<GridArea>>& aAreas,
bool aIsRow) {
MOZ_ASSERT(aLineInfo);
mLines.Clear();
if (!aTrackInfo) {
return;
}
uint32_t lineCount =
aTrackInfo->mEndFragmentTrack - aTrackInfo->mStartFragmentTrack + 1;
// If there is at least one track, line count is one more
// than the number of tracks.
if (lineCount > 0) {
nscoord lastTrackEdge = 0;
nscoord startOfNextTrack;
uint32_t repeatIndex = 0;
uint32_t numRepeatTracks = aTrackInfo->mRemovedRepeatTracks.Length();
uint32_t numAddedLines = 0;
// For the calculation of negative line numbers, we need to know
// the total number of leading implicit and explicit tracks.
// This might be different from the number of tracks sizes in
// aTrackInfo, because some of those tracks may be auto-fits that
// have been removed.
uint32_t leadingTrackCount =
aTrackInfo->mNumLeadingImplicitTracks + aTrackInfo->mNumExplicitTracks;
if (numRepeatTracks > 0) {
for (auto& removedTrack : aTrackInfo->mRemovedRepeatTracks) {
if (removedTrack) {
++leadingTrackCount;
}
}
}
for (uint32_t i = aTrackInfo->mStartFragmentTrack;
i < aTrackInfo->mEndFragmentTrack + 1; i++) {
// Since line indexes are 1-based, calculate a 1-based value
// for this track to simplify some calculations.
const uint32_t line1Index = i + 1;
startOfNextTrack = (i < aTrackInfo->mEndFragmentTrack)
? aTrackInfo->mPositions[i]
: lastTrackEdge;
// Get the line names for the current line. aLineInfo->mNames
// may contain duplicate names. This is intentional, since grid
// layout works fine with duplicate names, and we don't want to
// detect and remove duplicates in layout since it is an O(n^2)
// problem. We do the work here since this is only run when
// requested by devtools, and slowness here will not affect
// normal browsing.
nsTArray<RefPtr<nsAtom>> empty{};
const nsTArray<RefPtr<nsAtom>>& possiblyDuplicateLineNames(
aLineInfo->mNames.SafeElementAt(i, empty));
nsTArray<RefPtr<nsAtom>> lineNames;
AddLineNamesIfNotPresent(lineNames, possiblyDuplicateLineNames);
// Add in names from grid areas where this line is used as a boundary.
for (auto area : aAreas) {
// We specifically ignore line names from implicitly named areas,
// because it can be confusing for designers who might naturally use
// a named line of "-start" or "-end" and create an implicit named
// area without meaning to.
if (area->Type() == GridDeclaration::Implicit) {
continue;
}
bool haveNameToAdd = false;
nsAutoString nameToAdd;
area->GetName(nameToAdd);
if (aIsRow) {
if (area->RowStart() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-start");
} else if (area->RowEnd() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-end");
}
} else {
if (area->ColumnStart() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-start");
} else if (area->ColumnEnd() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-end");
}
}
if (haveNameToAdd) {
RefPtr<nsAtom> name = NS_Atomize(nameToAdd);
AddLineNameIfNotPresent(lineNames, name);
}
}
if (i >= (aTrackInfo->mRepeatFirstTrack +
aTrackInfo->mNumLeadingImplicitTracks) &&
repeatIndex < numRepeatTracks) {
numAddedLines += AppendRemovedAutoFits(
aTrackInfo, aLineInfo, lastTrackEdge, repeatIndex, numRepeatTracks,
leadingTrackCount, lineNames);
}
// If this line is the one that ends a repeat, then add
// in the mNamesFollowingRepeat names from aLineInfo.
if (numRepeatTracks > 0 && i == (aTrackInfo->mRepeatFirstTrack +
aTrackInfo->mNumLeadingImplicitTracks +
numRepeatTracks - numAddedLines)) {
AddLineNamesIfNotPresent(lineNames, aLineInfo->mNamesFollowingRepeat);
}
RefPtr<GridLine> line = new GridLine(this);
mLines.AppendElement(line);
MOZ_ASSERT(line1Index > 0, "line1Index must be positive.");
bool isBeforeFirstExplicit =
(line1Index <= aTrackInfo->mNumLeadingImplicitTracks);
bool isAfterLastExplicit = line1Index > (leadingTrackCount + 1);
// Calculate an actionable line number for this line, that could be used
// in a css grid property to align a grid item or area at that line.
// For implicit lines that appear before line 1, report a number of 0.
// We can't report negative indexes, because those have a different
// meaning in the css grid spec (negative indexes are negative-1-based
// from the end of the grid decreasing towards the front).
uint32_t lineNumber = isBeforeFirstExplicit
? 0
: (line1Index + numAddedLines -
aTrackInfo->mNumLeadingImplicitTracks);
// The negativeNumber is counted back from the leadingTrackCount.
int32_t lineNegativeNumber =
isAfterLastExplicit
? 0
: (line1Index + numAddedLines - (leadingTrackCount + 2));
GridDeclaration lineType = (isBeforeFirstExplicit || isAfterLastExplicit)
? GridDeclaration::Implicit
: GridDeclaration::Explicit;
line->SetLineValues(
lineNames, nsPresContext::AppUnitsToDoubleCSSPixels(lastTrackEdge),
nsPresContext::AppUnitsToDoubleCSSPixels(startOfNextTrack -
lastTrackEdge),
lineNumber, lineNegativeNumber, lineType);
if (i < aTrackInfo->mEndFragmentTrack) {
lastTrackEdge = aTrackInfo->mPositions[i] + aTrackInfo->mSizes[i];
}
}
// Define a function that gets the mLines index for a given line number.
// This is necessary since it's possible for a line number to not be
// represented in mLines. If this is the case, then return -1.
const int32_t lineCount = mLines.Length();
const uint32_t lastLineNumber = mLines[lineCount - 1]->Number();
auto IndexForLineNumber =
[lineCount, lastLineNumber](uint32_t aLineNumber) -> int32_t {
if (lastLineNumber == 0) {
// None of the lines have addressable numbers, so none of them can have
// aLineNumber
return -1;
}
int32_t possibleIndex = (int32_t)aLineNumber - 1;
if (possibleIndex < 0 || possibleIndex > lineCount - 1) {
// aLineNumber is not represented in mLines.
return -1;
}
return possibleIndex;
};
// Post-processing loop for implicit grid areas.
for (const auto& area : aAreas) {
if (area->Type() == GridDeclaration::Implicit) {
// Get the appropriate indexes for the area's start and end lines as
// they are represented in mLines.
int32_t startIndex =
IndexForLineNumber(aIsRow ? area->RowStart() : area->ColumnStart());
int32_t endIndex =
IndexForLineNumber(aIsRow ? area->RowEnd() : area->ColumnEnd());
// If both start and end indexes are -1, then stop here since we cannot
// reason about the naming for either lines.
if (startIndex < 0 && endIndex < 0) {
break;
}
// Get the "-start" and "-end" line names of the grid area.
nsAutoString startLineName;
area->GetName(startLineName);
startLineName.AppendLiteral("-start");
nsAutoString endLineName;
area->GetName(endLineName);
endLineName.AppendLiteral("-end");
// Get the list of existing line names for the start and end of the grid
// area. In the case where one of the start or end indexes are -1, use a
// dummy line as a substitute for the start/end line.
RefPtr<GridLine> dummyLine = new GridLine(this);
RefPtr<GridLine> areaStartLine =
startIndex > -1 ? mLines[startIndex] : dummyLine;
nsTArray<RefPtr<nsAtom>> startLineNames(areaStartLine->Names().Clone());
RefPtr<GridLine> areaEndLine =
endIndex > -1 ? mLines[endIndex] : dummyLine;
nsTArray<RefPtr<nsAtom>> endLineNames(areaEndLine->Names().Clone());
RefPtr<nsAtom> start = NS_Atomize(startLineName);
RefPtr<nsAtom> end = NS_Atomize(endLineName);
if (startLineNames.Contains(end) || endLineNames.Contains(start)) {
// Add the reversed line names.
AddLineNameIfNotPresent(startLineNames, end);
AddLineNameIfNotPresent(endLineNames, start);
} else {
// Add the normal line names.
AddLineNameIfNotPresent(startLineNames, start);
AddLineNameIfNotPresent(endLineNames, end);
}
areaStartLine->SetLineNames(startLineNames);
areaEndLine->SetLineNames(endLineNames);
}
}
}
}
uint32_t GridLines::AppendRemovedAutoFits(
const ComputedGridTrackInfo* aTrackInfo,
const ComputedGridLineInfo* aLineInfo, nscoord aLastTrackEdge,
uint32_t& aRepeatIndex, uint32_t aNumRepeatTracks,
uint32_t aNumLeadingTracks, nsTArray<RefPtr<nsAtom>>& aLineNames) {
bool extractedExplicitLineNames = false;
nsTArray<RefPtr<nsAtom>> explicitLineNames;
uint32_t linesAdded = 0;
while (aRepeatIndex < aNumRepeatTracks &&
aTrackInfo->mRemovedRepeatTracks[aRepeatIndex]) {
// If this is not the very first call to this function, and if we
// haven't already added a line this call, pull all the explicit
// names to pass along to the next line that will be added after
// this function completes.
if (aRepeatIndex > 0 && linesAdded == 0) {
// Find the names that didn't match the before or after names,
// and extract them.
for (const auto& name : aLineNames) {
if (!aLineInfo->mNamesBefore.Contains(name) &&
!aLineInfo->mNamesAfter.Contains(name)) {
explicitLineNames.AppendElement(name);
}
}
for (const auto& extractedName : explicitLineNames) {
aLineNames.RemoveElement(extractedName);
}
extractedExplicitLineNames = true;
}
AddLineNamesIfNotPresent(aLineNames, aLineInfo->mNamesBefore);
RefPtr<GridLine> line = new GridLine(this);
mLines.AppendElement(line);
// Time to calculate the line numbers. For the positive numbers
// we count with a 1-based index from mRepeatFirstTrack. Although
// this number is the index of the first repeat track AFTER all
// the leading implicit tracks, that's still what we want since
// all those leading implicit tracks have line number 0.
uint32_t lineNumber = aTrackInfo->mRepeatFirstTrack + aRepeatIndex + 1;
// The negative number does have to account for the leading
// implicit tracks. We've been passed aNumLeadingTracks which is
// the total of the leading implicit tracks plus the explicit
// tracks. So all we have to do is subtract that number plus one
// from the 0-based index of this track.
int32_t lineNegativeNumber =
(aTrackInfo->mNumLeadingImplicitTracks + aTrackInfo->mRepeatFirstTrack +
aRepeatIndex) -
(aNumLeadingTracks + 1);
line->SetLineValues(
aLineNames, nsPresContext::AppUnitsToDoubleCSSPixels(aLastTrackEdge),
nsPresContext::AppUnitsToDoubleCSSPixels(0), lineNumber,
lineNegativeNumber, GridDeclaration::Explicit);
// No matter what, the next line should have the after names associated
// with it. If we go through the loop again, the before names will also
// be added.
aLineNames = aLineInfo->mNamesAfter.Clone();
aRepeatIndex++;
linesAdded++;
}
aRepeatIndex++;
if (extractedExplicitLineNames) {
// Pass on the explicit names we saved to the next explicit line.
AddLineNamesIfNotPresent(aLineNames, explicitLineNames);
}
// If we haven't finished adding auto-repeated tracks, then we need to put
// back the before names, in case we cleared them above.
if (aRepeatIndex < aNumRepeatTracks) {
AddLineNamesIfNotPresent(aLineNames, aLineInfo->mNamesBefore);
}
return linesAdded;
}
} // namespace mozilla::dom