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-rw-r--r--dom/grid/GridLines.cpp372
1 files changed, 372 insertions, 0 deletions
diff --git a/dom/grid/GridLines.cpp b/dom/grid/GridLines.cpp
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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 http://mozilla.org/MPL/2.0/. */
+
+#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
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