[css-grid] Rename GridResolvedPosition to GridPositionsResolver

third_party/WebKit/Source/core/style/GridResolvedPosition.cpp

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "core/style/GridResolvedPosition.h"
-
-#include "core/layout/LayoutBox.h"
-#include "core/style/GridCoordinate.h"
-#include <algorithm>
-
-namespace blink {
-
-static const NamedGridLinesMap& gridLinesForSide(const ComputedStyle& style, GridPositionSide side)
-{
-    return (side == ColumnStartSide || side == ColumnEndSide) ? style.namedGridColumnLines() : style.namedGridRowLines();
-}
-
-static inline String implicitNamedGridLineForSide(const String& lineName, GridPositionSide side)
-{
-    return lineName + ((side == ColumnStartSide || side == RowStartSide) ? "-start" : "-end");
-}
-
-bool GridResolvedPosition::isValidNamedLineOrArea(const String& lineName, const ComputedStyle& style, GridPositionSide side)
-{
-    const NamedGridLinesMap& gridLineNames = gridLinesForSide(style, side);
-
-    return gridLineNames.contains(implicitNamedGridLineForSide(lineName, side)) || gridLineNames.contains(lineName);
-}
-
-GridPositionSide GridResolvedPosition::initialPositionSide(GridTrackSizingDirection direction)
-{
-    return (direction == ForColumns) ? ColumnStartSide : RowStartSide;
-}
-
-GridPositionSide GridResolvedPosition::finalPositionSide(GridTrackSizingDirection direction)
-{
-    return (direction == ForColumns) ? ColumnEndSide : RowEndSide;
-}
-
-static void initialAndFinalPositionsFromStyle(const ComputedStyle& gridContainerStyle, const LayoutBox& gridItem, GridTrackSizingDirection direction, GridPosition& initialPosition, GridPosition& finalPosition)
-{
-    initialPosition = (direction == ForColumns) ? gridItem.style()->gridColumnStart() : gridItem.style()->gridRowStart();
-    finalPosition = (direction == ForColumns) ? gridItem.style()->gridColumnEnd() : gridItem.style()->gridRowEnd();
-
-    // We must handle the placement error handling code here instead of in the StyleAdjuster because we don't want to
-    // overwrite the specified values.
-    if (initialPosition.isSpan() && finalPosition.isSpan())
-        finalPosition.setAutoPosition();
-
-    if (gridItem.isOutOfFlowPositioned()) {
-        // Early detect the case of non existing named grid lines for positioned items.
-        if (initialPosition.isNamedGridArea() && !GridResolvedPosition::isValidNamedLineOrArea(initialPosition.namedGridLine(), gridContainerStyle, GridResolvedPosition::initialPositionSide(direction)))
-            initialPosition.setAutoPosition();
-
-        if (finalPosition.isNamedGridArea() && !GridResolvedPosition::isValidNamedLineOrArea(finalPosition.namedGridLine(), gridContainerStyle, GridResolvedPosition::finalPositionSide(direction)))
-            finalPosition.setAutoPosition();
-    }
-
-    // If the grid item has an automatic position and a grid span for a named line in a given dimension, instead treat the grid span as one.
-    if (initialPosition.isAuto() && finalPosition.isSpan() && !finalPosition.namedGridLine().isNull())
-        finalPosition.setSpanPosition(1, String());
-    if (finalPosition.isAuto() && initialPosition.isSpan() && !initialPosition.namedGridLine().isNull())
-        initialPosition.setSpanPosition(1, String());
-}
-
-static size_t lookAheadForNamedGridLine(int start, size_t numberOfLines, const Vector<size_t>* namedGridLinesIndexes, size_t gridLastLine)
-{
-    ASSERT(numberOfLines);
-
-    // Only implicit lines on the search direction are assumed to have the given name, so we can start to look from first line.
-    // See: https://drafts.csswg.org/css-grid/#grid-placement-span-int
-    size_t end = std::max(start, 0);
-
-    if (!namedGridLinesIndexes) {
-        end = std::max(end, gridLastLine + 1);
-        return end + numberOfLines - 1;
-    }
-
-    for (; numberOfLines; ++end) {
-        if (end > gridLastLine || namedGridLinesIndexes->contains(end))
-            numberOfLines--;
-    }
-
-    ASSERT(end);
-    return end - 1;
-}
-
-static int lookBackForNamedGridLine(int end, size_t numberOfLines, const Vector<size_t>* namedGridLinesIndexes, int gridLastLine)
-{
-    ASSERT(numberOfLines);
-
-    // Only implicit lines on the search direction are assumed to have the given name, so we can start to look from last line.
-    // See: https://drafts.csswg.org/css-grid/#grid-placement-span-int
-    int start = std::min(end, gridLastLine);
-
-    if (!namedGridLinesIndexes) {
-        start = std::min(start, -1);
-        return start - numberOfLines + 1;
-    }
-
-    for (; numberOfLines; --start) {
-        if (start < 0 || namedGridLinesIndexes->contains(static_cast<size_t>(start)))
-            numberOfLines--;
-    }
-
-    return start + 1;
-}
-
-static GridSpan definiteGridSpanWithNamedSpanAgainstOpposite(int resolvedOppositePosition, const GridPosition& position, GridPositionSide side, const Vector<size_t>* gridLines, int lastLine)
-{
-    int start, end;
-
-    if (side == RowStartSide || side == ColumnStartSide) {
-        start = lookBackForNamedGridLine(resolvedOppositePosition - 1, position.spanPosition(), gridLines, lastLine);
-        end = resolvedOppositePosition;
-    } else {
-        start = resolvedOppositePosition;
-        end = lookAheadForNamedGridLine(resolvedOppositePosition + 1, position.spanPosition(), gridLines, lastLine);
-    }
-
-    return GridSpan::untranslatedDefiniteGridSpan(start, end);
-}
-
-size_t GridResolvedPosition::explicitGridColumnCount(const ComputedStyle& gridContainerStyle)
-{
-    return std::min<size_t>(gridContainerStyle.gridTemplateColumns().size(), kGridMaxTracks);
-}
-
-size_t GridResolvedPosition::explicitGridRowCount(const ComputedStyle& gridContainerStyle)
-{
-    return std::min<size_t>(gridContainerStyle.gridTemplateRows().size(), kGridMaxTracks);
-}
-
-static size_t explicitGridSizeForSide(const ComputedStyle& gridContainerStyle, GridPositionSide side)
-{
-    return (side == ColumnStartSide || side == ColumnEndSide) ? GridResolvedPosition::explicitGridColumnCount(gridContainerStyle) : GridResolvedPosition::explicitGridRowCount(gridContainerStyle);
-}
-
-static GridSpan resolveNamedGridLinePositionAgainstOppositePosition(const ComputedStyle& gridContainerStyle, int resolvedOppositePosition, const GridPosition& position, GridPositionSide side)
-{
-    ASSERT(position.isSpan());
-    ASSERT(!position.namedGridLine().isNull());
-    // Negative positions are not allowed per the specification and should have been handled during parsing.
-    ASSERT(position.spanPosition() > 0);
-
-    const NamedGridLinesMap& gridLinesNames = gridLinesForSide(gridContainerStyle, side);
-    NamedGridLinesMap::const_iterator it = gridLinesNames.find(position.namedGridLine());
-    const Vector<size_t>* gridLines = it == gridLinesNames.end() ? nullptr : &it->value;
-    size_t lastLine = explicitGridSizeForSide(gridContainerStyle, side);
-    return definiteGridSpanWithNamedSpanAgainstOpposite(resolvedOppositePosition, position, side, gridLines, lastLine);
-}
-
-static GridSpan definiteGridSpanWithSpanAgainstOpposite(size_t resolvedOppositePosition, const GridPosition& position, GridPositionSide side)
-{
-    size_t positionOffset = position.spanPosition();
-    if (side == ColumnStartSide || side == RowStartSide)
-        return GridSpan::untranslatedDefiniteGridSpan(resolvedOppositePosition - positionOffset, resolvedOppositePosition);
-
-    return GridSpan::untranslatedDefiniteGridSpan(resolvedOppositePosition, resolvedOppositePosition + positionOffset);
-}
-
-static GridSpan resolveGridPositionAgainstOppositePosition(const ComputedStyle& gridContainerStyle, int resolvedOppositePosition, const GridPosition& position, GridPositionSide side)
-{
-    if (position.isAuto()) {
-        if (side == ColumnStartSide || side == RowStartSide)
-            return GridSpan::untranslatedDefiniteGridSpan(resolvedOppositePosition - 1, resolvedOppositePosition);
-        return GridSpan::untranslatedDefiniteGridSpan(resolvedOppositePosition, resolvedOppositePosition + 1);
-    }
-
-    ASSERT(position.isSpan());
-    ASSERT(position.spanPosition() > 0);
-
-    if (!position.namedGridLine().isNull()) {
-        // span 2 'c' -> we need to find the appropriate grid line before / after our opposite position.
-        return resolveNamedGridLinePositionAgainstOppositePosition(gridContainerStyle, resolvedOppositePosition, position, side);
-    }
-
-    return definiteGridSpanWithSpanAgainstOpposite(resolvedOppositePosition, position, side);
-}
-
-size_t GridResolvedPosition::spanSizeForAutoPlacedItem(const ComputedStyle& gridContainerStyle, const LayoutBox& gridItem, GridTrackSizingDirection direction)
-{
-    GridPosition initialPosition, finalPosition;
-    initialAndFinalPositionsFromStyle(gridContainerStyle, gridItem, direction, initialPosition, finalPosition);
-
-    // This method will only be used when both positions need to be resolved against the opposite one.
-    ASSERT(initialPosition.shouldBeResolvedAgainstOppositePosition() && finalPosition.shouldBeResolvedAgainstOppositePosition());
-
-    if (initialPosition.isAuto() && finalPosition.isAuto())
-        return 1;
-
-    GridPosition position = initialPosition.isSpan() ? initialPosition : finalPosition;
-    ASSERT(position.isSpan());
-    ASSERT(position.spanPosition());
-    return position.spanPosition();
-}
-
-static int resolveNamedGridLinePositionFromStyle(const ComputedStyle& gridContainerStyle, const GridPosition& position, GridPositionSide side)
-{
-    ASSERT(!position.namedGridLine().isNull());
-
-    const NamedGridLinesMap& gridLinesNames = gridLinesForSide(gridContainerStyle, side);
-    NamedGridLinesMap::const_iterator it = gridLinesNames.find(position.namedGridLine());
-    const Vector<size_t>* gridLines = it == gridLinesNames.end() ? nullptr : &it->value;
-    size_t lastLine = explicitGridSizeForSide(gridContainerStyle, side);
-    if (position.isPositive())
-        return lookAheadForNamedGridLine(0, abs(position.integerPosition()), gridLines, lastLine);
-    else
-        return lookBackForNamedGridLine(lastLine, abs(position.integerPosition()), gridLines, lastLine);
-}
-
-static int resolveGridPositionFromStyle(const ComputedStyle& gridContainerStyle, const GridPosition& position, GridPositionSide side)
-{
-    switch (position.type()) {
-    case ExplicitPosition: {
-        ASSERT(position.integerPosition());
-
-        if (!position.namedGridLine().isNull())
-            return resolveNamedGridLinePositionFromStyle(gridContainerStyle, position, side);
-
-        // Handle <integer> explicit position.
-        if (position.isPositive())
-            return position.integerPosition() - 1;
-
-        size_t resolvedPosition = abs(position.integerPosition()) - 1;
-        size_t endOfTrack = explicitGridSizeForSide(gridContainerStyle, side);
-
-        return endOfTrack - resolvedPosition;
-    }
-    case NamedGridAreaPosition:
-    {
-        // First attempt to match the grid area's edge to a named grid area: if there is a named line with the name
-        // ''<custom-ident>-start (for grid-*-start) / <custom-ident>-end'' (for grid-*-end), contributes the first such
-        // line to the grid item's placement.
-        String namedGridLine = position.namedGridLine();
-        ASSERT(!position.namedGridLine().isNull());
-
-        const NamedGridLinesMap& gridLineNames = gridLinesForSide(gridContainerStyle, side);
-        NamedGridLinesMap::const_iterator implicitLineIter = gridLineNames.find(implicitNamedGridLineForSide(namedGridLine, side));
-        if (implicitLineIter != gridLineNames.end())
-            return implicitLineIter->value[0];
-
-        // Otherwise, if there is a named line with the specified name, contributes the first such line to the grid
-        // item's placement.
-        NamedGridLinesMap::const_iterator explicitLineIter = gridLineNames.find(namedGridLine);
-        if (explicitLineIter != gridLineNames.end())
-            return explicitLineIter->value[0];
-
-        ASSERT(!GridResolvedPosition::isValidNamedLineOrArea(namedGridLine, gridContainerStyle, side));
-        // If none of the above works specs mandate to assume that all the lines in the implicit grid have this name.
-        size_t lastLine = explicitGridSizeForSide(gridContainerStyle, side);
-        return lastLine + 1;
-    }
-    case AutoPosition:
-    case SpanPosition:
-        // 'auto' and span depend on the opposite position for resolution (e.g. grid-row: auto / 1 or grid-column: span 3 / "myHeader").
-        ASSERT_NOT_REACHED();
-        return 0;
-    }
-    ASSERT_NOT_REACHED();
-    return 0;
-}
-
-GridSpan GridResolvedPosition::resolveGridPositionsFromStyle(const ComputedStyle& gridContainerStyle, const LayoutBox& gridItem, GridTrackSizingDirection direction)
-{
-    GridPosition initialPosition, finalPosition;
-    initialAndFinalPositionsFromStyle(gridContainerStyle, gridItem, direction, initialPosition, finalPosition);
-
-    GridPositionSide initialSide = initialPositionSide(direction);
-    GridPositionSide finalSide = finalPositionSide(direction);
-
-    if (initialPosition.shouldBeResolvedAgainstOppositePosition() && finalPosition.shouldBeResolvedAgainstOppositePosition()) {
-        // We can't get our grid positions without running the auto placement algorithm.
-        return GridSpan::indefiniteGridSpan();
-    }
-
-    if (initialPosition.shouldBeResolvedAgainstOppositePosition()) {
-        // Infer the position from the final position ('auto / 1' or 'span 2 / 3' case).
-        int finalResolvedPosition = resolveGridPositionFromStyle(gridContainerStyle, finalPosition, finalSide);
-        return resolveGridPositionAgainstOppositePosition(gridContainerStyle, finalResolvedPosition, initialPosition, initialSide);
-    }
-
-    if (finalPosition.shouldBeResolvedAgainstOppositePosition()) {
-        // Infer our position from the initial position ('1 / auto' or '3 / span 2' case).
-        int initialResolvedPosition = resolveGridPositionFromStyle(gridContainerStyle, initialPosition, initialSide);
-        return resolveGridPositionAgainstOppositePosition(gridContainerStyle, initialResolvedPosition, finalPosition, finalSide);
-    }
-
-    int resolvedInitialPosition = resolveGridPositionFromStyle(gridContainerStyle, initialPosition, initialSide);
-    int resolvedFinalPosition = resolveGridPositionFromStyle(gridContainerStyle, finalPosition, finalSide);
-
-    if (resolvedFinalPosition < resolvedInitialPosition)
-        std::swap(resolvedFinalPosition, resolvedInitialPosition);
-    else if (resolvedFinalPosition == resolvedInitialPosition)
-        resolvedFinalPosition = resolvedInitialPosition + 1;
-
-    return GridSpan::untranslatedDefiniteGridSpan(resolvedInitialPosition, resolvedFinalPosition);
-}
-
-} // namespace blink