mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
255 lines
13 KiB
C++
255 lines
13 KiB
C++
// 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 "config.h"
|
||
#include "core/rendering/style/GridResolvedPosition.h"
|
||
|
||
#include "core/rendering/RenderBox.h"
|
||
#include "core/rendering/style/GridCoordinate.h"
|
||
|
||
namespace blink {
|
||
|
||
static const NamedGridLinesMap& gridLinesForSide(const RenderStyle& 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");
|
||
}
|
||
|
||
static bool isValidNamedLineOrArea(const String& lineName, const RenderStyle& style, GridPositionSide side)
|
||
{
|
||
const NamedGridLinesMap& gridLineNames = gridLinesForSide(style, side);
|
||
|
||
return gridLineNames.contains(implicitNamedGridLineForSide(lineName, side)) || gridLineNames.contains(lineName);
|
||
}
|
||
|
||
static GridPositionSide calculateInitialPositionSide(GridTrackSizingDirection direction)
|
||
{
|
||
return (direction == ForColumns) ? ColumnStartSide : RowStartSide;
|
||
}
|
||
|
||
static GridPositionSide calculateFinalPositionSide(GridTrackSizingDirection direction)
|
||
{
|
||
return (direction == ForColumns) ? ColumnEndSide : RowEndSide;
|
||
}
|
||
|
||
void GridResolvedPosition::initialAndFinalPositionsFromStyle(const RenderStyle& gridContainerStyle, const RenderBox& 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();
|
||
GridPositionSide initialPositionSide = calculateInitialPositionSide(direction);
|
||
GridPositionSide finalPositionSide = calculateFinalPositionSide(direction);
|
||
|
||
// 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();
|
||
|
||
// Try to early detect the case of non existing named grid lines. This way we could assume later that
|
||
// GridResolvedPosition::resolveGrisPositionFromStyle() always return a valid resolved position.
|
||
if (initialPosition.isNamedGridArea() && !isValidNamedLineOrArea(initialPosition.namedGridLine(), gridContainerStyle, initialPositionSide))
|
||
initialPosition.setAutoPosition();
|
||
|
||
if (finalPosition.isNamedGridArea() && !isValidNamedLineOrArea(finalPosition.namedGridLine(), gridContainerStyle, finalPositionSide))
|
||
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());
|
||
}
|
||
|
||
GridSpan GridResolvedPosition::resolveGridPositionsFromAutoPlacementPosition(const RenderStyle& gridContainerStyle, const RenderBox& gridItem, GridTrackSizingDirection direction, const GridResolvedPosition& resolvedInitialPosition)
|
||
{
|
||
GridPosition initialPosition, finalPosition;
|
||
initialAndFinalPositionsFromStyle(gridContainerStyle, gridItem, direction, initialPosition, finalPosition);
|
||
|
||
GridPositionSide finalPositionSide = calculateFinalPositionSide(direction);
|
||
|
||
// This method will only be used when both positions need to be resolved against the opposite one.
|
||
ASSERT(initialPosition.shouldBeResolvedAgainstOppositePosition() && finalPosition.shouldBeResolvedAgainstOppositePosition());
|
||
|
||
GridResolvedPosition resolvedFinalPosition = resolvedInitialPosition;
|
||
|
||
if (initialPosition.isSpan()) {
|
||
resolvedFinalPosition = resolveGridPositionAgainstOppositePosition(gridContainerStyle, resolvedInitialPosition, initialPosition, finalPositionSide)->resolvedFinalPosition;
|
||
} else if (finalPosition.isSpan()) {
|
||
resolvedFinalPosition = resolveGridPositionAgainstOppositePosition(gridContainerStyle, resolvedInitialPosition, finalPosition, finalPositionSide)->resolvedFinalPosition;
|
||
}
|
||
|
||
return GridSpan(resolvedInitialPosition, resolvedFinalPosition);
|
||
}
|
||
|
||
PassOwnPtr<GridSpan> GridResolvedPosition::resolveGridPositionsFromStyle(const RenderStyle& gridContainerStyle, const RenderBox& gridItem, GridTrackSizingDirection direction)
|
||
{
|
||
GridPosition initialPosition, finalPosition;
|
||
initialAndFinalPositionsFromStyle(gridContainerStyle, gridItem, direction, initialPosition, finalPosition);
|
||
|
||
GridPositionSide initialPositionSide = calculateInitialPositionSide(direction);
|
||
GridPositionSide finalPositionSide = calculateFinalPositionSide(direction);
|
||
|
||
if (initialPosition.shouldBeResolvedAgainstOppositePosition() && finalPosition.shouldBeResolvedAgainstOppositePosition()) {
|
||
// FIXME: Implement properly "stack" value in auto-placement algorithm.
|
||
if (gridContainerStyle.isGridAutoFlowAlgorithmStack())
|
||
return adoptPtr(new GridSpan(0, 0));
|
||
|
||
// We can't get our grid positions without running the auto placement algorithm.
|
||
return nullptr;
|
||
}
|
||
|
||
if (initialPosition.shouldBeResolvedAgainstOppositePosition()) {
|
||
// Infer the position from the final position ('auto / 1' or 'span 2 / 3' case).
|
||
GridResolvedPosition finalResolvedPosition = resolveGridPositionFromStyle(gridContainerStyle, finalPosition, finalPositionSide);
|
||
return resolveGridPositionAgainstOppositePosition(gridContainerStyle, finalResolvedPosition, initialPosition, initialPositionSide);
|
||
}
|
||
|
||
if (finalPosition.shouldBeResolvedAgainstOppositePosition()) {
|
||
// Infer our position from the initial position ('1 / auto' or '3 / span 2' case).
|
||
GridResolvedPosition initialResolvedPosition = resolveGridPositionFromStyle(gridContainerStyle, initialPosition, initialPositionSide);
|
||
return resolveGridPositionAgainstOppositePosition(gridContainerStyle, initialResolvedPosition, finalPosition, finalPositionSide);
|
||
}
|
||
|
||
GridResolvedPosition resolvedInitialPosition = resolveGridPositionFromStyle(gridContainerStyle, initialPosition, initialPositionSide);
|
||
GridResolvedPosition resolvedFinalPosition = resolveGridPositionFromStyle(gridContainerStyle, finalPosition, finalPositionSide);
|
||
|
||
// If 'grid-after' specifies a line at or before that specified by 'grid-before', it computes to 'span 1'.
|
||
if (resolvedFinalPosition < resolvedInitialPosition)
|
||
resolvedFinalPosition = resolvedInitialPosition;
|
||
|
||
return adoptPtr(new GridSpan(resolvedInitialPosition, resolvedFinalPosition));
|
||
}
|
||
|
||
size_t GridResolvedPosition::explicitGridColumnCount(const RenderStyle& gridContainerStyle)
|
||
{
|
||
return gridContainerStyle.gridTemplateColumns().size();
|
||
}
|
||
|
||
size_t GridResolvedPosition::explicitGridRowCount(const RenderStyle& gridContainerStyle)
|
||
{
|
||
return gridContainerStyle.gridTemplateRows().size();
|
||
}
|
||
|
||
size_t GridResolvedPosition::explicitGridSizeForSide(const RenderStyle& gridContainerStyle, GridPositionSide side)
|
||
{
|
||
return (side == ColumnStartSide || side == ColumnEndSide) ? explicitGridColumnCount(gridContainerStyle) : explicitGridRowCount(gridContainerStyle);
|
||
}
|
||
|
||
GridResolvedPosition GridResolvedPosition::resolveNamedGridLinePositionFromStyle(const RenderStyle& gridContainerStyle, const GridPosition& position, GridPositionSide side)
|
||
{
|
||
ASSERT(!position.namedGridLine().isNull());
|
||
|
||
const NamedGridLinesMap& gridLinesNames = gridLinesForSide(gridContainerStyle, side);
|
||
NamedGridLinesMap::const_iterator it = gridLinesNames.find(position.namedGridLine());
|
||
if (it == gridLinesNames.end()) {
|
||
if (position.isPositive())
|
||
return GridResolvedPosition(0);
|
||
const size_t lastLine = explicitGridSizeForSide(gridContainerStyle, side);
|
||
return adjustGridPositionForSide(lastLine, side);
|
||
}
|
||
|
||
size_t namedGridLineIndex;
|
||
if (position.isPositive())
|
||
namedGridLineIndex = std::min<size_t>(position.integerPosition(), it->value.size()) - 1;
|
||
else
|
||
namedGridLineIndex = std::max<int>(it->value.size() - abs(position.integerPosition()), 0);
|
||
return adjustGridPositionForSide(it->value[namedGridLineIndex], side);
|
||
}
|
||
|
||
GridResolvedPosition GridResolvedPosition::resolveGridPositionFromStyle(const RenderStyle& 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 adjustGridPositionForSide(position.integerPosition() - 1, side);
|
||
|
||
size_t resolvedPosition = abs(position.integerPosition()) - 1;
|
||
const size_t endOfTrack = explicitGridSizeForSide(gridContainerStyle, side);
|
||
|
||
// Per http://lists.w3.org/Archives/Public/www-style/2013Mar/0589.html, we clamp negative value to the first line.
|
||
if (endOfTrack < resolvedPosition)
|
||
return GridResolvedPosition(0);
|
||
|
||
return adjustGridPositionForSide(endOfTrack - resolvedPosition, side);
|
||
}
|
||
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(isValidNamedLineOrArea(namedGridLine, gridContainerStyle, side));
|
||
|
||
const NamedGridLinesMap& gridLineNames = gridLinesForSide(gridContainerStyle, side);
|
||
NamedGridLinesMap::const_iterator implicitLineIter = gridLineNames.find(implicitNamedGridLineForSide(namedGridLine, side));
|
||
if (implicitLineIter != gridLineNames.end())
|
||
return adjustGridPositionForSide(implicitLineIter->value[0], side);
|
||
|
||
// 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 adjustGridPositionForSide(explicitLineIter->value[0], side);
|
||
|
||
// If none of the above works specs mandate us to treat it as auto BUT we should have detected it before calling
|
||
// this function in GridResolvedPosition::resolveGridPositionsFromStyle(). We should be also covered by the
|
||
// ASSERT at the beginning of this block.
|
||
ASSERT_NOT_REACHED();
|
||
return GridResolvedPosition(0);
|
||
}
|
||
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 GridResolvedPosition(0);
|
||
}
|
||
ASSERT_NOT_REACHED();
|
||
return GridResolvedPosition(0);
|
||
}
|
||
|
||
PassOwnPtr<GridSpan> GridResolvedPosition::resolveGridPositionAgainstOppositePosition(const RenderStyle& gridContainerStyle, const GridResolvedPosition& resolvedOppositePosition, const GridPosition& position, GridPositionSide side)
|
||
{
|
||
if (position.isAuto())
|
||
return GridSpan::create(resolvedOppositePosition, resolvedOppositePosition);
|
||
|
||
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 GridSpan::createWithSpanAgainstOpposite(resolvedOppositePosition, position, side);
|
||
}
|
||
|
||
PassOwnPtr<GridSpan> GridResolvedPosition::resolveNamedGridLinePositionAgainstOppositePosition(const RenderStyle& gridContainerStyle, const GridResolvedPosition& 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());
|
||
|
||
// If there is no named grid line of that name, we resolve the position to 'auto' (which is equivalent to 'span 1' in this case).
|
||
// See http://lists.w3.org/Archives/Public/www-style/2013Jun/0394.html.
|
||
if (it == gridLinesNames.end())
|
||
return GridSpan::create(resolvedOppositePosition, resolvedOppositePosition);
|
||
|
||
return GridSpan::createWithNamedSpanAgainstOpposite(resolvedOppositePosition, position, side, it->value);
|
||
}
|
||
|
||
} // namespace blink
|