| // Copyright 2016 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/layout/ng/ng_length_utils.h" |
| |
| #include "core/layout/ng/ng_constraint_space.h" |
| #include "core/layout/ng/ng_fragment.h" |
| #include "core/style/ComputedStyle.h" |
| #include "platform/LayoutUnit.h" |
| #include "platform/Length.h" |
| #include "wtf/Optional.h" |
| |
| namespace blink { |
| // TODO(layout-ng): |
| // - positioned and/or replaced calculations |
| // - Take scrollbars into account |
| |
| namespace { |
| |
| // Converts physical dimensions to logical ones per |
| // https://drafts.csswg.org/css-writing-modes-3/#logical-to-physical |
| // For now it's only used to calculate abstract values for margins. |
| NGBoxStrut ToLogicalDimensions(const NGPhysicalBoxStrut& physical_dim, |
| const NGWritingMode writing_mode, |
| const NGDirection direction) { |
| bool is_ltr = direction == LeftToRight; |
| NGBoxStrut logical_dim; |
| switch (writing_mode) { |
| case VerticalRightLeft: |
| case SidewaysRightLeft: |
| logical_dim = {is_ltr ? physical_dim.top : physical_dim.bottom, |
| is_ltr ? physical_dim.bottom : physical_dim.top, |
| physical_dim.right, physical_dim.left}; |
| break; |
| case VerticalLeftRight: |
| logical_dim = {is_ltr ? physical_dim.top : physical_dim.bottom, |
| is_ltr ? physical_dim.bottom : physical_dim.top, |
| physical_dim.left, physical_dim.right}; |
| break; |
| case SidewaysLeftRight: |
| logical_dim = {is_ltr ? physical_dim.bottom : physical_dim.top, |
| is_ltr ? physical_dim.top : physical_dim.bottom, |
| physical_dim.left, physical_dim.right}; |
| break; |
| default: |
| NOTREACHED(); |
| /* FALLTHROUGH */ |
| case HorizontalTopBottom: |
| logical_dim = {is_ltr ? physical_dim.left : physical_dim.right, |
| is_ltr ? physical_dim.right : physical_dim.left, |
| physical_dim.top, physical_dim.bottom}; |
| break; |
| } |
| return logical_dim; |
| } |
| |
| } // namespace |
| |
| bool NeedMinAndMaxContentSizes(const ComputedStyle& style) { |
| // TODO(layout-ng): In the future we may pass a shrink-to-fit flag through the |
| // constraint space; if so, this function needs to take a constraint space |
| // as well to take that into account. |
| // This check is technically too broad (fill-available does not need intrinsic |
| // size computation) but that's a rare case and only affects performance, not |
| // correctness. |
| return style.logicalWidth().isIntrinsic() || |
| style.logicalMinWidth().isIntrinsic() || |
| style.logicalMaxWidth().isIntrinsic(); |
| } |
| |
| LayoutUnit ResolveInlineLength( |
| const NGConstraintSpace& constraintSpace, |
| const ComputedStyle& style, |
| const WTF::Optional<MinAndMaxContentSizes>& min_and_max, |
| const Length& length, |
| LengthResolveType type) { |
| // TODO(layout-ng): Handle min/max/fit-content |
| DCHECK(!length.isMaxSizeNone()); |
| DCHECK_GE(constraintSpace.AvailableSize().inline_size, LayoutUnit()); |
| |
| if (type == LengthResolveType::MinSize && length.isAuto()) |
| return LayoutUnit(); |
| |
| if (type == LengthResolveType::MarginBorderPaddingSize && length.isAuto()) |
| return LayoutUnit(); |
| |
| // We don't need this when we're resolving margin/border/padding; skip |
| // computing it as an optimization and to simplify the code below. |
| NGBoxStrut border_and_padding; |
| if (type != LengthResolveType::MarginBorderPaddingSize) { |
| border_and_padding = |
| ComputeBorders(style) + ComputePadding(constraintSpace, style); |
| } |
| switch (length.type()) { |
| case Auto: |
| case FillAvailable: { |
| LayoutUnit content_size = constraintSpace.AvailableSize().inline_size; |
| NGBoxStrut margins = |
| ComputeMargins(constraintSpace, style, |
| FromPlatformWritingMode(style.getWritingMode()), |
| FromPlatformDirection(style.direction())); |
| return std::max(border_and_padding.InlineSum(), |
| content_size - margins.InlineSum()); |
| } |
| case Percent: |
| case Fixed: |
| case Calculated: { |
| LayoutUnit percentage_resolution_size = |
| constraintSpace.PercentageResolutionSize().inline_size; |
| LayoutUnit value = valueForLength(length, percentage_resolution_size); |
| if (style.boxSizing() == BoxSizingContentBox) { |
| value += border_and_padding.InlineSum(); |
| } else { |
| value = std::max(border_and_padding.InlineSum(), value); |
| } |
| return value; |
| } |
| case MinContent: |
| case MaxContent: |
| case FitContent: { |
| DCHECK(min_and_max.has_value()); |
| LayoutUnit available_size = constraintSpace.AvailableSize().inline_size; |
| LayoutUnit value; |
| if (length.isMinContent()) { |
| value = min_and_max->min_content; |
| } else if (length.isMaxContent() || available_size == LayoutUnit::max()) { |
| // If the available space is infinite, fit-content resolves to |
| // max-content. See css-sizing section 2.1. |
| value = min_and_max->max_content; |
| } else { |
| NGBoxStrut margins = |
| ComputeMargins(constraintSpace, style, |
| FromPlatformWritingMode(style.getWritingMode()), |
| FromPlatformDirection(style.direction())); |
| LayoutUnit fill_available = |
| std::max(LayoutUnit(), available_size - margins.InlineSum() - |
| border_and_padding.InlineSum()); |
| value = std::min(min_and_max->max_content, |
| std::max(min_and_max->min_content, fill_available)); |
| } |
| return value + border_and_padding.InlineSum(); |
| } |
| case DeviceWidth: |
| case DeviceHeight: |
| case ExtendToZoom: |
| NOTREACHED() << "These should only be used for viewport definitions"; |
| case MaxSizeNone: |
| default: |
| NOTREACHED(); |
| return border_and_padding.InlineSum(); |
| } |
| } |
| |
| LayoutUnit ResolveBlockLength(const NGConstraintSpace& constraintSpace, |
| const ComputedStyle& style, |
| const Length& length, |
| LayoutUnit contentSize, |
| LengthResolveType type) { |
| DCHECK(!length.isMaxSizeNone()); |
| DCHECK(type != LengthResolveType::MarginBorderPaddingSize); |
| |
| if (type == LengthResolveType::MinSize && length.isAuto()) |
| return LayoutUnit(); |
| |
| // Make sure that indefinite percentages resolve to NGSizeIndefinite, not to |
| // a random negative number. |
| if (length.isPercentOrCalc() && |
| constraintSpace.PercentageResolutionSize().block_size == NGSizeIndefinite) |
| return contentSize; |
| |
| // We don't need this when we're resolving margin/border/padding; skip |
| // computing it as an optimization and to simplify the code below. |
| NGBoxStrut border_and_padding; |
| if (type != LengthResolveType::MarginBorderPaddingSize) { |
| border_and_padding = |
| ComputeBorders(style) + ComputePadding(constraintSpace, style); |
| } |
| switch (length.type()) { |
| case FillAvailable: { |
| LayoutUnit content_size = constraintSpace.AvailableSize().block_size; |
| NGBoxStrut margins = |
| ComputeMargins(constraintSpace, style, |
| FromPlatformWritingMode(style.getWritingMode()), |
| FromPlatformDirection(style.direction())); |
| return std::max(border_and_padding.BlockSum(), |
| content_size - margins.BlockSum()); |
| } |
| case Percent: |
| case Fixed: |
| case Calculated: { |
| LayoutUnit percentage_resolution_size = |
| constraintSpace.PercentageResolutionSize().block_size; |
| LayoutUnit value = valueForLength(length, percentage_resolution_size); |
| if (style.boxSizing() == BoxSizingContentBox) { |
| value += border_and_padding.BlockSum(); |
| } else { |
| value = std::max(border_and_padding.BlockSum(), value); |
| } |
| return value; |
| } |
| case Auto: |
| case MinContent: |
| case MaxContent: |
| case FitContent: |
| // Due to how contentSize is calculated, it should always include border |
| // and padding. |
| if (contentSize != LayoutUnit(-1)) |
| DCHECK_GE(contentSize, border_and_padding.BlockSum()); |
| return contentSize; |
| case DeviceWidth: |
| case DeviceHeight: |
| case ExtendToZoom: |
| NOTREACHED() << "These should only be used for viewport definitions"; |
| case MaxSizeNone: |
| default: |
| NOTREACHED(); |
| return border_and_padding.BlockSum(); |
| } |
| } |
| |
| LayoutUnit ComputeInlineSizeForFragment( |
| const NGConstraintSpace& constraintSpace, |
| const ComputedStyle& style, |
| const WTF::Optional<MinAndMaxContentSizes>& min_and_max) { |
| if (constraintSpace.FixedInlineSize()) |
| return constraintSpace.AvailableSize().inline_size; |
| |
| LayoutUnit extent = |
| ResolveInlineLength(constraintSpace, style, min_and_max, |
| style.logicalWidth(), LengthResolveType::ContentSize); |
| |
| Length maxLength = style.logicalMaxWidth(); |
| if (!maxLength.isMaxSizeNone()) { |
| LayoutUnit max = ResolveInlineLength(constraintSpace, style, min_and_max, |
| maxLength, LengthResolveType::MaxSize); |
| extent = std::min(extent, max); |
| } |
| |
| LayoutUnit min = |
| ResolveInlineLength(constraintSpace, style, min_and_max, |
| style.logicalMinWidth(), LengthResolveType::MinSize); |
| extent = std::max(extent, min); |
| return extent; |
| } |
| |
| LayoutUnit ComputeBlockSizeForFragment(const NGConstraintSpace& constraintSpace, |
| const ComputedStyle& style, |
| LayoutUnit contentSize) { |
| if (constraintSpace.FixedBlockSize()) |
| return constraintSpace.AvailableSize().block_size; |
| |
| LayoutUnit extent = |
| ResolveBlockLength(constraintSpace, style, style.logicalHeight(), |
| contentSize, LengthResolveType::ContentSize); |
| if (extent == NGSizeIndefinite) { |
| DCHECK_EQ(contentSize, NGSizeIndefinite); |
| return extent; |
| } |
| |
| Length maxLength = style.logicalMaxHeight(); |
| if (!maxLength.isMaxSizeNone()) { |
| LayoutUnit max = |
| ResolveBlockLength(constraintSpace, style, maxLength, contentSize, |
| LengthResolveType::MaxSize); |
| extent = std::min(extent, max); |
| } |
| |
| LayoutUnit min = |
| ResolveBlockLength(constraintSpace, style, style.logicalMinHeight(), |
| contentSize, LengthResolveType::MinSize); |
| extent = std::max(extent, min); |
| return extent; |
| } |
| |
| NGBoxStrut ComputeMargins(const NGConstraintSpace& constraintSpace, |
| const ComputedStyle& style, |
| const NGWritingMode writing_mode, |
| const NGDirection direction) { |
| // We don't need these for margin computations |
| MinAndMaxContentSizes empty_sizes; |
| // Margins always get computed relative to the inline size: |
| // https://www.w3.org/TR/CSS2/box.html#value-def-margin-width |
| NGPhysicalBoxStrut physical_dim; |
| physical_dim.left = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.marginLeft(), |
| LengthResolveType::MarginBorderPaddingSize); |
| physical_dim.right = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.marginRight(), |
| LengthResolveType::MarginBorderPaddingSize); |
| physical_dim.top = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.marginTop(), |
| LengthResolveType::MarginBorderPaddingSize); |
| physical_dim.bottom = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.marginBottom(), |
| LengthResolveType::MarginBorderPaddingSize); |
| return ToLogicalDimensions(physical_dim, writing_mode, direction); |
| } |
| |
| NGBoxStrut ComputeBorders(const ComputedStyle& style) { |
| NGBoxStrut borders; |
| borders.inline_start = LayoutUnit(style.borderStartWidth()); |
| borders.inline_end = LayoutUnit(style.borderEndWidth()); |
| borders.block_start = LayoutUnit(style.borderBeforeWidth()); |
| borders.block_end = LayoutUnit(style.borderAfterWidth()); |
| return borders; |
| } |
| |
| NGBoxStrut ComputePadding(const NGConstraintSpace& constraintSpace, |
| const ComputedStyle& style) { |
| // We don't need these for padding computations |
| MinAndMaxContentSizes empty_sizes; |
| // Padding always gets computed relative to the inline size: |
| // https://www.w3.org/TR/CSS2/box.html#value-def-padding-width |
| NGBoxStrut padding; |
| padding.inline_start = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.paddingStart(), |
| LengthResolveType::MarginBorderPaddingSize); |
| padding.inline_end = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.paddingEnd(), |
| LengthResolveType::MarginBorderPaddingSize); |
| padding.block_start = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.paddingBefore(), |
| LengthResolveType::MarginBorderPaddingSize); |
| padding.block_end = ResolveInlineLength( |
| constraintSpace, style, empty_sizes, style.paddingAfter(), |
| LengthResolveType::MarginBorderPaddingSize); |
| return padding; |
| } |
| |
| void ApplyAutoMargins(const NGConstraintSpace& constraint_space, |
| const ComputedStyle& style, |
| const NGFragmentBase& fragment, |
| NGBoxStrut* margins) { |
| DCHECK(margins) << "Margins cannot be NULL here"; |
| const LayoutUnit used_space = fragment.InlineSize() + margins->InlineSum(); |
| const LayoutUnit available_space = |
| constraint_space.AvailableSize().inline_size - used_space; |
| if (available_space < LayoutUnit()) |
| return; |
| if (style.marginStart().isAuto() && style.marginEnd().isAuto()) { |
| margins->inline_start = available_space / 2; |
| margins->inline_end = available_space - margins->inline_start; |
| } else if (style.marginStart().isAuto()) { |
| margins->inline_start = available_space; |
| } else if (style.marginEnd().isAuto()) { |
| margins->inline_end = available_space; |
| } |
| } |
| |
| } // namespace blink |
