| // 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_constraint_space_builder.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): |
| // - replaced calculations |
| // - Take scrollbars into account |
| |
| bool NeedMinAndMaxContentSizes(const NGConstraintSpace& constraint_space, |
| const ComputedStyle& style) { |
| // 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 constraint_space.IsShrinkToFit() || |
| style.logicalWidth().isIntrinsic() || |
| style.logicalMinWidth().isIntrinsic() || |
| style.logicalMaxWidth().isIntrinsic(); |
| } |
| |
| bool NeedMinAndMaxContentSizesForContentContribution( |
| const ComputedStyle& style) { |
| return style.logicalWidth().isIntrinsicOrAuto() || |
| style.logicalMinWidth().isIntrinsic() || |
| style.logicalMaxWidth().isIntrinsic(); |
| } |
| |
| LayoutUnit ResolveInlineLength( |
| const NGConstraintSpace& constraint_space, |
| const ComputedStyle& style, |
| const WTF::Optional<MinAndMaxContentSizes>& min_and_max, |
| const Length& length, |
| LengthResolveType type) { |
| DCHECK(!length.isMaxSizeNone()); |
| DCHECK_GE(constraint_space.AvailableSize().inline_size, LayoutUnit()); |
| DCHECK_GE(constraint_space.PercentageResolutionSize().inline_size, |
| LayoutUnit()); |
| |
| if (type == LengthResolveType::kMinSize && length.isAuto()) |
| return LayoutUnit(); |
| |
| if (type == LengthResolveType::kMarginBorderPaddingSize && 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::kMarginBorderPaddingSize) { |
| border_and_padding = |
| ComputeBorders(style) + ComputePadding(constraint_space, style); |
| } |
| switch (length.type()) { |
| case Auto: |
| case FillAvailable: { |
| LayoutUnit content_size = constraint_space.AvailableSize().inline_size; |
| NGBoxStrut margins = ComputeMargins( |
| constraint_space, style, |
| FromPlatformWritingMode(style.getWritingMode()), style.direction()); |
| return std::max(border_and_padding.InlineSum(), |
| content_size - margins.InlineSum()); |
| } |
| case Percent: |
| case Fixed: |
| case Calculated: { |
| LayoutUnit percentage_resolution_size = |
| constraint_space.PercentageResolutionSize().inline_size; |
| LayoutUnit value = valueForLength(length, percentage_resolution_size); |
| if (style.boxSizing() == EBoxSizing::kContentBox) { |
| 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 = constraint_space.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( |
| constraint_space, style, |
| FromPlatformWritingMode(style.getWritingMode()), style.direction()); |
| LayoutUnit fill_available = |
| std::max(LayoutUnit(), available_size - margins.InlineSum() - |
| border_and_padding.InlineSum()); |
| value = min_and_max->ShrinkToFit(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& constraint_space, |
| const ComputedStyle& style, |
| const Length& length, |
| LayoutUnit content_size, |
| LengthResolveType type) { |
| DCHECK(!length.isMaxSizeNone()); |
| DCHECK(type != LengthResolveType::kMarginBorderPaddingSize); |
| |
| if (type == LengthResolveType::kMinSize && length.isAuto()) |
| return LayoutUnit(); |
| |
| // Make sure that indefinite percentages resolve to NGSizeIndefinite, not to |
| // a random negative number. |
| if (length.isPercentOrCalc() && |
| constraint_space.PercentageResolutionSize().block_size == |
| NGSizeIndefinite) |
| return content_size; |
| |
| // 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::kMarginBorderPaddingSize) { |
| border_and_padding = |
| ComputeBorders(style) + ComputePadding(constraint_space, style); |
| } |
| switch (length.type()) { |
| case FillAvailable: { |
| LayoutUnit content_size = constraint_space.AvailableSize().block_size; |
| NGBoxStrut margins = ComputeMargins( |
| constraint_space, style, |
| FromPlatformWritingMode(style.getWritingMode()), style.direction()); |
| return std::max(border_and_padding.BlockSum(), |
| content_size - margins.BlockSum()); |
| } |
| case Percent: |
| case Fixed: |
| case Calculated: { |
| LayoutUnit percentage_resolution_size = |
| constraint_space.PercentageResolutionSize().block_size; |
| LayoutUnit value = valueForLength(length, percentage_resolution_size); |
| if (style.boxSizing() == EBoxSizing::kContentBox) { |
| 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 content_size is calculated, it should always include border |
| // and padding. |
| if (content_size != LayoutUnit(-1)) |
| DCHECK_GE(content_size, border_and_padding.BlockSum()); |
| return content_size; |
| case DeviceWidth: |
| case DeviceHeight: |
| case ExtendToZoom: |
| NOTREACHED() << "These should only be used for viewport definitions"; |
| case MaxSizeNone: |
| default: |
| NOTREACHED(); |
| return border_and_padding.BlockSum(); |
| } |
| } |
| |
| MinAndMaxContentSizes ComputeMinAndMaxContentContribution( |
| const ComputedStyle& style, |
| const WTF::Optional<MinAndMaxContentSizes>& min_and_max) { |
| // Synthesize a zero-sized constraint space for passing to |
| // ResolveInlineLength. |
| NGWritingMode writing_mode = FromPlatformWritingMode(style.getWritingMode()); |
| NGConstraintSpaceBuilder builder(writing_mode); |
| NGConstraintSpace* space = builder.ToConstraintSpace(); |
| |
| MinAndMaxContentSizes computed_sizes; |
| Length inline_size = style.logicalWidth(); |
| if (inline_size.isAuto()) { |
| CHECK(min_and_max.has_value()); |
| NGBoxStrut border_and_padding = |
| ComputeBorders(style) + ComputePadding(*space, style); |
| computed_sizes.min_content = |
| min_and_max->min_content + border_and_padding.InlineSum(); |
| computed_sizes.max_content = |
| min_and_max->max_content + border_and_padding.InlineSum(); |
| } else { |
| computed_sizes.min_content = computed_sizes.max_content = |
| ResolveInlineLength(*space, style, min_and_max, inline_size, |
| LengthResolveType::kContentSize); |
| } |
| |
| Length max_length = style.logicalMaxWidth(); |
| if (!max_length.isMaxSizeNone()) { |
| LayoutUnit max = ResolveInlineLength(*space, style, min_and_max, max_length, |
| LengthResolveType::kMaxSize); |
| computed_sizes.min_content = std::min(computed_sizes.min_content, max); |
| computed_sizes.max_content = std::min(computed_sizes.max_content, max); |
| } |
| |
| LayoutUnit min = |
| ResolveInlineLength(*space, style, min_and_max, style.logicalMinWidth(), |
| LengthResolveType::kMinSize); |
| computed_sizes.min_content = std::max(computed_sizes.min_content, min); |
| computed_sizes.max_content = std::max(computed_sizes.max_content, min); |
| |
| NGBoxStrut margins = |
| ComputeMargins(*space, style, writing_mode, style.direction()); |
| computed_sizes.min_content += margins.InlineSum(); |
| computed_sizes.max_content += margins.InlineSum(); |
| return computed_sizes; |
| } |
| |
| LayoutUnit ComputeInlineSizeForFragment( |
| const NGConstraintSpace& space, |
| const ComputedStyle& style, |
| const WTF::Optional<MinAndMaxContentSizes>& min_and_max) { |
| if (space.IsFixedSizeInline()) |
| return space.AvailableSize().inline_size; |
| |
| Length logicalWidth = style.logicalWidth(); |
| if (logicalWidth.isAuto() && space.IsShrinkToFit()) |
| logicalWidth = Length(FitContent); |
| |
| LayoutUnit extent = ResolveInlineLength( |
| space, style, min_and_max, logicalWidth, LengthResolveType::kContentSize); |
| |
| Optional<LayoutUnit> max_length; |
| if (!style.logicalMaxWidth().isMaxSizeNone()) { |
| max_length = |
| ResolveInlineLength(space, style, min_and_max, style.logicalMaxWidth(), |
| LengthResolveType::kMaxSize); |
| } |
| Optional<LayoutUnit> min_length = |
| ResolveInlineLength(space, style, min_and_max, style.logicalMinWidth(), |
| LengthResolveType::kMinSize); |
| return ConstrainByMinMax(extent, min_length, max_length); |
| } |
| |
| LayoutUnit ComputeBlockSizeForFragment( |
| const NGConstraintSpace& constraint_space, |
| const ComputedStyle& style, |
| LayoutUnit content_size) { |
| if (constraint_space.IsFixedSizeBlock()) |
| return constraint_space.AvailableSize().block_size; |
| |
| LayoutUnit extent = |
| ResolveBlockLength(constraint_space, style, style.logicalHeight(), |
| content_size, LengthResolveType::kContentSize); |
| if (extent == NGSizeIndefinite) { |
| DCHECK_EQ(content_size, NGSizeIndefinite); |
| return extent; |
| } |
| Optional<LayoutUnit> max_length; |
| if (!style.logicalMaxHeight().isMaxSizeNone()) { |
| max_length = |
| ResolveBlockLength(constraint_space, style, style.logicalMaxHeight(), |
| content_size, LengthResolveType::kMaxSize); |
| } |
| Optional<LayoutUnit> min_length = |
| ResolveBlockLength(constraint_space, style, style.logicalMinHeight(), |
| content_size, LengthResolveType::kMinSize); |
| return ConstrainByMinMax(extent, min_length, max_length); |
| } |
| |
| int ResolveUsedColumnCount(int computed_count, |
| LayoutUnit computed_size, |
| LayoutUnit used_gap, |
| LayoutUnit available_size) { |
| if (computed_size == NGSizeIndefinite) { |
| DCHECK(computed_count); |
| return computed_count; |
| } |
| DCHECK(computed_size > LayoutUnit()); |
| int count_from_width = |
| ((available_size + used_gap) / (computed_size + used_gap)).toInt(); |
| count_from_width = std::max(1, count_from_width); |
| if (!computed_count) |
| return count_from_width; |
| return std::max(1, std::min(computed_count, count_from_width)); |
| } |
| |
| LayoutUnit ResolveUsedColumnInlineSize(int computed_count, |
| LayoutUnit computed_size, |
| LayoutUnit used_gap, |
| LayoutUnit available_size) { |
| int used_count = ResolveUsedColumnCount(computed_count, computed_size, |
| used_gap, available_size); |
| return ((available_size + used_gap) / used_count) - used_gap; |
| } |
| |
| LayoutUnit ResolveUsedColumnInlineSize(LayoutUnit available_size, |
| const ComputedStyle& style) { |
| // Should only attempt to resolve this if columns != auto. |
| DCHECK(!style.hasAutoColumnCount() || !style.hasAutoColumnWidth()); |
| |
| LayoutUnit computed_size = |
| style.hasAutoColumnWidth() |
| ? NGSizeIndefinite |
| : std::max(LayoutUnit(1), LayoutUnit(style.columnWidth())); |
| int computed_count = style.hasAutoColumnCount() ? 0 : style.columnCount(); |
| LayoutUnit used_gap = ResolveUsedColumnGap(style); |
| return ResolveUsedColumnInlineSize(computed_count, computed_size, used_gap, |
| available_size); |
| } |
| |
| LayoutUnit ResolveUsedColumnGap(const ComputedStyle& style) { |
| if (style.hasNormalColumnGap()) |
| return LayoutUnit(style.getFontDescription().computedPixelSize()); |
| return LayoutUnit(style.columnGap()); |
| } |
| |
| NGBoxStrut ComputeMargins(const NGConstraintSpace& constraint_space, |
| const ComputedStyle& style, |
| const NGWritingMode writing_mode, |
| const TextDirection 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( |
| constraint_space, style, empty_sizes, style.marginLeft(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| physical_dim.right = ResolveInlineLength( |
| constraint_space, style, empty_sizes, style.marginRight(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| physical_dim.top = ResolveInlineLength( |
| constraint_space, style, empty_sizes, style.marginTop(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| physical_dim.bottom = ResolveInlineLength( |
| constraint_space, style, empty_sizes, style.marginBottom(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| return physical_dim.ConvertToLogical(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& constraint_space, |
| 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( |
| constraint_space, style, empty_sizes, style.paddingStart(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| padding.inline_end = ResolveInlineLength( |
| constraint_space, style, empty_sizes, style.paddingEnd(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| padding.block_start = ResolveInlineLength( |
| constraint_space, style, empty_sizes, style.paddingBefore(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| padding.block_end = ResolveInlineLength( |
| constraint_space, style, empty_sizes, style.paddingAfter(), |
| LengthResolveType::kMarginBorderPaddingSize); |
| return padding; |
| } |
| |
| void ApplyAutoMargins(const NGConstraintSpace& constraint_space, |
| const ComputedStyle& style, |
| const LayoutUnit& inline_size, |
| NGBoxStrut* margins) { |
| DCHECK(margins) << "Margins cannot be NULL here"; |
| const LayoutUnit used_space = inline_size + 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; |
| } |
| } |
| |
| LayoutUnit ConstrainByMinMax(LayoutUnit length, |
| Optional<LayoutUnit> min, |
| Optional<LayoutUnit> max) { |
| if (max && length > max.value()) |
| length = max.value(); |
| if (min && length < min.value()) |
| length = min.value(); |
| return length; |
| } |
| |
| } // namespace blink |
