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| -rw-r--r-- | Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp index f69b82afbf..0726d07c4a 100644 --- a/Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp +++ b/Userland/Libraries/LibWeb/Layout/GridFormattingContext.cpp @@ -407,6 +407,124 @@ void GridFormattingContext::run(Box const& box, LayoutMode) grid_columns.append({ CSS::GridTrackSize::make_auto(), CSS::GridTrackSize::make_auto() }); for (int row_index = grid_rows.size(); row_index < static_cast<int>(occupation_grid.size()); row_index++) grid_rows.append({ CSS::GridTrackSize::make_auto(), CSS::GridTrackSize::make_auto() }); + + // https://drafts.csswg.org/css-grid/#algo-overview + // 12.1. Grid Sizing Algorithm + // FIXME: Deals with subgrids, min-content, and justify-content.. not implemented yet + + // https://drafts.csswg.org/css-grid/#algo-track-sizing + // 12.3. Track Sizing Algorithm + + // The remainder of this section is the track sizing algorithm, which calculates from the min and + // max track sizing functions the used track size. Each track has a base size, a <length> which + // grows throughout the algorithm and which will eventually be the track’s final size, and a growth + // limit, a <length> which provides a desired maximum size for the base size. There are 5 steps: + + // 1. Initialize Track Sizes + // 2. Resolve Intrinsic Track Sizes + // 3. Maximize Tracks + // 4. Expand Flexible Tracks + // 5. [[#algo-stretch|Expand Stretched auto Tracks]] + + // https://drafts.csswg.org/css-grid/#algo-init + // 12.4. Initialize Track Sizes + + // Initialize each track’s base size and growth limit. + for (auto& grid_column : grid_columns) { + // For each track, if the track’s min track sizing function is: + switch (grid_column.min_track_sizing_function.type()) { + // - A fixed sizing function + // Resolve to an absolute length and use that size as the track’s initial base size. + // Indefinite lengths cannot occur, as they’re treated as auto. + case CSS::GridTrackSize::Type::Length: + if (!grid_column.min_track_sizing_function.length().is_auto()) + grid_column.base_size = grid_column.min_track_sizing_function.length().to_px(box); + break; + case CSS::GridTrackSize::Type::Percentage: + grid_column.base_size = grid_column.min_track_sizing_function.percentage().as_fraction() * box_state.content_width(); + break; + // - An intrinsic sizing function + // Use an initial base size of zero. + case CSS::GridTrackSize::Type::FlexibleLength: + break; + default: + VERIFY_NOT_REACHED(); + } + + // For each track, if the track’s max track sizing function is: + switch (grid_column.max_track_sizing_function.type()) { + // - A fixed sizing function + // Resolve to an absolute length and use that size as the track’s initial growth limit. + case CSS::GridTrackSize::Type::Length: + if (!grid_column.max_track_sizing_function.length().is_auto()) + grid_column.growth_limit = grid_column.max_track_sizing_function.length().to_px(box); + else + // - An intrinsic sizing function + // Use an initial growth limit of infinity. + grid_column.growth_limit = -1; + break; + case CSS::GridTrackSize::Type::Percentage: + grid_column.growth_limit = grid_column.max_track_sizing_function.percentage().as_fraction() * box_state.content_width(); + break; + // - A flexible sizing function + // Use an initial growth limit of infinity. + case CSS::GridTrackSize::Type::FlexibleLength: + grid_column.growth_limit = -1; + break; + default: + VERIFY_NOT_REACHED(); + } + } + + // Initialize each track’s base size and growth limit. + for (auto& grid_row : grid_rows) { + // For each track, if the track’s min track sizing function is: + switch (grid_row.min_track_sizing_function.type()) { + // - A fixed sizing function + // Resolve to an absolute length and use that size as the track’s initial base size. + // Indefinite lengths cannot occur, as they’re treated as auto. + case CSS::GridTrackSize::Type::Length: + if (!grid_row.min_track_sizing_function.length().is_auto()) + grid_row.base_size = grid_row.min_track_sizing_function.length().to_px(box); + break; + case CSS::GridTrackSize::Type::Percentage: + grid_row.base_size = grid_row.min_track_sizing_function.percentage().as_fraction() * box_state.content_height(); + break; + // - An intrinsic sizing function + // Use an initial base size of zero. + case CSS::GridTrackSize::Type::FlexibleLength: + break; + default: + VERIFY_NOT_REACHED(); + } + + // For each track, if the track’s max track sizing function is: + switch (grid_row.max_track_sizing_function.type()) { + // - A fixed sizing function + // Resolve to an absolute length and use that size as the track’s initial growth limit. + case CSS::GridTrackSize::Type::Length: + if (!grid_row.max_track_sizing_function.length().is_auto()) + grid_row.growth_limit = grid_row.max_track_sizing_function.length().to_px(box); + else + // - An intrinsic sizing function + // Use an initial growth limit of infinity. + grid_row.growth_limit = -1; + break; + case CSS::GridTrackSize::Type::Percentage: + grid_row.growth_limit = grid_row.max_track_sizing_function.percentage().as_fraction() * box_state.content_height(); + break; + // - A flexible sizing function + // Use an initial growth limit of infinity. + case CSS::GridTrackSize::Type::FlexibleLength: + grid_row.growth_limit = -1; + break; + default: + VERIFY_NOT_REACHED(); + } + } + + // FIXME: In all cases, if the growth limit is less than the base size, increase the growth limit to match + // the base size. } } |