TableFormattingContext.cpp 87 KB

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  1. /*
  2. * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
  3. *
  4. * SPDX-License-Identifier: BSD-2-Clause
  5. */
  6. #include <LibWeb/DOM/Node.h>
  7. #include <LibWeb/HTML/BrowsingContext.h>
  8. #include <LibWeb/HTML/HTMLTableCellElement.h>
  9. #include <LibWeb/HTML/HTMLTableColElement.h>
  10. #include <LibWeb/HTML/HTMLTableRowElement.h>
  11. #include <LibWeb/Layout/BlockFormattingContext.h>
  12. #include <LibWeb/Layout/Box.h>
  13. #include <LibWeb/Layout/InlineFormattingContext.h>
  14. #include <LibWeb/Layout/TableFormattingContext.h>
  15. struct GridPosition {
  16. size_t x;
  17. size_t y;
  18. };
  19. inline bool operator==(GridPosition const& a, GridPosition const& b)
  20. {
  21. return a.x == b.x && a.y == b.y;
  22. }
  23. namespace AK {
  24. template<>
  25. struct Traits<GridPosition> : public GenericTraits<GridPosition> {
  26. static unsigned hash(GridPosition const& key)
  27. {
  28. return pair_int_hash(key.x, key.y);
  29. }
  30. };
  31. }
  32. namespace Web::Layout {
  33. TableFormattingContext::TableFormattingContext(LayoutState& state, Box const& root, FormattingContext* parent)
  34. : FormattingContext(Type::Table, state, root, parent)
  35. {
  36. }
  37. TableFormattingContext::~TableFormattingContext() = default;
  38. static inline bool is_table_row_group(Box const& box)
  39. {
  40. auto const& display = box.display();
  41. return display.is_table_row_group() || display.is_table_header_group() || display.is_table_footer_group();
  42. }
  43. static inline bool is_table_row(Box const& box)
  44. {
  45. return box.display().is_table_row();
  46. }
  47. static inline bool is_table_column_group(Box const& box)
  48. {
  49. return box.display().is_table_column_group();
  50. }
  51. static inline bool is_table_column(Box const& box)
  52. {
  53. return box.display().is_table_column();
  54. }
  55. template<typename Matcher, typename Callback>
  56. static void for_each_child_box_matching(Box const& parent, Matcher matcher, Callback callback)
  57. {
  58. parent.for_each_child_of_type<Box>([&](Box const& child_box) {
  59. if (matcher(child_box))
  60. callback(child_box);
  61. });
  62. }
  63. CSSPixels TableFormattingContext::run_caption_layout(LayoutMode layout_mode, CSS::CaptionSide phase)
  64. {
  65. CSSPixels caption_height = 0;
  66. for (auto* child = table_box().first_child(); child; child = child->next_sibling()) {
  67. if (!child->display().is_table_caption() || child->computed_values().caption_side() != phase) {
  68. continue;
  69. }
  70. // The caption boxes are principal block-level boxes that retain their own content, padding, margin, and border areas,
  71. // and are rendered as normal block boxes inside the table wrapper box, as described in https://www.w3.org/TR/CSS22/tables.html#model
  72. auto caption_context = make<BlockFormattingContext>(m_state, *verify_cast<BlockContainer>(child), this);
  73. caption_context->run(table_box(), layout_mode, *m_available_space);
  74. VERIFY(child->is_box());
  75. auto const& child_box = static_cast<Box const&>(*child);
  76. // FIXME: Since caption only has inline children, BlockFormattingContext doesn't resolve the vertical metrics.
  77. // We need to do it manually here.
  78. caption_context->resolve_vertical_box_model_metrics(child_box);
  79. auto const& caption_state = m_state.get(child_box);
  80. if (phase == CSS::CaptionSide::Top) {
  81. m_state.get_mutable(table_box()).set_content_y(caption_state.content_height() + caption_state.margin_box_bottom());
  82. } else {
  83. m_state.get_mutable(child_box).set_content_y(
  84. m_state.get(table_box()).margin_box_height() + caption_state.margin_box_top());
  85. }
  86. caption_height += caption_state.margin_box_height();
  87. }
  88. return caption_height;
  89. }
  90. void TableFormattingContext::calculate_row_column_grid(Box const& box)
  91. {
  92. // Implements https://html.spec.whatwg.org/multipage/tables.html#forming-a-table
  93. HashMap<GridPosition, bool> grid;
  94. size_t x_width = 0, y_height = 0;
  95. size_t x_current = 0, y_current = 0;
  96. size_t max_cell_x = 0, max_cell_y = 0;
  97. // Implements https://html.spec.whatwg.org/multipage/tables.html#algorithm-for-processing-rows
  98. auto process_row = [&](auto& row) {
  99. if (y_height == y_current)
  100. y_height++;
  101. x_current = 0;
  102. for (auto* child = row.first_child(); child; child = child->next_sibling()) {
  103. if (child->display().is_table_cell()) {
  104. // Cells: While x_current is less than x_width and the slot with coordinate (x_current, y_current) already has a cell assigned to it, increase x_current by 1.
  105. while (x_current < x_width && grid.contains(GridPosition { x_current, y_current }))
  106. x_current++;
  107. Box const* box = static_cast<Box const*>(child);
  108. if (x_current == x_width)
  109. x_width++;
  110. size_t colspan = 1, rowspan = 1;
  111. if (box->dom_node() && is<HTML::HTMLTableCellElement>(*box->dom_node())) {
  112. auto const& node = static_cast<HTML::HTMLTableCellElement const&>(*box->dom_node());
  113. colspan = node.col_span();
  114. rowspan = node.row_span();
  115. }
  116. if (x_width < x_current + colspan)
  117. x_width = x_current + colspan;
  118. if (y_height < y_current + rowspan)
  119. y_height = y_current + rowspan;
  120. for (size_t y = y_current; y < y_current + rowspan; y++)
  121. for (size_t x = x_current; x < x_current + colspan; x++)
  122. grid.set(GridPosition { x, y }, true);
  123. m_cells.append(Cell { *box, x_current, y_current, colspan, rowspan });
  124. max_cell_x = max(x_current, max_cell_x);
  125. max_cell_y = max(y_current, max_cell_y);
  126. x_current += colspan;
  127. }
  128. }
  129. m_rows.append(Row { row });
  130. y_current++;
  131. };
  132. for_each_child_box_matching(box, is_table_row_group, [&](auto& row_group_box) {
  133. for_each_child_box_matching(row_group_box, is_table_row, [&](auto& row_box) {
  134. process_row(row_box);
  135. return IterationDecision::Continue;
  136. });
  137. });
  138. for_each_child_box_matching(box, is_table_row, [&](auto& row_box) {
  139. process_row(row_box);
  140. return IterationDecision::Continue;
  141. });
  142. m_columns.resize(x_width);
  143. for (auto& cell : m_cells) {
  144. // Clip spans to the end of the table.
  145. cell.row_span = min(cell.row_span, m_rows.size() - cell.row_index);
  146. cell.column_span = min(cell.column_span, m_columns.size() - cell.column_index);
  147. }
  148. m_cells_by_coordinate.resize(max_cell_y + 1);
  149. for (auto& position_to_cell_row : m_cells_by_coordinate) {
  150. position_to_cell_row.resize(max_cell_x + 1);
  151. }
  152. for (auto const& cell : m_cells) {
  153. m_cells_by_coordinate[cell.row_index][cell.column_index] = cell;
  154. m_columns[cell.column_index].has_originating_cells = true;
  155. }
  156. }
  157. void TableFormattingContext::compute_constrainedness()
  158. {
  159. // Definition of constrainedness: https://www.w3.org/TR/css-tables-3/#constrainedness
  160. size_t column_index = 0;
  161. for_each_child_box_matching(table_box(), is_table_column_group, [&](auto& column_group_box) {
  162. for_each_child_box_matching(column_group_box, is_table_column, [&](auto& column_box) {
  163. auto const& computed_values = column_box.computed_values();
  164. if (!computed_values.width().is_auto() && !computed_values.width().is_percentage()) {
  165. m_columns[column_index].is_constrained = true;
  166. }
  167. auto const& col_node = static_cast<HTML::HTMLTableColElement const&>(*column_box.dom_node());
  168. unsigned span = col_node.attribute(HTML::AttributeNames::span).to_uint().value_or(1);
  169. column_index += span;
  170. });
  171. });
  172. for (auto& row : m_rows) {
  173. auto const& computed_values = row.box->computed_values();
  174. if (!computed_values.height().is_auto() && !computed_values.height().is_percentage()) {
  175. row.is_constrained = true;
  176. }
  177. }
  178. for (auto& cell : m_cells) {
  179. auto const& computed_values = cell.box->computed_values();
  180. if (!computed_values.width().is_auto() && !computed_values.width().is_percentage()) {
  181. m_columns[cell.column_index].is_constrained = true;
  182. }
  183. if (!computed_values.height().is_auto() && !computed_values.height().is_percentage()) {
  184. m_rows[cell.row_index].is_constrained = true;
  185. }
  186. }
  187. }
  188. void TableFormattingContext::compute_cell_measures(AvailableSpace const& available_space)
  189. {
  190. // Implements https://www.w3.org/TR/css-tables-3/#computing-cell-measures.
  191. auto const& containing_block = m_state.get(*table_wrapper().containing_block());
  192. compute_constrainedness();
  193. for (auto& cell : m_cells) {
  194. auto const& computed_values = cell.box->computed_values();
  195. CSSPixels padding_top = computed_values.padding().top().to_px(cell.box, containing_block.content_height());
  196. CSSPixels padding_bottom = computed_values.padding().bottom().to_px(cell.box, containing_block.content_height());
  197. CSSPixels padding_left = computed_values.padding().left().to_px(cell.box, containing_block.content_width());
  198. CSSPixels padding_right = computed_values.padding().right().to_px(cell.box, containing_block.content_width());
  199. auto const& cell_state = m_state.get(cell.box);
  200. auto use_collapsing_borders_model = cell_state.override_borders_data().has_value();
  201. // Implement the collapsing border model https://www.w3.org/TR/CSS22/tables.html#collapsing-borders.
  202. CSSPixels border_top = use_collapsing_borders_model ? round(cell_state.border_top / 2) : computed_values.border_top().width;
  203. CSSPixels border_bottom = use_collapsing_borders_model ? round(cell_state.border_bottom / 2) : computed_values.border_bottom().width;
  204. CSSPixels border_left = use_collapsing_borders_model ? round(cell_state.border_left / 2) : computed_values.border_left().width;
  205. CSSPixels border_right = use_collapsing_borders_model ? round(cell_state.border_right / 2) : computed_values.border_right().width;
  206. auto min_content_height = calculate_min_content_height(cell.box, available_space.width);
  207. auto max_content_height = calculate_max_content_height(cell.box, available_space.width);
  208. auto min_content_width = calculate_min_content_width(cell.box);
  209. auto max_content_width = calculate_max_content_width(cell.box);
  210. // The outer min-content height of a table-cell is max(min-height, min-content height) adjusted by the cell intrinsic offsets.
  211. auto min_height = computed_values.min_height().to_px(cell.box, containing_block.content_height());
  212. auto cell_intrinsic_height_offsets = padding_top + padding_bottom + border_top + border_bottom;
  213. cell.outer_min_height = max(min_height, min_content_height) + cell_intrinsic_height_offsets;
  214. // The outer min-content width of a table-cell is max(min-width, min-content width) adjusted by the cell intrinsic offsets.
  215. auto min_width = computed_values.min_width().to_px(cell.box, containing_block.content_width());
  216. auto cell_intrinsic_width_offsets = padding_left + padding_right + border_left + border_right;
  217. cell.outer_min_width = max(min_width, min_content_width) + cell_intrinsic_width_offsets;
  218. // The tables specification isn't explicit on how to use the height and max-height CSS properties in the outer max-content formulas.
  219. // However, during this early phase we don't have enough information to resolve percentage sizes yet and the formulas for outer sizes
  220. // in the specification give enough clues to pick defaults in a way that makes sense.
  221. auto height = computed_values.height().is_length() ? computed_values.height().to_px(cell.box, containing_block.content_height()) : 0;
  222. auto max_height = computed_values.max_height().is_length() ? computed_values.max_height().to_px(cell.box, containing_block.content_height()) : INFINITY;
  223. if (m_rows[cell.row_index].is_constrained) {
  224. // The outer max-content height of a table-cell in a constrained row is
  225. // max(min-height, height, min-content height, min(max-height, height)) adjusted by the cell intrinsic offsets.
  226. // NB: min(max-height, height) doesn't have any effect here, we can simplify the expression to max(min-height, height, min-content height).
  227. cell.outer_max_height = max(min_height, max(height, min_content_height)) + cell_intrinsic_height_offsets;
  228. } else {
  229. // The outer max-content height of a table-cell in a non-constrained row is
  230. // max(min-height, height, min-content height, min(max-height, max-content height)) adjusted by the cell intrinsic offsets.
  231. cell.outer_max_height = max(min_height, max(height, max(min_content_height, min(max_height, max_content_height)))) + cell_intrinsic_height_offsets;
  232. }
  233. // See the explanation for height and max_height above.
  234. auto width = computed_values.width().is_length() ? computed_values.width().to_px(cell.box, containing_block.content_width()) : 0;
  235. auto max_width = computed_values.max_width().is_length() ? computed_values.max_width().to_px(cell.box, containing_block.content_width()) : INFINITY;
  236. if (m_columns[cell.column_index].is_constrained) {
  237. // The outer max-content width of a table-cell in a constrained column is
  238. // max(min-width, width, min-content width, min(max-width, width)) adjusted by the cell intrinsic offsets.
  239. // NB: min(max-width, width) doesn't have any effect here, we can simplify the expression to max(min-width, width, min-content width).
  240. cell.outer_max_width = max(min_width, max(width, min_content_width)) + cell_intrinsic_width_offsets;
  241. } else {
  242. // The outer max-content width of a table-cell in a non-constrained column is
  243. // max(min-width, width, min-content width, min(max-width, max-content width)) adjusted by the cell intrinsic offsets.
  244. cell.outer_max_width = max(min_width, max(width, max(min_content_width, min(max_width, max_content_width)))) + cell_intrinsic_width_offsets;
  245. }
  246. }
  247. }
  248. void TableFormattingContext::compute_outer_content_sizes()
  249. {
  250. auto const& containing_block = m_state.get(*table_wrapper().containing_block());
  251. size_t column_index = 0;
  252. for_each_child_box_matching(table_box(), is_table_column_group, [&](auto& column_group_box) {
  253. for_each_child_box_matching(column_group_box, is_table_column, [&](auto& column_box) {
  254. auto const& computed_values = column_box.computed_values();
  255. auto min_width = computed_values.min_width().to_px(column_box, containing_block.content_width());
  256. auto max_width = computed_values.max_width().is_length() ? computed_values.max_width().to_px(column_box, containing_block.content_width()) : INFINITY;
  257. auto width = computed_values.width().to_px(column_box, containing_block.content_width());
  258. // The outer min-content width of a table-column or table-column-group is max(min-width, width).
  259. m_columns[column_index].min_size = max(min_width, width);
  260. // The outer max-content width of a table-column or table-column-group is max(min-width, min(max-width, width)).
  261. m_columns[column_index].max_size = max(min_width, min(max_width, width));
  262. auto const& col_node = static_cast<HTML::HTMLTableColElement const&>(*column_box.dom_node());
  263. unsigned span = col_node.attribute(HTML::AttributeNames::span).to_uint().value_or(1);
  264. column_index += span;
  265. });
  266. });
  267. for (auto& row : m_rows) {
  268. auto const& computed_values = row.box->computed_values();
  269. auto min_height = computed_values.min_height().to_px(row.box, containing_block.content_height());
  270. auto max_height = computed_values.max_height().is_length() ? computed_values.max_height().to_px(row.box, containing_block.content_height()) : INFINITY;
  271. auto height = computed_values.height().to_px(row.box, containing_block.content_height());
  272. // The outer min-content height of a table-row or table-row-group is max(min-height, height).
  273. row.min_size = max(min_height, height);
  274. // The outer max-content height of a table-row or table-row-group is max(min-height, min(max-height, height)).
  275. row.max_size = max(min_height, min(max_height, height));
  276. }
  277. }
  278. template<>
  279. void TableFormattingContext::initialize_table_measures<TableFormattingContext::Row>()
  280. {
  281. auto const& containing_block = m_state.get(*table_wrapper().containing_block());
  282. for (auto& cell : m_cells) {
  283. auto const& computed_values = cell.box->computed_values();
  284. if (cell.row_span == 1) {
  285. auto specified_height = computed_values.height().to_px(cell.box, containing_block.content_height());
  286. // https://www.w3.org/TR/css-tables-3/#row-layout makes specified cell height part of the initialization formula for row table measures:
  287. // This is done by running the same algorithm as the column measurement, with the span=1 value being initialized (for min-content) with
  288. // the largest of the resulting height of the previous row layout, the height specified on the corresponding table-row (if any), and
  289. // the largest height specified on cells that span this row only (the algorithm starts by considering cells of span 2 on top of that assignment).
  290. m_rows[cell.row_index].min_size = max(m_rows[cell.row_index].min_size, max(cell.outer_min_height, specified_height));
  291. m_rows[cell.row_index].max_size = max(m_rows[cell.row_index].max_size, cell.outer_max_height);
  292. }
  293. }
  294. }
  295. template<>
  296. void TableFormattingContext::initialize_table_measures<TableFormattingContext::Column>()
  297. {
  298. for (auto& cell : m_cells) {
  299. if (cell.column_span == 1) {
  300. m_columns[cell.column_index].min_size = max(m_columns[cell.column_index].min_size, cell.outer_min_width);
  301. m_columns[cell.column_index].max_size = max(m_columns[cell.column_index].max_size, cell.outer_max_width);
  302. }
  303. }
  304. }
  305. template<class RowOrColumn>
  306. void TableFormattingContext::compute_intrinsic_percentage(size_t max_cell_span)
  307. {
  308. auto& rows_or_columns = table_rows_or_columns<RowOrColumn>();
  309. // https://www.w3.org/TR/css-tables-3/#intrinsic-percentage-width-of-a-column-based-on-cells-of-span-up-to-1
  310. initialize_intrinsic_percentages_from_rows_or_columns<RowOrColumn>();
  311. initialize_intrinsic_percentages_from_cells<RowOrColumn>();
  312. // Stores intermediate values for intrinsic percentage based on cells of span up to N for the iterative algorithm, to store them back at the end of the step.
  313. Vector<double> intrinsic_percentage_contribution_by_index;
  314. intrinsic_percentage_contribution_by_index.resize(rows_or_columns.size());
  315. for (size_t rc_index = 0; rc_index < rows_or_columns.size(); ++rc_index) {
  316. intrinsic_percentage_contribution_by_index[rc_index] = rows_or_columns[rc_index].intrinsic_percentage;
  317. }
  318. for (size_t current_span = 2; current_span <= max_cell_span; current_span++) {
  319. // https://www.w3.org/TR/css-tables-3/#intrinsic-percentage-width-of-a-column-based-on-cells-of-span-up-to-n-n--1
  320. for (auto& cell : m_cells) {
  321. auto cell_span_value = cell_span<RowOrColumn>(cell);
  322. if (cell_span_value != current_span) {
  323. continue;
  324. }
  325. auto cell_start_rc_index = cell_index<RowOrColumn>(cell);
  326. auto cell_end_rc_index = cell_start_rc_index + cell_span_value;
  327. // 1. Start with the percentage contribution of the cell.
  328. CSSPixels cell_contribution = cell_percentage_contribution<RowOrColumn>(cell);
  329. // 2. Subtract the intrinsic percentage width of the column based on cells of span up to N-1 of all columns
  330. // that the cell spans. If this gives a negative result, change it to 0%.
  331. for (auto rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  332. cell_contribution -= rows_or_columns[rc_index].intrinsic_percentage;
  333. cell_contribution = max(cell_contribution, 0);
  334. }
  335. // Compute the sum of the non-spanning max-content sizes of all rows / columns spanned by the cell that have an intrinsic percentage
  336. // size of the row / column based on cells of span up to N-1 equal to 0%, to be used in step 3 of the cell contribution algorithm.
  337. CSSPixels width_sum_of_columns_with_zero_intrinsic_percentage = 0;
  338. size_t number_of_columns_with_zero_intrinsic_percentage = 0;
  339. for (auto rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  340. if (rows_or_columns[rc_index].intrinsic_percentage == 0) {
  341. width_sum_of_columns_with_zero_intrinsic_percentage += rows_or_columns[rc_index].max_size;
  342. ++number_of_columns_with_zero_intrinsic_percentage;
  343. }
  344. }
  345. for (size_t rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  346. // If the intrinsic percentage width of a column based on cells of span up to N-1 is greater than 0%, then the intrinsic percentage width of
  347. // the column based on cells of span up to N is the same as the intrinsic percentage width of the column based on cells of span up to N-1.
  348. if (rows_or_columns[rc_index].intrinsic_percentage > 0) {
  349. continue;
  350. }
  351. // Otherwise, it is the largest of the contributions of the cells in the column whose colSpan is N,
  352. // where the contribution of a cell is the result of taking the following steps:
  353. // 1. Start with the percentage contribution of the cell.
  354. // 2. Subtract the intrinsic percentage width of the column based on cells of span up to N-1 of all columns
  355. // that the cell spans. If this gives a negative result, change it to 0%.
  356. // 3. Multiply by the ratio of the column’s non-spanning max-content width to the sum of the non-spanning max-content widths of all
  357. // columns spanned by the cell that have an intrinsic percentage width of the column based on cells of span up to N-1 equal to 0%.
  358. CSSPixels ajusted_cell_contribution;
  359. if (width_sum_of_columns_with_zero_intrinsic_percentage != 0) {
  360. ajusted_cell_contribution = cell_contribution * rows_or_columns[rc_index].max_size / width_sum_of_columns_with_zero_intrinsic_percentage;
  361. } else {
  362. // However, if this ratio is undefined because the denominator is zero, instead use the 1 divided by the number of columns
  363. // spanned by the cell that have an intrinsic percentage width of the column based on cells of span up to N-1 equal to zero.
  364. ajusted_cell_contribution = cell_contribution * 1 / number_of_columns_with_zero_intrinsic_percentage;
  365. }
  366. intrinsic_percentage_contribution_by_index[rc_index] = max(ajusted_cell_contribution.to_double(), intrinsic_percentage_contribution_by_index[rc_index]);
  367. }
  368. }
  369. for (size_t rc_index = 0; rc_index < rows_or_columns.size(); ++rc_index) {
  370. rows_or_columns[rc_index].intrinsic_percentage = intrinsic_percentage_contribution_by_index[rc_index];
  371. }
  372. }
  373. // Clamp total intrinsic percentage to 100%: https://www.w3.org/TR/css-tables-3/#intrinsic-percentage-width-of-a-column
  374. double total_intrinsic_percentage = 0;
  375. for (auto& rows_or_column : rows_or_columns) {
  376. rows_or_column.intrinsic_percentage = max(min(100 - total_intrinsic_percentage, rows_or_column.intrinsic_percentage), 0);
  377. total_intrinsic_percentage += rows_or_column.intrinsic_percentage;
  378. }
  379. }
  380. template<class RowOrColumn>
  381. void TableFormattingContext::compute_table_measures()
  382. {
  383. initialize_table_measures<RowOrColumn>();
  384. auto& rows_or_columns = table_rows_or_columns<RowOrColumn>();
  385. size_t max_cell_span = 1;
  386. for (auto& cell : m_cells) {
  387. max_cell_span = max(max_cell_span, cell_span<RowOrColumn>(cell));
  388. }
  389. // Since the intrinsic percentage specification uses non-spanning max-content size for the iterative algorithm,
  390. // run it before we compute the spanning max-content size with its own iterative algorithm for span up to N.
  391. compute_intrinsic_percentage<RowOrColumn>(max_cell_span);
  392. for (size_t current_span = 2; current_span <= max_cell_span; current_span++) {
  393. // https://www.w3.org/TR/css-tables-3/#min-content-width-of-a-column-based-on-cells-of-span-up-to-n-n--1
  394. Vector<Vector<CSSPixels>> cell_min_contributions_by_rc_index;
  395. cell_min_contributions_by_rc_index.resize(rows_or_columns.size());
  396. // https://www.w3.org/TR/css-tables-3/#max-content-width-of-a-column-based-on-cells-of-span-up-to-n-n--1
  397. Vector<Vector<CSSPixels>> cell_max_contributions_by_rc_index;
  398. cell_max_contributions_by_rc_index.resize(rows_or_columns.size());
  399. for (auto& cell : m_cells) {
  400. auto cell_span_value = cell_span<RowOrColumn>(cell);
  401. if (cell_span_value == current_span) {
  402. // Define the baseline max-content size as the sum of the max-content sizes based on cells of span up to N-1 of all columns that the cell spans.
  403. auto cell_start_rc_index = cell_index<RowOrColumn>(cell);
  404. auto cell_end_rc_index = cell_start_rc_index + cell_span_value;
  405. CSSPixels baseline_max_content_size = 0;
  406. for (auto rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  407. baseline_max_content_size += rows_or_columns[rc_index].max_size;
  408. }
  409. CSSPixels baseline_min_content_size = 0;
  410. for (auto rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  411. baseline_min_content_size += rows_or_columns[rc_index].min_size;
  412. }
  413. // Define the baseline border spacing as the sum of the horizontal border-spacing for any columns spanned by the cell, other than the one in which the cell originates.
  414. auto baseline_border_spacing = border_spacing<RowOrColumn>() * (cell_span_value - 1);
  415. // Add contribution from all rows / columns, since we've weighted the gap to the desired spanned size by the the
  416. // ratio of the max-content size based on cells of span up to N-1 of the row / column to the baseline max-content width.
  417. for (auto rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  418. // The contribution of the cell is the sum of:
  419. // the min-content size of the column based on cells of span up to N-1
  420. auto cell_min_contribution = rows_or_columns[rc_index].min_size;
  421. // the product of:
  422. // - the ratio of:
  423. // - the max-content size of the row / column based on cells of span up to N-1 of the row / column minus the
  424. // min-content size of the row / column based on cells of span up to N-1 of the row / column, to
  425. // - the baseline max-content size minus the baseline min-content size
  426. // or zero if this ratio is undefined, and
  427. // - the outer min-content size of the cell minus the baseline min-content size and the baseline border spacing, clamped
  428. // to be at least 0 and at most the difference between the baseline max-content size and the baseline min-content size
  429. auto normalized_max_min_diff = baseline_max_content_size != baseline_min_content_size
  430. ? (rows_or_columns[rc_index].max_size - rows_or_columns[rc_index].min_size) / (baseline_max_content_size - baseline_min_content_size)
  431. : 0;
  432. auto clamped_diff_to_baseline_min = min(
  433. max(cell_min_size<RowOrColumn>(cell) - baseline_min_content_size - baseline_border_spacing, 0),
  434. baseline_max_content_size - baseline_min_content_size);
  435. cell_min_contribution += normalized_max_min_diff * clamped_diff_to_baseline_min;
  436. // the product of:
  437. // - the ratio of the max-content size based on cells of span up to N-1 of the column to the baseline max-content size
  438. // - the outer min-content size of the cell minus the baseline max-content size and baseline border spacing, or 0 if this is negative
  439. cell_min_contribution += (rows_or_columns[rc_index].max_size / baseline_max_content_size)
  440. * max(CSSPixels(0), cell_min_size<RowOrColumn>(cell) - baseline_max_content_size - baseline_border_spacing);
  441. // The contribution of the cell is the sum of:
  442. // the max-content size of the column based on cells of span up to N-1
  443. auto cell_max_contribution = rows_or_columns[rc_index].max_size;
  444. // and the product of:
  445. // - the ratio of the max-content size based on cells of span up to N-1 of the column to the baseline max-content size
  446. // - the outer max-content size of the cell minus the baseline max-content size and the baseline border spacing, or 0 if this is negative
  447. cell_max_contribution += (rows_or_columns[rc_index].max_size / baseline_max_content_size)
  448. * max(CSSPixels(0), cell_max_size<RowOrColumn>(cell) - baseline_max_content_size - baseline_border_spacing);
  449. cell_min_contributions_by_rc_index[rc_index].append(cell_min_contribution);
  450. cell_max_contributions_by_rc_index[rc_index].append(cell_max_contribution);
  451. }
  452. }
  453. }
  454. for (size_t rc_index = 0; rc_index < rows_or_columns.size(); rc_index++) {
  455. // min-content size of a row / column based on cells of span up to N (N > 1) is
  456. // the largest of the min-content size of the row / column based on cells of span up to N-1 and
  457. // the contributions of the cells in the row / column whose rowSpan / colSpan is N
  458. for (auto min_contribution : cell_min_contributions_by_rc_index[rc_index])
  459. rows_or_columns[rc_index].min_size = max(rows_or_columns[rc_index].min_size, min_contribution);
  460. // max-content size of a row / column based on cells of span up to N (N > 1) is
  461. // the largest of the max-content size based on cells of span up to N-1 and the contributions of
  462. // the cells in the row / column whose rowSpan / colSpan is N
  463. for (auto max_contribution : cell_max_contributions_by_rc_index[rc_index])
  464. rows_or_columns[rc_index].max_size = max(rows_or_columns[rc_index].max_size, max_contribution);
  465. }
  466. }
  467. }
  468. CSSPixels TableFormattingContext::compute_capmin()
  469. {
  470. // The caption width minimum (CAPMIN) is the largest of the table captions min-content contribution:
  471. // https://drafts.csswg.org/css-tables-3/#computing-the-table-width
  472. CSSPixels capmin = 0;
  473. for (auto* child = table_box().first_child(); child; child = child->next_sibling()) {
  474. if (!child->display().is_table_caption()) {
  475. continue;
  476. }
  477. VERIFY(child->is_box());
  478. capmin = max(calculate_min_content_width(static_cast<Box const&>(*child)), capmin);
  479. }
  480. return capmin;
  481. }
  482. void TableFormattingContext::compute_table_width()
  483. {
  484. // https://drafts.csswg.org/css-tables-3/#computing-the-table-width
  485. auto& table_box_state = m_state.get_mutable(table_box());
  486. auto& computed_values = table_box().computed_values();
  487. CSSPixels width_of_table_containing_block = m_state.get(*table_box().containing_block()).content_width();
  488. // Percentages on 'width' and 'height' on the table are relative to the table wrapper box's containing block,
  489. // not the table wrapper box itself.
  490. CSSPixels width_of_table_wrapper_containing_block = m_state.get(*table_wrapper().containing_block()).content_width();
  491. // Compute undistributable space due to border spacing: https://www.w3.org/TR/css-tables-3/#computing-undistributable-space.
  492. auto undistributable_space = (m_columns.size() + 1) * border_spacing_horizontal();
  493. // The row/column-grid width minimum (GRIDMIN) width is the sum of the min-content width
  494. // of all the columns plus cell spacing or borders.
  495. CSSPixels grid_min = 0.0f;
  496. for (auto& column : m_columns) {
  497. grid_min += column.min_size;
  498. }
  499. grid_min += undistributable_space;
  500. // The row/column-grid width maximum (GRIDMAX) width is the sum of the max-content width
  501. // of all the columns plus cell spacing or borders.
  502. CSSPixels grid_max = 0.0f;
  503. for (auto& column : m_columns) {
  504. grid_max += column.max_size;
  505. }
  506. grid_max += undistributable_space;
  507. // The used min-width of a table is the greater of the resolved min-width, CAPMIN, and GRIDMIN.
  508. auto used_min_width = max(grid_min, compute_capmin());
  509. if (!computed_values.min_width().is_auto()) {
  510. used_min_width = max(used_min_width, computed_values.min_width().to_px(table_box(), width_of_table_wrapper_containing_block));
  511. }
  512. CSSPixels used_width;
  513. if (computed_values.width().is_auto()) {
  514. // If the table-root has 'width: auto', the used width is the greater of
  515. // min(GRIDMAX, the table’s containing block width), the used min-width of the table.
  516. used_width = max(min(grid_max, width_of_table_containing_block), used_min_width);
  517. // https://www.w3.org/TR/CSS22/tables.html#auto-table-layout
  518. // A percentage value for a column width is relative to the table width. If the table has 'width: auto',
  519. // a percentage represents a constraint on the column's width, which a UA should try to satisfy.
  520. CSSPixels adjusted_used_width = 0;
  521. for (auto& cell : m_cells) {
  522. auto const& cell_width = cell.box->computed_values().width();
  523. if (cell_width.is_percentage()) {
  524. adjusted_used_width = 100 / cell_width.percentage().value() * cell.outer_min_width;
  525. used_width = min(max(used_width, adjusted_used_width), width_of_table_containing_block);
  526. }
  527. }
  528. } else {
  529. // If the table-root’s width property has a computed value (resolving to
  530. // resolved-table-width) other than auto, the used width is the greater
  531. // of resolved-table-width, and the used min-width of the table.
  532. CSSPixels resolved_table_width = computed_values.width().to_px(table_box(), width_of_table_wrapper_containing_block);
  533. // Since used_width is content width, we need to subtract the border spacing from the specified width for a consistent comparison.
  534. used_width = max(resolved_table_width - table_box_state.border_box_left() - table_box_state.border_box_right(), used_min_width);
  535. if (!should_treat_max_width_as_none(table_box(), m_available_space->width))
  536. used_width = min(used_width, computed_values.max_width().to_px(table_box(), width_of_table_wrapper_containing_block));
  537. }
  538. table_box_state.set_content_width(used_width);
  539. }
  540. CSSPixels TableFormattingContext::compute_columns_total_used_width() const
  541. {
  542. CSSPixels total_used_width = 0;
  543. for (auto& column : m_columns) {
  544. total_used_width += column.used_width;
  545. }
  546. return total_used_width;
  547. }
  548. static CSSPixels compute_columns_total_candidate_width(Vector<CSSPixels> const& candidate_widths)
  549. {
  550. CSSPixels total_candidate_width = 0;
  551. for (auto width : candidate_widths) {
  552. total_candidate_width += width;
  553. }
  554. return total_candidate_width;
  555. }
  556. void TableFormattingContext::commit_candidate_column_widths(Vector<CSSPixels> const& candidate_widths)
  557. {
  558. VERIFY(candidate_widths.size() == m_columns.size());
  559. for (size_t i = 0; i < m_columns.size(); ++i) {
  560. m_columns[i].used_width = candidate_widths[i];
  561. }
  562. }
  563. void TableFormattingContext::assign_columns_width_linear_combination(Vector<CSSPixels> const& candidate_widths, CSSPixels available_width)
  564. {
  565. auto columns_total_candidate_width = compute_columns_total_candidate_width(candidate_widths);
  566. auto columns_total_used_width = compute_columns_total_used_width();
  567. if (columns_total_candidate_width == columns_total_used_width) {
  568. return;
  569. }
  570. auto candidate_weight = ((available_width - columns_total_used_width) / (columns_total_candidate_width - columns_total_used_width)).to_double();
  571. for (size_t i = 0; i < m_columns.size(); ++i) {
  572. auto& column = m_columns[i];
  573. column.used_width = candidate_weight * candidate_widths[i] + (1 - candidate_weight) * column.used_width;
  574. }
  575. }
  576. template<class ColumnFilter>
  577. bool TableFormattingContext::distribute_excess_width_proportionally_to_max_width(CSSPixels excess_width, ColumnFilter column_filter)
  578. {
  579. bool found_matching_columns = false;
  580. CSSPixels total_max_width = 0;
  581. for (auto const& column : m_columns) {
  582. if (column_filter(column)) {
  583. total_max_width += column.max_size;
  584. found_matching_columns = true;
  585. }
  586. }
  587. if (!found_matching_columns) {
  588. return false;
  589. }
  590. VERIFY(total_max_width > 0);
  591. for (auto& column : m_columns) {
  592. if (column_filter(column)) {
  593. column.used_width += excess_width * column.max_size / total_max_width;
  594. }
  595. }
  596. return true;
  597. }
  598. template<class ColumnFilter>
  599. bool TableFormattingContext::distribute_excess_width_equally(CSSPixels excess_width, ColumnFilter column_filter)
  600. {
  601. size_t matching_column_count = 0;
  602. for (auto const& column : m_columns) {
  603. if (column_filter(column)) {
  604. ++matching_column_count;
  605. }
  606. }
  607. if (matching_column_count == 0) {
  608. return false;
  609. }
  610. for (auto& column : m_columns) {
  611. if (column_filter(column)) {
  612. column.used_width += excess_width / matching_column_count;
  613. }
  614. }
  615. return matching_column_count;
  616. }
  617. template<class ColumnFilter>
  618. bool TableFormattingContext::distribute_excess_width_by_intrinsic_percentage(CSSPixels excess_width, ColumnFilter column_filter)
  619. {
  620. bool found_matching_columns = false;
  621. double total_percentage_width = 0;
  622. for (auto const& column : m_columns) {
  623. if (column_filter(column)) {
  624. found_matching_columns = true;
  625. total_percentage_width += column.intrinsic_percentage;
  626. }
  627. }
  628. if (!found_matching_columns) {
  629. return false;
  630. }
  631. for (auto& column : m_columns) {
  632. if (column_filter(column)) {
  633. column.used_width += excess_width * column.intrinsic_percentage / total_percentage_width;
  634. }
  635. }
  636. return true;
  637. }
  638. void TableFormattingContext::distribute_width_to_columns()
  639. {
  640. // Implements https://www.w3.org/TR/css-tables-3/#width-distribution-algorithm
  641. // The total horizontal border spacing is defined for each table:
  642. // - For tables laid out in separated-borders mode containing at least one column, the horizontal component of the computed value of the border-spacing property times one plus the number of columns in the table
  643. // - Otherwise, 0
  644. auto total_horizontal_border_spacing = m_columns.is_empty() ? 0 : (m_columns.size() + 1) * border_spacing_horizontal();
  645. // The assignable table width is the used width of the table minus the total horizontal border spacing (if any).
  646. // This is the width that we will be able to allocate to the columns.
  647. const CSSPixels available_width = m_state.get(table_box()).content_width() - total_horizontal_border_spacing;
  648. Vector<CSSPixels> candidate_widths;
  649. candidate_widths.resize(m_columns.size());
  650. // 1. The min-content sizing-guess is the set of column width assignments where each column is assigned its min-content width.
  651. for (size_t i = 0; i < m_columns.size(); ++i) {
  652. auto& column = m_columns[i];
  653. column.used_width = column.min_size;
  654. candidate_widths[i] = column.min_size;
  655. }
  656. // 2. The min-content-percentage sizing-guess is the set of column width assignments where:
  657. // - each percent-column is assigned the larger of:
  658. // - its intrinsic percentage width times the assignable width and
  659. // - its min-content width.
  660. // - all other columns are assigned their min-content width.
  661. for (size_t i = 0; i < m_columns.size(); ++i) {
  662. auto& column = m_columns[i];
  663. if (column.has_intrinsic_percentage) {
  664. candidate_widths[i] = max(column.min_size, column.intrinsic_percentage / 100 * available_width);
  665. }
  666. }
  667. // If the assignable table width is less than or equal to the max-content sizing-guess, the used widths of the columns must be the
  668. // linear combination (with weights adding to 1) of the two consecutive sizing-guesses whose width sums bound the available width.
  669. if (available_width < compute_columns_total_candidate_width(candidate_widths)) {
  670. assign_columns_width_linear_combination(candidate_widths, available_width);
  671. return;
  672. } else {
  673. commit_candidate_column_widths(candidate_widths);
  674. }
  675. // 3. The min-content-specified sizing-guess is the set of column width assignments where:
  676. // - each percent-column is assigned the larger of:
  677. // - its intrinsic percentage width times the assignable width and
  678. // - its min-content width
  679. // - any other column that is constrained is assigned its max-content width
  680. // - all other columns are assigned their min-content width.
  681. for (size_t i = 0; i < m_columns.size(); ++i) {
  682. auto& column = m_columns[i];
  683. if (column.is_constrained) {
  684. candidate_widths[i] = column.max_size;
  685. }
  686. }
  687. if (available_width < compute_columns_total_candidate_width(candidate_widths)) {
  688. assign_columns_width_linear_combination(candidate_widths, available_width);
  689. return;
  690. } else {
  691. commit_candidate_column_widths(candidate_widths);
  692. }
  693. // 4. The max-content sizing-guess is the set of column width assignments where:
  694. // - each percent-column is assigned the larger of:
  695. // - its intrinsic percentage width times the assignable width and
  696. // - its min-content width
  697. // - all other columns are assigned their max-content width.
  698. for (size_t i = 0; i < m_columns.size(); ++i) {
  699. auto& column = m_columns[i];
  700. if (!column.has_intrinsic_percentage) {
  701. candidate_widths[i] = column.max_size;
  702. }
  703. }
  704. if (available_width < compute_columns_total_candidate_width(candidate_widths)) {
  705. assign_columns_width_linear_combination(candidate_widths, available_width);
  706. return;
  707. } else {
  708. commit_candidate_column_widths(candidate_widths);
  709. }
  710. // Otherwise, the used widths of the columns are the result of starting from the max-content sizing-guess and distributing
  711. // the excess width to the columns of the table according to the rules for distributing excess width to columns (for used width).
  712. distribute_excess_width_to_columns(available_width);
  713. }
  714. void TableFormattingContext::distribute_excess_width_to_columns(CSSPixels available_width)
  715. {
  716. // Implements https://www.w3.org/TR/css-tables-3/#distributing-width-to-columns
  717. auto columns_total_used_width = compute_columns_total_used_width();
  718. if (columns_total_used_width >= available_width) {
  719. return;
  720. }
  721. auto excess_width = available_width - columns_total_used_width;
  722. if (excess_width == 0) {
  723. return;
  724. }
  725. // 1. If there are non-constrained columns that have originating cells with intrinsic percentage width of 0% and with nonzero
  726. // max-content width (aka the columns allowed to grow by this rule), the distributed widths of the columns allowed to grow
  727. // by this rule are increased in proportion to max-content width so the total increase adds to the excess width.
  728. if (distribute_excess_width_proportionally_to_max_width(
  729. excess_width,
  730. [](auto const& column) {
  731. return !column.is_constrained && column.has_originating_cells && column.intrinsic_percentage == 0 && column.max_size > 0;
  732. })) {
  733. excess_width = available_width - compute_columns_total_used_width();
  734. }
  735. if (excess_width == 0) {
  736. return;
  737. }
  738. // 2. Otherwise, if there are non-constrained columns that have originating cells with intrinsic percentage width of 0% (aka the columns
  739. // allowed to grow by this rule, which thanks to the previous rule must have zero max-content width), the distributed widths of the
  740. // columns allowed to grow by this rule are increased by equal amounts so the total increase adds to the excess width.
  741. if (distribute_excess_width_equally(excess_width,
  742. [](auto const& column) {
  743. return !column.is_constrained && column.has_originating_cells && column.intrinsic_percentage == 0;
  744. })) {
  745. excess_width = available_width - compute_columns_total_used_width();
  746. }
  747. if (excess_width == 0) {
  748. return;
  749. }
  750. // 3. Otherwise, if there are constrained columns with intrinsic percentage width of 0% and with nonzero max-content width
  751. // (aka the columns allowed to grow by this rule, which, due to other rules, must have originating cells), the distributed widths of the
  752. // columns allowed to grow by this rule are increased in proportion to max-content width so the total increase adds to the excess width.
  753. if (distribute_excess_width_proportionally_to_max_width(
  754. excess_width,
  755. [](auto const& column) {
  756. return column.is_constrained && column.intrinsic_percentage == 0 && column.max_size > 0;
  757. })) {
  758. excess_width = available_width - compute_columns_total_used_width();
  759. }
  760. if (excess_width == 0) {
  761. return;
  762. }
  763. // 4. Otherwise, if there are columns with intrinsic percentage width greater than 0% (aka the columns allowed to grow by this rule,
  764. // which, due to other rules, must have originating cells), the distributed widths of the columns allowed to grow by this rule are
  765. // increased in proportion to intrinsic percentage width so the total increase adds to the excess width.
  766. if (distribute_excess_width_by_intrinsic_percentage(excess_width, [](auto const& column) {
  767. return column.intrinsic_percentage > 0;
  768. })) {
  769. excess_width = available_width - compute_columns_total_used_width();
  770. }
  771. if (excess_width == 0) {
  772. return;
  773. }
  774. // 5. Otherwise, if there is any such column, the distributed widths of all columns that have originating cells are increased by equal amounts
  775. // so the total increase adds to the excess width.
  776. if (distribute_excess_width_equally(
  777. excess_width,
  778. [](auto const& column) { return column.has_originating_cells; })) {
  779. excess_width = available_width - compute_columns_total_used_width();
  780. }
  781. if (excess_width == 0) {
  782. return;
  783. }
  784. // 6. Otherwise, the distributed widths of all columns are increased by equal amounts so the total increase adds to the excess width.
  785. distribute_excess_width_equally(excess_width, [](auto const&) { return true; });
  786. }
  787. void TableFormattingContext::compute_table_height(LayoutMode layout_mode)
  788. {
  789. // First pass of row height calculation:
  790. for (auto& row : m_rows) {
  791. auto row_computed_height = row.box->computed_values().height();
  792. if (row_computed_height.is_length()) {
  793. auto height_of_containing_block = m_state.get(*row.box->containing_block()).content_height();
  794. auto row_used_height = row_computed_height.to_px(row.box, height_of_containing_block);
  795. row.base_height = max(row.base_height, row_used_height);
  796. }
  797. }
  798. // First pass of cells layout:
  799. for (auto& cell : m_cells) {
  800. auto& row = m_rows[cell.row_index];
  801. auto& cell_state = m_state.get_mutable(cell.box);
  802. CSSPixels span_width = 0;
  803. for (size_t i = 0; i < cell.column_span; ++i)
  804. span_width += m_columns[cell.column_index + i].used_width;
  805. auto width_of_containing_block = m_state.get(*cell.box->containing_block()).content_width();
  806. auto width_of_containing_block_as_length = CSS::Length::make_px(width_of_containing_block);
  807. auto height_of_containing_block = m_state.get(*cell.box->containing_block()).content_height();
  808. auto height_of_containing_block_as_length = CSS::Length::make_px(height_of_containing_block);
  809. cell_state.padding_top = cell.box->computed_values().padding().top().to_px(cell.box, width_of_containing_block);
  810. cell_state.padding_bottom = cell.box->computed_values().padding().bottom().to_px(cell.box, width_of_containing_block);
  811. cell_state.padding_left = cell.box->computed_values().padding().left().to_px(cell.box, width_of_containing_block);
  812. cell_state.padding_right = cell.box->computed_values().padding().right().to_px(cell.box, width_of_containing_block);
  813. if (cell.box->computed_values().border_collapse() == CSS::BorderCollapse::Separate) {
  814. cell_state.border_top = cell.box->computed_values().border_top().width;
  815. cell_state.border_bottom = cell.box->computed_values().border_bottom().width;
  816. cell_state.border_left = cell.box->computed_values().border_left().width;
  817. cell_state.border_right = cell.box->computed_values().border_right().width;
  818. }
  819. auto cell_computed_height = cell.box->computed_values().height();
  820. if (cell_computed_height.is_length()) {
  821. auto cell_used_height = cell_computed_height.to_px(cell.box, height_of_containing_block);
  822. cell_state.set_content_height(cell_used_height - cell_state.border_box_top() - cell_state.border_box_bottom());
  823. row.base_height = max(row.base_height, cell_used_height);
  824. }
  825. // Compute cell width as specified by https://www.w3.org/TR/css-tables-3/#bounding-box-assignment:
  826. // The position of any table-cell, table-track, or table-track-group box within the table is defined as the rectangle whose width/height is the sum of:
  827. // - the widths/heights of all spanned visible columns/rows
  828. // - the horizontal/vertical border-spacing times the amount of spanned visible columns/rows minus one
  829. // FIXME: Account for visibility.
  830. cell_state.set_content_width(span_width - cell_state.border_box_left() - cell_state.border_box_right() + (cell.column_span - 1) * border_spacing_horizontal());
  831. if (auto independent_formatting_context = layout_inside(cell.box, layout_mode, cell_state.available_inner_space_or_constraints_from(*m_available_space))) {
  832. cell_state.set_content_height(independent_formatting_context->automatic_content_height());
  833. independent_formatting_context->parent_context_did_dimension_child_root_box();
  834. }
  835. cell.baseline = box_baseline(cell.box);
  836. // Implements https://www.w3.org/TR/css-tables-3/#computing-the-table-height
  837. // The minimum height of a row is the maximum of:
  838. // - the computed height (if definite, percentages being considered 0px) of its corresponding table-row (if nay)
  839. // - the computed height of each cell spanning the current row exclusively (if definite, percentages being treated as 0px), and
  840. // - the minimum height (ROWMIN) required by the cells spanning the row.
  841. // Note that we've already applied the first rule at the top of the method.
  842. if (cell.row_span == 1) {
  843. row.base_height = max(row.base_height, cell_state.border_box_height());
  844. }
  845. row.base_height = max(row.base_height, m_rows[cell.row_index].min_size);
  846. row.baseline = max(row.baseline, cell.baseline);
  847. }
  848. CSSPixels sum_rows_height = 0;
  849. for (auto& row : m_rows) {
  850. sum_rows_height += row.base_height;
  851. }
  852. m_table_height = sum_rows_height;
  853. if (!table_box().computed_values().height().is_auto()) {
  854. // If the table has a height property with a value other than auto, it is treated as a minimum height for the
  855. // table grid, and will eventually be distributed to the height of the rows if their collective minimum height
  856. // ends up smaller than this number.
  857. CSSPixels height_of_table_containing_block = m_state.get(*table_wrapper().containing_block()).content_height();
  858. auto specified_table_height = table_box().computed_values().height().to_px(table_box(), height_of_table_containing_block);
  859. auto const& table_state = m_state.get(table_box());
  860. m_table_height = max(m_table_height, specified_table_height - table_state.border_box_top() - table_state.border_box_bottom());
  861. }
  862. for (auto& row : m_rows) {
  863. // Reference size is the largest of
  864. // - its initial base height and
  865. // - its new base height (the one evaluated during the second layout pass, where percentages used in
  866. // rowgroups/rows/cells' specified heights were resolved according to the table height, instead of
  867. // being ignored as 0px).
  868. // Assign reference size to base size. Later, the reference size might change to a larger value during
  869. // the second pass of rows layout.
  870. row.reference_height = row.base_height;
  871. }
  872. // Second pass of rows height calculation:
  873. // At this point, percentage row height can be resolved because the final table height is calculated.
  874. for (auto& row : m_rows) {
  875. auto row_computed_height = row.box->computed_values().height();
  876. if (row_computed_height.is_percentage()) {
  877. auto row_used_height = row_computed_height.to_px(row.box, m_table_height);
  878. row.reference_height = max(row.reference_height, row_used_height);
  879. } else {
  880. continue;
  881. }
  882. }
  883. // Second pass cells layout:
  884. // At this point, percentage cell height can be resolved because the final table height is calculated.
  885. for (auto& cell : m_cells) {
  886. auto& row = m_rows[cell.row_index];
  887. auto& cell_state = m_state.get_mutable(cell.box);
  888. CSSPixels span_width = 0;
  889. for (size_t i = 0; i < cell.column_span; ++i)
  890. span_width += m_columns[cell.column_index + i].used_width;
  891. auto cell_computed_height = cell.box->computed_values().height();
  892. if (cell_computed_height.is_percentage()) {
  893. auto cell_used_height = cell_computed_height.to_px(cell.box, m_table_height);
  894. cell_state.set_content_height(cell_used_height - cell_state.border_box_top() - cell_state.border_box_bottom());
  895. row.reference_height = max(row.reference_height, cell_used_height);
  896. } else {
  897. continue;
  898. }
  899. cell_state.set_content_width(span_width - cell_state.border_box_left() - cell_state.border_box_right() + (cell.column_span - 1) * border_spacing_horizontal());
  900. if (auto independent_formatting_context = layout_inside(cell.box, layout_mode, cell_state.available_inner_space_or_constraints_from(*m_available_space))) {
  901. independent_formatting_context->parent_context_did_dimension_child_root_box();
  902. }
  903. cell.baseline = box_baseline(cell.box);
  904. row.reference_height = max(row.reference_height, cell_state.border_box_height());
  905. row.baseline = max(row.baseline, cell.baseline);
  906. }
  907. }
  908. void TableFormattingContext::distribute_height_to_rows()
  909. {
  910. CSSPixels sum_reference_height = 0;
  911. for (auto& row : m_rows) {
  912. sum_reference_height += row.reference_height;
  913. }
  914. if (sum_reference_height == 0)
  915. return;
  916. Vector<Row&> rows_with_auto_height;
  917. for (auto& row : m_rows) {
  918. if (row.box->computed_values().height().is_auto()) {
  919. rows_with_auto_height.append(row);
  920. }
  921. }
  922. if (m_table_height <= sum_reference_height) {
  923. // If the table height is equal or smaller than sum of reference sizes, the final height assigned to each row
  924. // will be the weighted mean of the base and the reference size that yields the correct total height.
  925. for (auto& row : m_rows) {
  926. auto weight = row.reference_height / sum_reference_height;
  927. auto final_height = m_table_height * weight;
  928. row.final_height = final_height;
  929. }
  930. } else if (rows_with_auto_height.size() > 0) {
  931. // Else, if the table owns any “auto-height” row (a row whose size is only determined by its content size and
  932. // none of the specified heights), each non-auto-height row receives its reference height and auto-height rows
  933. // receive their reference size plus some increment which is equal to the height missing to amount to the
  934. // specified table height divided by the amount of such rows.
  935. for (auto& row : m_rows) {
  936. row.final_height = row.reference_height;
  937. }
  938. auto auto_height_rows_increment = (m_table_height - sum_reference_height) / rows_with_auto_height.size();
  939. for (auto& row : rows_with_auto_height) {
  940. row.final_height += auto_height_rows_increment;
  941. }
  942. } else {
  943. // Else, all rows receive their reference size plus some increment which is equal to the height missing to
  944. // amount to the specified table height divided by the amount of rows.
  945. auto increment = (m_table_height - sum_reference_height) / m_rows.size();
  946. for (auto& row : m_rows) {
  947. row.final_height = row.reference_height + increment;
  948. }
  949. }
  950. // Add undistributable space due to border spacing: https://www.w3.org/TR/css-tables-3/#computing-undistributable-space.
  951. m_table_height += (m_rows.size() + 1) * border_spacing_vertical();
  952. }
  953. void TableFormattingContext::position_row_boxes()
  954. {
  955. auto const& table_state = m_state.get(table_box());
  956. CSSPixels row_top_offset = table_state.offset.y() + table_state.padding_top + border_spacing_vertical();
  957. CSSPixels row_left_offset = table_state.border_left + table_state.padding_left + border_spacing_horizontal();
  958. for (size_t y = 0; y < m_rows.size(); y++) {
  959. auto& row = m_rows[y];
  960. auto& row_state = m_state.get_mutable(row.box);
  961. CSSPixels row_width = 0.0f;
  962. for (auto& column : m_columns) {
  963. row_width += column.used_width;
  964. }
  965. row_state.set_content_height(row.final_height);
  966. row_state.set_content_width(row_width);
  967. row_state.set_content_x(row_left_offset);
  968. row_state.set_content_y(row_top_offset);
  969. row_top_offset += row_state.content_height() + border_spacing_vertical();
  970. }
  971. CSSPixels row_group_top_offset = table_state.border_top + table_state.padding_top;
  972. CSSPixels row_group_left_offset = table_state.border_left + table_state.padding_left;
  973. for_each_child_box_matching(table_box(), is_table_row_group, [&](auto& row_group_box) {
  974. CSSPixels row_group_height = 0.0f;
  975. CSSPixels row_group_width = 0.0f;
  976. auto& row_group_box_state = m_state.get_mutable(row_group_box);
  977. row_group_box_state.set_content_x(row_group_left_offset);
  978. row_group_box_state.set_content_y(row_group_top_offset);
  979. for_each_child_box_matching(row_group_box, is_table_row, [&](auto& row) {
  980. auto const& row_state = m_state.get(row);
  981. row_group_height += row_state.border_box_height();
  982. row_group_width = max(row_group_width, row_state.border_box_width());
  983. });
  984. row_group_box_state.set_content_height(row_group_height);
  985. row_group_box_state.set_content_width(row_group_width);
  986. row_group_top_offset += row_group_height;
  987. });
  988. auto total_content_height = max(row_top_offset, row_group_top_offset) - table_state.offset.y() - table_state.padding_top;
  989. m_table_height = max(total_content_height, m_table_height);
  990. }
  991. void TableFormattingContext::position_cell_boxes()
  992. {
  993. CSSPixels left_column_offset = 0;
  994. for (auto& column : m_columns) {
  995. column.left_offset = left_column_offset;
  996. left_column_offset += column.used_width;
  997. }
  998. for (auto& cell : m_cells) {
  999. auto& cell_state = m_state.get_mutable(cell.box);
  1000. auto& row_state = m_state.get(m_rows[cell.row_index].box);
  1001. CSSPixels const cell_border_box_height = cell_state.content_height() + cell_state.border_box_top() + cell_state.border_box_bottom();
  1002. CSSPixels const row_content_height = compute_row_content_height(cell);
  1003. auto const& vertical_align = cell.box->computed_values().vertical_align();
  1004. // The following image shows various alignment lines of a row:
  1005. // https://www.w3.org/TR/css-tables-3/images/cell-align-explainer.png
  1006. if (vertical_align.has<CSS::VerticalAlign>()) {
  1007. auto height_diff = row_content_height - cell_border_box_height;
  1008. switch (vertical_align.get<CSS::VerticalAlign>()) {
  1009. case CSS::VerticalAlign::Middle: {
  1010. cell_state.padding_top += height_diff / 2;
  1011. cell_state.padding_bottom += height_diff / 2;
  1012. break;
  1013. }
  1014. case CSS::VerticalAlign::Top: {
  1015. cell_state.padding_bottom += height_diff;
  1016. break;
  1017. }
  1018. case CSS::VerticalAlign::Bottom: {
  1019. cell_state.padding_top += height_diff;
  1020. break;
  1021. }
  1022. case CSS::VerticalAlign::Baseline: {
  1023. cell_state.padding_top += m_rows[cell.row_index].baseline - cell.baseline;
  1024. cell_state.padding_bottom += height_diff;
  1025. break;
  1026. }
  1027. default:
  1028. VERIFY_NOT_REACHED();
  1029. }
  1030. }
  1031. // Compute cell position as specified by https://www.w3.org/TR/css-tables-3/#bounding-box-assignment:
  1032. // left/top location is the sum of:
  1033. // - for top: the height reserved for top captions (including margins), if any
  1034. // - the padding-left/padding-top and border-left-width/border-top-width of the table
  1035. // FIXME: Account for visibility.
  1036. cell_state.offset = row_state.offset.translated(
  1037. cell_state.border_box_left() + m_columns[cell.column_index].left_offset + cell.column_index * border_spacing_horizontal(),
  1038. cell_state.border_box_top());
  1039. }
  1040. }
  1041. bool TableFormattingContext::border_is_less_specific(const CSS::BorderData& a, const CSS::BorderData& b)
  1042. {
  1043. // Implements criteria for steps 1, 2 and 3 of border conflict resolution algorithm.
  1044. static HashMap<CSS::LineStyle, unsigned> const line_style_score = {
  1045. { CSS::LineStyle::Inset, 0 },
  1046. { CSS::LineStyle::Groove, 1 },
  1047. { CSS::LineStyle::Outset, 2 },
  1048. { CSS::LineStyle::Ridge, 3 },
  1049. { CSS::LineStyle::Dotted, 4 },
  1050. { CSS::LineStyle::Dashed, 5 },
  1051. { CSS::LineStyle::Solid, 6 },
  1052. { CSS::LineStyle::Double, 7 },
  1053. };
  1054. if (a.line_style == CSS::LineStyle::Hidden) {
  1055. return false;
  1056. }
  1057. if (b.line_style == CSS::LineStyle::Hidden) {
  1058. return true;
  1059. }
  1060. if (a.line_style == CSS::LineStyle::None) {
  1061. return true;
  1062. }
  1063. if (b.line_style == CSS::LineStyle::None) {
  1064. return false;
  1065. }
  1066. if (a.width > b.width) {
  1067. return false;
  1068. } else if (a.width < b.width) {
  1069. return true;
  1070. }
  1071. if (*line_style_score.get(a.line_style) > *line_style_score.get(b.line_style)) {
  1072. return false;
  1073. } else if (*line_style_score.get(a.line_style) < *line_style_score.get(b.line_style)) {
  1074. return true;
  1075. }
  1076. return false;
  1077. }
  1078. static const CSS::BorderData& winning_border_style(const CSS::BorderData& a, const CSS::BorderData& b)
  1079. {
  1080. return TableFormattingContext::border_is_less_specific(a, b) ? b : a;
  1081. }
  1082. const CSS::BorderData& TableFormattingContext::border_data_conflicting_edge(TableFormattingContext::ConflictingEdge const& conflicting_edge)
  1083. {
  1084. auto const& style = conflicting_edge.element->computed_values();
  1085. switch (conflicting_edge.side) {
  1086. case ConflictingSide::Top: {
  1087. return style.border_top();
  1088. }
  1089. case ConflictingSide::Bottom: {
  1090. return style.border_bottom();
  1091. }
  1092. case ConflictingSide::Left: {
  1093. return style.border_left();
  1094. }
  1095. case ConflictingSide::Right: {
  1096. return style.border_right();
  1097. }
  1098. default: {
  1099. VERIFY_NOT_REACHED();
  1100. }
  1101. }
  1102. }
  1103. void TableFormattingContext::border_conflict_resolution()
  1104. {
  1105. // Partially implements border conflict resolution, as described in
  1106. // https://www.w3.org/TR/CSS22/tables.html#border-conflict-resolution
  1107. BorderConflictFinder finder(this);
  1108. for (auto& cell : m_cells) {
  1109. auto& cell_state = m_state.get_mutable(cell.box);
  1110. cell_state.set_table_cell_coordinates(
  1111. Painting::PaintableBox::TableCellCoordinates {
  1112. .row_index = cell.row_index,
  1113. .column_index = cell.column_index,
  1114. .row_span = cell.row_span,
  1115. .column_span = cell.column_span });
  1116. if (cell.box->computed_values().border_collapse() == CSS::BorderCollapse::Separate) {
  1117. continue;
  1118. }
  1119. // Execute steps 1, 2 and 3 of the algorithm for each edge.
  1120. Painting::BordersData override_borders_data;
  1121. auto const& cell_style = cell.box->computed_values();
  1122. auto winning_border_left = cell_style.border_left();
  1123. for (auto const conflicting_edge : finder.conflicting_edges(cell, ConflictingSide::Left)) {
  1124. winning_border_left = winning_border_style(winning_border_left, border_data_conflicting_edge(conflicting_edge));
  1125. }
  1126. override_borders_data.left = winning_border_left;
  1127. cell_state.border_left = winning_border_left.width;
  1128. auto winning_border_right = cell_style.border_right();
  1129. for (auto const conflicting_edge : finder.conflicting_edges(cell, ConflictingSide::Right)) {
  1130. winning_border_right = winning_border_style(winning_border_right, border_data_conflicting_edge(conflicting_edge));
  1131. }
  1132. override_borders_data.right = winning_border_right;
  1133. cell_state.border_right = winning_border_right.width;
  1134. auto winning_border_top = cell_style.border_top();
  1135. for (auto const conflicting_edge : finder.conflicting_edges(cell, ConflictingSide::Top)) {
  1136. winning_border_top = winning_border_style(winning_border_top, border_data_conflicting_edge(conflicting_edge));
  1137. }
  1138. override_borders_data.top = winning_border_top;
  1139. cell_state.border_top = winning_border_top.width;
  1140. auto winning_border_bottom = cell_style.border_bottom();
  1141. for (auto const conflicting_edge : finder.conflicting_edges(cell, ConflictingSide::Bottom)) {
  1142. winning_border_bottom = winning_border_style(winning_border_bottom, border_data_conflicting_edge(conflicting_edge));
  1143. }
  1144. override_borders_data.bottom = winning_border_bottom;
  1145. cell_state.border_bottom = override_borders_data.bottom.width;
  1146. // FIXME: 4. If border styles differ only in color, then a style set on a cell wins over one on a row, which wins over a
  1147. // row group, column, column group and, lastly, table. When two elements of the same type conflict, then the one
  1148. // further to the left (if the table's 'direction' is 'ltr'; right, if it is 'rtl') and further to the top wins.
  1149. cell_state.set_override_borders_data(override_borders_data);
  1150. }
  1151. }
  1152. CSSPixels TableFormattingContext::compute_row_content_height(Cell const& cell) const
  1153. {
  1154. auto& row_state = m_state.get(m_rows[cell.row_index].box);
  1155. if (cell.row_span == 1) {
  1156. return row_state.content_height();
  1157. }
  1158. // The height of a cell is the sum of all spanned rows, as described in
  1159. // https://www.w3.org/TR/css-tables-3/#bounding-box-assignment
  1160. // When the row span is greater than 1, the borders of inner rows within the span have to be
  1161. // included in the content height of the spanning cell. First top and final bottom borders are
  1162. // excluded to be consistent with the handling of row span 1 case above, which uses the content
  1163. // height (no top and bottom borders) of the row.
  1164. CSSPixels span_height = 0;
  1165. for (size_t i = 0; i < cell.row_span; ++i) {
  1166. auto const& row_state = m_state.get(m_rows[cell.row_index + i].box);
  1167. if (i == 0) {
  1168. span_height += row_state.content_height() + row_state.border_box_bottom();
  1169. } else if (i == cell.row_span - 1) {
  1170. span_height += row_state.border_box_top() + row_state.content_height();
  1171. } else {
  1172. span_height += row_state.border_box_height();
  1173. }
  1174. }
  1175. // Compute cell height as specified by https://www.w3.org/TR/css-tables-3/#bounding-box-assignment:
  1176. // width/height is the sum of:
  1177. // - the widths/heights of all spanned visible columns/rows
  1178. // - the horizontal/vertical border-spacing times the amount of spanned visible columns/rows minus one
  1179. // FIXME: Account for visibility.
  1180. span_height += (cell.row_span - 1) * border_spacing_vertical();
  1181. return span_height;
  1182. }
  1183. TableFormattingContext::BorderConflictFinder::BorderConflictFinder(TableFormattingContext const* context)
  1184. : m_context(context)
  1185. {
  1186. collect_conflicting_col_elements();
  1187. collect_conflicting_row_group_elements();
  1188. }
  1189. void TableFormattingContext::BorderConflictFinder::collect_conflicting_col_elements()
  1190. {
  1191. m_col_elements_by_index.resize(m_context->m_columns.size());
  1192. for (auto* child = m_context->table_box().first_child(); child; child = child->next_sibling()) {
  1193. if (!child->display().is_table_column_group()) {
  1194. continue;
  1195. }
  1196. size_t column_index = 0;
  1197. for (auto* child_of_column_group = child->first_child(); child_of_column_group; child_of_column_group = child_of_column_group->next_sibling()) {
  1198. VERIFY(child_of_column_group->display().is_table_column());
  1199. auto const& col_node = static_cast<HTML::HTMLTableColElement const&>(*child_of_column_group->dom_node());
  1200. unsigned span = col_node.attribute(HTML::AttributeNames::span).to_uint().value_or(1);
  1201. for (size_t i = column_index; i < column_index + span; ++i) {
  1202. m_col_elements_by_index[i] = child_of_column_group;
  1203. }
  1204. column_index += span;
  1205. }
  1206. }
  1207. }
  1208. void TableFormattingContext::BorderConflictFinder::collect_conflicting_row_group_elements()
  1209. {
  1210. m_row_group_elements_by_index.resize(m_context->m_rows.size());
  1211. size_t current_row_index = 0;
  1212. for_each_child_box_matching(m_context->table_box(), is_table_row_group, [&](auto& row_group_box) {
  1213. auto start_row_index = current_row_index;
  1214. size_t row_count = 0;
  1215. for_each_child_box_matching(row_group_box, is_table_row, [&](auto&) {
  1216. ++row_count;
  1217. });
  1218. for_each_child_box_matching(row_group_box, is_table_row, [&](auto&) {
  1219. m_row_group_elements_by_index[current_row_index] = RowGroupInfo {
  1220. .row_group = &row_group_box, .start_index = start_row_index, .row_count = row_count
  1221. };
  1222. ++current_row_index;
  1223. return IterationDecision::Continue;
  1224. });
  1225. });
  1226. }
  1227. Vector<TableFormattingContext::ConflictingEdge> TableFormattingContext::BorderConflictFinder::conflicting_edges(
  1228. Cell const& cell, TableFormattingContext::ConflictingSide edge) const
  1229. {
  1230. Vector<ConflictingEdge> result = {};
  1231. if (cell.column_index >= cell.column_span && edge == ConflictingSide::Left) {
  1232. auto maybe_cell_to_left = m_context->m_cells_by_coordinate[cell.row_index][cell.column_index - cell.column_span];
  1233. if (maybe_cell_to_left.has_value()) {
  1234. result.append({ maybe_cell_to_left->box, ConflictingSide::Right });
  1235. }
  1236. }
  1237. if (cell.column_index + cell.column_span < m_context->m_cells_by_coordinate[cell.row_index].size() && edge == ConflictingSide::Right) {
  1238. auto maybe_cell_to_right = m_context->m_cells_by_coordinate[cell.row_index][cell.column_index + cell.column_span];
  1239. if (maybe_cell_to_right.has_value()) {
  1240. result.append({ maybe_cell_to_right->box, ConflictingSide::Left });
  1241. }
  1242. }
  1243. if (cell.row_index >= cell.row_span && edge == ConflictingSide::Top) {
  1244. auto maybe_cell_above = m_context->m_cells_by_coordinate[cell.row_index - cell.row_span][cell.column_index];
  1245. if (maybe_cell_above.has_value()) {
  1246. result.append({ maybe_cell_above->box, ConflictingSide::Bottom });
  1247. }
  1248. }
  1249. if (cell.row_index + cell.row_span < m_context->m_cells_by_coordinate.size() && edge == ConflictingSide::Bottom) {
  1250. auto maybe_cell_below = m_context->m_cells_by_coordinate[cell.row_index + cell.row_span][cell.column_index];
  1251. if (maybe_cell_below.has_value()) {
  1252. result.append({ maybe_cell_below->box, ConflictingSide::Top });
  1253. }
  1254. }
  1255. if (edge == ConflictingSide::Top) {
  1256. result.append({ m_context->m_rows[cell.row_index].box, ConflictingSide::Top });
  1257. }
  1258. if (edge == ConflictingSide::Bottom) {
  1259. result.append({ m_context->m_rows[cell.row_index].box, ConflictingSide::Bottom });
  1260. }
  1261. if (cell.row_index >= cell.row_span && edge == ConflictingSide::Top) {
  1262. result.append({ m_context->m_rows[cell.row_index - cell.row_span].box, ConflictingSide::Bottom });
  1263. }
  1264. if (cell.row_index + cell.row_span < m_context->m_rows.size() && edge == ConflictingSide::Bottom) {
  1265. result.append({ m_context->m_rows[cell.row_index + cell.row_span].box, ConflictingSide::Top });
  1266. }
  1267. auto const& maybe_row_group = m_row_group_elements_by_index[cell.row_index];
  1268. if (maybe_row_group.has_value() && cell.row_index == maybe_row_group->start_index && edge == ConflictingSide::Top) {
  1269. result.append({ maybe_row_group->row_group, ConflictingSide::Top });
  1270. }
  1271. if (cell.row_index >= cell.row_span) {
  1272. auto const& maybe_row_group_above = m_row_group_elements_by_index[cell.row_index - cell.row_span];
  1273. if (maybe_row_group_above.has_value() && cell.row_index == maybe_row_group_above->start_index + maybe_row_group_above->row_count && edge == ConflictingSide::Top) {
  1274. result.append({ maybe_row_group_above->row_group, ConflictingSide::Bottom });
  1275. }
  1276. }
  1277. if (maybe_row_group.has_value() && cell.row_index == maybe_row_group->start_index + maybe_row_group->row_count - 1 && edge == ConflictingSide::Bottom) {
  1278. result.append({ maybe_row_group->row_group, ConflictingSide::Bottom });
  1279. }
  1280. if (cell.row_index + cell.row_span < m_row_group_elements_by_index.size()) {
  1281. auto const& maybe_row_group_below = m_row_group_elements_by_index[cell.row_index + cell.row_span];
  1282. if (maybe_row_group_below.has_value() && cell.row_index + cell.row_span == maybe_row_group_below->start_index && edge == ConflictingSide::Bottom) {
  1283. result.append({ maybe_row_group_below->row_group, ConflictingSide::Top });
  1284. }
  1285. }
  1286. if (m_col_elements_by_index[cell.column_index] && edge == ConflictingSide::Left) {
  1287. result.append({ m_col_elements_by_index[cell.column_index], ConflictingSide::Left });
  1288. }
  1289. if (cell.column_index >= cell.column_span && m_col_elements_by_index[cell.column_index - cell.column_span] && edge == ConflictingSide::Left) {
  1290. result.append({ m_col_elements_by_index[cell.column_index - cell.column_span], ConflictingSide::Right });
  1291. }
  1292. if (m_col_elements_by_index[cell.column_index] && edge == ConflictingSide::Right) {
  1293. result.append({ m_col_elements_by_index[cell.column_index], ConflictingSide::Right });
  1294. }
  1295. if (cell.column_index + cell.column_span < m_col_elements_by_index.size() && m_col_elements_by_index[cell.column_index + cell.column_span] && edge == ConflictingSide::Right) {
  1296. result.append({ m_col_elements_by_index[cell.column_index + cell.column_span], ConflictingSide::Left });
  1297. }
  1298. if (cell.row_index == 0 && edge == ConflictingSide::Top) {
  1299. if (m_col_elements_by_index[cell.column_index]) {
  1300. result.append({ m_col_elements_by_index[cell.column_index], ConflictingSide::Top });
  1301. }
  1302. result.append({ &m_context->table_box(), ConflictingSide::Top });
  1303. }
  1304. if (cell.row_index == m_context->m_rows.size() - 1 && edge == ConflictingSide::Bottom) {
  1305. if (m_col_elements_by_index[cell.column_index]) {
  1306. result.append({ m_col_elements_by_index[cell.column_index], ConflictingSide::Bottom });
  1307. }
  1308. result.append({ &m_context->table_box(), ConflictingSide::Bottom });
  1309. }
  1310. if (cell.column_index == 0 && edge == ConflictingSide::Left) {
  1311. result.append({ m_context->m_rows[cell.row_index].box, ConflictingSide::Left });
  1312. if (m_row_group_elements_by_index[cell.row_index].has_value()) {
  1313. result.append({ m_row_group_elements_by_index[cell.row_index]->row_group, ConflictingSide::Left });
  1314. }
  1315. result.append({ &m_context->table_box(), ConflictingSide::Left });
  1316. }
  1317. if (cell.column_index == m_context->m_columns.size() - 1 && edge == ConflictingSide::Right) {
  1318. result.append({ m_context->m_rows[cell.row_index].box, ConflictingSide::Right });
  1319. if (m_row_group_elements_by_index[cell.row_index].has_value()) {
  1320. result.append({ m_row_group_elements_by_index[cell.row_index]->row_group, ConflictingSide::Right });
  1321. }
  1322. result.append({ &m_context->table_box(), ConflictingSide::Right });
  1323. }
  1324. return result;
  1325. }
  1326. void TableFormattingContext::run(Box const& box, LayoutMode layout_mode, AvailableSpace const& available_space)
  1327. {
  1328. m_available_space = available_space;
  1329. auto total_captions_height = run_caption_layout(layout_mode, CSS::CaptionSide::Top);
  1330. // Determine the number of rows/columns the table requires.
  1331. calculate_row_column_grid(box);
  1332. border_conflict_resolution();
  1333. // Compute the minimum width of each column.
  1334. compute_cell_measures(available_space);
  1335. compute_outer_content_sizes();
  1336. compute_table_measures<Column>();
  1337. // https://www.w3.org/TR/css-tables-3/#row-layout
  1338. // Since during row layout the specified heights of cells in the row were ignored and cells that were spanning more than one rows
  1339. // have not been sized correctly, their height will need to be eventually distributed to the set of rows they spanned. This is done
  1340. // by running the same algorithm as the column measurement, with the span=1 value being initialized (for min-content) with the largest
  1341. // of the resulting height of the previous row layout, the height specified on the corresponding table-row (if any), and the largest
  1342. // height specified on cells that span this row only (the algorithm starts by considering cells of span 2 on top of that assignment).
  1343. compute_table_measures<Row>();
  1344. // Compute the width of the table.
  1345. compute_table_width();
  1346. if (available_space.width.is_intrinsic_sizing_constraint() && !available_space.height.is_intrinsic_sizing_constraint()) {
  1347. return;
  1348. }
  1349. // Distribute the width of the table among columns.
  1350. distribute_width_to_columns();
  1351. compute_table_height(layout_mode);
  1352. distribute_height_to_rows();
  1353. position_row_boxes();
  1354. position_cell_boxes();
  1355. m_state.get_mutable(table_box()).set_content_height(m_table_height);
  1356. total_captions_height += run_caption_layout(layout_mode, CSS::CaptionSide::Bottom);
  1357. // Table captions are positioned between the table margins and its borders (outside the grid box borders) as described in
  1358. // https://www.w3.org/TR/css-tables-3/#bounding-box-assignment
  1359. // A visual representation of this model can be found at https://www.w3.org/TR/css-tables-3/images/table_container.png
  1360. m_state.get_mutable(table_box()).margin_bottom += total_captions_height;
  1361. m_automatic_content_height = m_table_height;
  1362. }
  1363. CSSPixels TableFormattingContext::automatic_content_width() const
  1364. {
  1365. return greatest_child_width(context_box());
  1366. }
  1367. CSSPixels TableFormattingContext::automatic_content_height() const
  1368. {
  1369. return m_automatic_content_height;
  1370. }
  1371. template<>
  1372. size_t TableFormattingContext::cell_span<TableFormattingContext::Row>(TableFormattingContext::Cell const& cell)
  1373. {
  1374. return cell.row_span;
  1375. }
  1376. template<>
  1377. size_t TableFormattingContext::cell_span<TableFormattingContext::Column>(TableFormattingContext::Cell const& cell)
  1378. {
  1379. return cell.column_span;
  1380. }
  1381. template<>
  1382. size_t TableFormattingContext::cell_index<TableFormattingContext::Row>(TableFormattingContext::Cell const& cell)
  1383. {
  1384. return cell.row_index;
  1385. }
  1386. template<>
  1387. size_t TableFormattingContext::cell_index<TableFormattingContext::Column>(TableFormattingContext::Cell const& cell)
  1388. {
  1389. return cell.column_index;
  1390. }
  1391. template<>
  1392. CSSPixels TableFormattingContext::cell_min_size<TableFormattingContext::Row>(TableFormattingContext::Cell const& cell)
  1393. {
  1394. return cell.outer_min_height;
  1395. }
  1396. template<>
  1397. CSSPixels TableFormattingContext::cell_min_size<TableFormattingContext::Column>(TableFormattingContext::Cell const& cell)
  1398. {
  1399. return cell.outer_min_width;
  1400. }
  1401. template<>
  1402. CSSPixels TableFormattingContext::cell_max_size<TableFormattingContext::Row>(TableFormattingContext::Cell const& cell)
  1403. {
  1404. return cell.outer_max_height;
  1405. }
  1406. template<>
  1407. CSSPixels TableFormattingContext::cell_max_size<TableFormattingContext::Column>(TableFormattingContext::Cell const& cell)
  1408. {
  1409. return cell.outer_max_width;
  1410. }
  1411. template<>
  1412. double TableFormattingContext::cell_percentage_contribution<TableFormattingContext::Row>(TableFormattingContext::Cell const& cell)
  1413. {
  1414. // Definition of percentage contribution: https://www.w3.org/TR/css-tables-3/#percentage-contribution
  1415. auto const& computed_values = cell.box->computed_values();
  1416. auto max_height_percentage = computed_values.max_height().is_percentage() ? computed_values.max_height().percentage().value() : static_cast<double>(INFINITY);
  1417. auto height_percentage = computed_values.height().is_percentage() ? computed_values.height().percentage().value() : 0;
  1418. return min(height_percentage, max_height_percentage);
  1419. }
  1420. template<>
  1421. double TableFormattingContext::cell_percentage_contribution<TableFormattingContext::Column>(TableFormattingContext::Cell const& cell)
  1422. {
  1423. // Definition of percentage contribution: https://www.w3.org/TR/css-tables-3/#percentage-contribution
  1424. auto const& computed_values = cell.box->computed_values();
  1425. auto max_width_percentage = computed_values.max_width().is_percentage() ? computed_values.max_width().percentage().value() : static_cast<double>(INFINITY);
  1426. auto width_percentage = computed_values.width().is_percentage() ? computed_values.width().percentage().value() : 0;
  1427. return min(width_percentage, max_width_percentage);
  1428. }
  1429. template<>
  1430. bool TableFormattingContext::cell_has_intrinsic_percentage<TableFormattingContext::Row>(TableFormattingContext::Cell const& cell)
  1431. {
  1432. return cell.box->computed_values().height().is_percentage();
  1433. }
  1434. template<>
  1435. bool TableFormattingContext::cell_has_intrinsic_percentage<TableFormattingContext::Column>(TableFormattingContext::Cell const& cell)
  1436. {
  1437. return cell.box->computed_values().width().is_percentage();
  1438. }
  1439. template<>
  1440. void TableFormattingContext::initialize_intrinsic_percentages_from_rows_or_columns<TableFormattingContext::Row>()
  1441. {
  1442. for (auto& row : m_rows) {
  1443. auto const& computed_values = row.box->computed_values();
  1444. // Definition of percentage contribution: https://www.w3.org/TR/css-tables-3/#percentage-contribution
  1445. auto max_height_percentage = computed_values.max_height().is_percentage() ? computed_values.max_height().percentage().value() : static_cast<double>(INFINITY);
  1446. auto height_percentage = computed_values.height().is_percentage() ? computed_values.height().percentage().value() : 0;
  1447. row.has_intrinsic_percentage = computed_values.max_height().is_percentage() || computed_values.height().is_percentage();
  1448. row.intrinsic_percentage = min(height_percentage, max_height_percentage);
  1449. }
  1450. }
  1451. template<>
  1452. void TableFormattingContext::initialize_intrinsic_percentages_from_rows_or_columns<TableFormattingContext::Column>()
  1453. {
  1454. size_t column_index = 0;
  1455. for_each_child_box_matching(table_box(), is_table_column_group, [&](auto& column_group_box) {
  1456. for_each_child_box_matching(column_group_box, is_table_column, [&](auto& column_box) {
  1457. auto const& computed_values = column_box.computed_values();
  1458. // Definition of percentage contribution: https://www.w3.org/TR/css-tables-3/#percentage-contribution
  1459. auto max_width_percentage = computed_values.max_width().is_percentage() ? computed_values.max_width().percentage().value() : static_cast<double>(INFINITY);
  1460. auto width_percentage = computed_values.width().is_percentage() ? computed_values.width().percentage().value() : 0;
  1461. m_columns[column_index].has_intrinsic_percentage = computed_values.max_width().is_percentage() || computed_values.width().is_percentage();
  1462. m_columns[column_index].intrinsic_percentage = min(width_percentage, max_width_percentage);
  1463. auto const& col_node = static_cast<HTML::HTMLTableColElement const&>(*column_box.dom_node());
  1464. unsigned span = col_node.attribute(HTML::AttributeNames::span).to_uint().value_or(1);
  1465. column_index += span;
  1466. });
  1467. });
  1468. }
  1469. template<class RowOrColumn>
  1470. void TableFormattingContext::initialize_intrinsic_percentages_from_cells()
  1471. {
  1472. auto& rows_or_columns = table_rows_or_columns<RowOrColumn>();
  1473. for (auto& cell : m_cells) {
  1474. auto cell_span_value = cell_span<RowOrColumn>(cell);
  1475. auto cell_start_rc_index = cell_index<RowOrColumn>(cell);
  1476. auto cell_end_rc_index = cell_start_rc_index + cell_span_value;
  1477. if (cell_has_intrinsic_percentage<RowOrColumn>(cell)) {
  1478. for (auto rc_index = cell_start_rc_index; rc_index < cell_end_rc_index; rc_index++) {
  1479. rows_or_columns[rc_index].has_intrinsic_percentage = true;
  1480. }
  1481. if (cell_span_value != 1) {
  1482. continue;
  1483. }
  1484. } else {
  1485. continue;
  1486. }
  1487. size_t rc_index = cell_index<RowOrColumn>(cell);
  1488. rows_or_columns[rc_index].has_intrinsic_percentage = true;
  1489. rows_or_columns[rc_index].intrinsic_percentage = max(cell_percentage_contribution<RowOrColumn>(cell), rows_or_columns[rc_index].intrinsic_percentage);
  1490. }
  1491. }
  1492. template<>
  1493. CSSPixels TableFormattingContext::border_spacing<TableFormattingContext::Row>()
  1494. {
  1495. return border_spacing_vertical();
  1496. }
  1497. template<>
  1498. CSSPixels TableFormattingContext::border_spacing<TableFormattingContext::Column>()
  1499. {
  1500. return border_spacing_horizontal();
  1501. }
  1502. CSSPixels TableFormattingContext::border_spacing_horizontal() const
  1503. {
  1504. auto const& computed_values = table_box().computed_values();
  1505. // When a table is laid out in collapsed-borders mode, the border-spacing of the table-root is ignored (as if it was set to 0px):
  1506. // https://www.w3.org/TR/css-tables-3/#collapsed-style-overrides
  1507. if (computed_values.border_collapse() == CSS::BorderCollapse::Collapse)
  1508. return 0;
  1509. return computed_values.border_spacing_horizontal().to_px(table_box());
  1510. }
  1511. CSSPixels TableFormattingContext::border_spacing_vertical() const
  1512. {
  1513. auto const& computed_values = table_box().computed_values();
  1514. // When a table is laid out in collapsed-borders mode, the border-spacing of the table-root is ignored (as if it was set to 0px):
  1515. // https://www.w3.org/TR/css-tables-3/#collapsed-style-overrides
  1516. if (computed_values.border_collapse() == CSS::BorderCollapse::Collapse)
  1517. return 0;
  1518. return computed_values.border_spacing_vertical().to_px(table_box());
  1519. }
  1520. template<>
  1521. Vector<TableFormattingContext::Row>& TableFormattingContext::table_rows_or_columns()
  1522. {
  1523. return m_rows;
  1524. }
  1525. template<>
  1526. Vector<TableFormattingContext::Column>& TableFormattingContext::table_rows_or_columns()
  1527. {
  1528. return m_columns;
  1529. }
  1530. }