LayoutBlock.cpp 32 KB

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  1. /*
  2. * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
  3. * All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions are met:
  7. *
  8. * 1. Redistributions of source code must retain the above copyright notice, this
  9. * list of conditions and the following disclaimer.
  10. *
  11. * 2. Redistributions in binary form must reproduce the above copyright notice,
  12. * this list of conditions and the following disclaimer in the documentation
  13. * and/or other materials provided with the distribution.
  14. *
  15. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  16. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18. * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  19. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21. * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  22. * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  23. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25. */
  26. #include <LibGUI/Painter.h>
  27. #include <LibWeb/CSS/StyleResolver.h>
  28. #include <LibWeb/DOM/Element.h>
  29. #include <LibWeb/Dump.h>
  30. #include <LibWeb/Layout/LayoutBlock.h>
  31. #include <LibWeb/Layout/LayoutDocument.h>
  32. #include <LibWeb/Layout/LayoutInline.h>
  33. #include <LibWeb/Layout/LayoutReplaced.h>
  34. #include <LibWeb/Layout/LayoutText.h>
  35. #include <LibWeb/Layout/LayoutWidget.h>
  36. #include <math.h>
  37. namespace Web {
  38. LayoutBlock::LayoutBlock(Document& document, const Node* node, NonnullRefPtr<StyleProperties> style)
  39. : LayoutBox(document, node, move(style))
  40. {
  41. }
  42. LayoutBlock::~LayoutBlock()
  43. {
  44. }
  45. LayoutNode& LayoutBlock::inline_wrapper()
  46. {
  47. if (!last_child() || !last_child()->is_block() || last_child()->node() != nullptr) {
  48. append_child(adopt(*new LayoutBlock(document(), nullptr, style_for_anonymous_block())));
  49. last_child()->set_children_are_inline(true);
  50. }
  51. return *last_child();
  52. }
  53. void LayoutBlock::layout(LayoutMode layout_mode)
  54. {
  55. compute_width();
  56. layout_inside(layout_mode);
  57. compute_height();
  58. layout_absolutely_positioned_descendants();
  59. }
  60. void LayoutBlock::layout_absolutely_positioned_descendant(LayoutBox& box)
  61. {
  62. box.layout(LayoutMode::Default);
  63. auto& box_model = box.box_model();
  64. auto zero_value = Length::make_px(0);
  65. auto specified_width = box.style().width().resolved_or_auto(box, width());
  66. box_model.margin.left = box.style().margin().left.resolved_or_auto(box, width());
  67. box_model.margin.top = box.style().margin().top.resolved_or_auto(box, height());
  68. box_model.margin.right = box.style().margin().right.resolved_or_auto(box, width());
  69. box_model.margin.bottom = box.style().margin().bottom.resolved_or_auto(box, height());
  70. box_model.offset.left = box.style().offset().left.resolved_or_auto(box, width());
  71. box_model.offset.top = box.style().offset().top.resolved_or_auto(box, height());
  72. box_model.offset.right = box.style().offset().right.resolved_or_auto(box, width());
  73. box_model.offset.bottom = box.style().offset().bottom.resolved_or_auto(box, height());
  74. if (box_model.offset.left.is_auto() && specified_width.is_auto() && box_model.offset.right.is_auto()) {
  75. if (box_model.margin.left.is_auto())
  76. box_model.margin.left = zero_value;
  77. if (box_model.margin.right.is_auto())
  78. box_model.margin.right = zero_value;
  79. }
  80. Gfx::FloatPoint used_offset;
  81. float x_offset = box_model.offset.left.to_px(box)
  82. + box_model.border_box(box).left
  83. - box_model.offset.right.to_px(box)
  84. - box_model.border_box(box).right;
  85. float y_offset = box_model.offset.top.to_px(box)
  86. + box_model.border_box(box).top
  87. - box_model.offset.bottom.to_px(box)
  88. - box_model.border_box(box).bottom;
  89. bool has_left_side_constraints = !box_model.offset.left.is_auto() || !box_model.margin.left.is_auto();
  90. bool has_right_side_constraints = !box_model.offset.right.is_auto() || !box_model.margin.right.is_auto();
  91. if (has_left_side_constraints && has_right_side_constraints) {
  92. // If both 'left' and 'right' are set, we will have stretched the width to accomodate both.
  93. x_offset += box_model.offset.right.to_px(box);
  94. }
  95. if (has_left_side_constraints) {
  96. used_offset.set_x(x_offset + box_model.margin.left.to_px(box));
  97. } else if (has_right_side_constraints) {
  98. used_offset.set_x(width() + x_offset - box.width() - box_model.margin.right.to_px(box));
  99. }
  100. if (!box_model.offset.top.is_auto()) {
  101. used_offset.set_y(y_offset + box_model.margin.top.to_px(box));
  102. } else if (!box_model.offset.bottom.is_auto()) {
  103. used_offset.set_y(height() + y_offset - box.height() - box_model.margin.bottom.to_px(box));
  104. }
  105. box.set_offset(used_offset);
  106. }
  107. void LayoutBlock::layout_inside(LayoutMode layout_mode)
  108. {
  109. if (children_are_inline())
  110. layout_inline_children(layout_mode);
  111. else
  112. layout_contained_boxes(layout_mode);
  113. }
  114. void LayoutBlock::layout_absolutely_positioned_descendants()
  115. {
  116. for_each_in_subtree_of_type<LayoutBox>([&](auto& box) {
  117. if (box.is_absolutely_positioned() && box.containing_block() == this) {
  118. layout_absolutely_positioned_descendant(box);
  119. }
  120. return IterationDecision::Continue;
  121. });
  122. }
  123. void LayoutBlock::layout_contained_boxes(LayoutMode layout_mode)
  124. {
  125. float content_height = 0;
  126. float content_width = 0;
  127. for_each_in_subtree_of_type<LayoutBox>([&](auto& box) {
  128. if (box.is_absolutely_positioned() || box.containing_block() != this)
  129. return IterationDecision::Continue;
  130. box.layout(layout_mode);
  131. if (box.is_replaced())
  132. place_block_level_replaced_element_in_normal_flow(to<LayoutReplaced>(box));
  133. else if (box.is_block())
  134. place_block_level_non_replaced_element_in_normal_flow(to<LayoutBlock>(box));
  135. else
  136. dbg() << "FIXME: LayoutBlock::layout_contained_boxes doesn't know how to place a " << box.class_name();
  137. content_height = max(content_height, box.effective_offset().y() + box.height() + box.box_model().margin_box(*this).bottom);
  138. content_width = max(content_width, to<LayoutBox>(box).width());
  139. return IterationDecision::Continue;
  140. });
  141. if (layout_mode != LayoutMode::Default) {
  142. if (style().width().is_undefined() || style().width().is_auto())
  143. set_width(content_width);
  144. }
  145. set_height(content_height);
  146. }
  147. void LayoutBlock::layout_inline_children(LayoutMode layout_mode)
  148. {
  149. ASSERT(children_are_inline());
  150. m_line_boxes.clear();
  151. for_each_child([&](auto& child) {
  152. ASSERT(child.is_inline());
  153. if (child.is_absolutely_positioned())
  154. return;
  155. child.split_into_lines(*this, layout_mode);
  156. });
  157. for (auto& line_box : m_line_boxes) {
  158. line_box.trim_trailing_whitespace();
  159. }
  160. auto text_align = style().text_align();
  161. float min_line_height = specified_style().line_height(*this);
  162. float line_spacing = min_line_height - specified_style().font().glyph_height();
  163. float content_height = 0;
  164. float max_linebox_width = 0;
  165. for (auto& line_box : m_line_boxes) {
  166. float max_height = min_line_height;
  167. for (auto& fragment : line_box.fragments()) {
  168. max_height = max(max_height, fragment.height());
  169. }
  170. float x_offset = 0;
  171. float excess_horizontal_space = (float)width() - line_box.width();
  172. switch (text_align) {
  173. case CSS::TextAlign::Center:
  174. case CSS::TextAlign::VendorSpecificCenter:
  175. x_offset += excess_horizontal_space / 2;
  176. break;
  177. case CSS::TextAlign::Right:
  178. x_offset += excess_horizontal_space;
  179. break;
  180. case CSS::TextAlign::Left:
  181. case CSS::TextAlign::Justify:
  182. default:
  183. break;
  184. }
  185. float excess_horizontal_space_including_whitespace = excess_horizontal_space;
  186. int whitespace_count = 0;
  187. if (text_align == CSS::TextAlign::Justify) {
  188. for (auto& fragment : line_box.fragments()) {
  189. if (fragment.is_justifiable_whitespace()) {
  190. ++whitespace_count;
  191. excess_horizontal_space_including_whitespace += fragment.width();
  192. }
  193. }
  194. }
  195. float justified_space_width = whitespace_count ? (excess_horizontal_space_including_whitespace / (float)whitespace_count) : 0;
  196. for (size_t i = 0; i < line_box.fragments().size(); ++i) {
  197. auto& fragment = line_box.fragments()[i];
  198. // Vertically align everyone's bottom to the line.
  199. // FIXME: Support other kinds of vertical alignment.
  200. fragment.set_offset({ roundf(x_offset + fragment.offset().x()), content_height + (max_height - fragment.height()) - (line_spacing / 2) });
  201. if (text_align == CSS::TextAlign::Justify) {
  202. if (fragment.is_justifiable_whitespace()) {
  203. if (fragment.width() != justified_space_width) {
  204. float diff = justified_space_width - fragment.width();
  205. fragment.set_width(justified_space_width);
  206. // Shift subsequent sibling fragments to the right to adjust for change in width.
  207. for (size_t j = i + 1; j < line_box.fragments().size(); ++j) {
  208. auto offset = line_box.fragments()[j].offset();
  209. offset.move_by(diff, 0);
  210. line_box.fragments()[j].set_offset(offset);
  211. }
  212. }
  213. }
  214. }
  215. if (fragment.layout_node().is_inline_block()) {
  216. auto& inline_block = const_cast<LayoutBlock&>(to<LayoutBlock>(fragment.layout_node()));
  217. inline_block.set_size(fragment.size());
  218. inline_block.layout(layout_mode);
  219. }
  220. float final_line_box_width = 0;
  221. for (auto& fragment : line_box.fragments())
  222. final_line_box_width += fragment.width();
  223. line_box.m_width = final_line_box_width;
  224. max_linebox_width = max(max_linebox_width, final_line_box_width);
  225. }
  226. content_height += max_height;
  227. }
  228. if (layout_mode != LayoutMode::Default) {
  229. set_width(max_linebox_width);
  230. }
  231. set_height(content_height);
  232. }
  233. void LayoutBlock::compute_width_for_absolutely_positioned_block()
  234. {
  235. auto& containing_block = *this->containing_block();
  236. auto zero_value = Length::make_px(0);
  237. auto margin_left = Length::make_auto();
  238. auto margin_right = Length::make_auto();
  239. const auto border_left = style().border_left().width;
  240. const auto border_right = style().border_right().width;
  241. const auto padding_left = style().padding().left.resolved(zero_value, *this, containing_block.width());
  242. const auto padding_right = style().padding().right.resolved(zero_value, *this, containing_block.width());
  243. auto try_compute_width = [&](const auto& a_width) {
  244. margin_left = style().margin().left.resolved(zero_value, *this, containing_block.width());
  245. margin_right = style().margin().right.resolved(zero_value, *this, containing_block.width());
  246. auto left = style().offset().left.resolved_or_auto(*this, containing_block.width());
  247. auto right = style().offset().right.resolved_or_auto(*this, containing_block.width());
  248. auto width = a_width;
  249. auto solve_for_left = [&] {
  250. return Length(containing_block.width() - margin_left.to_px(*this) - border_left - padding_left.to_px(*this) - width.to_px(*this) - padding_right.to_px(*this) - border_right - margin_right.to_px(*this) - right.to_px(*this), Length::Type::Px);
  251. };
  252. auto solve_for_width = [&] {
  253. return Length(containing_block.width() - left.to_px(*this) - margin_left.to_px(*this) - border_left - padding_left.to_px(*this) - padding_right.to_px(*this) - border_right - margin_right.to_px(*this) - right.to_px(*this), Length::Type::Px);
  254. };
  255. auto solve_for_right = [&] {
  256. return Length(containing_block.width() - left.to_px(*this) - margin_left.to_px(*this) - border_left - padding_left.to_px(*this) - width.to_px(*this) - padding_right.to_px(*this) - border_right - margin_right.to_px(*this), Length::Type::Px);
  257. };
  258. // If all three of 'left', 'width', and 'right' are 'auto':
  259. if (left.is_auto() && width.is_auto() && right.is_auto()) {
  260. // First set any 'auto' values for 'margin-left' and 'margin-right' to 0.
  261. if (margin_left.is_auto())
  262. margin_left = Length::make_px(0);
  263. if (margin_right.is_auto())
  264. margin_right = Length::make_px(0);
  265. // Then, if the 'direction' property of the element establishing the static-position containing block
  266. // is 'ltr' set 'left' to the static position and apply rule number three below;
  267. // otherwise, set 'right' to the static position and apply rule number one below.
  268. // FIXME: This is very hackish.
  269. left = Length::make_px(0);
  270. goto Rule3;
  271. }
  272. if (!left.is_auto() && !width.is_auto() && !right.is_auto()) {
  273. // FIXME: This should be solved in a more complicated way.
  274. return width;
  275. }
  276. if (margin_left.is_auto())
  277. margin_left = Length::make_px(0);
  278. if (margin_right.is_auto())
  279. margin_right = Length::make_px(0);
  280. // 1. 'left' and 'width' are 'auto' and 'right' is not 'auto',
  281. // then the width is shrink-to-fit. Then solve for 'left'
  282. if (left.is_auto() && width.is_auto() && !right.is_auto()) {
  283. auto result = calculate_shrink_to_fit_width();
  284. solve_for_left();
  285. auto available_width = solve_for_width();
  286. width = Length(min(max(result.preferred_minimum_width, available_width.to_px(*this)), result.preferred_width), Length::Type::Px);
  287. }
  288. // 2. 'left' and 'right' are 'auto' and 'width' is not 'auto',
  289. // then if the 'direction' property of the element establishing
  290. // the static-position containing block is 'ltr' set 'left'
  291. // to the static position, otherwise set 'right' to the static position.
  292. // Then solve for 'left' (if 'direction is 'rtl') or 'right' (if 'direction' is 'ltr').
  293. else if (left.is_auto() && right.is_auto() && !width.is_auto()) {
  294. // FIXME: Check direction
  295. // FIXME: Use the static-position containing block
  296. left = zero_value;
  297. right = solve_for_right();
  298. }
  299. // 3. 'width' and 'right' are 'auto' and 'left' is not 'auto',
  300. // then the width is shrink-to-fit. Then solve for 'right'
  301. else if (width.is_auto() && right.is_auto() && !left.is_auto()) {
  302. Rule3:
  303. auto result = calculate_shrink_to_fit_width();
  304. right = solve_for_right();
  305. auto available_width = solve_for_width();
  306. width = Length(min(max(result.preferred_minimum_width, available_width.to_px(*this)), result.preferred_width), Length::Type::Px);
  307. }
  308. // 4. 'left' is 'auto', 'width' and 'right' are not 'auto', then solve for 'left'
  309. else if (left.is_auto() && !width.is_auto() && !right.is_auto()) {
  310. left = solve_for_left();
  311. }
  312. // 5. 'width' is 'auto', 'left' and 'right' are not 'auto', then solve for 'width'
  313. else if (width.is_auto() && !left.is_auto() && !right.is_auto()) {
  314. width = solve_for_width();
  315. }
  316. // 6. 'right' is 'auto', 'left' and 'width' are not 'auto', then solve for 'right'
  317. else if (right.is_auto() && !left.is_auto() && !width.is_auto()) {
  318. right = solve_for_right();
  319. }
  320. return width;
  321. };
  322. auto specified_width = style().width().resolved_or_auto(*this, containing_block.width());
  323. // 1. The tentative used width is calculated (without 'min-width' and 'max-width')
  324. auto used_width = try_compute_width(specified_width);
  325. // 2. The tentative used width is greater than 'max-width', the rules above are applied again,
  326. // but this time using the computed value of 'max-width' as the computed value for 'width'.
  327. auto specified_max_width = style().max_width().resolved_or_auto(*this, containing_block.width());
  328. if (!specified_max_width.is_auto()) {
  329. if (used_width.to_px(*this) > specified_max_width.to_px(*this)) {
  330. used_width = try_compute_width(specified_max_width);
  331. }
  332. }
  333. // 3. If the resulting width is smaller than 'min-width', the rules above are applied again,
  334. // but this time using the value of 'min-width' as the computed value for 'width'.
  335. auto specified_min_width = style().min_width().resolved_or_auto(*this, containing_block.width());
  336. if (!specified_min_width.is_auto()) {
  337. if (used_width.to_px(*this) < specified_min_width.to_px(*this)) {
  338. used_width = try_compute_width(specified_min_width);
  339. }
  340. }
  341. set_width(used_width.to_px(*this));
  342. box_model().margin.left = margin_left;
  343. box_model().margin.right = margin_right;
  344. box_model().border.left = Length::make_px(border_left);
  345. box_model().border.right = Length::make_px(border_right);
  346. box_model().padding.left = padding_left;
  347. box_model().padding.right = padding_right;
  348. }
  349. void LayoutBlock::compute_width()
  350. {
  351. if (is_absolutely_positioned())
  352. return compute_width_for_absolutely_positioned_block();
  353. auto& containing_block = *this->containing_block();
  354. auto zero_value = Length::make_px(0);
  355. auto margin_left = Length::make_auto();
  356. auto margin_right = Length::make_auto();
  357. const auto padding_left = style().padding().left.resolved_or_zero(*this, containing_block.width());
  358. const auto padding_right = style().padding().right.resolved_or_zero(*this, containing_block.width());
  359. auto try_compute_width = [&](const auto& a_width) {
  360. Length width = a_width;
  361. margin_left = style().margin().left.resolved_or_zero(*this, containing_block.width());
  362. margin_right = style().margin().right.resolved_or_zero(*this, containing_block.width());
  363. float total_px = style().border_left().width + style().border_right().width;
  364. for (auto& value : { margin_left, padding_left, width, padding_right, margin_right }) {
  365. total_px += value.to_px(*this);
  366. }
  367. #ifdef HTML_DEBUG
  368. dbg() << "Total: " << total_px;
  369. #endif
  370. if (!is_replaced() && !is_inline()) {
  371. // 10.3.3 Block-level, non-replaced elements in normal flow
  372. // If 'width' is not 'auto' and 'border-left-width' + 'padding-left' + 'width' + 'padding-right' + 'border-right-width' (plus any of 'margin-left' or 'margin-right' that are not 'auto') is larger than the width of the containing block, then any 'auto' values for 'margin-left' or 'margin-right' are, for the following rules, treated as zero.
  373. if (width.is_auto() && total_px > containing_block.width()) {
  374. if (margin_left.is_auto())
  375. margin_left = zero_value;
  376. if (margin_right.is_auto())
  377. margin_right = zero_value;
  378. }
  379. // 10.3.3 cont'd.
  380. auto underflow_px = containing_block.width() - total_px;
  381. if (width.is_auto()) {
  382. if (margin_left.is_auto())
  383. margin_left = zero_value;
  384. if (margin_right.is_auto())
  385. margin_right = zero_value;
  386. if (underflow_px >= 0) {
  387. width = Length(underflow_px, Length::Type::Px);
  388. } else {
  389. width = zero_value;
  390. margin_right = Length(margin_right.to_px(*this) + underflow_px, Length::Type::Px);
  391. }
  392. } else {
  393. if (!margin_left.is_auto() && !margin_right.is_auto()) {
  394. margin_right = Length(margin_right.to_px(*this) + underflow_px, Length::Type::Px);
  395. } else if (!margin_left.is_auto() && margin_right.is_auto()) {
  396. margin_right = Length(underflow_px, Length::Type::Px);
  397. } else if (margin_left.is_auto() && !margin_right.is_auto()) {
  398. margin_left = Length(underflow_px, Length::Type::Px);
  399. } else { // margin_left.is_auto() && margin_right.is_auto()
  400. auto half_of_the_underflow = Length(underflow_px / 2, Length::Type::Px);
  401. margin_left = half_of_the_underflow;
  402. margin_right = half_of_the_underflow;
  403. }
  404. }
  405. } else if (!is_replaced() && is_inline_block()) {
  406. // 10.3.9 'Inline-block', non-replaced elements in normal flow
  407. // A computed value of 'auto' for 'margin-left' or 'margin-right' becomes a used value of '0'.
  408. if (margin_left.is_auto())
  409. margin_left = zero_value;
  410. if (margin_right.is_auto())
  411. margin_right = zero_value;
  412. // If 'width' is 'auto', the used value is the shrink-to-fit width as for floating elements.
  413. if (width.is_auto()) {
  414. // Find the available width: in this case, this is the width of the containing
  415. // block minus the used values of 'margin-left', 'border-left-width', 'padding-left',
  416. // 'padding-right', 'border-right-width', 'margin-right', and the widths of any relevant scroll bars.
  417. float available_width = containing_block.width()
  418. - margin_left.to_px(*this) - style().border_left().width - padding_left.to_px(*this)
  419. - padding_right.to_px(*this) - style().border_right().width - margin_right.to_px(*this);
  420. auto result = calculate_shrink_to_fit_width();
  421. // Then the shrink-to-fit width is: min(max(preferred minimum width, available width), preferred width).
  422. width = Length(min(max(result.preferred_minimum_width, available_width), result.preferred_width), Length::Type::Px);
  423. }
  424. }
  425. return width;
  426. };
  427. auto specified_width = style().width().resolved_or_auto(*this, containing_block.width());
  428. // 1. The tentative used width is calculated (without 'min-width' and 'max-width')
  429. auto used_width = try_compute_width(specified_width);
  430. // 2. The tentative used width is greater than 'max-width', the rules above are applied again,
  431. // but this time using the computed value of 'max-width' as the computed value for 'width'.
  432. auto specified_max_width = style().max_width().resolved_or_auto(*this, containing_block.width());
  433. if (!specified_max_width.is_auto()) {
  434. if (used_width.to_px(*this) > specified_max_width.to_px(*this)) {
  435. used_width = try_compute_width(specified_max_width);
  436. }
  437. }
  438. // 3. If the resulting width is smaller than 'min-width', the rules above are applied again,
  439. // but this time using the value of 'min-width' as the computed value for 'width'.
  440. auto specified_min_width = style().min_width().resolved_or_auto(*this, containing_block.width());
  441. if (!specified_min_width.is_auto()) {
  442. if (used_width.to_px(*this) < specified_min_width.to_px(*this)) {
  443. used_width = try_compute_width(specified_min_width);
  444. }
  445. }
  446. set_width(used_width.to_px(*this));
  447. box_model().margin.left = margin_left;
  448. box_model().margin.right = margin_right;
  449. box_model().border.left = Length::make_px(style().border_left().width);
  450. box_model().border.right = Length::make_px(style().border_right().width);
  451. box_model().padding.left = padding_left;
  452. box_model().padding.right = padding_right;
  453. }
  454. void LayoutBlock::place_block_level_replaced_element_in_normal_flow(LayoutReplaced& box)
  455. {
  456. ASSERT(!is_absolutely_positioned());
  457. auto& containing_block = *this;
  458. auto& replaced_element_box_model = box.box_model();
  459. replaced_element_box_model.margin.top = box.style().margin().top.resolved_or_zero(*this, containing_block.width());
  460. replaced_element_box_model.margin.bottom = box.style().margin().bottom.resolved_or_zero(*this, containing_block.width());
  461. replaced_element_box_model.border.top = Length::make_px(box.style().border_top().width);
  462. replaced_element_box_model.border.bottom = Length::make_px(box.style().border_bottom().width);
  463. replaced_element_box_model.padding.top = box.style().padding().top.resolved_or_zero(*this, containing_block.width());
  464. replaced_element_box_model.padding.bottom = box.style().padding().bottom.resolved_or_zero(*this, containing_block.width());
  465. float x = replaced_element_box_model.margin.left.to_px(*this)
  466. + replaced_element_box_model.border.left.to_px(*this)
  467. + replaced_element_box_model.padding.left.to_px(*this)
  468. + replaced_element_box_model.offset.left.to_px(*this);
  469. float y = replaced_element_box_model.margin_box(*this).top + box_model().offset.top.to_px(*this);
  470. box.set_offset(x, y);
  471. }
  472. LayoutBlock::ShrinkToFitResult LayoutBlock::calculate_shrink_to_fit_width()
  473. {
  474. auto greatest_child_width = [&] {
  475. float max_width = 0;
  476. if (children_are_inline()) {
  477. for (auto& box : line_boxes()) {
  478. max_width = max(max_width, box.width());
  479. }
  480. } else {
  481. for_each_child([&](auto& child) {
  482. if (child.is_box())
  483. max_width = max(max_width, to<LayoutBox>(child).width());
  484. });
  485. }
  486. return max_width;
  487. };
  488. // Calculate the preferred width by formatting the content without breaking lines
  489. // other than where explicit line breaks occur.
  490. layout_inside(LayoutMode::OnlyRequiredLineBreaks);
  491. float preferred_width = greatest_child_width();
  492. // Also calculate the preferred minimum width, e.g., by trying all possible line breaks.
  493. // CSS 2.2 does not define the exact algorithm.
  494. layout_inside(LayoutMode::AllPossibleLineBreaks);
  495. float preferred_minimum_width = greatest_child_width();
  496. return { preferred_width, preferred_minimum_width };
  497. }
  498. void LayoutBlock::place_block_level_non_replaced_element_in_normal_flow(LayoutBlock& block)
  499. {
  500. auto zero_value = Length::make_px(0);
  501. auto& containing_block = *this;
  502. auto& box = block.box_model();
  503. auto& style = block.style();
  504. box.margin.top = style.margin().top.resolved(zero_value, *this, containing_block.width());
  505. box.margin.bottom = style.margin().bottom.resolved(zero_value, *this, containing_block.width());
  506. box.border.top = Length::make_px(style.border_top().width);
  507. box.border.bottom = Length::make_px(style.border_bottom().width);
  508. box.padding.top = style.padding().top.resolved(zero_value, *this, containing_block.width());
  509. box.padding.bottom = style.padding().bottom.resolved(zero_value, *this, containing_block.width());
  510. float x = box.margin.left.to_px(*this)
  511. + box.border.left.to_px(*this)
  512. + box.padding.left.to_px(*this)
  513. + box.offset.left.to_px(*this);
  514. if (this->style().text_align() == CSS::TextAlign::VendorSpecificCenter) {
  515. x = (containing_block.width() / 2) - block.width() / 2;
  516. }
  517. float y = box.margin_box(*this).top
  518. + box.offset.top.to_px(*this);
  519. auto* relevant_sibling = block.previous_sibling();
  520. while (relevant_sibling != nullptr) {
  521. if (relevant_sibling->style().position() != CSS::Position::Absolute)
  522. break;
  523. relevant_sibling = relevant_sibling->previous_sibling();
  524. }
  525. if (relevant_sibling) {
  526. auto& sibling_box = relevant_sibling->box_model();
  527. y += relevant_sibling->effective_offset().y() + relevant_sibling->height();
  528. // Collapse top margin with bottom margin of previous sibling if necessary
  529. float previous_sibling_margin_bottom = sibling_box.margin.bottom.to_px(*relevant_sibling);
  530. float my_margin_top = box.margin.top.to_px(*this);
  531. if (my_margin_top < 0 || previous_sibling_margin_bottom < 0) {
  532. // Negative margins present.
  533. float largest_negative_margin = -min(my_margin_top, previous_sibling_margin_bottom);
  534. float largest_positive_margin = (my_margin_top < 0 && previous_sibling_margin_bottom < 0) ? 0 : max(my_margin_top, previous_sibling_margin_bottom);
  535. float final_margin = largest_positive_margin - largest_negative_margin;
  536. y += final_margin - my_margin_top;
  537. } else if (previous_sibling_margin_bottom > my_margin_top) {
  538. // Sibling's margin is larger than mine, adjust so we use sibling's.
  539. y += previous_sibling_margin_bottom - my_margin_top;
  540. }
  541. }
  542. block.set_offset(x, y);
  543. }
  544. void LayoutBlock::compute_height()
  545. {
  546. auto& containing_block = *this->containing_block();
  547. auto specified_height = style().height().resolved_or_auto(*this, containing_block.height());
  548. auto specified_max_height = style().max_height().resolved_or_auto(*this, containing_block.height());
  549. box_model().margin.top = style().margin().top.resolved_or_zero(*this, containing_block.width());
  550. box_model().margin.bottom = style().margin().bottom.resolved_or_zero(*this, containing_block.width());
  551. box_model().border.top = Length::make_px(style().border_top().width);
  552. box_model().border.bottom = Length::make_px(style().border_bottom().width);
  553. box_model().padding.top = style().padding().top.resolved_or_zero(*this, containing_block.width());
  554. box_model().padding.bottom = style().padding().bottom.resolved_or_zero(*this, containing_block.width());
  555. if (!specified_height.is_auto()) {
  556. float used_height = specified_height.to_px(*this);
  557. if (!specified_max_height.is_auto())
  558. used_height = min(used_height, specified_max_height.to_px(*this));
  559. set_height(used_height);
  560. }
  561. }
  562. void LayoutBlock::paint(PaintContext& context, PaintPhase phase)
  563. {
  564. if (!is_visible())
  565. return;
  566. LayoutBox::paint(context, phase);
  567. // FIXME: Inline backgrounds etc.
  568. if (phase == PaintPhase::Foreground) {
  569. if (children_are_inline()) {
  570. for (auto& line_box : m_line_boxes) {
  571. for (auto& fragment : line_box.fragments()) {
  572. if (context.should_show_line_box_borders())
  573. context.painter().draw_rect(enclosing_int_rect(fragment.absolute_rect()), Color::Green);
  574. fragment.render(context);
  575. }
  576. }
  577. }
  578. }
  579. }
  580. HitTestResult LayoutBlock::hit_test(const Gfx::IntPoint& position) const
  581. {
  582. if (!children_are_inline())
  583. return LayoutBox::hit_test(position);
  584. HitTestResult result;
  585. for (auto& line_box : m_line_boxes) {
  586. for (auto& fragment : line_box.fragments()) {
  587. if (enclosing_int_rect(fragment.absolute_rect()).contains(position)) {
  588. if (fragment.layout_node().is_block())
  589. return to<LayoutBlock>(fragment.layout_node()).hit_test(position);
  590. return { fragment.layout_node(), fragment.text_index_at(position.x()) };
  591. }
  592. }
  593. }
  594. // FIXME: This should be smarter about the text position if we're hitting a block
  595. // that has text inside it, but `position` is to the right of the text box.
  596. return { absolute_rect().contains(position.x(), position.y()) ? this : nullptr };
  597. }
  598. NonnullRefPtr<StyleProperties> LayoutBlock::style_for_anonymous_block() const
  599. {
  600. auto new_style = StyleProperties::create();
  601. specified_style().for_each_property([&](auto property_id, auto& value) {
  602. if (StyleResolver::is_inherited_property(property_id))
  603. new_style->set_property(property_id, value);
  604. });
  605. return new_style;
  606. }
  607. LineBox& LayoutBlock::ensure_last_line_box()
  608. {
  609. if (m_line_boxes.is_empty())
  610. m_line_boxes.append(LineBox());
  611. return m_line_boxes.last();
  612. }
  613. LineBox& LayoutBlock::add_line_box()
  614. {
  615. m_line_boxes.append(LineBox());
  616. return m_line_boxes.last();
  617. }
  618. void LayoutBlock::split_into_lines(LayoutBlock& container, LayoutMode layout_mode)
  619. {
  620. layout(layout_mode);
  621. auto* line_box = &container.ensure_last_line_box();
  622. if (layout_mode != LayoutMode::OnlyRequiredLineBreaks && line_box->width() > 0 && line_box->width() + width() > container.width()) {
  623. line_box = &container.add_line_box();
  624. }
  625. line_box->add_fragment(*this, 0, 0, width(), height());
  626. }
  627. }