From 0314e26ef4b77039ba7ba4b6f7de25da8b4505ec Mon Sep 17 00:00:00 2001 From: Andi Gallo Date: Fri, 14 Jul 2023 01:22:54 +0000 Subject: [PATCH] LibWeb: Linear interpolation between table width sizing guesses Make used widths of the columns a linear combination of two consecutive sizing-guesses when the assignable table width is less than or equal to the max-content sizing-guess, as the specification describes. --- .../LibWeb/Layout/TableFormattingContext.cpp | 110 +++++++++--------- 1 file changed, 57 insertions(+), 53 deletions(-) diff --git a/Userland/Libraries/LibWeb/Layout/TableFormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/TableFormattingContext.cpp index a8e53dc710..adfc9ca8ff 100644 --- a/Userland/Libraries/LibWeb/Layout/TableFormattingContext.cpp +++ b/Userland/Libraries/LibWeb/Layout/TableFormattingContext.cpp @@ -479,7 +479,10 @@ void TableFormattingContext::distribute_width_to_columns() // This is the width that we will be able to allocate to the columns. CSSPixels available_width = m_state.get(table_box()).content_width() - total_horizontal_border_spacing; - auto columns_total_used_width = [&]() { + Vector candidate_widths; + candidate_widths.resize(m_columns.size()); + + auto compute_columns_total_used_width = [&]() { CSSPixels total_used_width = 0; for (auto& column : m_columns) { total_used_width += column.used_width; @@ -487,54 +490,38 @@ void TableFormattingContext::distribute_width_to_columns() return total_used_width; }; - auto column_preferred_width = [&](Column& column) { - switch (column.type) { - case SizeType::Percent: { - return max(column.min_size, column.percentage_width / 100 * available_width); - } - case SizeType::Pixel: - case SizeType::Auto: { - return column.max_size; - } - default: { - VERIFY_NOT_REACHED(); + auto compute_columns_total_candidate_width = [&]() { + CSSPixels total_candidate_width = 0; + for (auto width : candidate_widths) { + total_candidate_width += width; } + return total_candidate_width; + }; + + auto commit_candidate_widths = [&]() { + for (size_t i = 0; i < m_columns.size(); ++i) { + auto& column = m_columns[i]; + column.used_width = candidate_widths[i]; } }; - auto expand_columns_to_fill_available_width = [&](SizeType column_type) { - CSSPixels remaining_available_width = available_width; - CSSPixels total_preferred_width_increment = 0; - for (auto& column : m_columns) { - remaining_available_width -= column.used_width; - if (column.type == column_type) { - total_preferred_width_increment += column_preferred_width(column) - column.min_size; - } - } - - if (total_preferred_width_increment == 0) + auto compute_linear_combination = [&](CSSPixels columns_total_candidate_width) { + auto columns_total_used_width = compute_columns_total_used_width(); + if (columns_total_candidate_width == columns_total_used_width) { return; - - for (auto& column : m_columns) { - if (column.type == column_type) { - CSSPixels preferred_width_increment = column_preferred_width(column) - column.min_size; - column.used_width += preferred_width_increment * remaining_available_width / total_preferred_width_increment; - } } - }; - - auto shrink_columns_to_fit_available_width = [&](SizeType column_type) { - for (auto& column : m_columns) { - if (column.type == column_type) - column.used_width = column.min_size; + auto candidate_weight = ((available_width - columns_total_used_width) / (columns_total_candidate_width - columns_total_used_width)).to_double(); + for (size_t i = 0; i < m_columns.size(); ++i) { + auto& column = m_columns[i]; + column.used_width = candidate_weight * candidate_widths[i] + (1 - candidate_weight) * column.used_width; } - - expand_columns_to_fill_available_width(column_type); }; // 1. The min-content sizing-guess is the set of column width assignments where each column is assigned its min-content width. - for (auto& column : m_columns) { + for (size_t i = 0; i < m_columns.size(); ++i) { + auto& column = m_columns[i]; column.used_width = column.min_size; + candidate_widths[i] = column.min_size; } // 2. The min-content-percentage sizing-guess is the set of column width assignments where: @@ -542,15 +529,21 @@ void TableFormattingContext::distribute_width_to_columns() // - its intrinsic percentage width times the assignable width and // - its min-content width. // - all other columns are assigned their min-content width. - for (auto& column : m_columns) { + for (size_t i = 0; i < m_columns.size(); ++i) { + auto& column = m_columns[i]; if (column.type == SizeType::Percent) { - column.used_width = max(column.min_size, column.percentage_width / 100 * available_width); + candidate_widths[i] = max(column.min_size, column.percentage_width / 100 * available_width); } } - if (columns_total_used_width() > available_width) { - shrink_columns_to_fit_available_width(SizeType::Percent); + auto columns_total_candidate_width = compute_columns_total_candidate_width(); + // 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 + // linear combination (with weights adding to 1) of the two consecutive sizing-guesses whose width sums bound the available width. + if (available_width < columns_total_candidate_width) { + compute_linear_combination(columns_total_candidate_width); return; + } else { + commit_candidate_widths(); } // 3. The min-content-specified sizing-guess is the set of column width assignments where: @@ -559,15 +552,19 @@ void TableFormattingContext::distribute_width_to_columns() // - its min-content width // - any other column that is constrained is assigned its max-content width // - all other columns are assigned their min-content width. - for (auto& column : m_columns) { - if (column.type == SizeType::Pixel) { - column.used_width = column.max_size; + for (size_t i = 0; i < m_columns.size(); ++i) { + auto& column = m_columns[i]; + if (column.is_constrained) { + candidate_widths[i] = column.max_size; } } - if (columns_total_used_width() > available_width) { - shrink_columns_to_fit_available_width(SizeType::Pixel); + columns_total_candidate_width = compute_columns_total_candidate_width(); + if (available_width < columns_total_candidate_width) { + compute_linear_combination(columns_total_candidate_width); return; + } else { + commit_candidate_widths(); } // 4. The max-content sizing-guess is the set of column width assignments where: @@ -575,21 +572,28 @@ void TableFormattingContext::distribute_width_to_columns() // - its intrinsic percentage width times the assignable width and // - its min-content width // - all other columns are assigned their max-content width. - for (auto& column : m_columns) { + for (size_t i = 0; i < m_columns.size(); ++i) { + auto& column = m_columns[i]; if (column.type != SizeType::Percent) { - column.used_width = column.max_size; + candidate_widths[i] = column.max_size; } } - // 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 - // linear combination (with weights adding to 1) of the two consecutive sizing-guesses whose width sums bound the available width. + columns_total_candidate_width = compute_columns_total_candidate_width(); + if (available_width < columns_total_candidate_width) { + compute_linear_combination(columns_total_candidate_width); + return; + } else { + commit_candidate_widths(); + } // Otherwise, the used widths of the columns are the result of starting from the max-content sizing-guess and distributing // the excess width to the columns of the table according to the rules for distributing excess width to columns (for used width). // Implements steps 1 and 2 of https://www.w3.org/TR/css-tables-3/#distributing-width-to-columns // FIXME: Implement steps 3-6 as well, which distribute excess width to constrained columns. - if (columns_total_used_width() < available_width) { + auto columns_total_used_width = compute_columns_total_used_width(); + if (columns_total_used_width < available_width) { // NOTE: if all columns got their max width and there is still width to distribute left // it should be assigned to columns proportionally to their max width CSSPixels grid_max = 0.0f; @@ -602,7 +606,7 @@ void TableFormattingContext::distribute_width_to_columns() ++unconstrained_column_count; } - auto width_to_distribute = available_width - columns_total_used_width(); + auto width_to_distribute = available_width - columns_total_used_width; if (grid_max == 0) { // If total max width of columns is zero then divide distributable width equally among them auto column_width = width_to_distribute / unconstrained_column_count;