mirror of
https://github.com/RGBCube/serenity
synced 2025-07-26 03:57:44 +00:00
LibWeb: Refactor text justification code + only justify below threshold
All the justification-related code is now in InlineFormattingContext::apply_justification_to_fragments and is performed after all the line boxes have been added. Text justification now only happens on the last line if the excess space including whitespace is below a certain threshold. 10% seemed reasonable since it prevents the "over-justification" of text. Note that fragments in line boxes before the last one are always justified.
This commit is contained in:
parent
f0a1ab6f84
commit
7fe3f2d970
3 changed files with 53 additions and 26 deletions
|
@ -17,6 +17,8 @@
|
|||
|
||||
namespace Web::Layout {
|
||||
|
||||
constexpr float text_justification_threshold = 0.1;
|
||||
|
||||
InlineFormattingContext::InlineFormattingContext(FormattingState& state, BlockContainer const& containing_block, BlockFormattingContext& parent)
|
||||
: FormattingContext(Type::Inline, state, containing_block, &parent)
|
||||
{
|
||||
|
@ -164,6 +166,45 @@ void InlineFormattingContext::dimension_box_on_line(Box const& box, LayoutMode l
|
|||
dump_tree(box);
|
||||
}
|
||||
|
||||
void InlineFormattingContext::apply_justification_to_fragments(FormattingState::NodeState const& containing_block_state, LineBox& line_box, bool is_last_line)
|
||||
{
|
||||
float excess_horizontal_space = containing_block_state.content_width - line_box.width();
|
||||
|
||||
// Only justify the text if the excess horizontal space is less than or
|
||||
// equal to 10%, or if we are not looking at the last line box.
|
||||
if (is_last_line && excess_horizontal_space / containing_block_state.content_width > text_justification_threshold)
|
||||
return;
|
||||
|
||||
float excess_horizontal_space_including_whitespace = excess_horizontal_space;
|
||||
size_t whitespace_count = 0;
|
||||
for (auto& fragment : line_box.fragments()) {
|
||||
if (fragment.is_justifiable_whitespace()) {
|
||||
++whitespace_count;
|
||||
excess_horizontal_space_including_whitespace += fragment.width();
|
||||
}
|
||||
}
|
||||
|
||||
float justified_space_width = whitespace_count > 0 ? (excess_horizontal_space_including_whitespace / static_cast<float>(whitespace_count)) : 0;
|
||||
|
||||
// This is the amount that each fragment will be offset by. If a whitespace
|
||||
// fragment is shorter than the justified space width, it increases to push
|
||||
// subsequent fragments, and decreases to pull them back otherwise.
|
||||
float running_diff = 0;
|
||||
for (size_t i = 0; i < line_box.fragments().size(); ++i) {
|
||||
auto& fragment = line_box.fragments()[i];
|
||||
|
||||
auto offset = fragment.offset();
|
||||
offset.translate_by(running_diff, 0);
|
||||
fragment.set_offset(offset);
|
||||
|
||||
if (fragment.is_justifiable_whitespace()
|
||||
&& fragment.width() != justified_space_width) {
|
||||
running_diff += justified_space_width - fragment.width();
|
||||
fragment.set_width(justified_space_width);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void InlineFormattingContext::generate_line_boxes(LayoutMode layout_mode)
|
||||
{
|
||||
auto& containing_block_state = m_state.get_mutable(containing_block());
|
||||
|
@ -221,6 +262,17 @@ void InlineFormattingContext::generate_line_boxes(LayoutMode layout_mode)
|
|||
}
|
||||
|
||||
line_builder.remove_last_line_if_empty();
|
||||
|
||||
auto const& containing_block = this->containing_block();
|
||||
auto text_align = containing_block.computed_values().text_align();
|
||||
if (text_align == CSS::TextAlign::Justify) {
|
||||
auto const& containing_block_state = m_state.get(containing_block);
|
||||
for (size_t i = 0; i < line_boxes.size(); i++) {
|
||||
auto& line_box = line_boxes[i];
|
||||
auto is_last_line = i == line_boxes.size() - 1;
|
||||
apply_justification_to_fragments(containing_block_state, line_box, is_last_line);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue