ladybird/Userland/Libraries/LibWeb/Layout/LineBox.cpp
Andreas Kling f2a917229a LibWeb: Support inline-level padding and border properly
Here's roughly how this works:

- InlineLevelIterator keeps a nesting stack of inline-level nodes with
  box model metrics.
- When entering a node with box model metrics, we add them to the
  current "leading metrics".
- When exiting a node with box model metrics, we add them to the
  current "trailing metrics".
- Pending leading metrics are consumed by the first fragment added
  to the line.
- Pending trailing metrics are consumed by the last fragment added
  to the line.

Like before, the position of a line box fragment is the top left of its
content box. However, fragments are placed horizontally along the line
with space inserted for padding and border.

InlineNode::paint() now expands the content rect as appropriate when
painting background and borders.

Note that margins and margin collapsing is not yet implemented.

This makes the eyes on ACID2 horizontally centered. :^)
2022-02-14 18:00:21 +01:00

75 lines
2.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/CharacterTypes.h>
#include <AK/TypeCasts.h>
#include <AK/Utf8View.h>
#include <LibWeb/Layout/Box.h>
#include <LibWeb/Layout/BreakNode.h>
#include <LibWeb/Layout/LineBox.h>
#include <LibWeb/Layout/Node.h>
#include <LibWeb/Layout/TextNode.h>
namespace Web::Layout {
void LineBox::add_fragment(Node& layout_node, int start, int length, float leading_size, float trailing_size, float content_width, float content_height, LineBoxFragment::Type fragment_type)
{
bool text_align_is_justify = layout_node.computed_values().text_align() == CSS::TextAlign::Justify;
if (!text_align_is_justify && !m_fragments.is_empty() && &m_fragments.last().layout_node() == &layout_node) {
// The fragment we're adding is from the last Layout::Node on the line.
// Expand the last fragment instead of adding a new one with the same Layout::Node.
m_fragments.last().m_length = (start - m_fragments.last().m_start) + length;
m_fragments.last().set_width(m_fragments.last().width() + content_width);
} else {
m_fragments.append(make<LineBoxFragment>(layout_node, start, length, Gfx::FloatPoint(m_width + leading_size, 0.0f), Gfx::FloatSize(content_width, content_height), fragment_type));
}
m_width += content_width + leading_size + trailing_size;
if (is<Box>(layout_node))
verify_cast<Box>(layout_node).set_containing_line_box_fragment(m_fragments.last());
}
void LineBox::trim_trailing_whitespace()
{
while (!m_fragments.is_empty() && m_fragments.last().is_justifiable_whitespace()) {
auto fragment = m_fragments.take_last();
m_width -= fragment->width();
}
if (m_fragments.is_empty())
return;
auto& last_fragment = m_fragments.last();
auto last_text = last_fragment.text();
if (last_text.is_null())
return;
while (last_fragment.length()) {
auto last_character = last_text[last_fragment.length() - 1];
if (!is_ascii_space(last_character))
break;
int last_character_width = last_fragment.layout_node().font().glyph_width(last_character);
last_fragment.m_length -= 1;
last_fragment.set_width(last_fragment.width() - last_character_width);
m_width -= last_character_width;
}
}
bool LineBox::is_empty_or_ends_in_whitespace() const
{
if (m_fragments.is_empty())
return true;
return m_fragments.last().ends_in_whitespace();
}
bool LineBox::ends_with_forced_line_break() const
{
return is<BreakNode>(m_fragments.last().layout_node());
}
}