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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <LibWeb/Dump.h>
#include <LibWeb/Layout/BlockFormattingContext.h>
#include <LibWeb/Layout/Box.h>
#include <LibWeb/Layout/FormattingContext.h>
#include <LibWeb/Layout/InlineFormattingContext.h>
#include <LibWeb/Layout/TableFormattingContext.h>
namespace Web::Layout {
FormattingContext::FormattingContext(Box& context_box, FormattingContext* parent)
: m_parent(parent)
, m_context_box(&context_box)
{
}
FormattingContext::~FormattingContext()
{
}
bool FormattingContext::creates_block_formatting_context(const Box& box)
{
if (box.is_root_element())
return true;
if (box.is_floating())
return true;
if (box.is_absolutely_positioned())
return true;
if (box.is_inline_block())
return true;
if (box.is_table_cell())
return true;
// FIXME: table-caption
// FIXME: anonymous table cells
// FIXME: Block elements where overflow has a value other than visible and clip.
// FIXME: display: flow-root
// FIXME: Elements with contain: layout, content, or paint.
// FIXME: flex
// FIXME: grid
// FIXME: multicol
// FIXME: column-span: all
return false;
}
void FormattingContext::layout_inside(Box& box, LayoutMode layout_mode)
{
if (creates_block_formatting_context(box)) {
BlockFormattingContext context(box, this);
context.run(layout_mode);
return;
}
if (box.is_table()) {
TableFormattingContext context(box, this);
context.run(layout_mode);
} else if (box.children_are_inline()) {
InlineFormattingContext context(box, this);
context.run(layout_mode);
} else {
// FIXME: This needs refactoring!
ASSERT(is_block_formatting_context());
auto& old_box = context_box();
set_context_box(box);
run(layout_mode);
set_context_box(old_box);
}
}
static float greatest_child_width(const Box& box)
{
float max_width = 0;
if (box.children_are_inline()) {
for (auto& child : box.line_boxes()) {
max_width = max(max_width, child.width());
}
} else {
box.for_each_child_of_type<Box>([&](auto& child) {
max_width = max(max_width, child.width());
});
}
return max_width;
}
FormattingContext::ShrinkToFitResult FormattingContext::calculate_shrink_to_fit_widths(Box& box)
{
// Calculate the preferred width by formatting the content without breaking lines
// other than where explicit line breaks occur.
layout_inside(box, LayoutMode::OnlyRequiredLineBreaks);
float preferred_width = greatest_child_width(box);
// Also calculate the preferred minimum width, e.g., by trying all possible line breaks.
// CSS 2.2 does not define the exact algorithm.
layout_inside(box, LayoutMode::AllPossibleLineBreaks);
float preferred_minimum_width = greatest_child_width(box);
return { preferred_width, preferred_minimum_width };
}
}
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