Files
ladybird/Libraries/LibWeb/Painting/ViewportPaintable.cpp
Aliaksandr Kalenik 9f541c363d LibWeb: Allow stacking context to only be created by PaintableBox
For a while we used the wider Paintable type for stacking context,
because it was allowed to be created by InlinePaintable and
PaintableBox. Now, when InlinePaintable type is gone, we can use more
specific PaintableBox type for a stacking context.
2024-11-18 20:07:30 +01:00

343 lines
16 KiB
C++

/*
* Copyright (c) 2023, Andreas Kling <andreas@ladybird.org>
* Copyright (c) 2024, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/DOM/Range.h>
#include <LibWeb/Layout/TextNode.h>
#include <LibWeb/Layout/Viewport.h>
#include <LibWeb/Painting/StackingContext.h>
#include <LibWeb/Painting/ViewportPaintable.h>
#include <LibWeb/Selection/Selection.h>
namespace Web::Painting {
GC_DEFINE_ALLOCATOR(ViewportPaintable);
GC::Ref<ViewportPaintable> ViewportPaintable::create(Layout::Viewport const& layout_viewport)
{
return layout_viewport.heap().allocate<ViewportPaintable>(layout_viewport);
}
ViewportPaintable::ViewportPaintable(Layout::Viewport const& layout_viewport)
: PaintableWithLines(layout_viewport)
{
}
ViewportPaintable::~ViewportPaintable() = default;
void ViewportPaintable::build_stacking_context_tree_if_needed()
{
if (stacking_context())
return;
build_stacking_context_tree();
}
void ViewportPaintable::build_stacking_context_tree()
{
set_stacking_context(make<StackingContext>(*this, nullptr, 0));
size_t index_in_tree_order = 1;
for_each_in_subtree_of_type<PaintableBox>([&](auto const& paintable_box) {
const_cast<PaintableBox&>(paintable_box).invalidate_stacking_context();
auto* parent_context = const_cast<PaintableBox&>(paintable_box).enclosing_stacking_context();
auto establishes_stacking_context = paintable_box.layout_node().establishes_stacking_context();
if ((paintable_box.is_positioned() || establishes_stacking_context) && paintable_box.computed_values().z_index().value_or(0) == 0)
parent_context->m_positioned_descendants_and_stacking_contexts_with_stack_level_0.append(paintable_box);
if (!paintable_box.is_positioned() && paintable_box.is_floating())
parent_context->m_non_positioned_floating_descendants.append(paintable_box);
if (!establishes_stacking_context) {
VERIFY(!paintable_box.stacking_context());
return TraversalDecision::Continue;
}
VERIFY(parent_context);
const_cast<PaintableBox&>(paintable_box).set_stacking_context(make<Painting::StackingContext>(const_cast<PaintableBox&>(paintable_box), parent_context, index_in_tree_order++));
return TraversalDecision::Continue;
});
stacking_context()->sort();
}
void ViewportPaintable::paint_all_phases(PaintContext& context)
{
build_stacking_context_tree_if_needed();
stacking_context()->paint(context);
}
void ViewportPaintable::assign_scroll_frames()
{
for_each_in_inclusive_subtree_of_type<PaintableBox>([&](auto& paintable_box) {
RefPtr<ScrollFrame> sticky_scroll_frame;
if (paintable_box.is_sticky_position()) {
auto const* nearest_scrollable_ancestor = paintable_box.nearest_scrollable_ancestor();
RefPtr<ScrollFrame const> parent_scroll_frame;
if (nearest_scrollable_ancestor) {
parent_scroll_frame = nearest_scrollable_ancestor->nearest_scroll_frame();
}
sticky_scroll_frame = m_scroll_state.create_sticky_frame_for(paintable_box, parent_scroll_frame);
const_cast<PaintableBox&>(paintable_box).set_enclosing_scroll_frame(sticky_scroll_frame);
const_cast<PaintableBox&>(paintable_box).set_own_scroll_frame(sticky_scroll_frame);
}
if (paintable_box.has_scrollable_overflow() || is<ViewportPaintable>(paintable_box)) {
RefPtr<ScrollFrame const> parent_scroll_frame;
if (sticky_scroll_frame) {
parent_scroll_frame = sticky_scroll_frame;
} else {
parent_scroll_frame = paintable_box.nearest_scroll_frame();
}
auto scroll_frame = m_scroll_state.create_scroll_frame_for(paintable_box, parent_scroll_frame);
paintable_box.set_own_scroll_frame(scroll_frame);
}
return TraversalDecision::Continue;
});
for_each_in_subtree([&](auto const& paintable) {
if (paintable.is_fixed_position()) {
return TraversalDecision::Continue;
}
if (paintable.is_sticky_position()) {
return TraversalDecision::Continue;
}
for (auto block = paintable.containing_block(); block; block = block->containing_block()) {
if (auto scroll_frame = block->own_scroll_frame(); scroll_frame) {
if (paintable.is_paintable_box()) {
auto const& paintable_box = static_cast<PaintableBox const&>(paintable);
const_cast<PaintableBox&>(paintable_box).set_enclosing_scroll_frame(*scroll_frame);
}
return TraversalDecision::Continue;
}
if (block->is_fixed_position()) {
return TraversalDecision::Continue;
}
}
VERIFY_NOT_REACHED();
});
}
void ViewportPaintable::assign_clip_frames()
{
for_each_in_subtree_of_type<PaintableBox>([&](auto const& paintable_box) {
auto overflow_x = paintable_box.computed_values().overflow_x();
auto overflow_y = paintable_box.computed_values().overflow_y();
auto has_hidden_overflow = overflow_x != CSS::Overflow::Visible && overflow_y != CSS::Overflow::Visible;
if (has_hidden_overflow || paintable_box.get_clip_rect().has_value()) {
auto clip_frame = adopt_ref(*new ClipFrame());
clip_state.set(paintable_box, move(clip_frame));
}
return TraversalDecision::Continue;
});
for_each_in_subtree([&](auto const& paintable) {
for (auto block = paintable.containing_block(); !block->is_viewport(); block = block->containing_block()) {
if (auto clip_frame = clip_state.get(block); clip_frame.has_value()) {
if (paintable.is_paintable_box()) {
auto const& paintable_box = static_cast<PaintableBox const&>(paintable);
const_cast<PaintableBox&>(paintable_box).set_enclosing_clip_frame(clip_frame.value());
}
break;
}
if (block->has_css_transform()) {
break;
}
}
return TraversalDecision::Continue;
});
for (auto& it : clip_state) {
auto const& paintable_box = *it.key;
auto& clip_frame = *it.value;
for (auto const* block = &paintable_box.layout_node_with_style_and_box_metrics(); !block->is_viewport(); block = block->containing_block()) {
auto const& paintable = block->first_paintable();
if (!paintable->is_paintable_box()) {
continue;
}
auto const& block_paintable_box = static_cast<PaintableBox const&>(*paintable);
auto block_overflow_x = block_paintable_box.computed_values().overflow_x();
auto block_overflow_y = block_paintable_box.computed_values().overflow_y();
if (block_overflow_x != CSS::Overflow::Visible && block_overflow_y != CSS::Overflow::Visible) {
auto rect = block_paintable_box.absolute_padding_box_rect();
clip_frame.add_clip_rect(rect, block_paintable_box.normalized_border_radii_data(ShrinkRadiiForBorders::Yes), block_paintable_box.enclosing_scroll_frame());
}
if (auto css_clip_property_rect = block_paintable_box.get_clip_rect(); css_clip_property_rect.has_value()) {
clip_frame.add_clip_rect(css_clip_property_rect.value(), {}, block_paintable_box.enclosing_scroll_frame());
}
if (block->has_css_transform()) {
break;
}
}
}
}
void ViewportPaintable::refresh_scroll_state()
{
if (!m_needs_to_refresh_scroll_state)
return;
m_needs_to_refresh_scroll_state = false;
m_scroll_state.for_each_sticky_frame([&](auto& scroll_frame) {
auto const& sticky_box = scroll_frame->paintable_box();
auto const& sticky_insets = sticky_box.sticky_insets();
auto const* nearest_scrollable_ancestor = sticky_box.nearest_scrollable_ancestor();
if (!nearest_scrollable_ancestor) {
return;
}
// Min and max offsets are needed to clamp the sticky box's position to stay within bounds of containing block.
CSSPixels min_y_offset_relative_to_nearest_scrollable_ancestor;
CSSPixels max_y_offset_relative_to_nearest_scrollable_ancestor;
CSSPixels min_x_offset_relative_to_nearest_scrollable_ancestor;
CSSPixels max_x_offset_relative_to_nearest_scrollable_ancestor;
auto const* containing_block_of_sticky_box = sticky_box.containing_block();
if (containing_block_of_sticky_box->is_scrollable()) {
min_y_offset_relative_to_nearest_scrollable_ancestor = 0;
max_y_offset_relative_to_nearest_scrollable_ancestor = containing_block_of_sticky_box->scrollable_overflow_rect()->height() - sticky_box.absolute_border_box_rect().height();
min_x_offset_relative_to_nearest_scrollable_ancestor = 0;
max_x_offset_relative_to_nearest_scrollable_ancestor = containing_block_of_sticky_box->scrollable_overflow_rect()->width() - sticky_box.absolute_border_box_rect().width();
} else {
auto containing_block_rect_relative_to_nearest_scrollable_ancestor = containing_block_of_sticky_box->absolute_border_box_rect().translated(-nearest_scrollable_ancestor->absolute_rect().top_left());
min_y_offset_relative_to_nearest_scrollable_ancestor = containing_block_rect_relative_to_nearest_scrollable_ancestor.top();
max_y_offset_relative_to_nearest_scrollable_ancestor = containing_block_rect_relative_to_nearest_scrollable_ancestor.bottom() - sticky_box.absolute_border_box_rect().height();
min_x_offset_relative_to_nearest_scrollable_ancestor = containing_block_rect_relative_to_nearest_scrollable_ancestor.left();
max_x_offset_relative_to_nearest_scrollable_ancestor = containing_block_rect_relative_to_nearest_scrollable_ancestor.right() - sticky_box.absolute_border_box_rect().width();
}
auto border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor = sticky_box.border_box_rect_relative_to_nearest_scrollable_ancestor();
// By default, the sticky box is shifted by the scroll offset of the nearest scrollable ancestor.
CSSPixelPoint sticky_offset = -nearest_scrollable_ancestor->scroll_offset();
CSSPixelRect const scrollport_rect { nearest_scrollable_ancestor->scroll_offset(), nearest_scrollable_ancestor->absolute_rect().size() };
if (sticky_insets.top.has_value()) {
auto top_inset = sticky_insets.top.value();
auto stick_to_top_scroll_offset_threshold = border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.top() - top_inset;
if (scrollport_rect.top() > stick_to_top_scroll_offset_threshold) {
sticky_offset.translate_by({ 0, -border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.top() });
sticky_offset.translate_by({ 0, min(scrollport_rect.top() + top_inset, max_y_offset_relative_to_nearest_scrollable_ancestor) });
}
}
if (sticky_insets.left.has_value()) {
auto left_inset = sticky_insets.left.value();
auto stick_to_left_scroll_offset_threshold = border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.left() - left_inset;
if (scrollport_rect.left() > stick_to_left_scroll_offset_threshold) {
sticky_offset.translate_by({ -border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.left(), 0 });
sticky_offset.translate_by({ min(scrollport_rect.left() + left_inset, max_x_offset_relative_to_nearest_scrollable_ancestor), 0 });
}
}
if (sticky_insets.bottom.has_value()) {
auto bottom_inset = sticky_insets.bottom.value();
auto stick_to_bottom_scroll_offset_threshold = border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.bottom() + bottom_inset;
if (scrollport_rect.bottom() < stick_to_bottom_scroll_offset_threshold) {
sticky_offset.translate_by({ 0, -border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.top() });
sticky_offset.translate_by({ 0, max(scrollport_rect.bottom() - sticky_box.absolute_border_box_rect().height() - bottom_inset, min_y_offset_relative_to_nearest_scrollable_ancestor) });
}
}
if (sticky_insets.right.has_value()) {
auto right_inset = sticky_insets.right.value();
auto stick_to_right_scroll_offset_threshold = border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.right() + right_inset;
if (scrollport_rect.right() < stick_to_right_scroll_offset_threshold) {
sticky_offset.translate_by({ -border_rect_of_sticky_box_relative_to_nearest_scrollable_ancestor.left(), 0 });
sticky_offset.translate_by({ max(scrollport_rect.right() - sticky_box.absolute_border_box_rect().width() - right_inset, min_x_offset_relative_to_nearest_scrollable_ancestor), 0 });
}
}
scroll_frame->set_own_offset(sticky_offset);
});
m_scroll_state.for_each_scroll_frame([&](auto& scroll_frame) {
scroll_frame->set_own_offset(-scroll_frame->paintable_box().scroll_offset());
});
}
void ViewportPaintable::resolve_paint_only_properties()
{
// Resolves layout-dependent properties not handled during layout and stores them in the paint tree.
// Properties resolved include:
// - Border radii
// - Box shadows
// - Text shadows
// - Transforms
// - Transform origins
// - Outlines
for_each_in_inclusive_subtree([&](Paintable& paintable) {
paintable.resolve_paint_properties();
return TraversalDecision::Continue;
});
}
GC::Ptr<Selection::Selection> ViewportPaintable::selection() const
{
return const_cast<DOM::Document&>(document()).get_selection();
}
void ViewportPaintable::recompute_selection_states(DOM::Range& range)
{
// 1. Start by resetting the selection state of all layout nodes to None.
for_each_in_inclusive_subtree([&](auto& layout_node) {
layout_node.set_selection_state(SelectionState::None);
return TraversalDecision::Continue;
});
auto* start_container = range.start_container();
auto* end_container = range.end_container();
// 2. If the selection starts and ends in the same node:
if (start_container == end_container) {
// 1. If the selection starts and ends at the same offset, return.
if (range.start_offset() == range.end_offset()) {
// NOTE: A zero-length selection should not be visible.
return;
}
// 2. If it's a text node, mark it as StartAndEnd and return.
if (is<DOM::Text>(*start_container)) {
if (auto* paintable = start_container->paintable())
paintable->set_selection_state(SelectionState::StartAndEnd);
return;
}
}
// 3. Mark the selection start node as Start (if text) or Full (if anything else).
if (auto* paintable = start_container->paintable()) {
if (is<DOM::Text>(*start_container))
paintable->set_selection_state(SelectionState::Start);
else
paintable->set_selection_state(SelectionState::Full);
}
// 4. Mark the selection end node as End (if text) or Full (if anything else).
if (auto* paintable = end_container->paintable()) {
if (is<DOM::Text>(*end_container))
paintable->set_selection_state(SelectionState::End);
else
paintable->set_selection_state(SelectionState::Full);
}
// 5. Mark the nodes between start node and end node (in tree order) as Full.
for (auto* node = start_container->next_in_pre_order(); node && node != end_container; node = node->next_in_pre_order()) {
if (auto* paintable = node->paintable())
paintable->set_selection_state(SelectionState::Full);
}
}
bool ViewportPaintable::handle_mousewheel(Badge<EventHandler>, CSSPixelPoint, unsigned, unsigned, int, int)
{
return false;
}
void ViewportPaintable::visit_edges(Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(clip_state);
}
}