LibWeb: Rename Layout::BlockBox => BlockContainer

There's a subtle difference here. A "block box" in the spec is a
block-level box, while a "block container" is a box whose children are
either all inline-level boxes in an IFC, or all block-level boxes
participating in a BFC.

Notably, an "inline-block" box is a "block container" but not a "block
box" since it is itself inline-level.

1 files changed, 150 insertions, 0 deletions

diff --git a/Userland/Libraries/LibWeb/Layout/BlockContainer.cpp b/Userland/Libraries/LibWeb/Layout/BlockContainer.cpp
new file mode 100644
index 0000000000..3624a94a84
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Layout/BlockContainer.cpp
@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibGfx/Painter.h>
+#include <LibWeb/Dump.h>
+#include <LibWeb/Layout/BlockContainer.h>
+#include <LibWeb/Layout/InitialContainingBlock.h>
+#include <LibWeb/Layout/InlineFormattingContext.h>
+#include <LibWeb/Layout/ReplacedBox.h>
+#include <LibWeb/Layout/TextNode.h>
+
+namespace Web::Layout {
+
+BlockContainer::BlockContainer(DOM::Document& document, DOM::Node* node, NonnullRefPtr<CSS::StyleProperties> style)
+    : Box(document, node, move(style))
+{
+}
+
+BlockContainer::BlockContainer(DOM::Document& document, DOM::Node* node, CSS::ComputedValues computed_values)
+    : Box(document, node, move(computed_values))
+{
+}
+
+BlockContainer::~BlockContainer()
+{
+}
+
+bool BlockContainer::should_clip_overflow() const
+{
+    return computed_values().overflow_x() != CSS::Overflow::Visible && computed_values().overflow_y() != CSS::Overflow::Visible;
+}
+
+void BlockContainer::paint(PaintContext& context, PaintPhase phase)
+{
+    if (!is_visible())
+        return;
+
+    Box::paint(context, phase);
+
+    if (!children_are_inline())
+        return;
+
+    if (should_clip_overflow()) {
+        context.painter().save();
+        // FIXME: Handle overflow-x and overflow-y being different values.
+        context.painter().add_clip_rect(enclosing_int_rect(padded_rect()));
+        context.painter().translate(-m_scroll_offset.to_type<int>());
+    }
+
+    for (auto& line_box : m_line_boxes) {
+        for (auto& fragment : line_box.fragments()) {
+            if (context.should_show_line_box_borders())
+                context.painter().draw_rect(enclosing_int_rect(fragment.absolute_rect()), Color::Green);
+            fragment.paint(context, phase);
+        }
+    }
+
+    if (should_clip_overflow()) {
+        context.painter().restore();
+    }
+
+    // FIXME: Merge this loop with the above somehow..
+    if (phase == PaintPhase::FocusOutline) {
+        for (auto& line_box : m_line_boxes) {
+            for (auto& fragment : line_box.fragments()) {
+                auto* node = fragment.layout_node().dom_node();
+                if (!node)
+                    continue;
+                auto* parent = node->parent_element();
+                if (!parent)
+                    continue;
+                if (parent->is_focused())
+                    context.painter().draw_rect(enclosing_int_rect(fragment.absolute_rect()), context.palette().focus_outline());
+            }
+        }
+    }
+}
+
+HitTestResult BlockContainer::hit_test(const Gfx::IntPoint& position, HitTestType type) const
+{
+    if (!children_are_inline())
+        return Box::hit_test(position, type);
+
+    HitTestResult last_good_candidate;
+    for (auto& line_box : m_line_boxes) {
+        for (auto& fragment : line_box.fragments()) {
+            if (is<Box>(fragment.layout_node()) && verify_cast<Box>(fragment.layout_node()).stacking_context())
+                continue;
+            if (enclosing_int_rect(fragment.absolute_rect()).contains(position)) {
+                if (is<BlockContainer>(fragment.layout_node()))
+                    return verify_cast<BlockContainer>(fragment.layout_node()).hit_test(position, type);
+                return { fragment.layout_node(), fragment.text_index_at(position.x()) };
+            }
+            if (fragment.absolute_rect().top() <= position.y())
+                last_good_candidate = { fragment.layout_node(), fragment.text_index_at(position.x()) };
+        }
+    }
+
+    if (type == HitTestType::TextCursor && last_good_candidate.layout_node)
+        return last_good_candidate;
+    return { absolute_rect().contains(position.x(), position.y()) ? this : nullptr };
+}
+
+void BlockContainer::split_into_lines(InlineFormattingContext& context, LayoutMode layout_mode)
+{
+    auto& containing_block = context.containing_block();
+    auto* line_box = &containing_block.ensure_last_line_box();
+
+    context.dimension_box_on_line(*this, layout_mode);
+
+    float available_width = context.available_width_at_line(containing_block.line_boxes().size() - 1);
+
+    if (layout_mode == LayoutMode::AllPossibleLineBreaks && line_box->width() > 0) {
+        line_box = &containing_block.add_line_box();
+    } else if (layout_mode == LayoutMode::Default && line_box->width() > 0 && line_box->width() + border_box_width() > available_width) {
+        line_box = &containing_block.add_line_box();
+    }
+    line_box->add_fragment(*this, 0, 0, border_box_width(), height());
+}
+
+bool BlockContainer::is_scrollable() const
+{
+    // FIXME: Support horizontal scroll as well (overflow-x)
+    return computed_values().overflow_y() == CSS::Overflow::Scroll;
+}
+
+void BlockContainer::set_scroll_offset(const Gfx::FloatPoint& offset)
+{
+    // FIXME: If there is horizontal and vertical scroll ignore only part of the new offset
+    if (offset.y() < 0 || m_scroll_offset == offset)
+        return;
+    m_scroll_offset = offset;
+    set_needs_display();
+}
+
+bool BlockContainer::handle_mousewheel(Badge<EventHandler>, const Gfx::IntPoint&, unsigned int, unsigned int, int wheel_delta)
+{
+    if (!is_scrollable())
+        return false;
+    auto new_offset = m_scroll_offset;
+    new_offset.translate_by(0, wheel_delta);
+    set_scroll_offset(new_offset);
+
+    return true;
+}
+
+}