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LibWeb: Make Range.setStart and Range.setEnd spec compliant

These functions are way more involved than simply setting their
respective boundary points :^)
This commit is contained in:
Luke Wilde 2022-01-31 18:05:54 +00:00 committed by Andreas Kling
parent af3c866898
commit 46ce50f74e
6 changed files with 185 additions and 11 deletions

View file

@ -6,6 +6,7 @@
*/
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/DocumentType.h>
#include <LibWeb/DOM/Node.h>
#include <LibWeb/DOM/Range.h>
#include <LibWeb/DOM/Window.h>
@ -46,6 +47,130 @@ Range::~Range()
{
}
// https://dom.spec.whatwg.org/#concept-range-root
Node& Range::root()
{
// The root of a live range is the root of its start node.
return m_start_container->root();
}
Node const& Range::root() const
{
return m_start_container->root();
}
enum class RelativeBoundaryPointPosition {
Equal,
Before,
After,
};
// https://dom.spec.whatwg.org/#concept-range-bp-position
static RelativeBoundaryPointPosition position_of_boundary_point_relative_to_other_boundary_point(Node const& node_a, u32 offset_a, Node const& node_b, u32 offset_b)
{
// 1. Assert: nodeA and nodeB have the same root.
VERIFY(&node_a.root() == &node_b.root());
// 2. If nodeA is nodeB, then return equal if offsetA is offsetB, before if offsetA is less than offsetB, and after if offsetA is greater than offsetB.
if (&node_a == &node_b) {
if (offset_a == offset_b)
return RelativeBoundaryPointPosition::Equal;
if (offset_a < offset_b)
return RelativeBoundaryPointPosition::Before;
return RelativeBoundaryPointPosition::After;
}
// 3. If nodeA is following nodeB, then if the position of (nodeB, offsetB) relative to (nodeA, offsetA) is before, return after, and if it is after, return before.
if (node_a.is_following(node_b)) {
auto relative_position = position_of_boundary_point_relative_to_other_boundary_point(node_b, offset_b, node_a, offset_a);
if (relative_position == RelativeBoundaryPointPosition::Before)
return RelativeBoundaryPointPosition::After;
if (relative_position == RelativeBoundaryPointPosition::After)
return RelativeBoundaryPointPosition::Before;
}
// 4. If nodeA is an ancestor of nodeB:
if (node_a.is_ancestor_of(node_b)) {
// 1. Let child be nodeB.
NonnullRefPtr<Node> child = node_b;
// 2. While child is not a child of nodeA, set child to its parent.
while (!node_a.is_parent_of(child)) {
auto* parent = child->parent();
VERIFY(parent);
child = *parent;
}
// 3. If childs index is less than offsetA, then return after.
if (child->index() < offset_a)
return RelativeBoundaryPointPosition::After;
}
// 5. Return before.
return RelativeBoundaryPointPosition::Before;
}
ExceptionOr<void> Range::set_start_or_end(Node& node, u32 offset, StartOrEnd start_or_end)
{
// To set the start or end of a range to a boundary point (node, offset), run these steps:
// 1. If node is a doctype, then throw an "InvalidNodeTypeError" DOMException.
if (is<DocumentType>(node))
return InvalidNodeTypeError::create("Node cannot be a DocumentType.");
// 2. If offset is greater than nodes length, then throw an "IndexSizeError" DOMException.
if (offset > node.length())
return IndexSizeError::create(String::formatted("Node does not contain a child at offset {}", offset));
// 3. Let bp be the boundary point (node, offset).
if (start_or_end == StartOrEnd::Start) {
// -> If these steps were invoked as "set the start"
// 1. If ranges root is not equal to nodes root, or if bp is after the ranges end, set ranges end to bp.
if (&root() != &node.root() || position_of_boundary_point_relative_to_other_boundary_point(node, offset, m_end_container, m_end_offset) == RelativeBoundaryPointPosition::After) {
m_end_container = node;
m_end_offset = offset;
}
// 2. Set ranges start to bp.
m_start_container = node;
m_start_offset = offset;
} else {
// -> If these steps were invoked as "set the end"
VERIFY(start_or_end == StartOrEnd::End);
// 1. If ranges root is not equal to nodes root, or if bp is before the ranges start, set ranges start to bp.
if (&root() != &node.root() || position_of_boundary_point_relative_to_other_boundary_point(node, offset, m_start_container, m_start_offset) == RelativeBoundaryPointPosition::Before) {
m_start_container = node;
m_start_offset = offset;
}
// 2. Set ranges end to bp.
m_end_container = node;
m_end_offset = offset;
}
return {};
}
// https://dom.spec.whatwg.org/#concept-range-bp-set
ExceptionOr<void> Range::set_start(Node& node, u32 offset)
{
// The setStart(node, offset) method steps are to set the start of this to boundary point (node, offset).
return set_start_or_end(node, offset, StartOrEnd::Start);
}
ExceptionOr<void> Range::set_end(Node& node, u32 offset)
{
// The setEnd(node, offset) method steps are to set the end of this to boundary point (node, offset).
return set_start_or_end(node, offset, StartOrEnd::End);
}
NonnullRefPtr<Range> Range::clone_range() const
{
return adopt_ref(*new Range(const_cast<Node&>(*m_start_container), m_start_offset, const_cast<Node&>(*m_end_container), m_end_offset));