LibWeb: Introduce Mutation{Record,Observer} and observer microtasks

2025-07-26 15:17:45 +00:00 · 2022-07-11 16:37:51 +01:00 · 2022-07-11 16:37:51 +01:00 · c9ba5531e0
commit c9ba5531e0
parent 116a7b74fe
15 changed files with 531 additions and 0 deletions
--- a/Userland/Libraries/LibWeb/DOM/MutationObserver.h
+++ b/Userland/Libraries/LibWeb/DOM/MutationObserver.h
@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/NonnullRefPtrVector.h>
+#include <AK/RefCounted.h>
+#include <LibJS/Heap/Handle.h>
+#include <LibWeb/Bindings/CallbackType.h>
+#include <LibWeb/Bindings/Wrappable.h>
+#include <LibWeb/DOM/ExceptionOr.h>
+#include <LibWeb/DOM/MutationRecord.h>
+
+namespace Web::DOM {
+
+// https://dom.spec.whatwg.org/#dictdef-mutationobserverinit
+struct MutationObserverInit {
+    bool child_list { false };
+    Optional<bool> attributes;
+    Optional<bool> character_data;
+    bool subtree { false };
+    Optional<bool> attribute_old_value;
+    Optional<bool> character_data_old_value;
+    Optional<Vector<String>> attribute_filter;
+};
+
+// https://dom.spec.whatwg.org/#mutationobserver
+class MutationObserver final
+    : public RefCounted<MutationObserver>
+    , public Bindings::Wrappable {
+public:
+    using WrapperType = Bindings::MutationObserverWrapper;
+
+    static NonnullRefPtr<MutationObserver> create_with_global_object(Bindings::WindowObject& window_object, Bindings::CallbackType callback)
+    {
+        return adopt_ref(*new MutationObserver(window_object, move(callback)));
+    }
+
+    virtual ~MutationObserver() override = default;
+
+    ExceptionOr<void> observe(Node& target, MutationObserverInit options = {});
+    void disconnect();
+    NonnullRefPtrVector<MutationRecord> take_records();
+
+    Vector<WeakPtr<Node>>& node_list() { return m_node_list; }
+    Vector<WeakPtr<Node>> const& node_list() const { return m_node_list; }
+
+    Bindings::CallbackType& callback() { return m_callback; }
+
+    void enqueue_record(Badge<Node>, NonnullRefPtr<MutationRecord> mutation_record)
+    {
+        m_record_queue.append(move(mutation_record));
+    }
+
+private:
+    MutationObserver(Bindings::WindowObject& window_object, Bindings::CallbackType callback);
+
+    // https://dom.spec.whatwg.org/#concept-mo-callback
+    Bindings::CallbackType m_callback;
+
+    // https://dom.spec.whatwg.org/#mutationobserver-node-list
+    Vector<WeakPtr<Node>> m_node_list;
+
+    // https://dom.spec.whatwg.org/#concept-mo-queue
+    NonnullRefPtrVector<MutationRecord> m_record_queue;
+};
+
+// https://dom.spec.whatwg.org/#registered-observer
+struct RegisteredObserver : public RefCounted<RegisteredObserver> {
+    static NonnullRefPtr<RegisteredObserver> create(MutationObserver& observer, MutationObserverInit& options)
+    {
+        return adopt_ref(*new RegisteredObserver(observer, options));
+    }
+
+    RegisteredObserver(MutationObserver& observer, MutationObserverInit& options)
+        : observer(observer)
+        , options(options)
+    {
+    }
+
+    virtual ~RegisteredObserver() = default;
+
+    NonnullRefPtr<MutationObserver> observer;
+    MutationObserverInit options;
+};
+
+// https://dom.spec.whatwg.org/#transient-registered-observer
+struct TransientRegisteredObserver final : public RegisteredObserver {
+    static NonnullRefPtr<TransientRegisteredObserver> create(MutationObserver& observer, MutationObserverInit& options, RegisteredObserver& source)
+    {
+        return adopt_ref(*new TransientRegisteredObserver(observer, options, source));
+    }
+
+    TransientRegisteredObserver(MutationObserver& observer, MutationObserverInit& options, RegisteredObserver& source)
+        : RegisteredObserver(observer, options)
+        , source(source)
+    {
+    }
+
+    virtual ~TransientRegisteredObserver() override = default;
+
+    NonnullRefPtr<RegisteredObserver> source;
+};
+
+}