LibWeb: Generate pseudo-element code from JSON

Initially, this generates the enum and to/from-string functions. The JSON itself contains more data than that, but it's unused for now.
Author: https://github.com/AtkinsSJ Commit: ffa1dba96a Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4021
2025-05-19 01:22:54 +00:00 · 2025-03-19 14:58:22 +00:00 · 2025-03-19 14:58:22 +00:00 · ffa1dba96a · 2025-03-24 09:51:30 +00:00
commit ffa1dba96a
parent 0ed2e71801
14 changed files with 244 additions and 106 deletions
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateCSSPseudoElement.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateCSSPseudoElement.cpp
@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2022-2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "GeneratorUtil.h"
+#include <AK/SourceGenerator.h>
+#include <LibCore/ArgsParser.h>
+#include <LibMain/Main.h>
+
+ErrorOr<void> generate_header_file(JsonObject& pseudo_elements_data, Core::File& file);
+ErrorOr<void> generate_implementation_file(JsonObject& pseudo_elements_data, Core::File& file);
+
+ErrorOr<int> serenity_main(Main::Arguments arguments)
+{
+    StringView generated_header_path;
+    StringView generated_implementation_path;
+    StringView json_path;
+
+    Core::ArgsParser args_parser;
+    args_parser.add_option(generated_header_path, "Path to the PseudoElements header file to generate", "generated-header-path", 'h', "generated-header-path");
+    args_parser.add_option(generated_implementation_path, "Path to the PseudoElements implementation file to generate", "generated-implementation-path", 'c', "generated-implementation-path");
+    args_parser.add_option(json_path, "Path to the JSON file to read from", "json-path", 'j', "json-path");
+    args_parser.parse(arguments);
+
+    auto json = TRY(read_entire_file_as_json(json_path));
+    VERIFY(json.is_object());
+    auto data = json.as_object();
+
+    auto generated_header_file = TRY(Core::File::open(generated_header_path, Core::File::OpenMode::Write));
+    auto generated_implementation_file = TRY(Core::File::open(generated_implementation_path, Core::File::OpenMode::Write));
+
+    TRY(generate_header_file(data, *generated_header_file));
+    TRY(generate_implementation_file(data, *generated_implementation_file));
+
+    return 0;
+}
+
+ErrorOr<void> generate_header_file(JsonObject& pseudo_elements_data, Core::File& file)
+{
+    StringBuilder builder;
+    SourceGenerator generator { builder };
+
+    auto pseudo_element_count = 0u;
+    pseudo_elements_data.for_each_member([&pseudo_element_count](auto const&, auto const&) { ++pseudo_element_count; });
+    generator.set("pseudo_element_underlying_type", underlying_type_for_enum(pseudo_element_count));
+
+    generator.append(R"~~~(
+#pragma once
+
+#include <AK/Optional.h>
+#include <AK/StringView.h>
+
+namespace Web::CSS {
+
+enum class PseudoElement : @pseudo_element_underlying_type@ {
+)~~~");
+
+    pseudo_elements_data.for_each_member([&](auto& name, auto&) {
+        auto member_generator = generator.fork();
+        member_generator.set("name:titlecase", title_casify(name));
+
+        member_generator.appendln("    @name:titlecase@,");
+    });
+    generator.append(R"~~~(
+    KnownPseudoElementCount,
+
+    UnknownWebKit,
+};
+
+Optional<PseudoElement> pseudo_element_from_string(StringView);
+StringView pseudo_element_name(PseudoElement);
+
+}
+)~~~");
+
+    TRY(file.write_until_depleted(generator.as_string_view().bytes()));
+    return {};
+}
+
+ErrorOr<void> generate_implementation_file(JsonObject& pseudo_elements_data, Core::File& file)
+{
+    StringBuilder builder;
+    SourceGenerator generator { builder };
+
+    generator.append(R"~~~(
+#include <LibWeb/CSS/PseudoElement.h>
+
+namespace Web::CSS {
+
+Optional<PseudoElement> pseudo_element_from_string(StringView string)
+{
+)~~~");
+
+    pseudo_elements_data.for_each_member([&](auto& name, auto&) {
+        auto member_generator = generator.fork();
+        member_generator.set("name", name);
+        member_generator.set("name:titlecase", title_casify(name));
+
+        member_generator.append(R"~~~(
+    if (string.equals_ignoring_ascii_case("@name@"sv))
+        return PseudoElement::@name:titlecase@;
+)~~~");
+    });
+
+    generator.append(R"~~~(
+
+    return {};
+}
+
+StringView pseudo_element_name(PseudoElement pseudo_element)
+{
+    switch (pseudo_element) {
+)~~~");
+
+    pseudo_elements_data.for_each_member([&](auto& name, auto&) {
+        auto member_generator = generator.fork();
+        member_generator.set("name", name);
+        member_generator.set("name:titlecase", title_casify(name));
+
+        member_generator.append(R"~~~(
+    case PseudoElement::@name:titlecase@:
+        return "@name@"sv;
+)~~~");
+    });
+
+    generator.append(R"~~~(
+    case PseudoElement::KnownPseudoElementCount:
+    case PseudoElement::UnknownWebKit:
+        VERIFY_NOT_REACHED();
+    }
+    VERIFY_NOT_REACHED();
+}
+
+}
+)~~~");
+
+    TRY(file.write_until_depleted(generator.as_string_view().bytes()));
+    return {};
+}