init

Telegram/lib_base/base/options.h

@@ -0,0 +1,140 @@
+// This file is part of Desktop App Toolkit,
+// a set of libraries for developing nice desktop applications.
+//
+// For license and copyright information please follow this link:
+// https://github.com/desktop-app/legal/blob/master/LEGAL
+//
+#pragma once
+
+#include "base/flags.h"
+#include "base/variant.h"
+#include "base/required.h"
+
+#ifdef linux // GCC, cmon..
+#undef linux
+#endif // linux
+
+namespace base::options {
+namespace details {
+
+using ValueType = std::variant<bool, int, QString>;
+
+enum class ScopeFlag : uchar {
+	Windows = (1 << 1),
+	Mac     = (1 << 2),
+	Linux   = (1 << 3),
+};
+inline constexpr bool is_flag_type(ScopeFlag) { return true; }
+using ScopeFlags = base::flags<ScopeFlag>;
+using ScopeFn = Fn<bool()>;
+using Scope = std::variant<ScopeFlags, ScopeFn>;
+
+class BasicOption {
+public:
+	BasicOption(
+		const char id[],
+		const char name[],
+		const char description[],
+		ValueType defaultValue,
+		Scope scope,
+		bool restartRequired);
+	BasicOption(const BasicOption&) = delete;
+	BasicOption operator=(const BasicOption&) = delete;
+
+	void set(ValueType value);
+	[[nodiscard]] const ValueType &value() const;
+	[[nodiscard]] const ValueType &defaultValue() const;
+
+	[[nodiscard]] const QString &id() const;
+	[[nodiscard]] const QString &name() const;
+	[[nodiscard]] const QString &description() const;
+
+	[[nodiscard]] bool relevant() const;
+	[[nodiscard]] Scope scope() const;
+
+	[[nodiscard]] bool restartRequired() const;
+
+private:
+	ValueType _value;
+	ValueType _defaultValue;
+
+	QString _id;
+	QString _name;
+	QString _description;
+	Scope _scope;
+	bool _restartRequired = false;
+
+};
+
+[[nodiscard]] BasicOption &Lookup(const char name[]);
+
+} // namespace details
+
+inline constexpr auto windows = details::ScopeFlag::Windows;
+inline constexpr auto macos = details::ScopeFlag::Mac;
+inline constexpr auto linux = details::ScopeFlag::Linux;
+
+template <typename Type>
+struct descriptor {
+	required<const char*> id;
+	const char *name = "";
+	const char *description = "";
+	Type defaultValue = Type();
+	details::Scope scope = windows | macos | linux;
+	bool restartRequired = false;
+};
+
+template <typename Type>
+class option final : details::BasicOption {
+public:
+	option(descriptor<Type> &&fields)
+	: BasicOption(
+		fields.id,
+		fields.name,
+		fields.description,
+		std::move(fields.defaultValue),
+		fields.scope,
+		fields.restartRequired) {
+	}
+
+	using BasicOption::id;
+	using BasicOption::name;
+	using BasicOption::description;
+	using BasicOption::relevant;
+	using BasicOption::scope;
+	using BasicOption::restartRequired;
+
+	void set(Type value) {
+		BasicOption::set(std::move(value));
+	}
+	[[nodiscard]] Type value() const {
+		return v::get<Type>(BasicOption::value());
+	}
+	[[nodiscard]] Type defaultValue() const {
+		return v::get<Type>(BasicOption::defaultValue());
+	}
+
+	[[nodiscard]] static option &Wrap(BasicOption &that) {
+		Expects(v::is<Type>(that.value()));
+
+		return static_cast<option&>(that);
+	}
+};
+
+using toggle = option<bool>;
+
+template <typename Type>
+[[nodiscard]] inline Type value(const char id[]) {
+	return v::get<Type>(details::Lookup(id).value());
+}
+
+template <typename Type>
+[[nodiscard]] inline option<Type> &lookup(const char id[]) {
+	return option<Type>::Wrap(details::Lookup(id));
+}
+
+[[nodiscard]] bool changed();
+void reset();
+void init(const QString &path);
+
+} // namespace base::options