RmlUi/Source/Core/IdNameMap.h

/*
 * This source file is part of RmlUi, the HTML/CSS Interface Middleware
 *
 * For the latest information, see http://github.com/mikke89/RmlUi
 *
 * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
 * Copyright (c) 2019 The RmlUi Team, and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

#ifndef RMLUICOREIDNAMEMAP_H
#define RMLUICOREIDNAMEMAP_H

#include "../../Include/RmlUi/Core/Header.h"
#include "../../Include/RmlUi/Core/Types.h"
#include <algorithm>

namespace Rml {
namespace Core {

template <typename ID>
class IdNameMap {
	std::vector<String> name_map;  // IDs are indices into the name_map
	UnorderedMap<String, ID> reverse_map;

protected:
	IdNameMap(size_t num_ids_to_reserve) {
		static_assert((int)ID::Invalid == 0, "Invalid id must be zero");
		name_map.reserve(num_ids_to_reserve);
		reverse_map.reserve(num_ids_to_reserve);
		AddPair(ID::Invalid, "invalid");
	}

public:
	void AddPair(ID id, const String& name)
	{
		// Should only be used for defined IDs
		if ((size_t)id >= name_map.size())
			name_map.resize(1 + (size_t)id);
		name_map[(size_t)id] = name;
		bool inserted = reverse_map.emplace(name, id).second;
		RMLUI_ASSERT(inserted);
		(void)inserted;
	}

	void AssertAllInserted(ID number_of_defined_ids) const
	{
		std::ptrdiff_t cnt = std::count_if(name_map.begin(), name_map.end(), [](const String& name) { return !name.empty(); });
		RMLUI_ASSERT(cnt == (std::ptrdiff_t)number_of_defined_ids && reverse_map.size() == (size_t)number_of_defined_ids);
		(void)number_of_defined_ids;
		(void)cnt;
	}

	ID GetId(const String& name) const
	{
		auto it = reverse_map.find(name);
		if (it != reverse_map.end())
			return it->second;
		return ID::Invalid;
	}
	const String& GetName(ID id) const
	{
		if (static_cast<size_t>(id) < name_map.size())
			return name_map[static_cast<size_t>(id)];
		return name_map[static_cast<size_t>(ID::Invalid)];
	}

	ID GetOrCreateId(const String& name)
	{
		// All predefined properties must be set before possibly adding custom properties here
		RMLUI_ASSERT(name_map.size() == reverse_map.size());

		ID next_id = static_cast<ID>(name_map.size());

		// Only insert if not already in list
		auto pair = reverse_map.emplace(name, next_id);
		const auto& it = pair.first;
		bool inserted = pair.second;

		if (inserted)
			name_map.push_back(name);

		// Return the property id that already existed, or the new one if inserted
		return it->second;
	}
};

class PropertyIdNameMap : public IdNameMap<PropertyId> {
public:
	PropertyIdNameMap(size_t reserve_num_properties) : IdNameMap(reserve_num_properties) {}
};

class ShorthandIdNameMap : public IdNameMap<ShorthandId> {
public:
	ShorthandIdNameMap(size_t reserve_num_shorthands) : IdNameMap(reserve_num_shorthands) {}
};

}
}

#endif