src/types/resourcevector.h

/*
 *  LDForge: LDraw parts authoring CAD
 *  Copyright (C) 2013 - 2017 Teemu Piippo
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <QVector>

/*
 * A vector that allocates elements on the heap and manages their lifetime.
 */
template<typename T>
class ResourceVector
{
public:
	~ResourceVector();
	void append(T) = delete;
	template<typename TT = T, typename... Args>
	T* append(Args&&... args);
	T** const begin() const;
	T** const end() const;
	template<typename TT = T, typename... Args>
	T* insert(int position, Args&&... args);
	void clear();
	void removeAt(int position);
	T* operator[](int position) const;
	int size() const;

private:
	QVector<T*> _data;
};

template<typename T>
int countof(const ResourceVector<T>& vector);

/*
 * Frees the resources when the vector is deleted.
 */
template<typename T>
ResourceVector<T>::~ResourceVector()
{
	clear();
}

/*
 * Creates a new resource and adds it to the end of this vector.
 */
template<typename T>
template<typename TT, typename... Args>
T* ResourceVector<T>::append(Args&&... args)
{
	_data.append(new TT {args...});
	return _data[size() - 1];
}

/*
 * Returns an iterator to the beginning of this vector.
 */
template<typename T>
T** const ResourceVector<T>::begin() const
{
	return _data.cbegin();
}

/*
 * Returns an iterator to the end of this vector.
 */
template<typename T>
T** const ResourceVector<T>::end() const
{
	return _data.cend();
}

/*
 * Creates a new resource and inserts it to the specified position in this vector.
 */
template<typename T>
template<typename TT, typename... Args>
T* ResourceVector<T>::insert(int position, Args&&... args)
{
	_data.insert(position, new TT {args...});
}

/*
 * Deletes all resources in this vector.
 */
template<typename T>
void ResourceVector<T>::clear()
{
	for (T* element : _data)
		delete element;

	_data.clear();
}

/*
 * Removes the resource at the provided position. Throws an exception if the index is out of range.
 */
template<typename T>
void ResourceVector<T>::removeAt(int position)
{
	if (position < _data.size())
	{
		delete _data[position];
		_data.removeAt(position);
	}
	else
	{
		throw std::domain_error {"index out of range"};
	}
}

/*
 * Returns the resource at the provided position. Throws an exception if the index is out of range.
 */
template<typename T>
T* ResourceVector<T>::operator[](int position) const
{
	if (position < _data.size())
		return _data[position];
	else
		throw std::domain_error {"index out of range"};
}

/*
 * Returns the amount of resources in this vector.
 */
template<typename T>
int ResourceVector<T>::size() const
{
	return _data.size();
}

/*
 * countof() overload for resource vectors. Returns the amount of resources in the given vector.
 */
template<typename T>
int countof(const ResourceVector<T>& vector)
{
	return vector.size();
}