src/model.cpp

/*
 *  LDForge: LDraw parts authoring CAD
 *  Copyright (C) 2013 - 2020 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 <QBrush>
#include <QFile>
#include <QFont>
#include "model.h"
#include "modeleditcontext.h"

/**
 * @brief Constructs a model
 * @param parent QObject parent to pass forward
 */
Model::Model(QObject* parent) : 
	Model{"", parent} {}

/**
 * @brief Constructs a model
 * @param path Path that was used to open the model
 * @param parent QObject parent to pass forward
 */
Model::Model(const QString& path, QObject *parent) :
	QAbstractListModel{parent},
	path{path}
{
	connect(this, &Model::dataChanged, [&](){ this->needRecache = true; });
}

/**
 * @returns the amount of elements in the model
 */
int Model::size() const
{
	return static_cast<int>(this->body.size());
}

/**
 * @brief Looks up the object ID at the specified index. If out of bounds, returns NULL_ID.
 * @param index Index of object to look up
 * @return object ID
 */
ldraw::id_t Model::at(int index) const
{
	if (index >= 0 and index < this->size())
	{
		return this->body[index]->id;
	}
	else
	{
		return ldraw::NULL_ID;
	}
}

/**
 * @brief Obtains an editing context for this model.
 * Editing contexts are used to perform modifications to the model.
 * @return editing context
 */
Model::EditContext Model::edit()
{
	this->editCounter += 1;
	return {*this};
}

/**
 * @brief @overload QAbstractListModel::rowCount
 * @return size
 */
int Model::rowCount(const QModelIndex&) const
{
	return this->size();
}

/**
 * @brief @overload QAbstractListModel::data
 * @param index
 * @param role
 * @return QVariant
 */
QVariant Model::data(const QModelIndex& index, int role) const
{
	const ldraw::Object* object = this->objectAt(index);
	switch(role)
	{
	case Qt::DisplayRole:
		return object->textRepresentation();
	case Qt::ForegroundRole:
		return object->textRepresentationForeground();
	case Qt::BackgroundRole:
		return object->textRepresentationBackground();
	case Qt::FontRole:
		return object->textRepresentationFont();
	default:
		return {};
	}
}

/**
 * @brief Gets a property of the header
 * @param property
 * @return QVariant
 */
QVariant Model::getHeaderProperty(const HeaderProperty property)
{
	switch (property)
	{
	case HeaderProperty::Name:
		return header.name;
	}
	return {};
}

/**
 * @brief Gets the specified property from the object at the specified index in the model.
 * @param index Index of object in the model
 * @param property Property to look up
 * @return QVariant
 */
QVariant Model::getObjectProperty(const int index, const ldraw::Property property) const
{
	const ldraw::Object* object = this->body[unsigned_cast(index)].get();
	return object->getProperty(property);
}

/**
 * @brief Gets a list of GL polygons that are used to represent this model.
 * @details Will build polygons if polygons are outdated.
 * @param documents Documents to use to resolve subfile references
 * @return vector of GL polygons
 */
std::vector<gl::Polygon> Model::getPolygons(DocumentManager* documents) const
{
	if (this->needRecache)
	{
		this->cachedPolygons.clear();
		ldraw::GetPolygonsContext context{documents};
		for (int i = 0; i < this->size(); i += 1)
		{
			this->getObjectPolygons(i, this->cachedPolygons, &context);
		}
		this->needRecache = false;
	}
	return this->cachedPolygons;
}

/**
 * @brief Finds the position of the specified object in the model
 * @param id Object id to look for
 * @return model index
 */
QModelIndex Model::lookup(ldraw::id_t id) const
{
	// FIXME: This linear search will probably cause performance issues
	for (std::size_t i = 0; i < this->body.size(); i += 1)
	{
		if (this->body[i]->id == id)
		{
			return this->index(static_cast<int>(i));
		}
	}
	return {};
}

/**
 * @brief Gets an object id by position in the model
 * @param index Position of the object in the model
 * @return id
 */
ldraw::id_t Model::resolve(const QModelIndex& index) const
{
	return this->objectAt(index)->id;
}

/**
 * @brief Gets the GL polygons of the object at the specified position in the model
 * @param index Index of object in the model
 * @param polygons_out Vector to add polygons into
 * @param context Context to use to resolve subfile references
 */
void Model::getObjectPolygons(
	const int index,
	std::vector<gl::Polygon>& polygons_out,
	ldraw::GetPolygonsContext* context) const
{
	const ldraw::Object* object = this->body[unsigned_cast(index)].get();
	object->getPolygons(polygons_out, context);
}

/**
 * @brief Called by the editing context to signal to the model that editing is done.
 */
void Model::editFinished()
{
	this->editCounter -= 1;
}

/**
 * @brief Called by the editing context to indicate that the specified object has been modified.
 * @param id ID of the object that has been modified
 */
void Model::objectModified(ldraw::id_t id)
{
	const QModelIndex index = this->lookup(id);
	Q_EMIT this->dataChanged(index, index);
}

/**
 * @brief Adds the given object into the model.
 * @param object r-value reference to the object
 */
void Model::append(ModelObjectPointer&& object)
{
	const int position = static_cast<int>(this->body.size());
	Q_EMIT beginInsertRows({}, position, position);
	this->body.push_back(std::move(object));
	Q_EMIT endInsertRows();
	this->needRecache = true;
}

/**
 * @brief Removes the object at the specified position
 * @param position
 */
void Model::remove(int position)
{
	if (position >= 0 and position < signed_cast(this->body.size()))
	{
		Q_EMIT beginRemoveRows({}, position, position);
		this->body.erase(std::begin(this->body) + position);
		Q_EMIT endRemoveRows();
		this->needRecache = true;
	}
}

/**
 * @brief Gets the object pointer at the specified position
 * @param index Position of the object
 * @returns object pointer
 */
ldraw::Object* Model::objectAt(const QModelIndex& index)
{
	return this->body[unsigned_cast(index.row())].get();
}

/**
 * @brief Gets the object pointer at the specified position
 * @param index Position of the object
 * @returns object pointer
 */
const ldraw::Object* Model::objectAt(const QModelIndex& index) const
{
	return this->body[unsigned_cast(index.row())].get();
}

/**
 * @brief Write out the model as text
 */
void Model::save() const
{
	QFile file{this->path};
	if (file.open(QIODevice::WriteOnly))
	{
		QTextStream out{&file};
		for (const ModelObjectPointer& object : this->body)
		{
			out << object.get()->textRepresentation() << "\r\n";
		}
		file.close();
	}
}