model.cpp Example File
itemviews/interview/model.cpp
#include "model.h"
#include <QIcon>
#include <QPixmap>
Model::Model(int rows, int columns, QObject *parent)
: QAbstractItemModel(parent),
services(QPixmap(":/images/services.png")),
rc(rows), cc(columns),
tree(new QVector<Node>(rows, Node(0)))
{
}
Model::~Model()
{
delete tree;
}
QModelIndex Model::index(int row, int column, const QModelIndex &parent) const
{
if (row < rc && row >= 0 && column < cc && column >= 0) {
Node *parentNode = static_cast<Node*>(parent.internalPointer());
Node *childNode = node(row, parentNode);
if (childNode)
return createIndex(row, column, childNode);
}
return QModelIndex();
}
QModelIndex Model::parent(const QModelIndex &child) const
{
if (child.isValid()) {
Node *childNode = static_cast<Node*>(child.internalPointer());
Node *parentNode = parent(childNode);
if (parentNode)
return createIndex(row(parentNode), 0, parentNode);
}
return QModelIndex();
}
int Model::rowCount(const QModelIndex &parent) const
{
return (parent.isValid() && parent.column() != 0) ? 0 : rc;
}
int Model::columnCount(const QModelIndex &parent) const
{
Q_UNUSED(parent);
return cc;
}
QVariant Model::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();
if (role == Qt::DisplayRole)
return QVariant("Item " + QString::number(index.row()) + ':' + QString::number(index.column()));
if (role == Qt::DecorationRole) {
if (index.column() == 0)
return iconProvider.icon(QFileIconProvider::Folder);
return iconProvider.icon(QFileIconProvider::File);
}
return QVariant();
}
QVariant Model::headerData(int section, Qt::Orientation orientation, int role) const
{
if (role == Qt::DisplayRole)
return QString::number(section);
if (role == Qt::DecorationRole)
return QVariant::fromValue(services);
return QAbstractItemModel::headerData(section, orientation, role);
}
bool Model::hasChildren(const QModelIndex &parent) const
{
if (parent.isValid() && parent.column() != 0)
return false;
return rc > 0 && cc > 0;
}
Qt::ItemFlags Model::flags(const QModelIndex &index) const
{
if (!index.isValid())
return 0;
return Qt::ItemIsDragEnabled|QAbstractItemModel::flags(index);
}
Model::Node *Model::node(int row, Node *parent) const
{
if (parent && !parent->children)
parent->children = new QVector<Node>(rc, Node(parent));
QVector<Node> *v = parent ? parent->children : tree;
return const_cast<Node*>(&(v->at(row)));
}
Model::Node *Model::parent(Node *child) const
{
return child ? child->parent : 0;
}
int Model::row(Node *node) const
{
const Node *first = node->parent ? &(node->parent->children->at(0)) : &(tree->at(0));
return node - first;
}