booleanmodel.cpp

QT4 gui programming的随书光盘

#include <QtCore>

#include "booleanmodel.h"
#include "booleanparser.h"

BooleanModel::BooleanModel(QObject *parent)
    : QAbstractItemModel(parent)
{
    rootNode = 0;
}

BooleanModel::~BooleanModel()
{
    delete rootNode;
}

void BooleanModel::setRootNode(Node *node)
{
    delete rootNode;
    rootNode = node;
    reset();
}

QModelIndex BooleanModel::index(int row, int column,
                                const QModelIndex &parent) const
{
    if (!rootNode || row < 0 || column < 0)
        return QModelIndex();
    Node *parentNode = nodeFromIndex(parent);
    Node *childNode = parentNode->children.value(row);
    if (!childNode)
        return QModelIndex();
    return createIndex(row, column, childNode);
}

QModelIndex BooleanModel::parent(const QModelIndex &child) const
{
    Node *node = nodeFromIndex(child);
    if (!node)
        return QModelIndex();
    Node *parentNode = node->parent;
    if (!parentNode)
        return QModelIndex();
    Node *grandparentNode = parentNode->parent;
    if (!grandparentNode)
        return QModelIndex();

    int row = grandparentNode->children.indexOf(parentNode);
    return createIndex(row, 0, parentNode);
}

int BooleanModel::rowCount(const QModelIndex &parent) const
{
    if (parent.column() > 0)
        return 0;
    Node *parentNode = nodeFromIndex(parent);
    if (!parentNode)
        return 0;
    return parentNode->children.count();
}

int BooleanModel::columnCount(const QModelIndex & /* parent */) const
{
    return 2;
}

QVariant BooleanModel::data(const QModelIndex &index, int role) const
{
    if (role != Qt::DisplayRole)
        return QVariant();

    Node *node = nodeFromIndex(index);
    if (!node)
        return QVariant();

    if (index.column() == 0) {
        switch (node->type) {
        case Node::Root:
             return tr("Root");
        case Node::OrExpression:
            return tr("OR Expression");
        case Node::AndExpression:
            return tr("AND Expression");
        case Node::NotExpression:
            return tr("NOT Expression");
        case Node::Atom:
            return tr("Atom");
        case Node::Identifier:
            return tr("Identifier");
        case Node::Operator:
            return tr("Operator");
        case Node::Punctuator:
            return tr("Punctuator");
        default:
            return tr("Unknown");
        }
    } else if (index.column() == 1) {
        return node->str;
    }
    return QVariant();
}

QVariant BooleanModel::headerData(int section,
                                  Qt::Orientation orientation,
                                  int role) const
{
    if (orientation == Qt::Horizontal && role == Qt::DisplayRole) {
        if (section == 0) {
            return tr("Node");
        } else if (section == 1) {
            return tr("Value");
        }
    }
    return QVariant();
}

Node *BooleanModel::nodeFromIndex(const QModelIndex &index) const
{
    if (index.isValid()) {
        return static_cast<Node *>(index.internalPointer());
    } else {
        return rootNode;
    }
}