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/*

    treemodel.cpp

    Provides a simple tree model to show how to create and use hierarchical

    models.

*/

#include <QtGui>

#include "treeitem.h"

#include "treemodel.h"

TreeModel::TreeModel(const QStringList &strings, QObject *parent)

    : QAbstractItemModel(parent)

{

    QList<QVariant> rootData;

    rootData << "Title" << "Summary";

    rootItem = new TreeItem(rootData);

    setupModelData(strings, rootItem);

}

TreeModel::~TreeModel()

{

    delete rootItem;

}

int TreeModel::columnCount(const QModelIndex &parent) const

{

    if (parent.isValid())

        return static_cast<TreeItem*>(parent.internalPointer())->columnCount();

    else

        return rootItem->columnCount();

}

QVariant TreeModel::data(const QModelIndex &index, int role) const

{

    if (!index.isValid())

        return QVariant();

    if (role != Qt::DisplayRole)

        return QVariant();

    TreeItem *item = static_cast<TreeItem*>(index.internalPointer());

    return item->data(index.column());

}

Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const

{

    if (!index.isValid())

        return Qt::ItemIsEnabled;

    return Qt::ItemIsEnabled | Qt::ItemIsSelectable;

}

QVariant TreeModel::headerData(int section, Qt::Orientation orientation,

                               int role) const

{

    if (orientation == Qt::Horizontal && role == Qt::DisplayRole)

        return rootItem->data(section);

    return QVariant();

}

QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent)

            const

{

    TreeItem *parentItem;

    if (!parent.isValid())

        parentItem = rootItem;

    else

        parentItem = static_cast<TreeItem*>(parent.internalPointer());

    TreeItem *childItem = parentItem->child(row);

    if (childItem)

        return createIndex(row, column, childItem);

    else

        return QModelIndex();

}

bool TreeModel::insertRows(int position, int rows, const QModelIndex &parent)

{

    TreeItem *parentItem;

    if (!parent.isValid())

        parentItem = rootItem;

    else

        parentItem = static_cast<TreeItem*>(parent.internalPointer());

    if (position < 0 || position > parentItem->childCount())

        return false;

    QList<QVariant> blankList;

    for (int column = 0; column < columnCount(); ++column)

        blankList << QVariant("");

    beginInsertRows(parent, position, position + rows - 1);

    for (int row = 0; row < rows; ++row) {

        TreeItem *newItem = new TreeItem(blankList, parentItem);

        if (!parentItem->insertChild(position, newItem))

            break;

    }

    endInsertRows();

    return true;

}

QModelIndex TreeModel::parent(const QModelIndex &index) const

{

    if (!index.isValid())

        return QModelIndex();

    TreeItem *childItem = static_cast<TreeItem*>(index.internalPointer());

    TreeItem *parentItem = childItem->parent();

    if (parentItem == rootItem)

        return QModelIndex();

    return createIndex(parentItem->row(), 0, parentItem);

}

bool TreeModel::removeRows(int position, int rows, const QModelIndex &parent)

{

    TreeItem *parentItem;

    if (!parent.isValid())

        parentItem = rootItem;

    else

        parentItem = static_cast<TreeItem*>(parent.internalPointer());

    if (position < 0 || position > parentItem->childCount())

        return false;

    beginRemoveRows(parent, position, position + rows - 1);

    for (int row = 0; row < rows; ++row) {

        if (!parentItem->removeChild(position))

            break;

    }

    endRemoveRows();

    return true;

}

int TreeModel::rowCount(const QModelIndex &parent) const

{

    TreeItem *parentItem;

    if (!parent.isValid())

        parentItem = rootItem;

    else

        parentItem = static_cast<TreeItem*>(parent.internalPointer());

    return parentItem->childCount();

}

bool TreeModel::setData(const QModelIndex &index,

                        const QVariant &value, int role)

{

    if (!index.isValid() || role != Qt::EditRole)

        return false;

    TreeItem *item = static_cast<TreeItem*>(index.internalPointer());

    if (item->setData(index.column(), value))

        emit dataChanged(index, index);

    else

        return false;

    return true;

}

void TreeModel::setupModelData(const QStringList &lines, TreeItem *parent)

{

    QList<TreeItem*> parents;

    QList<int> indentations;

    parents << parent;

    indentations << 0;

    int number = 0;

    while (number < lines.count()) {

        int position = 0;

        while (position < lines[number].length()) {

            if (lines[number].mid(position, 1) != " ")

                break;

            position++;

        }

        QString lineData = lines[number].mid(position).trimmed();

        if (!lineData.isEmpty()) {

            // Read the column data from the rest of the line.

            QStringList columnStrings = lineData.split("\t", QString::SkipEmptyParts);

            QList<QVariant> columnData;

            for (int column = 0; column < columnStrings.count(); ++column)

                columnData << columnStrings[column];

            if (position > indentations.last()) {

                // The last child of the current parent is now the new parent

                // unless the current parent has no children.

                if (parents.last()->childCount() > 0) {

                    parents << parents.last()->child(parents.last()->childCount()-1);

                    indentations << position;

                }

            } else {

                while (position < indentations.last() && parents.count() > 0) {

                    parents.pop_back();

                    indentations.pop_back();

                }

            }

            // Append a new item to the current parent's list of children.

            parents.last()->appendChild(new TreeItem(columnData, parents.last()));

        }

        number++;

    }

}