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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
/*
treemodel.cpp
Provides a simple tree model to show how to create and use hierarchical
models.
*/
#include "treemodel.h"
#include "treeitem.h"
#include <QStringList>
//! [0]
TreeModel::TreeModel(const QString &data, QObject *parent)
: QAbstractItemModel(parent)
{
rootItem = new TreeItem({tr("Title"), tr("Summary")});
setupModelData(data.split('\n'), rootItem);
}
//! [0]
//! [1]
TreeModel::~TreeModel()
{
delete rootItem;
}
//! [1]
//! [2]
int TreeModel::columnCount(const QModelIndex &parent) const
{
if (parent.isValid())
return static_cast<TreeItem*>(parent.internalPointer())->columnCount();
return rootItem->columnCount();
}
//! [2]
//! [3]
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());
}
//! [3]
//! [4]
Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const
{
if (!index.isValid())
return Qt::NoItemFlags;
return QAbstractItemModel::flags(index);
}
//! [4]
//! [5]
QVariant TreeModel::headerData(int section, Qt::Orientation orientation,
int role) const
{
if (orientation == Qt::Horizontal && role == Qt::DisplayRole)
return rootItem->data(section);
return QVariant();
}
//! [5]
//! [6]
QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent) const
{
if (!hasIndex(row, column, parent))
return QModelIndex();
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);
return QModelIndex();
}
//! [6]
//! [7]
QModelIndex TreeModel::parent(const QModelIndex &index) const
{
if (!index.isValid())
return QModelIndex();
TreeItem *childItem = static_cast<TreeItem*>(index.internalPointer());
TreeItem *parentItem = childItem->parentItem();
if (parentItem == rootItem)
return QModelIndex();
return createIndex(parentItem->row(), 0, parentItem);
}
//! [7]
//! [8]
int TreeModel::rowCount(const QModelIndex &parent) const
{
TreeItem *parentItem;
if (parent.column() > 0)
return 0;
if (!parent.isValid())
parentItem = rootItem;
else
parentItem = static_cast<TreeItem*>(parent.internalPointer());
return parentItem->childCount();
}
//! [8]
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].at(position) != ' ')
break;
position++;
}
const QString lineData = lines[number].mid(position).trimmed();
if (!lineData.isEmpty()) {
// Read the column data from the rest of the line.
const QStringList columnStrings =
lineData.split(QLatin1Char('\t'), Qt::SkipEmptyParts);
QList<QVariant> columnData;
columnData.reserve(columnStrings.count());
for (const QString &columnString : columnStrings)
columnData << columnString;
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;
}
}
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