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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>
++
++ using namespace Qt::StringLiterals;
++
++ //! [0]
++ TreeModel::TreeModel(const QString &data, QObject *parent)
++ : QAbstractItemModel(parent)
++ , rootItem(std::make_unique<TreeItem>(QVariantList{tr("Title"), tr("Summary")}))
++ {
++ setupModelData(QStringView{data}.split(u'\n'), rootItem.get());
++ }
++ //! [0]
++
++ //! [1]
++ TreeModel::~TreeModel() = default;
++ //! [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() || role != Qt::DisplayRole)
++ return {};
++
++ const auto *item = static_cast<const TreeItem*>(index.internalPointer());
++ return item->data(index.column());
++ }
++ //! [3]
++
++ //! [4]
++ Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const
++ {
++ return index.isValid()
++ ? QAbstractItemModel::flags(index) : Qt::ItemFlags(Qt::NoItemFlags);
++ }
++ //! [4]
++
++ //! [5]
++ QVariant TreeModel::headerData(int section, Qt::Orientation orientation,
++ int role) const
++ {
++ return orientation == Qt::Horizontal && role == Qt::DisplayRole
++ ? rootItem->data(section) : QVariant{};
++ }
++ //! [5]
++
++ //! [6]
++ QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent) const
++ {
++ if (!hasIndex(row, column, parent))
++ return {};
++
++ TreeItem *parentItem = parent.isValid()
++ ? static_cast<TreeItem*>(parent.internalPointer())
++ : rootItem.get();
++
++ if (auto *childItem = parentItem->child(row))
++ return createIndex(row, column, childItem);
++ return {};
++ }
++ //! [6]
++
++ //! [7]
++ QModelIndex TreeModel::parent(const QModelIndex &index) const
++ {
++ if (!index.isValid())
++ return {};
++
++ auto *childItem = static_cast<TreeItem*>(index.internalPointer());
++ TreeItem *parentItem = childItem->parentItem();
++
++ return parentItem != rootItem.get()
++ ? createIndex(parentItem->row(), 0, parentItem) : QModelIndex{};
++ }
++ //! [7]
++
++ //! [8]
++ int TreeModel::rowCount(const QModelIndex &parent) const
++ {
++ if (parent.column() > 0)
++ return 0;
++
++ const TreeItem *parentItem = parent.isValid()
++ ? static_cast<const TreeItem*>(parent.internalPointer())
++ : rootItem.get();
++
++ return parentItem->childCount();
++ }
++ //! [8]
++
++ void TreeModel::setupModelData(const QList<QStringView> &lines, TreeItem *parent)
++ {
++ struct ParentIndentation
++ {
++ TreeItem *parent;
++ qsizetype indentation;
++ };
++
++ QList<ParentIndentation> state{{parent, 0}};
++
++ for (const auto &line : lines) {
++ qsizetype position = 0;
++ for ( ; position < line.length() && line.at(position).isSpace(); ++position) {
++ }
++
++ const QStringView lineData = line.sliced(position).trimmed();
++ if (!lineData.isEmpty()) {
++ // Read the column data from the rest of the line.
++ const auto columnStrings = lineData.split(u'\t', Qt::SkipEmptyParts);
++ QVariantList columnData;
++ columnData.reserve(columnStrings.count());
++ for (const auto &columnString : columnStrings)
++ columnData << columnString.toString();
++
++ if (position > state.constLast().indentation) {
++ // The last child of the current parent is now the new parent
++ // unless the current parent has no children.
++ auto *lastParent = state.constLast().parent;
++ if (lastParent->childCount() > 0)
++ state.append({lastParent->child(lastParent->childCount() - 1), position});
++ } else {
++ while (position < state.constLast().indentation && !state.isEmpty())
++ state.removeLast();
++ }
++
++ // Append a new item to the current parent's list of children.
++ auto *lastParent = state.constLast().parent;
++ lastParent->appendChild(std::make_unique<TreeItem>(columnData, lastParent));
++ }
++ }
++ }