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50
51/*
52 treemodel.cpp
53
54 Provides a simple tree model to show how to create and use hierarchical
55 models.
56*/
57
58#include "treemodel.h"
59#include "treeitem.h"
60
61#include <QStringList>
62
63//! [0]
64TreeModel::TreeModel(const QString &data, QObject *parent)
65 : QAbstractItemModel(parent)
66{
67 rootItem = new TreeItem({tr(s: "Title"), tr(s: "Summary")});
68 setupModelData(lines: data.split(sep: '\n'), parent: rootItem);
69}
70//! [0]
71
72//! [1]
73TreeModel::~TreeModel()
74{
75 delete rootItem;
76}
77//! [1]
78
79//! [2]
80int TreeModel::columnCount(const QModelIndex &parent) const
81{
82 if (parent.isValid())
83 return static_cast<TreeItem*>(parent.internalPointer())->columnCount();
84 return rootItem->columnCount();
85}
86//! [2]
87
88//! [3]
89QVariant TreeModel::data(const QModelIndex &index, int role) const
90{
91 if (!index.isValid())
92 return QVariant();
93
94 if (role != Qt::DisplayRole)
95 return QVariant();
96
97 TreeItem *item = static_cast<TreeItem*>(index.internalPointer());
98
99 return item->data(column: index.column());
100}
101//! [3]
102
103//! [4]
104Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const
105{
106 if (!index.isValid())
107 return Qt::NoItemFlags;
108
109 return QAbstractItemModel::flags(index);
110}
111//! [4]
112
113//! [5]
114QVariant TreeModel::headerData(int section, Qt::Orientation orientation,
115 int role) const
116{
117 if (orientation == Qt::Horizontal && role == Qt::DisplayRole)
118 return rootItem->data(column: section);
119
120 return QVariant();
121}
122//! [5]
123
124//! [6]
125QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent) const
126{
127 if (!hasIndex(row, column, parent))
128 return QModelIndex();
129
130 TreeItem *parentItem;
131
132 if (!parent.isValid())
133 parentItem = rootItem;
134 else
135 parentItem = static_cast<TreeItem*>(parent.internalPointer());
136
137 TreeItem *childItem = parentItem->child(row);
138 if (childItem)
139 return createIndex(arow: row, acolumn: column, adata: childItem);
140 return QModelIndex();
141}
142//! [6]
143
144//! [7]
145QModelIndex TreeModel::parent(const QModelIndex &index) const
146{
147 if (!index.isValid())
148 return QModelIndex();
149
150 TreeItem *childItem = static_cast<TreeItem*>(index.internalPointer());
151 TreeItem *parentItem = childItem->parentItem();
152
153 if (parentItem == rootItem)
154 return QModelIndex();
155
156 return createIndex(arow: parentItem->row(), acolumn: 0, adata: parentItem);
157}
158//! [7]
159
160//! [8]
161int TreeModel::rowCount(const QModelIndex &parent) const
162{
163 TreeItem *parentItem;
164 if (parent.column() > 0)
165 return 0;
166
167 if (!parent.isValid())
168 parentItem = rootItem;
169 else
170 parentItem = static_cast<TreeItem*>(parent.internalPointer());
171
172 return parentItem->childCount();
173}
174//! [8]
175
176void TreeModel::setupModelData(const QStringList &lines, TreeItem *parent)
177{
178 QVector<TreeItem*> parents;
179 QVector<int> indentations;
180 parents << parent;
181 indentations << 0;
182
183 int number = 0;
184
185 while (number < lines.count()) {
186 int position = 0;
187 while (position < lines[number].length()) {
188 if (lines[number].at(i: position) != ' ')
189 break;
190 position++;
191 }
192
193 const QString lineData = lines[number].mid(position).trimmed();
194
195 if (!lineData.isEmpty()) {
196 // Read the column data from the rest of the line.
197 const QStringList columnStrings =
198 lineData.split(sep: QLatin1Char('\t'), behavior: Qt::SkipEmptyParts);
199 QVector<QVariant> columnData;
200 columnData.reserve(asize: columnStrings.count());
201 for (const QString &columnString : columnStrings)
202 columnData << columnString;
203
204 if (position > indentations.last()) {
205 // The last child of the current parent is now the new parent
206 // unless the current parent has no children.
207
208 if (parents.last()->childCount() > 0) {
209 parents << parents.last()->child(row: parents.last()->childCount()-1);
210 indentations << position;
211 }
212 } else {
213 while (position < indentations.last() && parents.count() > 0) {
214 parents.pop_back();
215 indentations.pop_back();
216 }
217 }
218
219 // Append a new item to the current parent's list of children.
220 parents.last()->appendChild(child: new TreeItem(columnData, parents.last()));
221 }
222 ++number;
223 }
224}
225

source code of qtbase/examples/widgets/itemviews/simpletreemodel/treemodel.cpp