qt5base-lts/examples/widgets/itemviews/editabletreemodel/treemodel.cpp
Samuel Gaist e65558c230 Fix Editable Tree Model example model rowCount and model instance leak
The rowCount method has been fixed to correctly pass the "Common error
test #3: the second column should NOT have the same children".

It also fixes the model being leaked.

Fixes: QTBUG-92178
Pick-to: 5.15
Change-Id: If92973e6f83ea9a2715bd335269f6e50d80f52c6
Reviewed-by: Luca Beldi <v.ronin@yahoo.it>
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>
2021-03-29 12:09:41 +01:00

304 lines
9.0 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "treemodel.h"
#include "treeitem.h"
#include <QtWidgets>
//! [0]
TreeModel::TreeModel(const QStringList &headers, const QString &data, QObject *parent)
: QAbstractItemModel(parent)
{
QList<QVariant> rootData;
for (const QString &header : headers)
rootData << header;
rootItem = new TreeItem(rootData);
setupModelData(data.split('\n'), rootItem);
}
//! [0]
//! [1]
TreeModel::~TreeModel()
{
delete rootItem;
}
//! [1]
//! [2]
int TreeModel::columnCount(const QModelIndex &parent) const
{
Q_UNUSED(parent);
return rootItem->columnCount();
}
//! [2]
QVariant TreeModel::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();
if (role != Qt::DisplayRole && role != Qt::EditRole)
return QVariant();
TreeItem *item = getItem(index);
return item->data(index.column());
}
//! [3]
Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const
{
if (!index.isValid())
return Qt::NoItemFlags;
return Qt::ItemIsEditable | QAbstractItemModel::flags(index);
}
//! [3]
//! [4]
TreeItem *TreeModel::getItem(const QModelIndex &index) const
{
if (index.isValid()) {
TreeItem *item = static_cast<TreeItem*>(index.internalPointer());
if (item)
return item;
}
return rootItem;
}
//! [4]
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]
QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent) const
{
if (parent.isValid() && parent.column() != 0)
return QModelIndex();
//! [5]
//! [6]
TreeItem *parentItem = getItem(parent);
if (!parentItem)
return QModelIndex();
TreeItem *childItem = parentItem->child(row);
if (childItem)
return createIndex(row, column, childItem);
return QModelIndex();
}
//! [6]
bool TreeModel::insertColumns(int position, int columns, const QModelIndex &parent)
{
beginInsertColumns(parent, position, position + columns - 1);
const bool success = rootItem->insertColumns(position, columns);
endInsertColumns();
return success;
}
bool TreeModel::insertRows(int position, int rows, const QModelIndex &parent)
{
TreeItem *parentItem = getItem(parent);
if (!parentItem)
return false;
beginInsertRows(parent, position, position + rows - 1);
const bool success = parentItem->insertChildren(position,
rows,
rootItem->columnCount());
endInsertRows();
return success;
}
//! [7]
QModelIndex TreeModel::parent(const QModelIndex &index) const
{
if (!index.isValid())
return QModelIndex();
TreeItem *childItem = getItem(index);
TreeItem *parentItem = childItem ? childItem->parent() : nullptr;
if (parentItem == rootItem || !parentItem)
return QModelIndex();
return createIndex(parentItem->childNumber(), 0, parentItem);
}
//! [7]
bool TreeModel::removeColumns(int position, int columns, const QModelIndex &parent)
{
beginRemoveColumns(parent, position, position + columns - 1);
const bool success = rootItem->removeColumns(position, columns);
endRemoveColumns();
if (rootItem->columnCount() == 0)
removeRows(0, rowCount());
return success;
}
bool TreeModel::removeRows(int position, int rows, const QModelIndex &parent)
{
TreeItem *parentItem = getItem(parent);
if (!parentItem)
return false;
beginRemoveRows(parent, position, position + rows - 1);
const bool success = parentItem->removeChildren(position, rows);
endRemoveRows();
return success;
}
//! [8]
int TreeModel::rowCount(const QModelIndex &parent) const
{
if (parent.isValid() && parent.column() > 0)
return 0;
const TreeItem *parentItem = getItem(parent);
return parentItem ? parentItem->childCount() : 0;
}
//! [8]
bool TreeModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
if (role != Qt::EditRole)
return false;
TreeItem *item = getItem(index);
bool result = item->setData(index.column(), value);
if (result)
emit dataChanged(index, index, {Qt::DisplayRole, Qt::EditRole});
return result;
}
bool TreeModel::setHeaderData(int section, Qt::Orientation orientation,
const QVariant &value, int role)
{
if (role != Qt::EditRole || orientation != Qt::Horizontal)
return false;
const bool result = rootItem->setData(section, value);
if (result)
emit headerDataChanged(orientation, section, section);
return result;
}
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.size());
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.
TreeItem *parent = parents.last();
parent->insertChildren(parent->childCount(), 1, rootItem->columnCount());
for (int column = 0; column < columnData.size(); ++column)
parent->child(parent->childCount() - 1)->setData(column, columnData[column]);
}
++number;
}
}