summaryrefslogtreecommitdiff
path: root/doc/src/snippets/modelview-subclasses/model.cpp
blob: b1f977bad8f7f299f9d26a4128499ae03260919e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 Nokia Corporation and its Subsidiary(-ies) 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."
** $QT_END_LICENSE$
**
****************************************************************************/

/*
  model.cpp

  A simple model that uses a QVector as its data source.
*/

#include "model.h"

/*!
    Returns the number of items in the string list as the number of rows
    in the model.
*/

int LinearModel::rowCount(const QModelIndex &parent) const
{
    Q_USING(parent);

    return values.count();
}

/*
    Returns an appropriate value for the requested data.
    If the view requests an invalid index, an invalid variant is returned.
    If a header is requested then we just return the column or row number,
    depending on the orientation of the header.
    Any valid index that corresponds to a string in the list causes that
    string to be returned.
*/

/*!
    Returns a model index for other component to use when referencing the
    item specified by the given row, column, and type. The parent index
    is ignored.
*/

QModelIndex LinearModel::index(int row, int column, const QModelIndex &parent) const
{
    if (parent == QModelIndex() && row >= 0 && row < rowCount()
        && column == 0)
        return createIndex(row, column, 0);
    else
        return QModelIndex();
}

QVariant LinearModel::data(const QModelIndex &index, int role) const
{
    Q_UNUSED(role);

    if (!index.isValid())
        return QVariant();

    return values.at(index.row());
}

/*!
    Returns Qt::ItemIsEditable so that all items in the vector can be edited.
*/

Qt::ItemFlags LinearModel::flags(const QModelIndex &index) const
{
    // all items in the model are editable
    return QAbstractListModel::flags(index) | Qt::ItemIsEditable;
}

/*!
    Changes an item in the string list, but only if the following conditions
    are met:

    * The index supplied is valid.
    * The index corresponds to an item to be shown in a view.
    * The role associated with editing text is specified.

    The dataChanged() signal is emitted if the item is changed.
*/

bool LinearModel::setData(const QModelIndex &index,
                          const QVariant &value, int role)
{
    if (!index.isValid() || role != Qt::EditRole)
        return false;
    values.replace(index.row(), value.toInt());
    emit dataChanged(index, index);
    return true;
}

/*!
    Inserts a number of rows into the model at the specified position.
*/

bool LinearModel::insertRows(int position, int rows, const QModelIndex &parent)
{
    beginInsertRows(parent, position, position + rows - 1);

    values.insert(position, rows, 0);

    endInsertRows();
    return true;
}

/*!
    Removes a number of rows from the model at the specified position.
*/

bool LinearModel::removeRows(int position, int rows, const QModelIndex &parent)
{
    beginRemoveRows(QModelIndex(), position, position+rows-1);

    values.remove(position, rows);

    endRemoveRows();
    return true;
}