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50
51#include "filelistmodel.h"
52
53#include <QGuiApplication>
54#include <QDir>
55#include <QPalette>
56
57FileListModel::FileListModel(QObject *parent)
58 : QAbstractListModel(parent), fileCount(0)
59{}
60
61//![4]
62int FileListModel::rowCount(const QModelIndex &parent) const
63{
64 return parent.isValid() ? 0 : fileCount;
65}
66
67QVariant FileListModel::data(const QModelIndex &index, int role) const
68{
69 if (!index.isValid())
70 return QVariant();
71
72 if (index.row() >= fileList.size() || index.row() < 0)
73 return QVariant();
74
75 if (role == Qt::DisplayRole) {
76 return fileList.at(i: index.row());
77 } else if (role == Qt::BackgroundRole) {
78 int batch = (index.row() / 100) % 2;
79 if (batch == 0)
80 return qApp->palette().base();
81 else
82 return qApp->palette().alternateBase();
83 }
84 return QVariant();
85}
86//![4]
87
88//![1]
89bool FileListModel::canFetchMore(const QModelIndex &parent) const
90{
91 if (parent.isValid())
92 return false;
93 return (fileCount < fileList.size());
94}
95//![1]
96
97//![2]
98void FileListModel::fetchMore(const QModelIndex &parent)
99{
100 if (parent.isValid())
101 return;
102 int remainder = fileList.size() - fileCount;
103 int itemsToFetch = qMin(a: 100, b: remainder);
104
105 if (itemsToFetch <= 0)
106 return;
107
108 beginInsertRows(parent: QModelIndex(), first: fileCount, last: fileCount + itemsToFetch - 1);
109
110 fileCount += itemsToFetch;
111
112 endInsertRows();
113
114 emit numberPopulated(number: itemsToFetch);
115}
116//![2]
117
118//![0]
119void FileListModel::setDirPath(const QString &path)
120{
121 QDir dir(path);
122
123 beginResetModel();
124 fileList = dir.entryList();
125 fileCount = 0;
126 endResetModel();
127}
128//![0]
129
130

source code of qtbase/examples/widgets/itemviews/fetchmore/filelistmodel.cpp