qtdeclarative/examples/quick/models/threadedfetchmore/threadedfetchmoremodel.cpp

104 lines
3.0 KiB
C++

// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "threadedfetchmoremodel.h"
ThreadedFetchMoreModel::ThreadedFetchMoreModel()
{
auto worker = new FetchWorker();
connect(&m_workerThread, &QThread::finished, worker, &QObject::deleteLater);
worker->moveToThread(&m_workerThread);
connect(this, &ThreadedFetchMoreModel::fetchDataBlock, worker, &FetchWorker::fetchDataBlock);
connect(worker, &FetchWorker::dataFetched, this, &ThreadedFetchMoreModel::dataReceived);
connect(worker, &FetchWorker::noMoreToFetch, this, &ThreadedFetchMoreModel::noMoreToFetch);
m_workerThread.start();
}
ThreadedFetchMoreModel::~ThreadedFetchMoreModel()
{
m_workerThread.requestInterruption();
m_workerThread.quit();
m_workerThread.wait();
}
int ThreadedFetchMoreModel::rowCount(const QModelIndex &parent) const
{
if (parent.isValid())
return 0;
return m_dataList.size();
}
QVariant ThreadedFetchMoreModel::data(const QModelIndex &index, int role) const
{
const auto item = m_dataList.at(index.row());
switch (static_cast<Role>(role)) {
case Role::Title:
return item.title;
case Role::Subtitle:
return item.subtitle;
case Role::Number:
return item.number;
case Role::LoadingElement:
return m_fetchOngoing && index.row() == (rowCount() - 1);
default:
break;
}
return QVariant{};
}
void ThreadedFetchMoreModel::fetchMore(const QModelIndex &parent)
{
Q_UNUSED(parent)
if (!m_fetchOngoing) {
addLoadingItem();
emit fetchDataBlock();
}
}
bool ThreadedFetchMoreModel::canFetchMore(const QModelIndex &parent) const
{
Q_UNUSED(parent)
if (m_fetchOngoing)
return false;
return m_hasUnfetchedItems;
}
void ThreadedFetchMoreModel::dataReceived(const QList<FetchWorker::DataBlock> &items)
{
removeLoadingItem();
beginInsertRows(QModelIndex{}, rowCount(), rowCount() + items.size() - 1);
m_dataList.append(items);
endInsertRows();
}
void ThreadedFetchMoreModel::noMoreToFetch()
{
m_hasUnfetchedItems = false;
}
void ThreadedFetchMoreModel::addLoadingItem()
{
beginInsertRows(QModelIndex{}, rowCount(), rowCount());
m_fetchOngoing = true;
m_dataList.append({{}, {}, 0});
endInsertRows();
}
void ThreadedFetchMoreModel::removeLoadingItem()
{
beginRemoveRows(QModelIndex{}, rowCount() - 1, rowCount() - 1);
m_fetchOngoing = false;
m_dataList.removeAt(rowCount() - 1);
endRemoveRows();
}
QHash<int, QByteArray> ThreadedFetchMoreModel::roleNames() const
{
static const QHash<int, QByteArray> names = {{static_cast<int>(Role::Title), "title"},
{static_cast<int>(Role::Subtitle), "subtitle"},
{static_cast<int>(Role::Number), "number"},
{static_cast<int>(Role::LoadingElement),
"isLoadingElement"}};
return names;
}