flightgear/utils/fgqcanvas/fgqcanvasimageloader.cpp
2022-10-20 20:29:11 +08:00

146 lines
4.2 KiB
C++

//
// Copyright (C) 2017 James Turner zakalawe@mac.com
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#include "fgqcanvasimageloader.h"
#include <QDebug>
#include <QNetworkAccessManager>
#include <QStandardPaths>
#include <QDir>
#include <QFile>
#include <QFileInfo>
class TransferSignalHolder : public QObject
{
Q_OBJECT
public:
TransferSignalHolder(QObject* pr) : QObject(pr) { }
signals:
void trigger();
};
FGQCanvasImageLoader::FGQCanvasImageLoader(QNetworkAccessManager* dl, QObject* pr)
: QObject(pr)
, m_downloader(dl)
{
}
void FGQCanvasImageLoader::onDownloadFinished()
{
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QPixmap pm;
if (!pm.loadFromData(reply->readAll())) {
qWarning() << "image loading failed";
} else {
QByteArray imagePath = reply->property("image").toByteArray();
m_cache.insert(imagePath, pm);
// cache on disk also, so snapshots work
writeToDiskCache(imagePath, reply);
TransferSignalHolder* signalHolder = reply->findChild<TransferSignalHolder*>("holder");
if (signalHolder) {
qDebug() << "triggering image updates";
signalHolder->trigger();
}
}
m_transfers.removeOne(reply);
reply->deleteLater();
}
void FGQCanvasImageLoader::writeToDiskCache(QByteArray imagePath, QNetworkReply* reply)
{
QDir cacheDir(QStandardPaths::writableLocation(QStandardPaths::CacheLocation));
QString absPath = cacheDir.absoluteFilePath(imagePath);
QFileInfo finfo(imagePath);
cacheDir.mkpath(finfo.dir().path());
QFile f(absPath);
if (!f.open(QIODevice::WriteOnly)) {
qWarning() << "failed to open cache file" << f.fileName();
}
f.write(reply->readAll());
f.close();
}
void FGQCanvasImageLoader::setHost(QString hostName, int portNumber)
{
m_hostName = hostName;
m_port = portNumber;
}
QPixmap FGQCanvasImageLoader::getImage(const QByteArray &imagePath)
{
if (m_cache.contains(imagePath)) {
// cached, easy
return m_cache.value(imagePath);
}
QString diskCachePath = QStandardPaths::locate(QStandardPaths::CacheLocation, imagePath);
if (!diskCachePath.isEmpty()) {
QPixmap pix;
pix.load(diskCachePath);
m_cache.insert(imagePath, pix);
qDebug() << "loaded from on-disk cache:" << imagePath;
return pix;
}
QUrl url;
url.setScheme("http");
url.setHost(m_hostName);
url.setPort(m_port);
url.setPath("/aircraft-dir/" + imagePath);
Q_FOREACH (QNetworkReply* transfer, m_transfers) {
if (transfer->url() == url) {
return QPixmap(); // transfer already active
}
}
QNetworkReply* reply = m_downloader->get(QNetworkRequest(url));
reply->setProperty("image", imagePath);
connect(reply, &QNetworkReply::finished, this, &FGQCanvasImageLoader::onDownloadFinished);
m_transfers.append(reply);
return QPixmap();
}
void FGQCanvasImageLoader::connectToImageLoaded(const QByteArray &imagePath, QObject *receiver, const char *slot)
{
Q_FOREACH (QNetworkReply* transfer, m_transfers) {
if (transfer->property("image").toByteArray() == imagePath) {
QObject* signalHolder = transfer->findChild<QObject*>("holder");
if (!signalHolder) {
signalHolder = new TransferSignalHolder(transfer);
signalHolder->setObjectName("holder");
}
connect(signalHolder, SIGNAL(trigger()), receiver, slot);
return;
}
}
qWarning() << "no transfer active for" << imagePath;
}
#include "fgqcanvasimageloader.moc"