Unity 8
croppedimagesizerasyncworker.cpp
1 /*
2  * Copyright (C) 2014 Canonical, Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 3.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program. If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include "croppedimagesizerasyncworker.h"
18 
19 #include "croppedimagesizer.h"
20 
21 #include <QNetworkReply>
22 #include <QtConcurrentRun>
23 
24 CroppedImageSizerAsyncWorker::CroppedImageSizerAsyncWorker(CroppedImageSizer *sizer, QNetworkReply *reply)
25  : m_sizer(sizer),
26  m_reply(reply),
27  m_ignoreAbort(false)
28 {
29  connect(m_reply, &QNetworkReply::finished, this, &CroppedImageSizerAsyncWorker::requestFinished);
30 }
31 
32 void CroppedImageSizerAsyncWorker::abort()
33 {
34  // This runs on main thread
35  QMutexLocker locker(&m_mutex);
36  m_sizer = nullptr;
37  // If we already started the future run we can't abort the reply
38  // since we don't know at which stage the future is, just let it finish
39  if (!m_ignoreAbort) {
40  QMetaObject::invokeMethod(m_reply, "abort", Qt::QueuedConnection);
41  }
42 }
43 
44 void CroppedImageSizerAsyncWorker::requestFinished()
45 {
46  // This runs on main thread
47  QMutexLocker locker(&m_mutex);
48  if (m_sizer) {
49  m_ignoreAbort = true;
50  QtConcurrent::run(processRequestFinished, this);
51  } else {
52  // We were aborted delete ourselves
53  m_reply->deleteLater();
54  deleteLater();
55  }
56 }
57 
58 void CroppedImageSizerAsyncWorker::processRequestFinished(CroppedImageSizerAsyncWorker *worker)
59 {
60  // This runs on non main thread
61  // m_reply has finished at this point and is protected against change by m_ignoreAbort
62  QImageReader reader(worker->m_reply);
63  const QSize imageSize = reader.size();
64 
65  worker->m_mutex.lock();
66  if (worker->m_sizer) {
67  QMetaObject::invokeMethod(worker->m_sizer, "setImageSize", Qt::QueuedConnection, Q_ARG(QSize, imageSize));
68  }
69  worker->m_mutex.unlock();
70 
71  // All work is done, delete ourselves
72  worker->m_reply->deleteLater();
73  worker->deleteLater();
74 }