Kaidan/src/QrCodeScannerFilter.h

127 lines
3.8 KiB
C++

/*
* Kaidan - A user-friendly XMPP client for every device!
*
* Copyright (C) 2016-2021 Kaidan developers and contributors
* (see the LICENSE file for a full list of copyright authors)
*
* Kaidan 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 3 of the License, or
* (at your option) any later version.
*
* In addition, as a special exception, the author of Kaidan gives
* permission to link the code of its release with the OpenSSL
* project's "OpenSSL" library (or with modified versions of it that
* use the same license as the "OpenSSL" library), and distribute the
* linked executables. You must obey the GNU General Public License in
* all respects for all of the code used other than "OpenSSL". If you
* modify this file, you may extend this exception to your version of
* the file, but you are not obligated to do so. If you do not wish to
* do so, delete this exception statement from your version.
*
* Kaidan 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 Kaidan. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <QObject>
#include <QAbstractVideoFilter>
#include <QFuture>
#include "QrCodeDecoder.h"
#include "QrCodeVideoFrame.h"
/**
* video filter to be registered in C++, instantiated and attached in QML
*/
class QrCodeScannerFilter : public QAbstractVideoFilter
{
friend class QrCodeScannerFilterRunnable;
Q_OBJECT
public:
/**
* Instantiates a QR code scanner filter.
*
* @param parent parent object
*/
explicit QrCodeScannerFilter(QObject *parent = nullptr);
~QrCodeScannerFilter() override;
/**
* @return decoder for decoding a video frame
*/
QrCodeDecoder *decoder();
QVideoFilterRunnable *createFilterRunnable() override;
/**
* Sets the video frame format of the QML Camera object to our default format
*
* @param qmlCamera Camera object from QML
*/
Q_INVOKABLE void setCameraDefaultVideoFormat(QObject *qmlCamera);
signals:
/**
* Emitted when the scanning of an image did not succeed, i.e. no valid QR code was found.
*/
void scanningFailed();
/**
* Emitted when the scanning of an image succeeded, i.e. a valid QR code was found and decoded.
*
* @param result decoded content of the QR code
*/
void scanningSucceeded(const QString& result);
/**
* Emitted when a video frame with an unsupported format is received.
*
* @param format format of the video frame which is not supported
*/
void unsupportedFormatReceived(const QString& format);
private:
QrCodeDecoder *m_decoder;
/**
* frame of the video which may contain a QR code
*/
QrCodeVideoFrame m_frame;
QFuture<void> m_processThread;
};
/**
* runnable which is created everytime the filter gets a new frame
*/
class QrCodeScannerFilterRunnable : public QObject, public QVideoFilterRunnable
{
Q_OBJECT
public:
explicit QrCodeScannerFilterRunnable(QrCodeScannerFilter *m_filter);
/**
* Runs the decoding in a new thread whenever a new frame is taken by the camera.
*/
QVideoFrame run(QVideoFrame *input, const QVideoSurfaceFormat &surfaceFormat, RunFlags flags) override;
/**
* Converts a given frame, which may contain a QR code, to an image and then tries to decode it.
*
* @param videoFrame frame to be converted and which may contain a QR code to be decoded
* @param filter filter of the current execution
*/
void processVideoFrameProbed(QrCodeVideoFrame videoFrame, QrCodeScannerFilter *filter);
private:
QrCodeScannerFilter *m_filter;
};