camera.cpp Example File

/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "camera.h"
#include "ui_camera.h"
#include "videosettings.h"
#include "imagesettings.h"
#include <QMediaService>
#include <QMediaRecorder>
#include <QCameraViewfinder>
#include <QCameraInfo>
#include <QMediaMetaData>
#include <QMessageBox>
#include <QPalette>
#include <QtWidgets>
Q_DECLARE_METATYPE(QCameraInfo)
Camera::Camera(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::Camera)
{
    ui->setupUi(this);
    //Camera devices:
    QActionGroup *videoDevicesGroup = new QActionGroup(this);
    videoDevicesGroup->setExclusive(true);
    const QList<QCameraInfo> availableCameras = QCameraInfo::availableCameras();
    for (const QCameraInfo &cameraInfo : availableCameras) {
        QAction *videoDeviceAction = new QAction(cameraInfo.description(), videoDevicesGroup);
        videoDeviceAction->setCheckable(true);
        videoDeviceAction->setData(QVariant::fromValue(cameraInfo));
        if (cameraInfo == QCameraInfo::defaultCamera())
            videoDeviceAction->setChecked(true);
        ui->menuDevices->addAction(videoDeviceAction);
    }
    connect(videoDevicesGroup, &QActionGroup::triggered, this, &Camera::updateCameraDevice);
    connect(ui->captureWidget, &QTabWidget::currentChanged, this, &Camera::updateCaptureMode);
    setCamera(QCameraInfo::defaultCamera());
}
Camera::~Camera()
{
    delete mediaRecorder;
    delete imageCapture;
    delete camera;
}
void Camera::setCamera(const QCameraInfo &cameraInfo)
{
    delete imageCapture;
    delete mediaRecorder;
    delete camera;
    camera = new QCamera(cameraInfo);
    connect(camera, &QCamera::stateChanged, this, &Camera::updateCameraState);
    connect(camera, QOverload<QCamera::Error>::of(&QCamera::error), this, &Camera::displayCameraError);
    mediaRecorder = new QMediaRecorder(camera);
    connect(mediaRecorder, &QMediaRecorder::stateChanged, this, &Camera::updateRecorderState);
    imageCapture = new QCameraImageCapture(camera);
    connect(mediaRecorder, &QMediaRecorder::durationChanged, this, &Camera::updateRecordTime);
    connect(mediaRecorder, QOverload<QMediaRecorder::Error>::of(&QMediaRecorder::error),
            this, &Camera::displayRecorderError);
    mediaRecorder->setMetaData(QMediaMetaData::Title, QVariant(QLatin1String("Test Title")));
    connect(ui->exposureCompensation, &QAbstractSlider::valueChanged, this, &Camera::setExposureCompensation);
    camera->setViewfinder(ui->viewfinder);
    updateCameraState(camera->state());
    updateLockStatus(camera->lockStatus(), QCamera::UserRequest);
    updateRecorderState(mediaRecorder->state());
    connect(imageCapture, &QCameraImageCapture::readyForCaptureChanged, this, &Camera::readyForCapture);
    connect(imageCapture, &QCameraImageCapture::imageCaptured, this, &Camera::processCapturedImage);
    connect(imageCapture, &QCameraImageCapture::imageSaved, this, &Camera::imageSaved);
    connect(imageCapture, QOverload<int, QCameraImageCapture::Error, const QString &>::of(&QCameraImageCapture::error),
            this, &Camera::displayCaptureError);
    connect(camera, QOverload<QCamera::LockStatus, QCamera::LockChangeReason>::of(&QCamera::lockStatusChanged),
            this, &Camera::updateLockStatus);
    ui->captureWidget->setTabEnabled(0, (camera->isCaptureModeSupported(QCamera::CaptureStillImage)));
    ui->captureWidget->setTabEnabled(1, (camera->isCaptureModeSupported(QCamera::CaptureVideo)));
    updateCaptureMode();
    camera->start();
}
void Camera::keyPressEvent(QKeyEvent * event)
{
    if (event->isAutoRepeat())
        return;
    switch (event->key()) {
    case Qt::Key_CameraFocus:
        displayViewfinder();
        camera->searchAndLock();
        event->accept();
        break;
    case Qt::Key_Camera:
        if (camera->captureMode() == QCamera::CaptureStillImage) {
            takeImage();
        } else {
            if (mediaRecorder->state() == QMediaRecorder::RecordingState)
                stop();
            else
                record();
        }
        event->accept();
        break;
    default:
        QMainWindow::keyPressEvent(event);
    }
}
void Camera::keyReleaseEvent(QKeyEvent *event)
{
    if (event->isAutoRepeat())
        return;
    switch (event->key()) {
    case Qt::Key_CameraFocus:
        camera->unlock();
        break;
    default:
        QMainWindow::keyReleaseEvent(event);
    }
}
void Camera::updateRecordTime()
{
    QString str = QString("Recorded %1 sec").arg(mediaRecorder->duration()/1000);
    ui->statusbar->showMessage(str);
}
void Camera::processCapturedImage(int requestId, const QImage& img)
{
    Q_UNUSED(requestId);
    QImage scaledImage = img.scaled(ui->viewfinder->size(),
                                    Qt::KeepAspectRatio,
                                    Qt::SmoothTransformation);
    ui->lastImagePreviewLabel->setPixmap(QPixmap::fromImage(scaledImage));
    // Display captured image for 4 seconds.
    displayCapturedImage();
    QTimer::singleShot(4000, this, &Camera::displayViewfinder);
}
void Camera::configureCaptureSettings()
{
    switch (camera->captureMode()) {
    case QCamera::CaptureStillImage:
        configureImageSettings();
        break;
    case QCamera::CaptureVideo:
        configureVideoSettings();
        break;
    default:
        break;
    }
}
void Camera::configureVideoSettings()
{
    VideoSettings settingsDialog(mediaRecorder);
    settingsDialog.setWindowFlags(settingsDialog.windowFlags() & ~Qt::WindowContextHelpButtonHint);
    settingsDialog.setAudioSettings(audioSettings);
    settingsDialog.setVideoSettings(videoSettings);
    settingsDialog.setFormat(videoContainerFormat);
    if (settingsDialog.exec()) {
        audioSettings = settingsDialog.audioSettings();
        videoSettings = settingsDialog.videoSettings();
        videoContainerFormat = settingsDialog.format();
        mediaRecorder->setEncodingSettings(
                    audioSettings,
                    videoSettings,
                    videoContainerFormat);
    }
}
void Camera::configureImageSettings()
{
    ImageSettings settingsDialog(imageCapture);
    settingsDialog.setWindowFlags(settingsDialog.windowFlags() & ~Qt::WindowContextHelpButtonHint);
    settingsDialog.setImageSettings(imageSettings);
    if (settingsDialog.exec()) {
        imageSettings = settingsDialog.imageSettings();
        imageCapture->setEncodingSettings(imageSettings);
    }
}
void Camera::record()
{
    mediaRecorder->record();
    updateRecordTime();
}
void Camera::pause()
{
    mediaRecorder->pause();
}
void Camera::stop()
{
    mediaRecorder->stop();
}
void Camera::setMuted(bool muted)
{
    mediaRecorder->setMuted(muted);
}
void Camera::toggleLock()
{
    switch (camera->lockStatus()) {
    case QCamera::Searching:
    case QCamera::Locked:
        camera->unlock();
        break;
    case QCamera::Unlocked:
        camera->searchAndLock();
    }
}
void Camera::updateLockStatus(QCamera::LockStatus status, QCamera::LockChangeReason reason)
{
    QColor indicationColor = Qt::black;
    switch (status) {
    case QCamera::Searching:
        indicationColor = Qt::yellow;
        ui->statusbar->showMessage(tr("Focusing..."));
        ui->lockButton->setText(tr("Focusing..."));
        break;
    case QCamera::Locked:
        indicationColor = Qt::darkGreen;
        ui->lockButton->setText(tr("Unlock"));
        ui->statusbar->showMessage(tr("Focused"), 2000);
        break;
    case QCamera::Unlocked:
        indicationColor = reason == QCamera::LockFailed ? Qt::red : Qt::black;
        ui->lockButton->setText(tr("Focus"));
        if (reason == QCamera::LockFailed)
            ui->statusbar->showMessage(tr("Focus Failed"), 2000);
    }
    QPalette palette = ui->lockButton->palette();
    palette.setColor(QPalette::ButtonText, indicationColor);
    ui->lockButton->setPalette(palette);
}
void Camera::takeImage()
{
    isCapturingImage = true;
    imageCapture->capture();
}
void Camera::displayCaptureError(int id, const QCameraImageCapture::Error error, const QString &errorString)
{
    Q_UNUSED(id);
    Q_UNUSED(error);
    QMessageBox::warning(this, tr("Image Capture Error"), errorString);
    isCapturingImage = false;
}
void Camera::startCamera()
{
    camera->start();
}
void Camera::stopCamera()
{
    camera->stop();
}
void Camera::updateCaptureMode()
{
    int tabIndex = ui->captureWidget->currentIndex();
    QCamera::CaptureModes captureMode = tabIndex == 0 ? QCamera::CaptureStillImage : QCamera::CaptureVideo;
    if (camera->isCaptureModeSupported(captureMode))
        camera->setCaptureMode(captureMode);
}
void Camera::updateCameraState(QCamera::State state)
{
    switch (state) {
    case QCamera::ActiveState:
        ui->actionStartCamera->setEnabled(false);
        ui->actionStopCamera->setEnabled(true);
        ui->captureWidget->setEnabled(true);
        ui->actionSettings->setEnabled(true);
        break;
    case QCamera::UnloadedState:
    case QCamera::LoadedState:
        ui->actionStartCamera->setEnabled(true);
        ui->actionStopCamera->setEnabled(false);
        ui->captureWidget->setEnabled(false);
        ui->actionSettings->setEnabled(false);
    }
}
void Camera::updateRecorderState(QMediaRecorder::State state)
{
    switch (state) {
    case QMediaRecorder::StoppedState:
        ui->recordButton->setEnabled(true);
        ui->pauseButton->setEnabled(true);
        ui->stopButton->setEnabled(false);
        break;
    case QMediaRecorder::PausedState:
        ui->recordButton->setEnabled(true);
        ui->pauseButton->setEnabled(false);
        ui->stopButton->setEnabled(true);
        break;
    case QMediaRecorder::RecordingState:
        ui->recordButton->setEnabled(false);
        ui->pauseButton->setEnabled(true);
        ui->stopButton->setEnabled(true);
        break;
    }
}
void Camera::setExposureCompensation(int index)
{
    camera->exposure()->setExposureCompensation(index*0.5);
}
void Camera::displayRecorderError()
{
    QMessageBox::warning(this, tr("Capture Error"), mediaRecorder->errorString());
}
void Camera::displayCameraError()
{
    QMessageBox::warning(this, tr("Camera Error"), camera->errorString());
}
void Camera::updateCameraDevice(QAction *action)
{
    setCamera(qvariant_cast<QCameraInfo>(action->data()));
}
void Camera::displayViewfinder()
{
    ui->stackedWidget->setCurrentIndex(0);
}
void Camera::displayCapturedImage()
{
    ui->stackedWidget->setCurrentIndex(1);
}
void Camera::readyForCapture(bool ready)
{
    ui->takeImageButton->setEnabled(ready);
}
void Camera::imageSaved(int id, const QString &fileName)
{
    Q_UNUSED(id);
    ui->statusbar->showMessage(tr("Captured \"%1\"").arg(QDir::toNativeSeparators(fileName)));
    isCapturingImage = false;
    if (applicationExiting)
        close();
}
void Camera::closeEvent(QCloseEvent *event)
{
    if (isCapturingImage) {
        setEnabled(false);
        applicationExiting = true;
        event->ignore();
    } else {
        event->accept();
    }
}