ImageViewer.cpp

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// This file is part of DynExp.
 
#include "stdafx.h"
#include "moc_ImageViewer.cpp"
#include "ui_ImageViewer.h"
#include "ImageViewer.h"
 
namespace DynExpModule::ImageViewer
{
    ImageViewerWidget::ImageViewerWidget(ImageViewer& Owner, QModuleWidget* parent)
        : QModuleWidget(Owner, parent),
        ui(std::make_unique<Ui::ImageViewer>()),
        HistogramContextMenu(new QMenu(this)), HistogramLinLogActionGroup(new QActionGroup(this)),
        HistogramBarSetI(nullptr), HistogramBarSetR(nullptr), HistogramBarSetG(nullptr), HistogramBarSetB(nullptr),
        HistogramBarSeries(new QBarSeries(this)), HistogramChart(nullptr), HistogramXAxis(new QValueAxis(this)), HistogramYAxis(new QValueAxis(this)),
        GraphicsView(nullptr), GraphicsPixmapItem(nullptr), GraphicsScene(new QGraphicsScene(this))
    {
        ui->setupUi(this);
 
        ui->action_Zoom_fit->setChecked(true);
 
        HistogramLinAction = HistogramLinLogActionGroup->addAction("&Linear");
        HistogramLinAction->setCheckable(true);
        HistogramLinAction->setChecked(true);
        HistogramLogAction = HistogramLinLogActionGroup->addAction("Lo&garithmic");
        HistogramLogAction->setCheckable(true);
        HistogramContextMenu->addActions(HistogramLinLogActionGroup->actions());
        HistogramContextMenu->addSeparator();
        HistogramBWAction = HistogramContextMenu->addAction("Show &intensity");
        HistogramBWAction->setCheckable(true);
        HistogramBWAction->setChecked(true);
        HistogramColorAction = HistogramContextMenu->addAction("Show &colors");
        HistogramColorAction->setCheckable(true);
 
        HistogramChart = new QChart();
        ui->Histogram->setChart(HistogramChart);                // Takes ownership of HistogramChart.
        ui->Histogram->setRenderHint(QPainter::Antialiasing);
        HistogramChart->addSeries(HistogramBarSeries);
        HistogramChart->setTheme(DynExpUI::DefaultQChartTheme);
        HistogramChart->legend()->setVisible(false);
        HistogramXAxis->setTitleText("pixel value");
        HistogramXAxis->setLabelFormat("%d");
        HistogramXAxis->setRange(0, 255);
        HistogramXAxis->setTickCount(255 / 85 + 1);
        HistogramChart->addAxis(HistogramXAxis, Qt::AlignBottom);
        HistogramYAxis->setTitleText("counts");
        HistogramYAxis->setLabelFormat("%.0e");
        HistogramYAxis->setRange(0, 1);
        HistogramChart->addAxis(HistogramYAxis, Qt::AlignLeft);
 
        GraphicsView = new Util::MarkerGraphicsView(ui->MainSplitter);
        GraphicsView->setObjectName(QString::fromUtf8("Image"));
        QSizePolicy ImageSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
        ImageSizePolicy.setHorizontalStretch(1);
        ImageSizePolicy.setVerticalStretch(0);
        ImageSizePolicy.setHeightForWidth(GraphicsView->sizePolicy().hasHeightForWidth());
        GraphicsView->setSizePolicy(ImageSizePolicy);
        GraphicsView->setMinimumSize(QSize(400, 300));
        GraphicsView->viewport()->setProperty("cursor", QVariant(QCursor(Qt::CrossCursor)));
        GraphicsView->setSizeAdjustPolicy(QAbstractScrollArea::AdjustToContentsOnFirstShow);
 
        GraphicsPixmapItem = GraphicsScene->addPixmap(Pixmap);
        GraphicsView->setScene(GraphicsScene);
        GraphicsView->setAlignment(Qt::AlignLeft | Qt::AlignTop);
        GraphicsView->viewport()->installEventFilter(this);
        GraphicsView->viewport()->setMouseTracking(true);
    }
 
    void ImageViewerWidget::SetImage(const QImage& NewImage) noexcept
    {
        Pixmap = QPixmap::fromImage(NewImage);  // deep copy
        Pixmap.detach();                        // just to be sure...
    }
 
    void ImageViewerWidget::SetImageViewEnabled(bool Enable)
    {
        if (GraphicsView)
            GraphicsView->setEnabled(Enable);
    }
 
    void ImageViewerWidget::SetIntensityHistogram(Util::ImageHistogramType&& NewIntensityHistogram) noexcept
    {
        IntensityHistogram = std::move(NewIntensityHistogram);
    }
 
    void ImageViewerWidget::SetRGBHistogram(Util::ImageRGBHistogramType&& NewRGBHistogram) noexcept
    {
        RGBHistogram = std::move(NewRGBHistogram);
    }
 
    auto ImageViewerWidget::GetComputeHistogram() const noexcept
    {
        using CHT = DynExpInstr::CameraData::ComputeHistogramType;
 
        if (!ui->ExposureTimeGroupBox->isVisible() || ui->ExposureTimeGroupBox->visibleRegion().isEmpty())
            return CHT::NoHistogram;
 
        if (HistogramBWAction->isChecked())
            return HistogramColorAction->isChecked() ? CHT::IntensityAndRGBHistogram : CHT::IntensityHistogram;
        if (HistogramColorAction->isChecked())
            return CHT::RGBHistogram;
 
        return CHT::NoHistogram;
    }
 
    void ImageViewerWidget::UpdateScene()
    {
        if (GraphicsView->isVisible() && !GraphicsView->visibleRegion().isEmpty() && !Pixmap.isNull())
        {
            GraphicsPixmapItem->setPixmap(Pixmap);
            GraphicsScene->update();
 
            OnZoomFitClicked(ui->action_Zoom_fit->isChecked());
        }
 
        if (ui->ExposureTimeGroupBox->isVisible() && !ui->ExposureTimeGroupBox->visibleRegion().isEmpty())
            UpdateHistogram();
 
        ui->ImageGeometry->setText(QString::number(Pixmap.width()) + " x " + QString::number(Pixmap.height()));
    }
 
    bool ImageViewerWidget::eventFilter(QObject* obj, QEvent* event)
    {
        if (GraphicsView->viewport())
            if (event->type() == QEvent::MouseMove)
            {
                OnImageMouseMove(static_cast<QMouseEvent*>(event));
 
                return true;
            }
            
        return QObject::eventFilter(obj, event);
    }
 
    void ImageViewerWidget::resizeEvent(QResizeEvent* event)
    {
        OnZoomFitClicked(ui->action_Zoom_fit->isChecked());
    }
 
    void ImageViewerWidget::UpdateHistogram()
    {
        using CHT = DynExpInstr::CameraData::ComputeHistogramType;
 
        auto ComputeHistogram = GetComputeHistogram();
        if (ComputeHistogram == CHT::NoHistogram || IntensityHistogram.size() >= std::numeric_limits<int>::max())
            return;
 
        // Remove all existing data series.
        if (HistogramBarSetI)
            if (HistogramBarSeries->remove(HistogramBarSetI))
                HistogramBarSetI = nullptr;
        if (HistogramBarSetR)
            if (HistogramBarSeries->remove(HistogramBarSetR))
                HistogramBarSetR = nullptr;
        if (HistogramBarSetG)
            if (HistogramBarSeries->remove(HistogramBarSetG))
                HistogramBarSetG = nullptr;
        if (HistogramBarSetB)
            if (HistogramBarSeries->remove(HistogramBarSetB))
                HistogramBarSetB = nullptr;
 
        // Some removals failed. Do not continue in order to avoid memory leaks.
        if (HistogramBarSetI || HistogramBarSetR || HistogramBarSetG || HistogramBarSetB)
            return;
 
        HistogramChart->removeSeries(HistogramBarSeries);
 
        // Create new data series.
        if (ComputeHistogram == CHT::IntensityHistogram ||
            ComputeHistogram == CHT::IntensityAndRGBHistogram)
        {
            HistogramBarSetI = new QBarSet("I", this);
            HistogramBarSetI->setColor(Qt::white);
            HistogramBarSetI->setBorderColor(Qt::white);
        }
        
        if (ComputeHistogram == CHT::RGBHistogram ||
            ComputeHistogram == CHT::IntensityAndRGBHistogram)
        {
            HistogramBarSetR = new QBarSet("R", this);
            HistogramBarSetG = new QBarSet("G", this);
            HistogramBarSetB = new QBarSet("B", this);
            HistogramBarSetR->setColor(Qt::red);
            HistogramBarSetR->setBorderColor(Qt::red);
            HistogramBarSetG->setColor(Qt::green);
            HistogramBarSetG->setBorderColor(Qt::green);
            HistogramBarSetB->setColor(Qt::blue);
            HistogramBarSetB->setBorderColor(Qt::blue);
        }
 
        bool LogPlot = HistogramLogAction->isChecked();
        qreal MaxValue = 1;
        for (int i = 0; i < static_cast<int>(IntensityHistogram.size()); ++i)
        {
            if (HistogramBarSetI)
            {
                // Add .1 in log case to avoid NaN if value is 0.
                *HistogramBarSetI << (LogPlot ? std::log10(IntensityHistogram[i] + .1) : IntensityHistogram[i]);
 
                MaxValue = std::max(MaxValue, HistogramBarSetI->at(i));
            }
 
            if (HistogramBarSetR && HistogramBarSetG && HistogramBarSetB)
            {
                // Add .1 in log case to avoid NaN if value is 0.
                *HistogramBarSetR << (LogPlot ? std::log10(std::get<0>(RGBHistogram)[i] + .1) : std::get<0>(RGBHistogram)[i]);
                *HistogramBarSetG << (LogPlot ? std::log10(std::get<1>(RGBHistogram)[i] + .1) : std::get<1>(RGBHistogram)[i]);
                *HistogramBarSetB << (LogPlot ? std::log10(std::get<2>(RGBHistogram)[i] + .1) : std::get<2>(RGBHistogram)[i]);
 
                MaxValue = std::max({ MaxValue, HistogramBarSetR->at(i), HistogramBarSetG->at(i), HistogramBarSetB->at(i) });
            }
        }
 
        if (HistogramBarSetI)
            HistogramBarSeries->append(HistogramBarSetI);
        if (HistogramBarSetR && HistogramBarSetG && HistogramBarSetB)
            HistogramBarSeries->append({ HistogramBarSetR, HistogramBarSetG, HistogramBarSetB });
        
        HistogramChart->addSeries(HistogramBarSeries);
        HistogramYAxis->setMax(MaxValue);
        HistogramBarSeries->attachAxis(HistogramXAxis);
        HistogramBarSeries->attachAxis(HistogramYAxis);
    }
 
    void ImageViewerWidget::OnHistogramContextMenuRequested(const QPoint& Position)
    {
        HistogramContextMenu->exec(ui->Histogram->mapToGlobal(Position));
    }
 
    void ImageViewerWidget::OnSaveImageClicked()
    {
        auto Filename = Util::PromptSaveFilePathModule(this, "Save image", ".png", "Portable Network Graphics image (*.png)");
        if (Filename.isEmpty())
            return;
 
        SaveImageFilename = Filename;
    }
 
    void ImageViewerWidget::OnZoomResetClicked()
    {
        ui->action_Zoom_fit->setChecked(false);
        GraphicsView->ZoomReset();
    }
 
    void ImageViewerWidget::OnZoomInClicked()
    {
        ui->action_Zoom_fit->setChecked(false);
        GraphicsView->ZoomIn();
    }
 
    void ImageViewerWidget::OnZoomOutClicked()
    {
        ui->action_Zoom_fit->setChecked(false);
        GraphicsView->ZoomOut();
    }
 
    void ImageViewerWidget::OnZoomFitClicked(bool Checked)
    {
        if (Checked)
            GraphicsView->fitInView(GraphicsPixmapItem, Qt::AspectRatioMode::KeepAspectRatio);
    }
 
    void ImageViewerWidget::OnImageMouseMove(QMouseEvent* Event)
    {
        auto LocalPoint = GraphicsView->mapFromGlobal(Event->globalPosition().toPoint());
 
        if (!GraphicsView->items(LocalPoint).empty())
        {
            auto Point = GraphicsView->mapToScene(LocalPoint).toPoint();
 
            ui->CursorPosition->setText("X:" + QString::number(Point.x()) + ", Y:" + QString::number(Point.y()));
        }
    }
 
    void ImageViewerData::ResetImpl(dispatch_tag<QModuleDataBase>)
    {
        Init();
    }
 
    double ImageViewerData::CalcBrennerGradientFromImage() const
    {
        if (CurrentImage.isNull())
            return std::numeric_limits<double>::quiet_NaN();
 
        const auto GrayImage = CurrentImage.convertToFormat(QImage::Format::Format_Grayscale8);
        auto RawImage = GrayImage.constBits();
        
        double BrennerGradient = .0;
        for (int y = 0; y < GrayImage.height(); ++y)
        {
            for (int x = 0; x < GrayImage.width() - 2; ++x)
            {
                BrennerGradient += std::pow((static_cast<double>(*RawImage) - static_cast<double>(*(RawImage + 2))) / 255.0, 2);
 
                ++RawImage;
            }
 
            RawImage += 2;
        }
 
        // Multiply by 1000 for convenience since we are normally dealing with very small gradients.
        return BrennerGradient / GrayImage.width() / GrayImage.height() * 1e3;
    }
 
    void ImageViewerData::Init()
    {
        UIInitialized = false;
 
        CameraModes.clear();
        CapturingState = DynExpInstr::CameraData::CapturingStateType::Stopped;
        TimeType MinExposureTime = TimeType();
        TimeType MaxExposureTime = TimeType();
        TimeType CurrentExposureTime = TimeType();
        CurrentFPS = 0.f;
        ComputeHistogram = DynExpInstr::CameraData::ComputeHistogramType::NoHistogram;
        AutoSaveFilename.clear();
 
        CurrentImage = QImage();
        HasImageChanged = false;
        ImageCapturingPaused = false;
        CaptureAfterPause = false;
 
        IntensityHistogram = {};
        RGBHistogram = {};
    }
 
    ImageViewer::ImageViewer(const std::thread::id OwnerThreadID, DynExp::ParamsBasePtrType&& Params)
        : QModuleBase(OwnerThreadID, std::move(Params)),
        StateMachine(ReadyState,
            AutofocusInitState, AutofocusGotoSampleState, AutofocusWaitBeforeCaptureState,
            AutofocusWaitForImageState, AutofocusStepState, AutofocusFinishedState),
        PauseUpdatingUI(std::make_shared<std::atomic<bool>>(false))
    {
    }
 
    ImageViewer::~ImageViewer()
    {
    }
 
    void ImageViewer::OnSaveImage(DynExp::ModuleInstance* Instance, QString Filename) const
    {
        QImage Image;
        {
            auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
            Image = ModuleData->CurrentImage.copy();
        } // ModuleData unlocked here for heavy save operation.
 
        if (!Image.save(Filename))
            Util::EventLog().Log("[ImageViewer] Saving image as \"" + Filename.toStdString() + "\" to file failed.", Util::ErrorType::Error);
    }
 
    Util::DynExpErrorCodes::DynExpErrorCodes ImageViewer::ModuleMainLoop(DynExp::ModuleInstance& Instance)
    {
        try
        {
            StateMachine.Invoke(*this, Instance);
 
            NumFailedUpdateAttempts = 0;
        }
        catch (const Util::TimeoutException& e)
        {
            if (NumFailedUpdateAttempts++ >= 3)
                Instance.GetOwner().SetWarning(e);
        }
 
        return Util::DynExpErrorCodes::NoError;
    }
 
    void ImageViewer::ResetImpl(dispatch_tag<QModuleBase>)
    {
        StateMachine.SetCurrentState(StateType::Ready);
 
        AutofocusParams = {};
        AutofocusResults = {};
        AutofocusIsPerformingFineSweep = false;
        AutofocusSamples.clear();
        AutofocusCurrentSample = AutofocusSamples.end();
 
        *PauseUpdatingUI = false;
        NumFailedUpdateAttempts = 0;
    }
 
    std::unique_ptr<DynExp::QModuleWidget> ImageViewer::MakeUIWidget()
    {
        auto Widget = std::make_unique<ImageViewerWidget>(*this);
 
        Connect(Widget->ui->CBCameraMode, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &ImageViewer::OnCameraModeChanged);
        Connect(Widget->ui->ExposureTime, QOverload<int>::of(&QSpinBox::valueChanged), this, &ImageViewer::OnExposureTimeChanged);
        Connect(Widget->ui->action_Capture_Frame, &QAction::triggered, this, &ImageViewer::OnCaptureSingle);
        Connect(Widget->ui->action_Capture_continuously, &QAction::triggered, this, &ImageViewer::OnCaptureContinuously);
        Connect(Widget->ui->action_Autofocus, &QAction::triggered, this, &ImageViewer::OnAutofocusClicked);
 
        return Widget;
    }
 
    void ImageViewer::UpdateUIChild(const ModuleBase::ModuleDataGetterType& ModuleDataGetter)
    {
        using CHT = DynExpInstr::CameraData::ComputeHistogramType;
 
        if (*PauseUpdatingUI)
            return;
 
        auto Widget = GetWidget<ImageViewerWidget>();
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(ModuleDataGetter());
 
        // ModuleData is locked now. This syncs writing CameraData's settings with OnAutofocus().
        const bool Ready = IsReadyState();
        const bool Autofocusing = IsAutofocusingState();
 
        if (!ModuleData->UIInitialized)
        {
            Widget->ui->action_Autofocus->setEnabled(ModuleData->Focus.valid());
 
            if (ModuleData->CameraModes.empty())
                Widget->ui->CameraModeGroupBox->setVisible(false);
            else
            {
                for (const auto& Mode : ModuleData->CameraModes)
                {
                    Widget->ui->CBCameraMode->insertItem(Widget->ui->CBCameraMode->count(), QString::fromStdString(Mode));
                    Widget->ui->CBCameraMode->setItemData(Widget->ui->CBCameraMode->count() - 1, QString::fromStdString(Mode), Qt::ToolTipRole);
                }
 
                // Triggers QComboBox::currentIndexChanged().
                Widget->ui->CBCameraMode->setCurrentIndex(0);
            }
 
            ModuleData->UIInitialized = true;
        }
 
        Widget->ui->action_Save_Image->setEnabled(Ready);
        Widget->ui->action_Capture_Frame->setEnabled(Ready);
        Widget->ui->action_Capture_continuously->setEnabled(Ready);
        Widget->ui->CameraModeGroupBox->setEnabled(Ready);
        Widget->ui->ImageModifiersGroupBox->setEnabled(Ready);
        Widget->ui->Histogram->setEnabled(Ready);
        Widget->SetImageViewEnabled(Ready);
 
        Widget->ui->ExposureTimeGroupBox->setEnabled(Ready && ModuleData->Camera->CanSetExposureTime());
        Widget->ui->ExposureTimeMinValue->setText("min. " + QString::number(ModuleData->MinExposureTime.count()) + " ms");
        Widget->ui->ExposureTimeMaxValue->setText("max. " + QString::number(ModuleData->MaxExposureTime.count()) + " ms");
        Widget->ui->ExposureTime->setMinimum(ModuleData->MinExposureTime.count());
        Widget->ui->ExposureTime->setMaximum(ModuleData->MaxExposureTime.count());
 
        if (!Widget->ui->ExposureTime->hasFocus())
        {
            const QSignalBlocker Blocker(Widget->ui->ExposureTime);
            Widget->ui->ExposureTime->setValue(Util::NumToT<int>(ModuleData->CurrentExposureTime.count()));
        }
 
        if (!Autofocusing && !ModuleData->ImageCapturingPaused)
        {
            DynExpInstr::CameraData::ImageTransformationType ImageTransformation;
            if (Widget->ui->ImageModifiersGroupBox->isChecked())
            {
                // Values from controls ranging from -10 to 10.
                ImageTransformation.BrightnessFactor = Widget->ui->ImageModifiersBrightness->value() / 10.f;
                ImageTransformation.ContrastFactor = std::pow(10, Widget->ui->ImageModifiersContrast->value() / 10.f);
                ImageTransformation.IsEnabled = true;
            }
 
            {
                auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
                CameraData->SetImageTransformation(ImageTransformation);
            } // CameraData unlocked here.
        }
 
        ModuleData->ComputeHistogram = Widget->GetComputeHistogram();
 
        if (!ModuleData->CurrentImage.isNull() && ModuleData->HasImageChanged)
        {
            // SetImage creates a deep copy of CurrentImage.
            Widget->SetImage(ModuleData->CurrentImage);
            ModuleData->HasImageChanged = false;
 
            if (ModuleData->ComputeHistogram == CHT::IntensityHistogram ||
                ModuleData->ComputeHistogram == CHT::IntensityAndRGBHistogram)
                Widget->SetIntensityHistogram(std::move(ModuleData->IntensityHistogram));
            if (ModuleData->ComputeHistogram == CHT::RGBHistogram ||
                ModuleData->ComputeHistogram == CHT::IntensityAndRGBHistogram)
                Widget->SetRGBHistogram(std::move(ModuleData->RGBHistogram));
 
            Widget->UpdateScene();
        }
 
        if (Ready && !Widget->GetSaveImageFilename().isEmpty())
        {
            ModuleData->Camera->StopCapturing();
            MakeAndEnqueueEvent(this, &ImageViewer::OnSaveImage, Widget->GetSaveImageFilename());
 
            Widget->ResetSaveImageFilename();
        }
 
        Widget->ui->action_Capture_continuously->setChecked(ModuleData->CapturingState == DynExpInstr::CameraData::CapturingStateType::CapturingContinuously);
        Widget->ui->action_Autofocus->setChecked(Autofocusing);
 
        if (Autofocusing)
            Widget->ui->CurrentFPS->setText("Autofocusing...");
        else if (ModuleData->CapturingState == DynExpInstr::CameraData::CapturingStateType::CapturingSingle)
            Widget->ui->CurrentFPS->setText("Capturing frame...");
        else if (ModuleData->CapturingState == DynExpInstr::CameraData::CapturingStateType::CapturingContinuously)
        {
#ifdef DYNEXP_DEBUG
            Widget->ui->CurrentFPS->setText("Capturing... (FPS: " + QString::number(ModuleData->CurrentFPS, 'f', 1) +
                + ", Brenner gradient: " + QString::number(ModuleData->CalcBrennerGradientFromImage(), 'f', 3) + ")");
#else
            Widget->ui->CurrentFPS->setText("Capturing... (FPS: " + QString::number(ModuleData->CurrentFPS, 'f', 1) + ")");
#endif // DYNEXP_DEBUG
        }
        else
            Widget->ui->CurrentFPS->setText("Stopped");
    }
 
    bool ImageViewer::IsReadyState() const
    {
        const auto CurrentState = StateMachine.GetCurrentState()->GetState();
 
        return CurrentState == StateType::Ready;
    }
 
    bool ImageViewer::IsAutofocusingState() const
    {
        const auto CurrentState = StateMachine.GetCurrentState()->GetState();
 
        return CurrentState == StateType::AutofocusInit ||
            CurrentState == StateType::AutofocusGotoSample ||
            CurrentState == StateType::AutofocusWaitBeforeCapture ||
            CurrentState == StateType::AutofocusWaitForImage ||
            CurrentState == StateType::AutofocusStep ||
            CurrentState == StateType::AutofocusFinished;
    }
 
    void ImageViewer::FinishAutofocus(Util::SynchronizedPointer<ModuleDataType>& ModuleData, const FinishedAutofocusEvent& Event) const
    {
        if (ModuleData->Communicator.valid())
            ModuleData->Communicator->PostEvent(*this, Event);
 
        if (ModuleData->CaptureAfterPause)
            ModuleData->Camera->StartCapturing();
    }
 
    void ImageViewer::OnInit(DynExp::ModuleInstance* Instance) const
    {
        SetFilenameEvent::Register(*this, &ImageViewer::OnSetFilename);
        TriggerEvent::Register(*this, &ImageViewer::OnTrigger);
        StopEvent::Register(*this, &ImageViewer::OnStop);
        PauseImageCapturingEvent::Register(*this, &ImageViewer::OnPauseImageCapturing);
        ResumeImageCapturingEvent::Register(*this, &ImageViewer::OnResumeImageCapturing);
        AutofocusEvent::Register(*this, &ImageViewer::OnAutofocus);
 
        auto ModuleParams = DynExp::dynamic_Params_cast<ImageViewer>(Instance->ParamsGetter());
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        Instance->LockObject(ModuleParams->Camera, ModuleData->Camera);
        if (ModuleParams->Focus.ContainsID())
        {
            Instance->LockObject(ModuleParams->Focus, ModuleData->Focus);
 
            AutofocusParams.MinVoltage = ModuleData->Focus->GetUserMinValue();
            AutofocusParams.MaxVoltage = ModuleData->Focus->GetUserMaxValue();
        }
        if (ModuleParams->Communicator.ContainsID())
            Instance->LockObject(ModuleParams->Communicator, ModuleData->Communicator);
 
        auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
        ModuleData->CameraModes = CameraData->GetCameraModes();
    }
 
    void ImageViewer::OnExit(DynExp::ModuleInstance* Instance) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        Instance->UnlockObject(ModuleData->Camera);
        Instance->UnlockObject(ModuleData->Focus);
        Instance->UnlockObject(ModuleData->Communicator);
 
        SetFilenameEvent::Deregister(*this);
        TriggerEvent::Deregister(*this);
        StopEvent::Deregister(*this);
        PauseImageCapturingEvent::Deregister(*this);
        ResumeImageCapturingEvent::Deregister(*this);
        AutofocusEvent::Deregister(*this);
    }
 
    void ImageViewer::OnCameraModeChanged(DynExp::ModuleInstance* Instance, int Index) const
    {
        if (Index < 0)
            return;
 
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        *PauseUpdatingUI = true;
        ModuleData->Camera->SetCameraMode(Util::NumToT<size_t>(Index),
            DynExp::TaskBase::CallbackType::FuncType([Pause = PauseUpdatingUI](const DynExp::TaskBase*, DynExp::ExceptionContainer&) {
                *Pause = false;
            }
        ));
    }
 
    void ImageViewer::OnExposureTimeChanged(DynExp::ModuleInstance* Instance, int Value) const
    {
        try
        {
            auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
            if (ModuleData->Camera->CanSetExposureTime())
            {
                *PauseUpdatingUI = true;
                ModuleData->Camera->SetExposureTime(std::chrono::milliseconds(Value),
                    DynExp::TaskBase::CallbackType::FuncType([Pause = PauseUpdatingUI](const DynExp::TaskBase*, DynExp::ExceptionContainer&) {
                        *Pause = false;
                    }
                ));
            }
        }
        catch ([[maybe_unused]] const Util::TimeoutException& e)
        {
            // Swallow since it is likely that this exception occurs here when the user
            // very quickly scrolls through the range of exposure times. It may take
            // time to transfer the new exposure time to the camera.
        }
    }
 
    void ImageViewer::OnCaptureSingle(DynExp::ModuleInstance* Instance, bool) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
        ModuleData->AutoSaveFilename.clear();
        ModuleData->ImageCapturingPaused = false;
        ModuleData->CaptureAfterPause = false;
 
        ModuleData->Camera->CaptureSingle();
    }
 
    void ImageViewer::OnCaptureContinuously(DynExp::ModuleInstance* Instance, bool Checked) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
        ModuleData->AutoSaveFilename.clear();
        ModuleData->ImageCapturingPaused = false;
        ModuleData->CaptureAfterPause = false;
 
        if (Checked)
            ModuleData->Camera->StartCapturing();
        else
            ModuleData->Camera->StopCapturing();
    }
 
    void ImageViewer::OnSetFilename(DynExp::ModuleInstance* Instance, const std::string& SaveFilename) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        OnStop(Instance);
        ModuleData->AutoSaveFilename = SaveFilename + ".png";
    }
 
    void ImageViewer::OnTrigger(DynExp::ModuleInstance* Instance) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
        // Keep ModuleData->AutoSaveFilename to save the image.
        ModuleData->ImageCapturingPaused = false;
        ModuleData->CaptureAfterPause = false;
 
        ModuleData->Camera->CaptureSingle();
    }
 
    void ImageViewer::OnStop(DynExp::ModuleInstance* Instance) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        if (IsReadyState())
            OnCaptureContinuously(Instance, false);
        else
        {
            StateMachine.SetCurrentState(StateType::Ready);
            ModuleData->Communicator->PostEvent(*this, FinishedAutofocusEvent{ false });
        }
    }
 
    void ImageViewer::OnPauseImageCapturing(DynExp::ModuleInstance* Instance, bool ResetImageTransformation) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        {
            auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
 
            ModuleData->ImageCapturingPaused = true;
            ModuleData->CaptureAfterPause = CameraData->IsCapturingContinuously();
 
            if (ResetImageTransformation)
                CameraData->SetImageTransformation({});
        } // CameraData unlocked here.
 
        if (ModuleData->Communicator.valid())
            ModuleData->Communicator->PostEvent(*this, ImageCapturingPausedEvent{});
    }
 
    void ImageViewer::OnResumeImageCapturing(DynExp::ModuleInstance* Instance) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        if (!ModuleData->ImageCapturingPaused)
            return;
        ModuleData->ImageCapturingPaused = false;
 
        if (ModuleData->CaptureAfterPause)
            ModuleData->Camera->StartCapturing();
 
        if (ModuleData->Communicator.valid())
            ModuleData->Communicator->PostEvent(*this, ImageCapturingResumedEvent{});
    }
 
    void ImageViewer::OnAutofocusClicked(DynExp::ModuleInstance* Instance, bool Checked) const
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        if (!ModuleData->Focus.valid())
            return;
 
        if (Checked)
            OnAutofocus(Instance);
        else
        {
            if (ModuleData->Communicator.valid())
                ModuleData->Communicator->PostEvent(*this, FinishedAutofocusEvent{ false });
 
            StateMachine.SetCurrentState(StateType::Ready);
        }
    }
 
    void ImageViewer::OnAutofocus(DynExp::ModuleInstance* Instance, bool ResetImageTransformation) const
    {
        using CHT = DynExpInstr::CameraData::ComputeHistogramType;
 
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance->ModuleDataGetter());
 
        if (!ModuleData->Focus.valid())
        {
            if (ModuleData->Communicator.valid())
                ModuleData->Communicator->PostEvent(*this, FinishedAutofocusEvent{ false });
 
            return;
        }
 
        {
            auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
 
            if (ResetImageTransformation)
                CameraData->SetImageTransformation({});
 
            ModuleData->CaptureAfterPause = CameraData->IsCapturingContinuously();
        } // CameraData unlocked here.
 
        ModuleData->Camera->StopCapturingSync();
 
        {
            auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
            CameraData->SetComputeHistogram(CHT::NoHistogram);
        } // CameraData unlocked here.
 
        StateMachine.SetCurrentState(StateType::AutofocusInit);
    }
 
    StateType ImageViewer::ReadyStateFunc(DynExp::ModuleInstance& Instance)
    {
        using CHT = DynExpInstr::CameraData::ComputeHistogramType;
 
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance.ModuleDataGetter());
        bool ImageAvailable = false;
 
        {
            auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
 
            ModuleData->CapturingState = CameraData->GetCapturingState();
            ModuleData->MinExposureTime = CameraData->GetMinExposureTime();
            ModuleData->MaxExposureTime = CameraData->GetMaxExposureTime();
            ModuleData->CurrentExposureTime = CameraData->GetExposureTime();
            ModuleData->CurrentFPS = CameraData->GetCurrentFPS();
 
            CameraData->SetComputeHistogram(ModuleData->ComputeHistogram);
 
            ImageAvailable = CameraData->IsImageAvailbale() && !ModuleData->ImageCapturingPaused;
            if (ImageAvailable)
            {
                ModuleData->CurrentImage = CameraData->GetImage();
                ModuleData->HasImageChanged = true;
 
                if (ModuleData->ComputeHistogram == CHT::IntensityHistogram ||
                    ModuleData->ComputeHistogram == CHT::IntensityAndRGBHistogram)
                    ModuleData->IntensityHistogram = CameraData->GetIntensityHistogram();
                if (ModuleData->ComputeHistogram == CHT::RGBHistogram ||
                    ModuleData->ComputeHistogram == CHT::IntensityAndRGBHistogram)
                    ModuleData->RGBHistogram = CameraData->GetRGBHistogram();
            }
        } // CameraData unlocked here.
 
        if (ImageAvailable && !ModuleData->AutoSaveFilename.empty())
        {
            QImage Image = ModuleData->CurrentImage.copy();
            if (!Image.save(QString::fromStdString(ModuleData->AutoSaveFilename)))
                Util::EventLog().Log("[ImageViewer] Saving image as \"" + ModuleData->AutoSaveFilename + "\" to file failed.", Util::ErrorType::Error);
 
            if (ModuleData->Communicator.valid())
                ModuleData->Communicator->PostEvent(*this, FinishedEvent{});
 
            ModuleData->AutoSaveFilename.clear();
        }
 
        return StateType::Ready;
    }
 
    StateType ImageViewer::AutofocusInitStateFunc(DynExp::ModuleInstance& Instance)
    {
        {
            auto ModuleParams = DynExp::dynamic_Params_cast<ImageViewer>(Instance.ParamsGetter());
 
            AutofocusParams.NumSteps = ModuleParams->AutofocusNumSteps;
            AutofocusParams.WaitTimeBeforeCapture = std::chrono::milliseconds(ModuleParams->AutofocusFocusChangeTime);
        } // ModuleParams unlocked here.
 
        AutofocusResults = {};
        AutofocusIsPerformingFineSweep = false;
 
        AutofocusSamples.clear();
        for (double Voltage = AutofocusParams.MinVoltage; Voltage <= AutofocusParams.MaxVoltage; Voltage += AutofocusParams.GetVoltageIncrement())
            AutofocusSamples.emplace_back(Voltage, std::numeric_limits<double>::quiet_NaN());
        AutofocusCurrentSample = AutofocusSamples.begin();
 
        return StateType::AutofocusGotoSample;
    }
 
    StateType ImageViewer::AutofocusGotoSampleStateFunc(DynExp::ModuleInstance& Instance)
    {
        if (AutofocusCurrentSample == AutofocusSamples.end())
            return StateType::AutofocusStep;
        else
        {
            auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance.ModuleDataGetter());
            ModuleData->Focus->SetSync(AutofocusCurrentSample->Voltage);
 
            AutofocusWaitingEndTimePoint = std::chrono::system_clock::now() + AutofocusParams.WaitTimeBeforeCapture;
 
            return StateType::AutofocusWaitBeforeCapture;
        }
    }
 
    StateType ImageViewer::AutofocusWaitBeforeCaptureStateFunc(DynExp::ModuleInstance& Instance)
    {
        if (std::chrono::system_clock::now() >= AutofocusWaitingEndTimePoint)
        {
            auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance.ModuleDataGetter());
            auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
 
            CameraData->ClearImage();
            ModuleData->Camera->CaptureSingle();
 
            return StateType::AutofocusWaitForImage;
        }
 
        return StateType::AutofocusWaitBeforeCapture;
    }
 
    StateType ImageViewer::AutofocusWaitForImageStateFunc(DynExp::ModuleInstance& Instance)
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance.ModuleDataGetter());
        auto CameraData = DynExp::dynamic_InstrumentData_cast<DynExpInstr::Camera>(ModuleData->Camera->GetInstrumentData());
 
        if (CameraData->IsImageAvailbale())
        {
            ModuleData->CurrentExposureTime = CameraData->GetExposureTime();
            ModuleData->CurrentImage = CameraData->GetImage();
            ModuleData->HasImageChanged = true;
 
            // Employing Brenner gradient as the figure of merit to maximize for autofocusing
            // in the fine mode and the image's variance in the coarse mode.
            // (S. Yazdanfar et al. Opt. Expres 16 (12), 8670-8677 (2008)).
            AutofocusCurrentSample->Result = ModuleData->CalcBrennerGradientFromImage();
            AutofocusCurrentSample++;
 
            return StateType::AutofocusGotoSample;
        }
 
        return StateType::AutofocusWaitForImage;
    }
 
    StateType ImageViewer::AutofocusStepStateFunc(DynExp::ModuleInstance& Instance)
    {
        double OptimalVoltage = std::max_element(AutofocusSamples.cbegin(), AutofocusSamples.cend(), [](const auto& a, const auto& b) {
            return a.Result < b.Result;
        })->Voltage;
 
        if (!AutofocusIsPerformingFineSweep)
        {
            AutofocusIsPerformingFineSweep = true;
            
            AutofocusSamples.clear();
            for (double Voltage = std::max(AutofocusParams.MinVoltage, OptimalVoltage - AutofocusParams.GetVoltageIncrement());
                Voltage <= std::min(AutofocusParams.MaxVoltage, OptimalVoltage + AutofocusParams.GetVoltageIncrement());
                Voltage += AutofocusParams.GetVoltageIncrement(true))
                AutofocusSamples.emplace_back(Voltage, std::numeric_limits<double>::quiet_NaN());
            AutofocusCurrentSample = AutofocusSamples.begin();
 
            return StateType::AutofocusGotoSample;
        }
        else
        {
            AutofocusResults.Success = OptimalVoltage > AutofocusSamples.front().Voltage + AutofocusParams.GetVoltageIncrement(true) / 2.0 &&
                OptimalVoltage < AutofocusSamples.back().Voltage - AutofocusParams.GetVoltageIncrement(true) / 2.0;
            if (AutofocusResults.Success)
                AutofocusResults.FocusVoltage = OptimalVoltage;
        }
 
        return StateType::AutofocusFinished;
    }
 
    StateType ImageViewer::AutofocusFinishedStateFunc(DynExp::ModuleInstance& Instance)
    {
        auto ModuleData = DynExp::dynamic_ModuleData_cast<ImageViewer>(Instance.ModuleDataGetter());
 
        if (AutofocusResults.Success)
            ModuleData->Focus->SetSync(AutofocusResults.FocusVoltage);
 
        FinishAutofocus(ModuleData, FinishedAutofocusEvent{ AutofocusResults.Success, AutofocusResults.FocusVoltage });
 
        return StateType::Ready;
    }
}