Warning, file /frameworks/kwindowsystem/tests/backgroundcontrasttest.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*
     This file is part of the KDE libraries
     SPDX-FileCopyrightText: 2013 Nicolás Alvarez <nicolas.alvarez@gmail.com>
 
     SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
 #include <optional>
 
 #include <QApplication>
 #include <QColorDialog>
 #include <QDebug>
 #include <QPaintEvent>
 #include <QPainter>
 #include <QPushButton>
 #include <QScopeGuard>
 #include <QSlider>
 #include <QVBoxLayout>
 #include <QWidget>
 
 #include <kwindoweffects.h>
 
 class ContrastTestWindow : public QWidget
 {
 public:
     ContrastTestWindow();
 
     void resizeEvent(QResizeEvent *) override;
 
 private:
     QPushButton *m_btnNothing;
     QPushButton *m_btnFullWindow;
     QPushButton *m_btnRect;
     QPushButton *m_btnEllipse;
 
     QPushButton *m_frost;
     QColor m_frostColor;
 
     QPushButton *m_blur;
     bool m_doBlur;
 
     QPushButton *m_bg;
     QColor m_bgColour;
 
     QSlider *m_contSlider;
     QSlider *m_intSlider;
     QSlider *m_satSlider;
     QWidget *m_area;
 
     qreal m_contrast;
     qreal m_intensity;
     qreal m_saturation;
 
     enum { Nothing, FullWindow, Rect, Ellipse } m_state;
 
     void disableContrast();
     void enableContrast();
     void enableContrastRect();
     void enableContrastEllipse();
     void updateContrast(int contrast);
     void updateIntensity(int contrast);
     void updateSaturation(int contrast);
     void update();
 
     void paintEvent(QPaintEvent *event) override
     {
         Q_UNUSED(event)
 
         QPainter p(this);
         p.setPen(Qt::transparent);
         p.setBrush(m_bgColour);
         p.drawRect(this->rect());
 
         QWidget::paintEvent(event);
     }
 };
 
 ContrastTestWindow::ContrastTestWindow()
 {
     m_state = Nothing;
     m_contrast = 1;
     m_intensity = 1;
     m_saturation = 1;
     m_bgColour = Qt::transparent;
     setAttribute(Qt::WA_TranslucentBackground);
     setAttribute(Qt::WA_NoSystemBackground, true);
 
     m_btnNothing = new QPushButton("Nothing");
     m_btnFullWindow = new QPushButton("Full window");
     m_btnRect = new QPushButton("Rectangle");
     m_btnEllipse = new QPushButton("Ellipse");
     m_frost = new QPushButton("Enable Frost");
     m_frost->setCheckable(true);
     m_blur = new QPushButton("Enable Blur");
     m_blur->setCheckable(true);
     m_bg = new QPushButton("Set Background Colour...");
     connect(m_bg, &QPushButton::pressed, this, [this]() {
         m_bgColour = QColorDialog::getColor(Qt::white, nullptr, "pick colour", QColorDialog::ShowAlphaChannel);
 
         repaint();
     });
 
     connect(m_frost, &QPushButton::toggled, this, [this](bool checked) {
         m_frost->setText(checked ? "Disable Frost" : "Enable Frost");
 
         if (!checked) {
             m_frostColor = QColor();
 
             update();
 
             return;
         }
 
         m_frostColor = QColorDialog::getColor(Qt::white, nullptr, "pick colour", QColorDialog::ShowAlphaChannel);
 
         update();
     });
     connect(m_blur, &QPushButton::toggled, this, [this](bool checked) {
         m_blur->setText(checked ? "Disable Blur" : "Enable Blur");
         m_doBlur = checked;
 
         update();
     });
 
     m_contSlider = new QSlider();
     m_contSlider->setMaximum(200);
     m_contSlider->setValue(100);
     m_contSlider->setOrientation(Qt::Horizontal);
 
     m_intSlider = new QSlider();
     m_intSlider->setMaximum(200);
     m_intSlider->setValue(100);
     m_intSlider->setOrientation(Qt::Horizontal);
 
     m_satSlider = new QSlider();
     m_satSlider->setMaximum(200);
     m_satSlider->setValue(100);
     m_satSlider->setOrientation(Qt::Horizontal);
 
     m_area = new QWidget;
     m_area->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
     connect(m_btnNothing, &QPushButton::clicked, this, &ContrastTestWindow::disableContrast);
     connect(m_btnFullWindow, &QPushButton::clicked, this, &ContrastTestWindow::enableContrast);
     connect(m_btnRect, &QPushButton::clicked, this, &ContrastTestWindow::enableContrastRect);
     connect(m_btnEllipse, &QPushButton::clicked, this, &ContrastTestWindow::enableContrastEllipse);
 
     connect(m_contSlider, &QSlider::valueChanged, this, &ContrastTestWindow::updateContrast);
     connect(m_intSlider, &QSlider::valueChanged, this, &ContrastTestWindow::updateIntensity);
     connect(m_satSlider, &QSlider::valueChanged, this, &ContrastTestWindow::updateSaturation);
 
     QVBoxLayout *layout = new QVBoxLayout(this);
     layout->addWidget(m_btnNothing);
     layout->addWidget(m_btnFullWindow);
     layout->addWidget(m_btnRect);
     layout->addWidget(m_btnEllipse);
     layout->addWidget(m_contSlider);
     layout->addWidget(m_intSlider);
     layout->addWidget(m_satSlider);
     layout->addWidget(m_area);
     layout->addWidget(m_frost);
     layout->addWidget(m_blur);
     layout->addWidget(m_bg);
 
     winId(); // force creation of the associated window
 }
 
 void ContrastTestWindow::update()
 {
     const auto s = qScopeGuard([this]() {
         repaint();
     });
 
     if (m_state == Nothing) {
         KWindowEffects::enableBackgroundContrast(windowHandle(), false);
         KWindowEffects::enableBlurBehind(windowHandle(), false);
     }
 
     auto region = QRegion();
     switch (m_state) {
     case Nothing:
     case FullWindow:
         break;
     case Rect:
         region = m_area->geometry();
         break;
     case Ellipse:
         region = QRegion(m_area->geometry(), QRegion::Ellipse);
         break;
     }
 
     KWindowEffects::enableBlurBehind(windowHandle(), m_doBlur, region);
 
     if (!m_frostColor.isValid()) {
         KWindowEffects::enableBackgroundContrast(windowHandle(), true, m_contrast, m_intensity, m_saturation, region);
     } else {
         qWarning() << "frost color";
         KWindowEffects::setBackgroundFrost(windowHandle(), m_frostColor, region);
     }
 
     repaint();
 }
 
 void ContrastTestWindow::disableContrast()
 {
     m_state = Nothing;
 
     update();
 }
 void ContrastTestWindow::enableContrast()
 {
     m_state = FullWindow;
 
     update();
 }
 void ContrastTestWindow::enableContrastRect()
 {
     m_state = Rect;
 
     update();
 }
 void ContrastTestWindow::enableContrastEllipse()
 {
     m_state = Ellipse;
 
     update();
 }
 
 void ContrastTestWindow::updateContrast(int contrast)
 {
     m_contrast = (qreal)contrast / 100;
 
     update();
 }
 
 void ContrastTestWindow::updateIntensity(int contrast)
 {
     m_intensity = (qreal)contrast / 100;
 
     update();
 }
 
 void ContrastTestWindow::updateSaturation(int contrast)
 {
     m_saturation = (qreal)contrast / 100;
 
     update();
 }
 
 void ContrastTestWindow::resizeEvent(QResizeEvent *)
 {
     update();
 }
 
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
 
     ContrastTestWindow wnd;
     wnd.show();
 
     return app.exec();
 }