Warning, file /frameworks/kwindowsystem/tests/blurbehindtest.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 <QApplication>
 #include <QPushButton>
 #include <QVBoxLayout>
 #include <QWidget>
 
 #include <kwindoweffects.h>
 
 class BlurTestWindow : public QWidget
 {
 public:
     BlurTestWindow();
 
     void resizeEvent(QResizeEvent *) override;
 
 private:
     QPushButton *m_btnNothing;
     QPushButton *m_btnFullWindow;
     QPushButton *m_btnRect;
     QPushButton *m_btnEllipse;
     QWidget *m_area;
 
     enum { Nothing, FullWindow, Rect, Ellipse } m_state;
 
     void setWindowAlpha(int alpha);
 
     void disableBlur();
     void enableBlur();
     void enableBlurRect();
     void enableBlurEllipse();
 };
 
 BlurTestWindow::BlurTestWindow()
 {
     m_state = Nothing;
     setAttribute(Qt::WA_TranslucentBackground);
     setAttribute(Qt::WA_NoSystemBackground, false);
     setWindowAlpha(192);
 
     m_btnNothing = new QPushButton("Nothing");
     m_btnFullWindow = new QPushButton("Full window");
     m_btnRect = new QPushButton("Rectangle");
     m_btnEllipse = new QPushButton("Ellipse");
 
     m_area = new QWidget;
     m_area->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
     connect(m_btnNothing, &QPushButton::clicked, this, &BlurTestWindow::disableBlur);
     connect(m_btnFullWindow, &QPushButton::clicked, this, &BlurTestWindow::enableBlur);
     connect(m_btnRect, &QPushButton::clicked, this, &BlurTestWindow::enableBlurRect);
     connect(m_btnEllipse, &QPushButton::clicked, this, &BlurTestWindow::enableBlurEllipse);
 
     QVBoxLayout *layout = new QVBoxLayout(this);
     layout->addWidget(m_btnNothing);
     layout->addWidget(m_btnFullWindow);
     layout->addWidget(m_btnRect);
     layout->addWidget(m_btnEllipse);
     layout->addWidget(m_area);
 
     winId(); // force creation of the associated window
 }
 
 void BlurTestWindow::disableBlur()
 {
     m_state = Nothing;
     KWindowEffects::enableBlurBehind(windowHandle(), false);
     repaint();
 }
 void BlurTestWindow::enableBlur()
 {
     m_state = FullWindow;
     KWindowEffects::enableBlurBehind(windowHandle(), true);
     repaint();
 }
 void BlurTestWindow::enableBlurRect()
 {
     m_state = Rect;
     QRegion rgn(m_area->geometry());
     KWindowEffects::enableBlurBehind(windowHandle(), true, rgn);
     repaint();
 }
 void BlurTestWindow::enableBlurEllipse()
 {
     m_state = Ellipse;
     QRegion rgn(m_area->geometry(), QRegion::Ellipse);
     KWindowEffects::enableBlurBehind(windowHandle(), true, rgn);
     repaint();
 }
 
 void BlurTestWindow::resizeEvent(QResizeEvent *)
 {
     if (m_state == Rect) {
         enableBlurRect();
     } else if (m_state == Ellipse) {
         enableBlurEllipse();
     }
 }
 
 void BlurTestWindow::setWindowAlpha(int alpha)
 {
     QPalette pal = this->palette();
     QColor windowColor = pal.color(QPalette::Window);
     windowColor.setAlpha(alpha);
     pal.setColor(QPalette::Window, windowColor);
     this->setPalette(pal);
 }
 
 int main(int argc, char **argv)
 {
     QApplication app(argc, argv);
 
     BlurTestWindow wnd;
     wnd.show();
 
     return app.exec();
 }