title: Black Screen App
tags: qt pyside6
h1:

The use case is to black out one screen while playing a video on the other. Run it, move it to the desired screen, and press f to toggle fullscreen. This was produced by chatgpt using the following prompt and worked first time:
```poem
Simple app in pyside6 that displays a black window, 
and goes fullscreen with pressing a key like f. 
The aim is to be able to black out one screen 
while the machine is playing on the other, 
such as playing a movie on a TV from a laptop.
```

```py
#!/usr/bin/env/python

import sys
from PySide6.QtWidgets import QApplication, QWidget
from PySide6.QtGui import QKeyEvent, QPalette, QColor
from PySide6.QtCore import Qt

class BlackoutWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Blackout Screen")
        self.setAutoFillBackground(True)
        palette = self.palette()
        palette.setColor(QPalette.Window, QColor("black"))
        self.setPalette(palette)

        self.fullscreen = False
        self.showNormal()
        self.resize(800, 600)  # Default size

    def keyPressEvent(self, event: QKeyEvent):
        if event.key() == Qt.Key_F:
            self.toggle_fullscreen()
        elif event.key() == Qt.Key_Escape:
            self.close()

    def toggle_fullscreen(self):
        if self.fullscreen:
            self.showNormal()
            self.fullscreen = False
        else:
            self.showFullScreen()
            self.fullscreen = True

if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = BlackoutWindow()
    window.show()
    sys.exit(app.exec())
```