08Android · SystemsAndroid · MediaProjection API · Kotlin
ScreenWatcher — Android
Watches a screen region for pixel changes and triggers an alarm when movement is detected.
Open source (MIT) on GitHub
One API, done properly
MediaProjection grants access to the screen through a consent flow and a virtual display; ScreenWatcher samples a chosen region of that surface and raises an alarm when pixels move past the detection threshold.
The project stays intentionally narrow: one API, one job, published under MIT so the implementation details are readable.
What makes it technically interesting
- Region-based pixel-change detection built on MediaProjection’s virtual-display surface
- Alarm trigger when movement crosses the threshold inside the watched region
- Kept deliberately small: a focused systems/API experiment, published open source under MIT