Simple Example app for android.os.FileObserver

This is android app example to test android.os.FileObserver API in Java.
As official API reference document says, it requires android API 29(android OS version 10).

refer: https://developer.android.com/reference/android/os/FileObserver

Requirements

• android studio to build apk from source, tested version: 2021.3.1.16.
• android terminal, OS version 10 and later to test, tested terminal: Google Pixel 3a
• tested java compiler version: openjdk-11-jdk

basic use:

1. build apk from source in android-studio
2. run app from android-studio
3. play app with camera app on your terminal.
   press Start button on the app, then take photo, then press Stop button on the app.

about this app and source

• This app is a minimalist. :-)
• This app observes DCIM/Camera folder, as defined in source (MainActivity)
• This app has just simplest UI (AppCompatActivity) created from 'Empty Activity'
• This app has just two source file, MainActivity and MyFileObserver.
• MyFileObserver shows observed events in TextView area on the app.