Android Dev Notes

android_dev_notes.txt

Kotlin, Java, C++

1. App components (entry points of app):
  - Activity
  - Service
  - Broadcast receiver
  - Content Provider
 
2. Activity (UI)
  - Represents a single screen
  - One app can have multiple activities, each is an different interface
  - Other apps can start any activities if allowed
  - "Activity" class
  
3. Service
  - No interface, run in background for long-running operations
  - Can bind with Activity (or processes)
  - Lower chance being killed if bound to an important process
  - Two types (based on user awareness):
    - User aware (e.g. Music): foregroud with a notification
    - Not user aware (e.g. GDrive sync): higher chance being killed by the system
  - "Service" class
  
4. Broadcast receiver
  - Receive events outside a regular user flow
  - Even when the app is not running
  - System broadcasts, app broadcasts
  - Can create a status bar notification
  - Can be just a gateway to other components to do a small amount of work
  - "BroadcastReceiver" class, broadcasts are just "Intent"s
  
5. Content provider
  -