App Framework

App Model

Sticky device-side apps follow a unified app model:

App Lifecycle

Each app has a clear lifecycle:

  1. Load — Load app resources from storage
  2. Initialize — Initialize app state and data
  3. Run — App is in foreground, responding to user actions
  4. Background — App is switched to background, state preserved
  5. Destroy — App is uninstalled or resources reclaimed by system

App Interfaces

Each app must implement these standard interfaces:

  • onCreate() — Called when the app is created
  • onStart() — Called when the app starts
  • onResume() — Called when the app returns to foreground
  • onPause() — Called when the app enters background
  • onDestroy() — Called when the app is destroyed
  • onRender() — Called when the app needs to render

Page Rendering

Apps render content to the e-ink screen through the rendering engine:

  • Supports full refresh and partial refresh modes
  • Full refresh: Entire screen update, better display quality but slower
  • Partial refresh: Only updates changed areas, faster but may show ghosting

Event System

Apps interact with the system and users through the event system:

  • Touch events: Tap, swipe
  • Button events: AI button, page buttons
  • System events: Network change, battery change
  • Timer events: Scheduled tasks

SenseCraft HMI

Sticky comes pre-installed with SenseCraft HMI, a native app that provides HMI interaction interface and content display capabilities.

Next Steps

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