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Deep Focus

Deep Focus is implemented as a per-goal blocking flow that is activated when tracking starts and deactivated when tracking stops.

Main files​

  • HomeScreen.kt / AddGoalScreen.kt / EditGoalScreen.kt: expose the deepFocus flag on goals and guard start-up with the accessibility setup dialog.
  • TrackingViewModel.kt: starts/stops tracking and toggles blocking state through the repository/service layer.
  • DeepFocusAccessibilityService.kt: observes foreground window changes, filters launcher/system surfaces, and decides when to show or remove the overlay.
  • DeepFocusOverlayController.kt: builds and removes the accessibility overlay UI.
  • DeepFocusConfig.kt: stores the shared preference key that enables/disables blocking.

Runtime flow​

  1. A goal is saved with deepFocus = true.
  2. Starting tracking enables the blocking flag.
  3. The accessibility service reacts to TYPE_WINDOW_STATE_CHANGED events and shows the overlay for non-allowed apps.
  4. The overlay’s return action launches Purrsistence again and uses a short grace window to avoid immediate re-attach.
  5. stopTracking() clears blocking and removes any active overlay.

Notes​

  • Android does not provide a built-in API for fully disabling an app; Deep Focus uses accessibility services to display an overlay instead.
  • This is different from iOS, where Screen Time provides a dedicated API for app restriction.
  • Accessibility must be enabled manually in Android Settings before Deep Focus can block apps.
  • Launcher and system UI packages are intentionally excluded from blocking to avoid trapping the user.