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Architecture Deep-Dive

ReelLock leverages Android's AccessibilityService API to inspect window hierarchy changes in real-time, specifically monitoring Instagram's process tree (com.instagram.android).

High-Level System Architecture

graph TD
    SubGraph1[Android System Framework]
    SubGraph2[ReelLock Core Engine]

    A[Instagram App Window Event] -->|TYPE_WINDOW_CONTENT_CHANGED| B[ReelBlockerService.kt]
    A -->|TYPE_WINDOW_STATE_CHANGED| B

    B --> C[Root AccessibilityNodeInfo Node]
    C --> D[Recursive Heuristic Node Inspector]

    D -->|Resource ID / Content-Desc match| E{Reel Container Detected?}

    E -- Yes --> F[Action Mode Dispatcher]
    E -- No --> G[Ignore Event]

    F -->|Mode: Auto Back| H[performGlobalAction GLOBAL_ACTION_BACK]
    F -->|Mode: Go Home| I[Intent ACTION_MAIN / CATEGORY_HOME]
    F -->|Mode: Overlay| J[WindowManager.addView Overlay Layout]

Key Components

1. ReelBlockerService.kt

  • Extends android.accessibilityservice.AccessibilityService.
  • Configured via accessibility_service_config.xml to filter events from com.instagram.android.
  • Overrides onAccessibilityEvent(event: AccessibilityEvent).

2. Node Traversal Heuristic

Instagram dynamically obfuscates view resource IDs across updates. ReelLock employs multi-layered heuristic checks: 1. ClassName Inspection: Identifies Reels surface views and video container view groups. 2. Resource-ID & Content-Description Matching: Looks for keywords such as clips_viewer, reels_tab, reels_video_container, and related content descriptions. 3. View Structure Parsing: Recursively traverses AccessibilityNodeInfo tree roots.

3. Action Execution Engine

When a positive match occurs, ReelBlockerService executes the user's selected mode: - MODE_AUTO_BACK: Calls performGlobalAction(GLOBAL_ACTION_BACK). - MODE_GO_HOME: Launches an Intent with Intent.ACTION_MAIN and Intent.CATEGORY_HOME. - MODE_OVERLAY: Inflates overlay_reels_blocked.xml and adds it to the system window manager using TYPE_APPLICATION_OVERLAY.

Data Persistence & Security Model

  • SharedPreferences: Stores mode preferences (key_block_mode) and block counts (key_block_count).
  • Privacy Assurance: ReelLock reads zero text fields, credentials, or personal messages. It strictly inspects node layout structures matching Reels video players.