> ## Documentation Index
> Fetch the complete documentation index at: https://committ.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Appear On Top

> Renders blocking overlays to prevent app skipping.

# Appear On Top (System Overlay)

The **Appear On Top** permission (known natively as the `SYSTEM_ALERT_WINDOW` or System Overlay permission) is critical to CommitT's digital enforcement engine. It allows the background blocker thread to render an interactive, un-skippable blocking screen when a user attempts to launch a restricted app.

***

## Why it is Required

When a restricted app (like Instagram) is opened:

1. The **Accessibility Service** detects the app launch.
2. The service queries the local SQLite engine for active block rules.
3. If active, the overlay window is spawned immediately using WindowManager.
4. The overlay intercepts touch events, rendering the CommitT blocking UI.

***

## Native Implementation

The permission is checked using the system's `Settings.canDrawOverlays` API on Android Marshmallow (API 23) and above:

```kotlin theme={null}
val overlayEnabled = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    Settings.canDrawOverlays(context)
} else {
    true // Autopassed on pre-Marshmallow Android
}
```

***

## Requesting the Permission

To request this permission, the native module triggers a targeted system intent directly to the drawing settings page for CommitT, saving the user from searching through system settings menus:

```kotlin theme={null}
"overlay" -> if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION).apply {
        // Points the settings directly to the CommitT package
        data = Uri.parse("package:${context.packageName}")
    }
} else null
```