Android - Using Camera Flash [duplicate]

Answer 1

I would research about android.permission.FLASHLIGHT. Android manifests' permission looks promising:

<!-- Allows access to the flashlight -->
<permission android:name="android.permission.FLASHLIGHT"
    android:permissionGroup="android.permission-group.HARDWARE_CONTROLS"
    android:protectionLevel="normal"
    android:label="@string/permlab_flashlight"
    android:description="@string/permdesc_flashlight" />

EDIT:

I just found a project that uses this permission. Check quick-settings' src code.

I would look into /src/com/bwx/bequick/flashlight.