Android: Glasses Keys and System Broadcasts

Overview

Rokid glasses leg keys and touchpad events arrive as system broadcasts. CXRSWithCXRLSample dynamically registers a BroadcastReceiver in MainActivity, converts events to strings, and reports them via CXRServiceBridge.sendMessage(“rk_custom_key”, Caps) — same reply channel as Custom Commands.

Activity onKeyDown / onKeyUp and OnBackPressedCallback also call sendMessage to compare broadcast vs KeyEvent paths.

Prerequisites

• CXRServiceBridge initialized and subscribe registered (see Custom Commands chapter).
• CustomApp session built; phone Custom Commands page can receive rk_custom_key.

KeyType system broadcasts

KeyReceiver enum and actions:

Dynamic registration

Sample registers in MainActivity.onCreate, unregisters in onDestroy:

registerReceiver(viewModel.keyReceiver, IntentFilter().apply {
    KeyType.entries.forEach { addAction(it.action) }
})

override fun onDestroy() {
    unregisterReceiver(viewModel.keyReceiver)
    super.onDestroy()
}

KeyReceiver.onReceive dispatches to KeyEventListener.onKeyEvent and calls abortBroadcast() to avoid duplicate handling.

Relation to sendMessage

override fun onKeyEvent(keyType: KeyType) {
    sendMessage(“Listener: key action = ${keyType.name}”)
}

viewModel.sendMessage(“Down keyCode = $keyCode， event = ${event?.action}”)
viewModel.sendMessage(“Back Pressed”)

Phone parses in CustomCmdViewModel.onCustomCmdResult(“rk_custom_key”, …).

Permissions

• Sample does not declare these actions in Manifest; relies on system ordered broadcasts to registered receivers.
• Runtime registration only; no extra CXR permissions for keys themselves.
• Using abortBroadcast may affect other receivers — validate on target devices.

Constraints

• Actions may expand with OS versions; validate on hardware.
• High-frequency keys: mind Caps size and phone UI refresh.
• Always unregisterReceiver in onDestroy.

Appendix: Sample