Following the example in the photo below, I want to migrate a function with callback to a SuspendCoroutine function:
1) Is it possible to transpose the code below to SuspendCoroutine? (I ask why there may be reserved codes from the library, type: onGpioEdge and registerGpioCallback.
2) How can I do this?
class ButtonActivity : Activity() {
// GPIO port wired to the button
private lateinit var buttonGpio: Gpio
// Step 4. Register an event callback.
private val callback = object : GpioCallback() {
fun onGpioEdge(gpio: Gpio): Boolean {
Log.i(TAG, "GPIO changed, button pressed")
// Step 5. Return true to keep callback active.
return true
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val manager = PeripheralManager.getInstance()
try {
// Step 1. Create GPIO connection.
buttonGpio = manager.openGpio(BUTTON_PIN_NAME)
// Step 2. Configure as an input.
buttonGpio.setDirection(Gpio.DIRECTION_IN)
// Step 3. Enable edge trigger events.
buttonGpio.setEdgeTriggerType(Gpio.EDGE_FALLING)
// Step 4. Register an event callback.
buttonGpio.registerGpioCallback(mCallback)
} catch (e: IOException) {
Log.e(TAG, "Error on PeripheralIO API", e)
}
}
override fun onDestroy() {
super.onDestroy()
// Step 6. Close the resource
if (buttonGpio != null)
{
buttonGpio.unregisterGpioCallback(mCallback)
try {
buttonGpio.close()
} catch (e: IOException) {
Log.e(TAG, "Error on PeripheralIO API", e)
}
}
}
That's an interesting idea, but I'm not sure coroutines are the best fit for GPIO.
Coroutines work great for asynchronous operations that return a value, such as API calls. GPIO is more of al listener that can happen at any time, it's a different type of callback. I would compare it to onClickListeners, and I don't think those are a good fit for coroutines either.