refactor: log the output of onPermissionResult

Author: superus8r

app/src/main/java/org/kabiri/android/usbterminal/data/repository/UsbRepository.kt

@@ -7,13 +7,15 @@ import android.content.IntentFilter
 import android.hardware.usb.UsbDevice
 import android.hardware.usb.UsbManager
 import androidx.core.content.ContextCompat
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import org.kabiri.android.usbterminal.Constants
 import javax.inject.Inject
 
 internal interface IUsbRepository {
     val usbDevice: StateFlow<UsbDevice?>
+    val infoMessageFlow: Flow<String>
     fun scanForArduinoDevices(): List<UsbDevice>
     fun requestUsbPermission(device: UsbDevice)
     fun onPermissionResult(device: UsbDevice?, granted: Boolean)
@@ -29,6 +31,10 @@ internal class UsbRepository
     private val _usbDevice = MutableStateFlow<UsbDevice?>(null)
     override val usbDevice: StateFlow<UsbDevice?> get() = _usbDevice
 
+    private val _infoMessageFlow = MutableStateFlow("")
+    override val infoMessageFlow: Flow<String>
+        get() = _infoMessageFlow
+
     override fun scanForArduinoDevices(): List<UsbDevice> {
         val deviceList = usbManager.deviceList
         return deviceList.values.toList()
@@ -52,6 +58,7 @@ internal class UsbRepository
     }
 
     override fun onPermissionResult(device: UsbDevice?, granted: Boolean) {
+        _infoMessageFlow.value = "Permission result: ${device?.vendorId}, granted: $granted\n"
         if (granted && device != null) {
             _usbDevice.value = device
         } else {

app/src/main/java/org/kabiri/android/usbterminal/domain/UsbUseCase.kt

@@ -1,12 +1,14 @@
 package org.kabiri.android.usbterminal.domain
 
 import android.hardware.usb.UsbDevice
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.StateFlow
 import org.kabiri.android.usbterminal.data.repository.IUsbRepository
 import javax.inject.Inject
 
 internal interface IUsbUseCase {
     val usbDevice: StateFlow<UsbDevice?>
+    val infoMessageFlow: Flow<String>
     fun scanForUsbDevices(): List<UsbDevice>
     fun requestPermission(device: UsbDevice)
     fun disconnect()
@@ -18,6 +20,8 @@ internal class UsbUseCase
 ): IUsbUseCase {
     override val usbDevice: StateFlow<UsbDevice?> get() = usbRepository.usbDevice
 
+    override val infoMessageFlow: Flow<String> = usbRepository.infoMessageFlow
+
     override fun scanForUsbDevices(): List<UsbDevice> = usbRepository.scanForArduinoDevices()
 
     override fun requestPermission(device: UsbDevice) = usbRepository.requestUsbPermission(device)

app/src/main/java/org/kabiri/android/usbterminal/viewmodel/MainActivityViewModel.kt

@@ -34,15 +34,6 @@ internal class MainActivityViewModel
     private val resourceProvider: IResourceProvider,
 ): ViewModel() {
 
-    init {
-        // Subscribe to USB device changes.
-        viewModelScope.launch {
-            usbUseCase.usbDevice.collect { device ->
-                device?.let { openDeviceAndPort(it) }
-            }
-        }
-    }
-
     private val _infoMessageFlow = MutableStateFlow("")
     val infoMessage: StateFlow<String>
         get() = _infoMessageFlow
@@ -57,6 +48,16 @@ internal class MainActivityViewModel
 
     val output2 = SnapshotStateList<OutputText>()
 
+    init {
+        // Subscribe to USB device changes.
+        viewModelScope.launch {
+            usbUseCase.usbDevice.collect { device ->
+                _infoMessageFlow.value = "device discovered: ${device?.vendorId}\n"
+                device?.let { openDeviceAndPort(it) }
+            }
+        }
+    }
+
     fun connect() {
         val usbDeviceList = usbUseCase.scanForUsbDevices()
         if (usbDeviceList.isEmpty()) {
@@ -121,6 +122,13 @@ internal class MainActivityViewModel
             return@map outputText
         }
 
+        val usbInfoOutput: Flow<OutputText> = usbUseCase.infoMessageFlow.map {
+            _outputLive.value = _outputLive.value + it
+            val outputText = OutputText(it, OutputText.OutputType.TYPE_INFO)
+            output2.add(outputText)
+            return@map outputText
+        }
+
         val arduinoDefaultOutput: Flow<OutputText> = arduinoUseCase.messageFlow.map {
             _outputLive.value = _outputLive.value + it
             val outputText = OutputText(it, OutputText.OutputType.TYPE_NORMAL)
@@ -157,6 +165,14 @@ internal class MainActivityViewModel
                 arduinoInfo.text.isNotEmpty() -> arduinoInfo
                 else -> arduinoDefault
             }
-        }.stateIn(viewModelScope)
+        }.combine(usbInfoOutput) { outputText, usbInfo ->
+            // Prioritize USB info output over the rest.
+            if (usbInfo.text.isNotEmpty()) {
+                usbInfo
+            } else {
+                outputText
+            }
+        }
+            .stateIn(viewModelScope)
     }
 }