#1901 prompt user to set default USB configuration to 'No data transfer' after starting pro mode

Author: sds100

CHANGELOG.md

@@ -9,6 +9,10 @@
 - #1414 constraint for when the keyboard is showing.
 - #1900 log to logcat if extra logging is enabled.
 
+## Bug fixes
+
+- #1901 prompt user to set default USB configuration to 'No data transfer' after starting pro mode.
+
 ## [4.0.0 Beta 2](https://github.com/sds100/KeyMapper/releases/tag/v4.0.0-beta.02)
 
 #### 08 November 2025

app/proguard-rules.pro

@@ -79,6 +79,8 @@
 -keep class com.android.internal.telephony.ITelephony$Stub { *; }
 -keep class android.net.ITetheringConnector { *; }
 -keep class android.net.ITetheringConnector$Stub { *; }
+-keep class android.hardware.usb.IUsbManager { *; }
+-keep class android.hardware.usb.IUsbManager$Stub { *; }
 -keep class android.net.* { *; }
 
 -keepattributes *Annotation*, InnerClasses

base/src/main/java/io/github/sds100/keymapper/base/promode/ProModeScreen.kt

@@ -1,6 +1,7 @@
 package io.github.sds100.keymapper.base.promode
 
 import android.os.Build
+import android.provider.Settings
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.expandVertically
 import androidx.compose.animation.fadeIn
@@ -33,6 +34,7 @@ import androidx.compose.material.icons.rounded.Notifications
 import androidx.compose.material.icons.rounded.Numbers
 import androidx.compose.material.icons.rounded.RestartAlt
 import androidx.compose.material.icons.rounded.Tune
+import androidx.compose.material.icons.rounded.Usb
 import androidx.compose.material.icons.rounded.WarningAmber
 import androidx.compose.material3.BottomAppBar
 import androidx.compose.material3.ButtonDefaults
@@ -54,6 +56,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextAlign
@@ -68,6 +71,7 @@ import io.github.sds100.keymapper.base.utils.ui.compose.SwitchPreferenceCompose
 import io.github.sds100.keymapper.base.utils.ui.compose.icons.FakeShizuku
 import io.github.sds100.keymapper.base.utils.ui.compose.icons.KeyMapperIcon
 import io.github.sds100.keymapper.base.utils.ui.compose.icons.KeyMapperIcons
+import io.github.sds100.keymapper.common.utils.SettingsUtils
 import io.github.sds100.keymapper.common.utils.State
 
 @Composable
@@ -295,7 +299,17 @@ private fun LoadedContent(
         }
 
         when (state) {
-            ProModeState.Started -> {
+            is ProModeState.Started -> {
+                if (!state.isDefaultUsbModeCompatible) {
+                    IncompatibleUsbModeCard(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 8.dp),
+                    )
+
+                    Spacer(Modifier.height(8.dp))
+                }
+
                 ProModeStartedCard(
                     modifier = Modifier
                         .fillMaxWidth()
@@ -429,6 +443,44 @@ private fun LoadedContent(
     }
 }
 
+@Composable
+private fun IncompatibleUsbModeCard(modifier: Modifier = Modifier) {
+    val ctx = LocalContext.current
+    SetupCard(
+        modifier = modifier,
+        color = MaterialTheme.colorScheme.errorContainer,
+        icon = {
+            Icon(
+                imageVector = Icons.Rounded.Usb,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurface,
+            )
+        },
+        title = stringResource(
+            R.string.pro_mode_setup_wizard_change_default_usb_configuration_title,
+        ),
+        content = {
+            Text(
+                text = stringResource(
+                    R.string.pro_mode_setup_wizard_change_default_usb_configuration_description,
+                ),
+                style = MaterialTheme.typography.bodyMedium,
+            )
+        },
+        buttonText = stringResource(
+            R.string.button_fix,
+        ),
+        onButtonClick = {
+            // Go to developer options and highlight the "Default USB configuration" option
+            SettingsUtils.launchSettingsScreen(
+                ctx,
+                Settings.ACTION_APPLICATION_DEVELOPMENT_SETTINGS,
+                "default_usb_configuration",
+            )
+        },
+    )
+}
+
 @Composable
 private fun WarningCard(
     modifier: Modifier = Modifier,
@@ -692,7 +744,7 @@ private fun PreviewDark() {
         ProModeScreen {
             Content(
                 warningState = ProModeWarningState.Understood,
-                setupState = State.Data(ProModeState.Started),
+                setupState = State.Data(ProModeState.Started(isDefaultUsbModeCompatible = true)),
                 showInfoCard = false,
                 onInfoCardDismiss = {},
                 autoStartAtBoot = true,
@@ -728,7 +780,7 @@ private fun PreviewStarted() {
         ProModeScreen {
             Content(
                 warningState = ProModeWarningState.Understood,
-                setupState = State.Data(ProModeState.Started),
+                setupState = State.Data(ProModeState.Started(isDefaultUsbModeCompatible = false)),
                 showInfoCard = false,
                 onInfoCardDismiss = {},
                 autoStartAtBoot = false,

base/src/main/java/io/github/sds100/keymapper/base/promode/ProModeViewModel.kt

@@ -12,7 +12,7 @@ import io.github.sds100.keymapper.base.utils.navigation.navigate
 import io.github.sds100.keymapper.base.utils.ui.DialogProvider
 import io.github.sds100.keymapper.base.utils.ui.ResourceProvider
 import io.github.sds100.keymapper.common.utils.State
-import javax.inject.Inject
+import io.github.sds100.keymapper.common.utils.valueOrNull
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
@@ -25,6 +25,7 @@ import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import javax.inject.Inject
 
 @HiltViewModel
 class ProModeViewModel @Inject constructor(
@@ -156,7 +157,12 @@ class ProModeViewModel @Inject constructor(
         isNotificationPermissionGranted: Boolean,
     ): State<ProModeState> {
         if (isSystemBridgeConnected) {
-            return State.Data(ProModeState.Started)
+            return State.Data(
+                ProModeState.Started(
+                    isDefaultUsbModeCompatible =
+                    useCase.isCompatibleUsbModeSelected().valueOrNull() ?: false,
+                ),
+            )
         } else {
             return State.Data(
                 ProModeState.Stopped(
@@ -182,5 +188,5 @@ sealed class ProModeState {
         val isNotificationPermissionGranted: Boolean,
     ) : ProModeState()
 
-    data object Started : ProModeState()
+    data class Started(val isDefaultUsbModeCompatible: Boolean) : ProModeState()
 }

base/src/main/java/io/github/sds100/keymapper/base/promode/SystemBridgeSetupUseCase.kt

@@ -1,9 +1,11 @@
 package io.github.sds100.keymapper.base.promode
 
 import android.os.Build
+import android.os.Process
 import androidx.annotation.RequiresApi
 import dagger.hilt.android.scopes.ViewModelScoped
 import io.github.sds100.keymapper.common.utils.Constants
+import io.github.sds100.keymapper.common.utils.KMResult
 import io.github.sds100.keymapper.common.utils.firstBlocking
 import io.github.sds100.keymapper.data.Keys
 import io.github.sds100.keymapper.data.PreferenceDefaults
@@ -19,7 +21,6 @@ import io.github.sds100.keymapper.system.permissions.Permission
 import io.github.sds100.keymapper.system.permissions.PermissionAdapter
 import io.github.sds100.keymapper.system.root.SuAdapter
 import io.github.sds100.keymapper.system.shizuku.ShizukuAdapter
-import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
@@ -29,6 +30,7 @@ import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
+import javax.inject.Inject
 
 @RequiresApi(Constants.SYSTEM_BRIDGE_MIN_API)
 @ViewModelScoped
@@ -42,6 +44,15 @@ class SystemBridgeSetupUseCaseImpl @Inject constructor(
     private val accessibilityServiceAdapter: AccessibilityServiceAdapter,
     private val networkAdapter: NetworkAdapter,
 ) : SystemBridgeSetupUseCase {
+
+    companion object {
+        /**
+         * This is specified in android/hardware/usb/UsbManager.java and called
+         * FUNCTION_NONE in that file.
+         */
+        private const val USB_FUNCTION_NONE = 0
+    }
+
     override val isWarningUnderstood: Flow<Boolean> =
         preferences.get(Keys.isProModeWarningUnderstood).map { it ?: false }
 
@@ -198,6 +209,24 @@ class SystemBridgeSetupUseCaseImpl @Inject constructor(
         }
     }
 
+    /**
+     * This applies to older Android versions (tested on Android 11 and 13).
+     * Having the "Default USB Configuration" in developer options set to something other
+     * than "No data transfer" causes the system bridge (ADB) process to be killed when the device
+     * is locked. Not 100% sure what the mechanic is but it can be reproduced by pressing the
+     * power button. On Android 15 this is not the case because it seems like turning on
+     * wireless debugging or ADB resets the setting to "No data transfer".
+     */
+    override fun isCompatibleUsbModeSelected(): KMResult<Boolean> {
+        return systemBridgeConnectionManager
+            .run { systemBridge ->
+                // The USB setting does not matter if the system bridge is running as root
+                // because it doesn't rely on the ADB process.
+                systemBridge.processUid == Process.SHELL_UID &&
+                    systemBridge.usbScreenUnlockedFunctions.toInt() == 0
+            }
+    }
+
     @RequiresApi(Build.VERSION_CODES.R)
     private fun getNextStep(
         accessibilityServiceState: AccessibilityServiceState,
@@ -253,4 +282,6 @@ interface SystemBridgeSetupUseCase {
     fun startSystemBridgeWithRoot()
     fun startSystemBridgeWithShizuku()
     suspend fun startSystemBridgeWithAdb()
+
+    fun isCompatibleUsbModeSelected(): KMResult<Boolean>
 }

base/src/main/res/values/strings.xml

@@ -1697,6 +1697,9 @@
     <string name="pro_mode_setup_wizard_enable_notification_permission_description">Key Mapper needs permission to notify you if there are any issues with the set up process.</string>
     <string name="pro_mode_setup_wizard_enable_notification_permission_button">Give permission</string>
 
+    <string name="pro_mode_setup_wizard_change_default_usb_configuration_title">Incompatible USB configuration</string>
+    <string name="pro_mode_setup_wizard_change_default_usb_configuration_description">You must select \'No data transfer\' as your default USB configuration so that PRO Mode is not killed every time you lock your device.</string>
+
     <string name="pro_mode_setup_assistant_notification_channel">Setup assistant</string>
 
     <string name="pro_mode_setup_wizard_complete_title">PRO mode is running</string>

sysbridge/src/main/aidl/io/github/sds100/keymapper/sysbridge/ISystemBridge.aidl

@@ -46,4 +46,6 @@ interface ISystemBridge {
    boolean isTetheringEnabled() = 19;
 
    void setTetheringEnabled(boolean enable) = 20;
+
+   long getUsbScreenUnlockedFunctions() = 21;
 }

sysbridge/src/main/java/io/github/sds100/keymapper/sysbridge/service/SystemBridge.kt

@@ -12,6 +12,7 @@ import android.content.pm.ApplicationInfo
 import android.content.pm.IPackageManager
 import android.content.pm.PackageManager
 import android.hardware.input.IInputManager
+import android.hardware.usb.IUsbManager
 import android.media.IAudioService
 import android.net.IConnectivityManager
 import android.net.ITetheringConnector
@@ -31,6 +32,7 @@ import android.os.Handler
 import android.os.IBinder
 import android.os.Looper
 import android.os.Process
+import android.os.RemoteException
 import android.os.ServiceManager
 import android.permission.IPermissionManager
 import android.permission.PermissionManagerApis
@@ -188,6 +190,7 @@ internal class SystemBridge : ISystemBridge.Stub() {
     private val activityManager: IActivityManager
     private val activityTaskManager: IActivityTaskManager
     private val audioService: IAudioService?
+    private val usbManager: IUsbManager?
 
     private val processPackageName: String = when (Process.myUid()) {
         Process.ROOT_UID -> "root"
@@ -281,6 +284,10 @@ internal class SystemBridge : ISystemBridge.Stub() {
             tetheringConnector = null
         }
 
+        waitSystemService(Context.USB_SERVICE)
+        usbManager =
+            IUsbManager.Stub.asInterface(ServiceManager.getService(Context.USB_SERVICE))
+
         val applicationInfo = getKeyMapperPackageInfo()
 
         if (applicationInfo == null) {
@@ -767,4 +774,12 @@ internal class SystemBridge : ISystemBridge.Stub() {
             tetheringConnector.stopTethering(TETHERING_WIFI, processPackageName, null, null)
         }
     }
+
+    override fun getUsbScreenUnlockedFunctions(): Long {
+        return try {
+            usbManager?.screenUnlockedFunctions ?: 0
+        } catch (_: RemoteException) {
+            -1
+        }
+    }
 }

systemstubs/src/main/aidl/android/hardware/usb/IUsbManager.aidl

@@ -0,0 +1,5 @@
+package android.hardware.usb;
+
+interface IUsbManager {
+  long getScreenUnlockedFunctions();
+}