Request ACCESS_LOCAL_NETWORK permission on android 17 and up

Show the permission dialog the first time host or connect is clicked.

While the permission is not granted, show an info box at the bottom of the netplay setup screen explaining the need for the permission with a button to grant permission. Launch the app settings menu where the permission can be granted manually if the user has denied twice previously preventing us from showing the permission dialog.

Workarounds using the shouldShowRationale flag and detecting if the dialog showed via onPause to account for well known limitations in the android permissions API.

Source/Android/app/build.gradle.kts

@@ -170,6 +170,8 @@ dependencies {
     implementation(libs.androidx.compose.ui)
     implementation(libs.androidx.compose.ui.tooling)
     implementation(libs.androidx.compose.ui.tooling.preview)
+
+    implementation(libs.accompanist)
 }
 
 fun getGitVersion(): String {

Source/Android/app/src/main/AndroidManifest.xml

@@ -26,6 +26,7 @@
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_LOCAL_NETWORK"/>
     <uses-permission android:name="com.android.providers.tv.permission.READ_EPG_DATA"/>
     <uses-permission android:name="com.android.providers.tv.permission.WRITE_EPG_DATA"/>
     <uses-permission android:name="android.permission.VIBRATE"/>

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplaySetupScreen.kt

@@ -1,9 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-@file:OptIn(ExperimentalMaterial3Api::class)
+@file:OptIn(ExperimentalMaterial3Api::class, ExperimentalPermissionsApi::class)
 
 package org.dolphinemu.dolphinemu.features.netplay.ui
 
+import android.Manifest
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import android.provider.Settings
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
@@ -19,6 +24,7 @@ import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Warning
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.Checkbox
 import androidx.compose.material3.CircularProgressIndicator
@@ -42,13 +48,22 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.compose.LifecycleEventEffect
+import com.google.accompanist.permissions.ExperimentalPermissionsApi
+import com.google.accompanist.permissions.PermissionState
+import com.google.accompanist.permissions.isGranted
+import com.google.accompanist.permissions.rememberPermissionState
+import com.google.accompanist.permissions.shouldShowRationale
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.emptyFlow
@@ -58,6 +73,7 @@ import org.dolphinemu.dolphinemu.features.netplay.model.ConnectionType
 import org.dolphinemu.dolphinemu.ui.theme.DolphinScaffold
 import org.dolphinemu.dolphinemu.ui.theme.DolphinTheme
 import org.dolphinemu.dolphinemu.ui.theme.MenuSpacer
+import org.dolphinemu.dolphinemu.ui.theme.OutlinedBox
 
 private data class ErrorDialogState(val message: String) {
     val onDismissed = CompletableDeferred<Unit>()
@@ -87,6 +103,23 @@ fun NetplaySetupScreen(
     onHostClicked: () -> Unit,
     onConnectClicked: () -> Unit,
 ) {
+    val localNetworkPermissionState: PermissionState? =
+        if (
+            connectionType is ConnectionType.DirectConnection &&
+            Build.VERSION.SDK_INT >= Build.VERSION_CODES.CINNAMON_BUN
+        ) {
+            rememberPermissionState(Manifest.permission.ACCESS_LOCAL_NETWORK) { _ ->
+                // Try to connect even if the user denied the permission. The warning is on screen
+                // so it's up to them to determine if they are using local network and need to grant it.
+                when (connectionRole) {
+                    ConnectionRole.Host -> onHostClicked()
+                    ConnectionRole.Connect -> onConnectClicked()
+                }
+            }
+        } else {
+            null
+        }
+
     DolphinScaffold(
         title = { Text(stringResource(R.string.netplay_setup_title)) },
         navigationIcon = {
@@ -99,9 +132,19 @@ fun NetplaySetupScreen(
         },
         floatingActionButton = {
             ExtendedFloatingActionButton(
-                onClick = when(connectionRole) {
-                    ConnectionRole.Host -> onHostClicked
-                    ConnectionRole.Connect -> onConnectClicked
+                onClick = {
+                    if (
+                        localNetworkPermissionState != null &&
+                        !localNetworkPermissionState.status.isGranted &&
+                        !localNetworkPermissionState.status.shouldShowRationale
+                    ) {
+                        localNetworkPermissionState.launchPermissionRequest()
+                    } else {
+                        when (connectionRole) {
+                            ConnectionRole.Host -> onHostClicked()
+                            ConnectionRole.Connect -> onConnectClicked()
+                        }
+                    }
                 },
             ) {
                 if (connecting) {
@@ -238,6 +281,10 @@ private fun NetplaySetupContent(
             onUseUpnpChanged = onUseUpnpChanged,
         )
     }
+
+    LocalNetworkPermissionInfo(
+        connectionType = connectionType,
+    )
 }
 
 @Composable
@@ -374,8 +421,87 @@ private fun HostMenu(
                 )
             }
         }
+    }
+}
 
-        MenuSpacer()
+@Composable
+private fun LocalNetworkPermissionInfo(
+    connectionType: ConnectionType,
+) {
+    if (
+        connectionType is ConnectionType.DirectConnection &&
+        Build.VERSION.SDK_INT >= Build.VERSION_CODES.CINNAMON_BUN
+    ) {
+        val context = LocalContext.current
+
+        // Android permissions do not differentiate between isGranted being false because the user
+        // has never been asked and isGranted being false because the user denied twice. We only
+        // get shouldShowRationale which, if the user keeps denying goes false, true, always false.
+        // So if the value does not change after calling launchPermissionRequest we know we are in
+        // the final denied state and launch app settings for the user to manually grant from there.
+        var previousShouldShowRationale by rememberSaveable { mutableStateOf(false) }
+
+        // Check if the permission dialog actually showed by detecting an onPause event, this allows
+        // us to detect if the dialog was dismissed with the back button which would prevent
+        // previousShouldShowRationale from toggling as described above.
+        var dialogShown by rememberSaveable { mutableStateOf(false) }
+        LifecycleEventEffect(Lifecycle.Event.ON_PAUSE) { dialogShown = true }
+
+        lateinit var permissionState: PermissionState
+        permissionState =
+            rememberPermissionState(Manifest.permission.ACCESS_LOCAL_NETWORK) { granted ->
+                if (
+                    !granted &&
+                    !dialogShown &&
+                    previousShouldShowRationale == permissionState.status.shouldShowRationale
+                ) {
+                    context.startActivity(
+                        Intent(
+                            Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
+                            Uri.fromParts("package", context.packageName, null)
+                        )
+                    )
+                }
+                previousShouldShowRationale = permissionState.status.shouldShowRationale
+            }
+
+        if (!permissionState.status.isGranted) {
+            MenuSpacer()
+
+            OutlinedBox(
+                label = {
+                    Icon(
+                        imageVector = Icons.Default.Warning,
+                        tint = MaterialTheme.colorScheme.error,
+                        contentDescription = null,
+                    )
+                }
+            ) {
+                Column(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                ) {
+                    Text(
+                        text = stringResource(R.string.netplay_local_network_permission_info),
+                        color = MaterialTheme.colorScheme.secondary,
+                        style = MaterialTheme.typography.bodyMedium,
+                    )
+
+                    Spacer(modifier = Modifier.height(8.dp))
+
+                    TextButton(
+                        onClick = {
+                            previousShouldShowRationale = permissionState.status.shouldShowRationale
+                            dialogShown = false
+                            permissionState.launchPermissionRequest()
+                        },
+                        modifier = Modifier.align(Alignment.End)
+                    ) {
+                        Text(text = stringResource(R.string.netplay_give_permission))
+                    }
+                }
+            }
+        }
     }
 }
 

Source/Android/app/src/main/res/values/strings.xml

@@ -1062,4 +1062,6 @@ It can efficiently compress both junk data and encrypted Wii data.
     <string name="netplay_address_share">Share address</string>
     <string name="netplay_address_retry">Retry</string>
     <string name="netplay_transfer_progress">%1$s/%2$s MiB</string>
+    <string name="netplay_local_network_permission_info">Dolphin needs permission to connect to devices on a local network. If you only want to use netplay over the internet, the permission is not required.</string>
+    <string name="netplay_give_permission">Give permission</string>
 </resources>

Source/Android/gradle/libs.versions.toml

@@ -26,6 +26,7 @@ slidingpanelayout = "1.2.0"
 swiperefreshlayout = "1.2.0"
 tvprovider = "1.1.0"
 uiautomator = "2.4.0"
+accompanist = "0.37.3"
 
 [libraries]
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose" }
@@ -64,6 +65,7 @@ filepicker = { group = "com.nononsenseapps", name = "filepicker", version.ref =
 kotlinx-coroutines-android = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-android", version.ref = "kotlinxCoroutinesAndroid" }
 kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerializationJson" }
 material = { group = "com.google.android.material", name = "material", version.ref = "material" }
+accompanist = { group = "com.google.accompanist", name = "accompanist-permissions", version.ref = "accompanist" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }