chenxiaolong · Sep 25, 2026 · Sep 25, 2026
diff --git a/app/src/main/java/com/chiller3/basicsync/Preferences.kt b/app/src/main/java/com/chiller3/basicsync/Preferences.kt
@@ -25,6 +25,7 @@ class Preferences(context: Context) {
         const val PREF_REMOTE_CONTROL = "remote_control"
         const val PREF_ALLOW_AUTO_MODE = "allow_auto_mode"
         const val PREF_START_ON_BOOT = "start_on_boot"
+        const val PREF_PROXY_OVERRIDE = "proxy_override"
         const val PREF_REQUIRE_UNMETERED_NETWORK = "require_unmetered_network"
         const val PREF_NETWORK_ALLOW_WIFI = "network_allow_wifi"
         const val PREF_NETWORK_ALLOW_CELLULAR = "network_allow_cellular"
@@ -97,6 +98,10 @@ class Preferences(context: Context) {
         get() = prefs.getBoolean(PREF_START_ON_BOOT, true)
         set(enabled) = prefs.edit { putBoolean(PREF_START_ON_BOOT, enabled) }
 
+    var proxyOverride: String?
+        get() = prefs.getString(PREF_PROXY_OVERRIDE, null)
+        set(url) = prefs.edit { putString(PREF_PROXY_OVERRIDE, url?.ifEmpty { null }) }
+
     var requireUnmeteredNetwork: Boolean
         get() = prefs.getBoolean(PREF_REQUIRE_UNMETERED_NETWORK, true)
         set(enabled) = prefs.edit { putBoolean(PREF_REQUIRE_UNMETERED_NETWORK, enabled) }

diff --git a/app/src/main/java/com/chiller3/basicsync/settings/ProxyOverrideDialog.kt b/app/src/main/java/com/chiller3/basicsync/settings/ProxyOverrideDialog.kt
@@ -0,0 +1,88 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Andrew Gunnerson
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package com.chiller3.basicsync.settings
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.text.input.TextFieldLineLimits
+import androidx.compose.foundation.text.input.rememberTextFieldState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.DialogProperties
+import androidx.core.net.toUri
+import com.chiller3.basicsync.R
+
+@Composable
+fun ProxyOverrideDialog(
+    initialUrl: String?,
+    onSelect: (String?) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val input = rememberTextFieldState(initialText = initialUrl ?: "")
+    val url = tryParseInput(input.text.toString())
+
+    AlertDialog(
+        title = { Text(text = stringResource(R.string.pref_proxy_override_name)) },
+        text = {
+            Column(modifier = Modifier.verticalScroll(state = rememberScrollState())) {
+                Text(text = stringResource(R.string.pref_proxy_override_desc))
+
+                OutlinedTextField(
+                    state = input,
+                    modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
+                    label = { Text(text = stringResource(R.string.dialog_proxy_override_hint)) },
+                    placeholder = { Text(text = "{http,https,socks5}://1.2.3.4:5678") },
+                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Uri),
+                    lineLimits = TextFieldLineLimits.SingleLine,
+                )
+            }
+        },
+        onDismissRequest = onDismiss,
+        confirmButton = {
+            TextButton(
+                onClick = { onSelect(url!!.ifEmpty { null }) },
+                enabled = url != null,
+            ) {
+                Text(text = stringResource(android.R.string.ok))
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text(text = stringResource(android.R.string.cancel))
+            }
+        },
+        properties = DialogProperties(
+            dismissOnBackPress = false,
+            dismissOnClickOutside = false,
+        ),
+    )
+}
+
+private fun tryParseInput(input: String): String? {
+    if (input.isEmpty()) {
+        return input
+    }
+
+    val uri = input.toUri()
+
+    if ((uri.scheme == "http" || uri.scheme == "https" || uri.scheme == "socks5")
+            && !uri.authority.isNullOrEmpty()) {
+        return input
+    }
+
+    return null
+}
diff --git a/app/src/main/java/com/chiller3/basicsync/settings/SettingsScreen.kt b/app/src/main/java/com/chiller3/basicsync/settings/SettingsScreen.kt
@@ -113,6 +113,7 @@ fun SettingsScreen(
     val remoteControl = remember(reloadPrefs) { prefs.remoteControl }
     val allowAutoMode = remember(reloadPrefs) { prefs.allowAutoMode }
     val startOnBoot = remember(reloadPrefs) { prefs.startOnBoot }
+    val proxyOverride = remember(reloadPrefs) { prefs.proxyOverride }
     val isDebugMode = remember(reloadPrefs) { prefs.isDebugMode }
 
     var reloadPerms by remember { mutableIntStateOf(0) }
@@ -336,6 +337,7 @@ fun SettingsScreen(
             remoteControl = remoteControl,
             allowAutoMode = allowAutoMode,
             startOnBoot = startOnBoot,
+            proxyOverride = proxyOverride,
             isDebugMode = isDebugMode,
             onInhibitBatteryOptGrant = {
                 requestInhibitBatteryOpt.launch(Permissions.getInhibitBatteryOptIntent(context))
@@ -470,6 +472,10 @@ fun SettingsScreen(
                 prefs.startOnBoot = enabled
                 reloadPrefs++
             },
+            onProxyOverrideChange = { url ->
+                prefs.proxyOverride = url
+                reloadPrefs++
+            },
             onDebugModeChange = { enabled ->
                 prefs.isDebugMode = enabled
                 reloadPrefs++
@@ -577,6 +583,7 @@ private fun SettingsContent(
     remoteControl: Boolean,
     allowAutoMode: Boolean,
     startOnBoot: Boolean,
+    proxyOverride: String?,
     isDebugMode: Boolean,
     onInhibitBatteryOptGrant: () -> Unit,
     onNotificationsGrant: () -> Unit,
@@ -602,6 +609,7 @@ private fun SettingsContent(
     onRemoteControlChange: (Boolean) -> Unit,
     onAllowAutoModeChange: (Boolean) -> Unit,
     onStartOnBootChange: (Boolean) -> Unit,
+    onProxyOverrideChange: (String?) -> Unit,
     onDebugModeChange: (Boolean) -> Unit,
     onSourceRepoOpen: () -> Unit,
     onSaveLogs: () -> Unit,
@@ -668,6 +676,7 @@ private fun SettingsContent(
     val runState = serviceState?.runState
 
     var showMinBatteryLevelDialog by rememberSaveable { mutableStateOf(false) }
+    var showProxyOverrideDialog by rememberSaveable { mutableStateOf(false) }
 
     PreferenceColumn(contentPadding = contentPadding) {
         if (missingPermissions.isNotEmpty()) {
@@ -914,13 +923,23 @@ private fun SettingsContent(
             SwitchPreference(
                 checked = startOnBoot,
                 onCheckedChange = onStartOnBootChange,
-                shapes = BetterSegmentedShapes.bottom(),
+                shapes = BetterSegmentedShapes.middle(),
                 title = { Text(text = stringResource(R.string.pref_start_on_boot_name)) },
                 summary = { Text(text = stringResource(R.string.pref_start_on_boot_desc)) },
                 modifier = Modifier.animateItem(),
             )
         }
 
+        item(key = "proxy_override") {
+            Preference(
+                onClick = { showProxyOverrideDialog = true },
+                shapes = BetterSegmentedShapes.bottom(),
+                title = { Text(text = stringResource(R.string.pref_proxy_override_name)) },
+                summary = { Text(text = stringResource(R.string.pref_proxy_override_desc)) },
+                modifier = Modifier.animateItem(),
+            )
+        }
+
         item(key = "about") {
             PreferenceCategory(
                 title = { Text(text = stringResource(R.string.pref_header_about)) },
@@ -971,6 +990,19 @@ private fun SettingsContent(
             },
         )
     }
+
+    if (showProxyOverrideDialog) {
+        ProxyOverrideDialog(
+            initialUrl = proxyOverride,
+            onSelect = { url ->
+                onProxyOverrideChange(url)
+                showProxyOverrideDialog = false
+            },
+            onDismiss = {
+                showProxyOverrideDialog = false
+            },
+        )
+    }
 }
 
 @Composable
@@ -1074,6 +1106,7 @@ private fun PreviewSettingsScreen() {
                 remoteControl = false,
                 allowAutoMode = true,
                 startOnBoot = true,
+                proxyOverride = null,
                 isDebugMode = true,
                 onInhibitBatteryOptGrant = {},
                 onNotificationsGrant = {},
@@ -1099,6 +1132,7 @@ private fun PreviewSettingsScreen() {
                 onRemoteControlChange = {},
                 onAllowAutoModeChange = {},
                 onStartOnBootChange = {},
+                onProxyOverrideChange = {},
                 onDebugModeChange = {},
                 onSourceRepoOpen = {},
                 onSaveLogs = {},

diff --git a/app/src/main/java/com/chiller3/basicsync/syncthing/SyncthingService.kt b/app/src/main/java/com/chiller3/basicsync/syncthing/SyncthingService.kt
@@ -440,8 +440,11 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
     private lateinit var deviceStateTracker: DeviceStateTracker
     @GuardedBy("stateLock")
     private var deviceState = DeviceState()
+
+    @GuardedBy("stateLock")
+    private var desiredProxyInfo = ProxyInfo(proxy = "", noProxy = "")
     @GuardedBy("stateLock")
-    private var runningProxyInfo: ProxyInfo? = null
+    private var runningProxyInfo = desiredProxyInfo
 
     @GuardedBy("stateLock")
     private var blockedReasons = EnumSet.noneOf(BlockedReason::class.java)
@@ -632,6 +635,7 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
         Log.d(TAG, "Preference $key changed")
 
         var recomputeBlockedReasons = false
+        var recomputeProxyInfo = false
 
         // We have to switch foreground service and network callback types when location becomes
         // needed or no longer needed.
@@ -640,19 +644,21 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
         when (key) {
             in BLOCKED_REASONS_PREFS, in DeviceState.PREFS -> recomputeBlockedReasons = true
             in STATE_CHANGE_PREFS -> {}
+            Preferences.PREF_PROXY_OVERRIDE -> recomputeProxyInfo = true
             else -> return
         }
 
         stateChanged(
             recomputeBlockedReasons = recomputeBlockedReasons,
+            recomputeProxyInfo = recomputeProxyInfo,
             forceShowNotification = forceShowNotification,
         )
     }
 
     override fun onDeviceStateChanged(state: DeviceState) {
         synchronized(stateLock) {
             deviceState = state
-            stateChanged(recomputeBlockedReasons = true)
+            stateChanged(recomputeBlockedReasons = true, recomputeProxyInfo = true)
         }
     }
 
@@ -678,6 +684,7 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
 
     private fun stateChanged(
         recomputeBlockedReasons: Boolean = false,
+        recomputeProxyInfo: Boolean = false,
         forceShowNotification: Boolean = false,
     ) {
         synchronized(stateLock) {
@@ -702,6 +709,12 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
                 }
             }
 
+            if (recomputeProxyInfo) {
+                desiredProxyInfo = prefs.proxyOverride
+                    ?.let { ProxyInfo(proxy = it, noProxy = "") }
+                    ?: deviceState.proxyInfo
+            }
+
             handleStateChangeLocked()
 
             if (!shouldThreadRun) {
@@ -773,7 +786,7 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
         // The service needs to be restarted for proxy changes to take effect. The hack we do to set
         // the proxy on the golang side can't be made thread-safe.
         val needFullRestart = !shouldThreadRun
-                || runningProxyInfo != deviceState.proxyInfo
+                || runningProxyInfo != desiredProxyInfo
                 || preRunActions.isNotEmpty()
                 || recheckPermissions
 
@@ -811,8 +824,8 @@ class SyncthingService : Service(), SyncthingStatusReceiver, DeviceStateListener
                 actions.addAll(preRunActions)
                 preRunActions.clear()
 
-                runningProxyInfo = deviceState.proxyInfo
-                proxyInfo = deviceState.proxyInfo
+                runningProxyInfo = desiredProxyInfo
+                proxyInfo = desiredProxyInfo
 
                 // recheckPermissions is cleared in onCheckStoragePermissions().
                 recheckOnly = !shouldStart

diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
@@ -110,6 +110,10 @@
     <string name="pref_start_on_boot_name">Start on boot</string>
     <!-- Description for the preference to start the app after a reboot. -->
     <string name="pref_start_on_boot_desc">Automatically start the app after a reboot.</string>
+    <!-- Title for the preference to override Android's proxy settings. -->
+    <string name="pref_proxy_override_name">Override proxy settings</string>
+    <!-- Description for the preference to override Android's proxy settings. -->
+    <string name="pref_proxy_override_desc">Use a custom proxy instead of the proxy specified in Android\'s network settings.</string>
     <!-- Title for the preference that shows the version number. The description is two lines: the first line is BasicSync's version and the second line in Syncthing's version. -->
     <string name="pref_version_name">Version</string>
     <!-- Title for the debug preference that saves logs to a file. -->
@@ -248,6 +252,8 @@
     <string name="dialog_wifi_network_message">Enter the name (SSID) of the Wi-Fi network. This also works for hidden Wi-Fi networks.</string>
     <!-- Textbox hint shown in the dialog for manually adding an allowed Wi-Fi network. -->
     <string name="dialog_wifi_network_hint">SSID</string>
+    <!-- Textbox hint shown in the dialog for overriding the proxy URL. -->
+    <string name="dialog_proxy_override_hint">Proxy URL</string>
 
     <!-- Tooltip shown in Syncthing's web UI for selecting a local folder when adding a new shared Syncthing folder. Keep as short as possible. -->
     <string name="web_ui_select_folder">Select folder</string>

diff --git a/external/syncthing b/external/syncthing