Add support for Android TV

README.md

@@ -92,6 +92,20 @@ These broadcasts can also be sent via `adb`. For example:
 adb shell am broadcast -a com.chiller3.basicsync.AUTO_MODE com.chiller3.basicsync
 ```
 
+## Android TV
+
+BasicSync has basic support for Android TV. The UI is still the same phone/tablet UI, so navigation may be a bit awkward, but most functionality is accessible using the TV remote's arrow keys, including Syncthing's web UI.
+
+However, there are several things that cannot be supported due to Android TV's limitations:
+
+* Importing and exporting the configuration, as well as saving logs via debug mode, are not supported because Android TV does not include DocumentsUI (the system file manager and file picker).
+* There is no way to see BasicSync's notification because Android TV does not support notifications from third party apps at all. BasicSync still needs to request the useless notifications permission to run Syncthing reliably in the background.
+* Android TV has no UI for disabling "battery" optimizations, but it is also required for Syncthing to run reliably in the background. This must be done via adb instead:
+
+    ```bash
+    adb shell dumpsys deviceidle whitelist +com.chiller3.basicsync
+    ```
+
 ## Persistent notification
 
 Android 14 and newer [no longer allow](https://developer.android.com/about/versions/14/behavior-changes-all#non-dismissable-notifications) regular apps to prevent persistent notifications from being dismissed. To work around this, BasicSync will automatically show the persistent notification again whenever it is dismissed.

app/src/main/AndroidManifest.xml

@@ -8,6 +8,15 @@
     <uses-feature
         android:name="android.hardware.camera"
         android:required="false" />
+    <uses-feature
+        android:name="android.hardware.location.gps"
+        android:required="false" />
+    <uses-feature
+        android:name="android.hardware.touchscreen"
+        android:required="false" />
+    <uses-feature
+        android:name="android.software.leanback"
+        android:required="false" />
 
     <!-- For Syncthing to run at all. -->
     <uses-permission
@@ -43,7 +52,8 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
     <!-- For optionally running only when connected to specific Wi-Fi networks. -->
-    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"
+        tools:ignore="LeanbackUsesWifi" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION"
@@ -70,7 +80,7 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.BasicSync"
         tools:targetApi="tiramisu"
-        tools:ignore="DataExtractionRules">
+        tools:ignore="MissingTvBanner">
         <meta-data android:name="android.webkit.WebView.MetricsOptOut"
             android:value="true" />
         <meta-data android:name="android.webkit.WebView.EnableSafeBrowsing"
@@ -84,6 +94,7 @@
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
+                <category android:name="android.intent.category.LEANBACK_LAUNCHER" />
             </intent-filter>
         </activity>
 

app/src/main/java/com/chiller3/basicsync/settings/ErrorDetailsDialog.kt

@@ -25,6 +25,7 @@ import com.chiller3.basicsync.R
 fun ErrorDetailsDialog(
     message: String?,
     onDismiss: () -> Unit,
+    showCopy: Boolean = true,
 ) {
     val context = LocalContext.current
 
@@ -46,7 +47,7 @@ fun ErrorDetailsDialog(
             }
         },
         dismissButton = {
-            message?.let {
+            if (message != null && showCopy) {
                 TextButton(
                     onClick = {
                         val clipboardManager = context.getSystemService(ClipboardManager::class.java)

app/src/main/java/com/chiller3/basicsync/settings/SettingsAlert.kt

@@ -6,6 +6,7 @@
 package com.chiller3.basicsync.settings
 
 import android.net.Uri
+import com.chiller3.basicsync.BuildConfig
 
 sealed interface SettingsAlert {
     data object ImportSucceeded : SettingsAlert
@@ -25,4 +26,8 @@ sealed interface SettingsAlert {
     data class LogcatFailed(val uri: Uri, val error: String) : SettingsAlert
 
     data object BrowserNotFound : SettingsAlert
+
+    data object TvInhibitBatteryOpt : SettingsAlert {
+        const val COMMAND = "adb shell dumpsys deviceidle whitelist +${BuildConfig.APPLICATION_ID}"
+    }
 }

app/src/main/java/com/chiller3/basicsync/settings/SettingsScreen.kt

@@ -6,9 +6,11 @@
 package com.chiller3.basicsync.settings
 
 import android.annotation.SuppressLint
+import android.app.Activity
 import android.content.ActivityNotFoundException
 import android.content.Intent
 import android.content.IntentFilter
+import android.content.pm.PackageManager
 import android.content.res.Configuration
 import android.os.BatteryManager
 import android.os.Build
@@ -91,6 +93,8 @@ fun SettingsScreen(
     val context = LocalContext.current
     val resources = LocalResources.current
 
+    val isTv = remember { context.packageManager.hasSystemFeature(PackageManager.FEATURE_LEANBACK) }
+
     val prefs = remember { Preferences(context) }
     var reloadPrefs by remember { mutableIntStateOf(0) }
     val isManualMode = remember(reloadPrefs) { prefs.isManualMode }
@@ -121,6 +125,15 @@ fun SettingsScreen(
     val conflicts by viewModel.conflicts.collectAsStateWithLifecycle()
     val importExportState by viewModel.importExportState.collectAsStateWithLifecycle()
 
+    val requestInhibitBatteryOpt = rememberLauncherForActivityResult(
+        ActivityResultContracts.StartActivityForResult(),
+    ) {
+        if (it.resultCode == Activity.RESULT_CANCELED && isTv) {
+            viewModel.addAlert(SettingsAlert.TvInhibitBatteryOpt)
+        } else {
+            reloadPerms++
+        }
+    }
     val requestPermissionActivity = rememberLauncherForActivityResult(
         ActivityResultContracts.StartActivityForResult(),
     ) {
@@ -215,6 +228,8 @@ fun SettingsScreen(
                         resources.getString(R.string.alert_logcat_failure, alert.uri.formattedString)
                     SettingsAlert.BrowserNotFound ->
                         resources.getString(R.string.alert_browser_not_found)
+                    SettingsAlert.TvInhibitBatteryOpt ->
+                        resources.getString(R.string.alert_tv_inhibit_battery_opt)
                 }
                 val details = when (alert) {
                     SettingsAlert.ImportSucceeded -> null
@@ -226,12 +241,26 @@ fun SettingsScreen(
                     is SettingsAlert.LogcatSucceeded -> null
                     is SettingsAlert.LogcatFailed -> alert.error
                     SettingsAlert.BrowserNotFound -> null
+                    is SettingsAlert.TvInhibitBatteryOpt -> buildString {
+                        append(resources.getString(R.string.alert_tv_inhibit_battery_opt_details))
+                        append("\n\n")
+                        append(alert.COMMAND)
+                    }
+                }
+
+                // Snack bars are not focusable on TVs, so just show the dialog directly.
+                if (isTv) {
+                    showErrorDialog = details
                 }
 
                 val result = params.snackbarHostState.showSnackbar(
                     message = msg,
-                    details?.let { resources.getString(R.string.action_details) },
-                    withDismissAction = true,
+                    if (isTv) {
+                        null
+                    } else {
+                        details?.let { resources.getString(R.string.action_details) }
+                    },
+                    withDismissAction = !isTv,
                 )
                 viewModel.acknowledgeFirstAlert()
 
@@ -246,6 +275,7 @@ fun SettingsScreen(
             ErrorDetailsDialog(
                 message = message,
                 onDismiss = { showErrorDialog = null },
+                showCopy = !isTv,
             )
         }
 
@@ -268,7 +298,7 @@ fun SettingsScreen(
             showExit = showExit,
             isDebugMode = isDebugMode,
             onInhibitBatteryOptGrant = {
-                requestPermissionActivity.launch(Permissions.getInhibitBatteryOptIntent(context))
+                requestInhibitBatteryOpt.launch(Permissions.getInhibitBatteryOptIntent(context))
             },
             onNotificationsGrant = {
                 requestPermissionsRequired.launch(Permissions.NOTIFICATION)

app/src/main/java/com/chiller3/basicsync/settings/WebUiScreen.kt

@@ -9,6 +9,7 @@ import android.annotation.SuppressLint
 import android.app.Activity.RESULT_OK
 import android.content.ActivityNotFoundException
 import android.content.Intent
+import android.content.pm.PackageManager
 import android.net.Uri
 import android.net.http.SslCertificate
 import android.net.http.SslError
@@ -149,6 +150,10 @@ fun WebUiScreen(
         webView.evaluateJavascript("onDeviceIdScanned(\"${jsEscape(deviceId)}\");") {}
     }
 
+    fun setTvMode(enable: Boolean) {
+        webView.evaluateJavascript("setTvMode($enable);") {}
+    }
+
     val requestQrScanner = rememberLauncherForActivityResult(
         ActivityResultContracts.StartActivityForResult()
     ) {
@@ -253,6 +258,10 @@ fun WebUiScreen(
                 }
 
                 view.evaluateJavascript(script) {}
+
+                val isTv = context.packageManager.hasSystemFeature(PackageManager.FEATURE_LEANBACK)
+                Log.d(TAG, "Setting TV mode: $isTv")
+                setTvMode(isTv)
             }
 
             override fun doUpdateVisitedHistory(view: WebView, url: String, isReload: Boolean) {

app/src/main/java/com/chiller3/basicsync/ui/Preferences.kt

@@ -42,8 +42,13 @@ import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
+import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusProperties
+import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.semantics.Role
@@ -196,12 +201,14 @@ fun Preference(
 private fun PreferenceSwitch(
     checked: Boolean,
     onCheckedChange: ((Boolean) -> Unit)?,
+    modifier: Modifier = Modifier,
     enabled: Boolean = true,
     switchColors: SwitchColors = PreferenceDefaults.switchColors(),
 ) {
     Switch(
         checked = checked,
         onCheckedChange = onCheckedChange,
+        modifier = modifier,
         enabled = enabled,
         thumbContent = {
             Icon(
@@ -277,10 +284,17 @@ fun SplitSwitchPreference(
     switchColors: SwitchColors = PreferenceDefaults.switchColors(),
     title: @Composable () -> Unit,
 ) {
+    val preferenceFocus = remember { FocusRequester() }
+    val switchFocus = remember { FocusRequester() }
+
     SegmentedListItem(
         onClick = onClick,
         shapes = shapes,
-        modifier = Modifier.widthIn(max = PreferenceDefaults.MaxWidth).then(modifier),
+        modifier = Modifier
+            .widthIn(max = PreferenceDefaults.MaxWidth)
+            .focusRequester(preferenceFocus)
+            .focusProperties { end = switchFocus }
+            .then(modifier),
         enabled = enabled,
         trailingContent = {
             Row(verticalAlignment = Alignment.CenterVertically) {
@@ -306,12 +320,15 @@ fun SplitSwitchPreference(
                             width = PreferenceDefaults.DividerWidth,
                             height = PreferenceDefaults.DividerHeight,
                         )
-                        .background(color = supportingContentColor)
+                        .background(color = supportingContentColor),
                 )
 
                 PreferenceSwitch(
                     checked = checked,
                     onCheckedChange = onCheckedChange,
+                    modifier = Modifier
+                        .focusRequester(switchFocus)
+                        .focusProperties { start = preferenceFocus },
                     enabled = enabled,
                     switchColors = switchColors,
                 )

app/src/main/res/raw/webview_bridge.js

@@ -200,3 +200,39 @@ if (!tryMutate()) {
         subtree: true,
     });
 }
+
+// Prevent arrow keys from opening dropdown menus. There is no good way to leave the menu afterwards
+// because the up/down arrow keys are hijacked to only move within the list and a TV remote has no
+// escape button to close the menu. Spatial navigation already works very well for this use case.
+$(document).off('keydown.bs.dropdown.data-api');
+
+// This is atrocious. By default, the browser makes the up/down arrow keys adjust number inputs up
+// and down. preventDefault() stops this, but also prevents using spatial navigation to move to the
+// next element above or below the input. There is currently no way to trigger spatial navigation
+// programmatically. Instead, we'll just make the field read-only for a bit so that the arrow keys
+// don't change the value.
+$(document).on('keydown', 'input', function (e) {
+    if ((e.which == 38 || e.which == 40) && e.target.type == 'number') {
+        const wasReadOnly = e.target.readOnly;
+
+        e.target.readOnly = true;
+        if (!wasReadOnly) {
+            setTimeout(function() { e.target.readOnly = false; }, 100);
+        }
+    }
+});
+
+function setTvMode(enable) {
+    const currentStyle = document.getElementById('basicsync-tv-style');
+
+    if (enable == !!currentStyle) {
+        return;
+    } else if (enable) {
+        const style = document.createElement('style');
+        style.id = 'basicsync-tv-style';
+        style.innerHTML = ':focus { border: 3px dotted !important; }';
+        document.body.appendChild(style);
+    } else {
+        document.body.removeChild(currentStyle);
+    }
+}

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

@@ -169,6 +169,10 @@
     <string name="alert_browser_not_found">No web browser is available.</string>
     <!-- Alert shown when opening the system file manager (DocumentsUI) and it is disabled or removed (eg. in custom ROM). -->
     <string name="alert_documentsui_not_found">Android\'s builtin file manager (DocumentsUI) is unavailable.</string>
+    <!-- Alert shown when trying to disable "battery" optimizations on Android TV. -->
+    <string name="alert_tv_inhibit_battery_opt">Disabling \"battery\" optimizations requires manual steps on Android TV.</string>
+    <!-- Detailed message for alert shown when trying to disable "battery" optimizations on Android TV. -->
+    <string name="alert_tv_inhibit_battery_opt_details">Android TV has no UI for disabling \"battery\" optimizations, but it is still required to run Syncthing in the background reliably. This must be done by running the following adb command.</string>
 
     <!-- Button shown in the local filesystem folder picker to create a new local folder. -->
     <string name="dialog_new_folder_title">New folder</string>