manager: fix misleading tips when grant root failed.

manager/app/src/main/java/me/weishu/kernelsu/ui/MainActivity.kt

@@ -32,6 +32,7 @@ import me.weishu.kernelsu.ui.screen.NavGraphs
 import me.weishu.kernelsu.ui.theme.KernelSUTheme
 import me.weishu.kernelsu.ui.util.LocalDialogHost
 import me.weishu.kernelsu.ui.util.LocalSnackbarHost
+import me.weishu.kernelsu.ui.util.rootAvailable
 
 class MainActivity : ComponentActivity() {
 
@@ -66,7 +67,7 @@ class MainActivity : ComponentActivity() {
 @Composable
 private fun BottomBar(navController: NavHostController) {
     val isManager = Natives.becomeManager(ksuApp.packageName)
-    val fullFeatured = isManager && !Natives.requireNewKernel()
+    val fullFeatured = isManager && !Natives.requireNewKernel() && rootAvailable()
     NavigationBar(tonalElevation = 8.dp) {
         BottomBarDestination.values().forEach { destination ->
             if (!fullFeatured && destination.rootRequired) return@forEach

manager/app/src/main/java/me/weishu/kernelsu/ui/screen/Home.kt

@@ -69,6 +69,11 @@ fun HomeScreen(navigator: DestinationsNavigator) {
                     )
                 )
             }
+            if (!rootAvailable()) {
+                WarningCard(
+                    stringResource(id = R.string.grant_root_failed)
+                )
+            }
             val checkUpdate =
                 LocalContext.current.getSharedPreferences("settings", Context.MODE_PRIVATE)
                     .getBoolean("check_update", true)

manager/app/src/main/java/me/weishu/kernelsu/ui/util/KsuCli.kt

@@ -140,6 +140,11 @@ fun reboot(reason: String = "") {
     ShellUtils.fastCmd(shell, "/system/bin/svc power reboot $reason || /system/bin/reboot $reason")
 }
 
+fun rootAvailable(): Boolean {
+    val shell = getRootShell()
+    return shell.isRoot
+}
+
 fun overlayFsAvailable(): Boolean {
     val shell = getRootShell()
     // check /proc/filesystems