Hide root summary if rooted

src/main/scala/com/github/shadowsocks/ShadowsocksSettings.scala

@@ -5,7 +5,7 @@ import java.util.Locale
 import android.app.AlertDialog
 import android.content.{DialogInterface, Intent}
 import android.net.Uri
-import android.os.Bundle
+import android.os.{Build, Bundle}
 import android.preference.{Preference, PreferenceFragment}
 import android.webkit.{WebViewClient, WebView}
 import com.github.shadowsocks.utils.Key
@@ -30,7 +30,11 @@ class ShadowsocksSettings extends PreferenceFragment {
       true
     })
 
-    findPreference("flush_dnscache").setOnPreferenceClickListener((preference: Preference) => {
+    val flush = findPreference("flush_dnscache")
+    if (Build.VERSION.SDK_INT >= 17 && !ShadowsocksApplication.isRoot) {
+      flush.setEnabled(false)
+      flush.setSummary(R.string.flush_dnscache_summary_disabled)
+    } else flush.setOnPreferenceClickListener((preference: Preference) => {
       ShadowsocksApplication.track(Shadowsocks.TAG, "flush_dnscache")
       activity.flushDnsCache()
       true

src/main/scala/com/github/shadowsocks/utils/Utils.scala

@@ -55,7 +55,7 @@ import android.util.{DisplayMetrics, Base64, Log}
 import android.view.View.MeasureSpec
 import android.view.{Gravity, View, Window}
 import android.widget.Toast
-import com.github.shadowsocks.BuildConfig
+import com.github.shadowsocks.{ShadowsocksApplication, BuildConfig}
 import org.xbill.DNS._
 
 
@@ -155,24 +155,13 @@ object Utils {
 
   // Blocked > 3 seconds
   def toggleAirplaneMode(context: Context) {
-    if (Build.VERSION.SDK_INT >= 17) {
-      toggleAboveApiLevel17()
-    } else {
+    if (ShadowsocksApplication.isRoot) {
+      Console.runRootCommand(Array("ndc resolver flushdefaultif", "ndc resolver flushif wlan0"))
+    } else if (Build.VERSION.SDK_INT < 17) {
       toggleBelowApiLevel17(context)
     }
   }
 
-  private def toggleAboveApiLevel17() {
-    // Android 4.2 and above
-
-    Console.runRootCommand(Array("ndc resolver flushdefaultif", "ndc resolver flushif wlan0"))
-
-    //Utils.runRootCommand("settings put global airplane_mode_on 1\n"
-    //  + "am broadcast -a android.intent.action.AIRPLANE_MODE --ez state true\n"
-    //  + "settings put global airplane_mode_on 0\n"
-    //  + "am broadcast -a android.intent.action.AIRPLANE_MODE --ez state false\n")
-  }
-
   //noinspection ScalaDeprecation
   private def toggleBelowApiLevel17(context: Context) {
     // Android 4.2 below