Optimized UI refresh to save battery. Extracted all strings to xml to enable localizations.

app/src/main/java/eu/neilalexander/yggdrasil/DnsActivity.kt

@@ -108,7 +108,7 @@ class DnsActivity : AppCompatActivity() {
 
                     view.findViewById<ImageButton>(R.id.deletePeerButton).setOnClickListener { button ->
                         val builder: AlertDialog.Builder = AlertDialog.Builder(this)
-                        builder.setTitle("Remove ${server}?")
+                        builder.setTitle(getString(R.string.dns_remove_title, server))
                         builder.setPositiveButton(getString(R.string.remove)) { dialog, _ ->
                             servers.removeAt(button.tag as Int)
                             preferences.edit().apply {

app/src/main/java/eu/neilalexander/yggdrasil/GlobalApplication.kt

@@ -1,25 +1,27 @@
 package eu.neilalexander.yggdrasil
 
 import android.app.Application
-import android.content.IntentFilter
-import androidx.localbroadcastmanager.content.LocalBroadcastManager
 
 class GlobalApplication: Application() {
-    private var state = PacketTunnelState
     private lateinit var config: ConfigurationProxy
+    var updaterConnections: Int = 0
 
     override fun onCreate() {
         super.onCreate()
         config = ConfigurationProxy(applicationContext)
-
-        LocalBroadcastManager.getInstance(this).registerReceiver(
-            state, IntentFilter(PacketTunnelProvider.RECEIVER_INTENT)
-        )
     }
 
-    override fun onTerminate() {
+    fun subscribe() {
-        super.onTerminate()
+        updaterConnections++
+    }
 
-        LocalBroadcastManager.getInstance(this).unregisterReceiver(state)
+    fun unsubscribe() {
+        if (updaterConnections > 0) {
+            updaterConnections--
+        }
+    }
+
+    fun needUiUpdates(): Boolean {
+        return updaterConnections > 0
     }
 }

app/src/main/java/eu/neilalexander/yggdrasil/MainActivity.kt

@@ -12,12 +12,12 @@ import android.widget.Toast
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.localbroadcastmanager.content.LocalBroadcastManager
+import eu.neilalexander.yggdrasil.PacketTunnelProvider.Companion.STATE_INTENT
 import mobile.Mobile
+import org.json.JSONArray
 
 
 class MainActivity : AppCompatActivity() {
-    private var state = PacketTunnelState
-
     private lateinit var enabledSwitch: Switch
     private lateinit var enabledLabel: TextView
     private lateinit var ipAddressLabel: TextView
@@ -116,20 +116,27 @@ class MainActivity : AppCompatActivity() {
     override fun onResume() {
         super.onResume()
         LocalBroadcastManager.getInstance(this).registerReceiver(
-            receiver, IntentFilter(PacketTunnelState.RECEIVER_INTENT)
+            receiver, IntentFilter(STATE_INTENT)
         )
         val preferences = androidx.preference.PreferenceManager.getDefaultSharedPreferences(this.baseContext)
         val serverString = preferences.getString(KEY_DNS_SERVERS, "")
         if (serverString!!.isNotEmpty()) {
             val servers = serverString.split(",")
             dnsLabel.text = when (servers.size) {
-                0 -> "No servers"
+                0 -> getString(R.string.dns_no_servers)
-                1 -> "1 server"
+                1 -> getString(R.string.dns_one_server)
-                else -> "${servers.size} servers"
+                else -> getString(R.string.dns_many_servers, servers.size)
             }
         } else {
-            dnsLabel.text = "No servers"
+            dnsLabel.text = getString(R.string.dns_no_servers)
         }
+        (application as GlobalApplication).subscribe()
+    }
+
+    override fun onPause() {
+        super.onPause()
+        (application as GlobalApplication).unsubscribe()
+        LocalBroadcastManager.getInstance(this).unregisterReceiver(receiver)
     }
 
     private val receiver: BroadcastReceiver = object : BroadcastReceiver() {
@@ -138,33 +145,39 @@ class MainActivity : AppCompatActivity() {
                 "state" -> {
                     enabledLabel.text = if (intent.getBooleanExtra("started", false)) {
                         enabledSwitch.isChecked = true
-                        if (state.dhtCount() == 0) {
+                        var count = 0
+                        if (intent.hasExtra("dht")) {
+                            val dht = intent.getStringExtra("dht")
+                            if (dht != null && dht != "null") {
+                                val dhtState = JSONArray(dht)
+                                count = dhtState.length()
+                            }
+                        }
+                        if (count == 0) {
                             enabledLabel.setTextColor(Color.RED)
-                            "No connectivity"
+                            getString(R.string.main_no_connectivity)
                         } else {
                             enabledLabel.setTextColor(Color.GREEN)
-                            "Enabled"
+                            getString(R.string.main_enabled)
                         }
                     } else {
                         enabledSwitch.isChecked = false
                         enabledLabel.setTextColor(Color.GRAY)
-                        "Not enabled"
+                        getString(R.string.main_disabled)
                     }
                     ipAddressLabel.text = intent.getStringExtra("ip") ?: "N/A"
                     subnetLabel.text = intent.getStringExtra("subnet") ?: "N/A"
                     coordinatesLabel.text = intent.getStringExtra("coords") ?: "[]"
-                    peersLabel.text = when (val count = state.peerCount()) {
+                    if (intent.hasExtra("peers")) {
-                        0 -> "No peers"
+                        val peerState = JSONArray(intent.getStringExtra("peers") ?: "[]")
-                        1 -> "1 peer"
+                        peersLabel.text = when (val count = peerState.length()) {
-                        else -> "$count peers"
+                            0 -> getString(R.string.main_no_peers)
+                            1 -> getString(R.string.main_one_peer)
+                            else -> getString(R.string.main_many_peers, count)
+                        }
                     }
                 }
             }
         }
     }
-
-    override fun onPause() {
-        super.onPause()
-        LocalBroadcastManager.getInstance(this).unregisterReceiver(receiver)
-    }
 }

app/src/main/java/eu/neilalexander/yggdrasil/PacketTunnelProvider.kt

@@ -17,7 +17,7 @@ private const val TAG = "PacketTunnelProvider"
 
 class PacketTunnelProvider: VpnService() {
     companion object {
-        const val RECEIVER_INTENT = "eu.neilalexander.yggdrasil.PacketTunnelProvider.MESSAGE"
+        const val STATE_INTENT = "eu.neilalexander.yggdrasil.PacketTunnelProvider.STATE_MESSAGE"
 
         const val ACTION_START = "eu.neilalexander.yggdrasil.PacketTunnelProvider.START"
         const val ACTION_STOP = "eu.neilalexander.yggdrasil.PacketTunnelProvider.STOP"
@@ -130,7 +130,7 @@ class PacketTunnelProvider: VpnService() {
             updater()
         }
 
-        val intent = Intent(RECEIVER_INTENT)
+        val intent = Intent(STATE_INTENT)
         intent.putExtra("type", "state")
         intent.putExtra("started", true)
         intent.putExtra("ip", yggdrasil.addressString)
@@ -173,7 +173,7 @@ class PacketTunnelProvider: VpnService() {
             updateThread = null
         }
 
-        val intent = Intent(RECEIVER_INTENT)
+        val intent = Intent(STATE_INTENT)
         intent.putExtra("type", "state")
         intent.putExtra("started", false)
         LocalBroadcastManager.getInstance(this).sendBroadcast(intent)
@@ -183,15 +183,24 @@ class PacketTunnelProvider: VpnService() {
 
     private fun updater() {
         updates@ while (started.get()) {
-            val intent = Intent(RECEIVER_INTENT)
+            if ((application as  GlobalApplication).needUiUpdates()) {
-            intent.putExtra("type", "state")
+                Log.d(TAG, "Sending stats to UI...")
-            intent.putExtra("started", true)
+                val intent = Intent(STATE_INTENT)
-            intent.putExtra("ip", yggdrasil.addressString)
+                intent.putExtra("type", "state")
-            intent.putExtra("subnet", yggdrasil.subnetString)
+                intent.putExtra("started", true)
-            intent.putExtra("coords", yggdrasil.coordsString)
+                intent.putExtra("ip", yggdrasil.addressString)
-            intent.putExtra("peers", yggdrasil.peersJSON)
+                intent.putExtra("subnet", yggdrasil.subnetString)
-            intent.putExtra("dht", yggdrasil.dhtjson)
+                intent.putExtra("coords", yggdrasil.coordsString)
-            LocalBroadcastManager.getInstance(this).sendBroadcast(intent)
+                intent.putExtra("peers", yggdrasil.peersJSON)
+                intent.putExtra("dht", yggdrasil.dhtjson)
+                LocalBroadcastManager.getInstance(this).sendBroadcast(intent)
+            } else {
+                try {
+                    Thread.sleep(1000)
+                } catch (e: InterruptedException) {
+                    return
+                }
+            }
             if (Thread.currentThread().isInterrupted) {
                 break@updates
             }

app/src/main/java/eu/neilalexander/yggdrasil/PacketTunnelState.kt

@@ -1,53 +0,0 @@
-package eu.neilalexander.yggdrasil
-
-import android.content.BroadcastReceiver
-import android.content.Context
-import android.content.Intent
-import androidx.localbroadcastmanager.content.LocalBroadcastManager
-import org.json.JSONArray
-
-object PacketTunnelState: BroadcastReceiver() {
-    var dhtState: JSONArray? = null
-        private set
-
-    var peersState: JSONArray? = null
-        private set
-
-    const val RECEIVER_INTENT = "eu.neilalexander.yggdrasil.PacketTunnelState.MESSAGE"
-
-    fun peerCount(): Int {
-        if (peersState == null) {
-            return 0
-        }
-        return peersState!!.length()
-    }
-
-    fun dhtCount(): Int {
-        if (dhtState == null) {
-            return 0
-        }
-        return dhtState!!.length()
-    }
-
-    override fun onReceive(context: Context?, intent: Intent) {
-        when (intent.getStringExtra("type")) {
-            "state" -> {
-                var dht = intent.getStringExtra("dht")
-                var peers = intent.getStringExtra("peers")
-
-                if (dht == null || dht == "null") {
-                    dht = "[]"
-                }
-                if (peers == null || peers == "null") {
-                    peers = "[]"
-                }
-
-                peersState = JSONArray(peers)
-                dhtState = JSONArray(dht)
-
-                intent.action = RECEIVER_INTENT
-                LocalBroadcastManager.getInstance(context!!).sendBroadcast(intent)
-            }
-        }
-    }
-}

app/src/main/java/eu/neilalexander/yggdrasil/PeersActivity.kt

@@ -1,19 +1,25 @@
 package eu.neilalexander.yggdrasil
 
 import android.app.AlertDialog
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import android.view.ContextThemeWrapper
 import android.view.LayoutInflater
 import android.view.View
 import android.widget.*
+import androidx.localbroadcastmanager.content.LocalBroadcastManager
 import com.google.android.material.textfield.TextInputEditText
 import org.json.JSONArray
+import org.json.JSONObject
 
 class PeersActivity : AppCompatActivity() {
-    private var state = PacketTunnelState
     private lateinit var config: ConfigurationProxy
     private lateinit var inflater: LayoutInflater
+    private lateinit var peers: Array<JSONObject>
 
     private lateinit var connectedTableLayout: TableLayout
     private lateinit var connectedTableLabel: TextView
@@ -29,6 +35,7 @@ class PeersActivity : AppCompatActivity() {
 
         config = ConfigurationProxy(applicationContext)
         inflater = LayoutInflater.from(this)
+        peers = emptyArray()
 
         connectedTableLayout = findViewById(R.id.connectedPeersTableLayout)
         connectedTableLabel = findViewById(R.id.connectedPeersLabel)
@@ -52,16 +59,16 @@ class PeersActivity : AppCompatActivity() {
             val view = inflater.inflate(R.layout.dialog_addpeer, null)
             val input = view.findViewById<TextInputEditText>(R.id.addPeerInput)
             val builder: AlertDialog.Builder = AlertDialog.Builder(ContextThemeWrapper(this, R.style.Theme_MaterialComponents_DayNight_Dialog))
-            builder.setTitle("Add Configured Peer")
+            builder.setTitle(getString(R.string.peers_add_peer))
             builder.setView(view)
-            builder.setPositiveButton("Add") { dialog, _ ->
+            builder.setPositiveButton(getString(R.string.peers_add)) { dialog, _ ->
                 config.updateJSON { json ->
                     json.getJSONArray("Peers").put(input.text.toString().trim())
                 }
                 dialog.dismiss()
                 updateConfiguredPeers()
             }
-            builder.setNegativeButton("Cancel") { dialog, _ ->
+            builder.setNegativeButton(getString(R.string.cancel)) { dialog, _ ->
                 dialog.cancel()
             }
             builder.show()
@@ -70,22 +77,32 @@ class PeersActivity : AppCompatActivity() {
 
     override fun onResume() {
         super.onResume()
+        LocalBroadcastManager.getInstance(this).registerReceiver(
+            receiver, IntentFilter(PacketTunnelProvider.STATE_INTENT)
+        )
+        (application as GlobalApplication).subscribe()
 
         updateConfiguredPeers()
         updateConnectedPeers()
     }
 
+    override fun onPause() {
+        super.onPause()
+        (application as GlobalApplication).unsubscribe()
+        LocalBroadcastManager.getInstance(this).unregisterReceiver(receiver)
+    }
+
     private fun updateConfiguredPeers() {
         val peers = config.getJSON().getJSONArray("Peers")
 
         when (peers.length()) {
             0 -> {
                 configuredTableLayout.visibility = View.GONE
-                configuredTableLabel.text = "No peers currently configured"
+                configuredTableLabel.text = getString(R.string.peers_no_configured_title)
             }
             else -> {
                 configuredTableLayout.visibility = View.VISIBLE
-                configuredTableLabel.text = "Configured Peers"
+                configuredTableLabel.text = getString(R.string.peers_configured_title)
 
                 configuredTableLayout.removeAllViewsInLayout()
                 for (i in 0 until peers.length()) {
@@ -96,15 +113,15 @@ class PeersActivity : AppCompatActivity() {
 
                     view.findViewById<ImageButton>(R.id.deletePeerButton).setOnClickListener { button ->
                         val builder: AlertDialog.Builder = AlertDialog.Builder(this)
-                        builder.setTitle("Remove ${peer}?")
+                        builder.setTitle(getString(R.string.peers_remove_title, peer))
-                        builder.setPositiveButton("Remove") { dialog, _ ->
+                        builder.setPositiveButton(getString(R.string.peers_remove)) { dialog, _ ->
                             config.updateJSON { json ->
                                 json.getJSONArray("Peers").remove(button.tag as Int)
                             }
                             dialog.dismiss()
                             updateConfiguredPeers()
                         }
-                        builder.setNegativeButton("Cancel") { dialog, _ ->
+                        builder.setNegativeButton(getString(R.string.cancel)) { dialog, _ ->
                             dialog.cancel()
                         }
                         builder.show()
@@ -116,20 +133,17 @@ class PeersActivity : AppCompatActivity() {
     }
 
     private fun updateConnectedPeers() {
-        val peers = state.peersState ?: JSONArray("[]")
+        when (peers.size) {
-
-        when (peers.length()) {
             0 -> {
                 connectedTableLayout.visibility = View.GONE
-                connectedTableLabel.text = "No peers currently connected"
+                connectedTableLabel.text = getString(R.string.peers_no_connected_title)
             }
             else -> {
                 connectedTableLayout.visibility = View.VISIBLE
-                connectedTableLabel.text = "Connected Peers"
+                connectedTableLabel.text = getString(R.string.peers_connected_title)
 
                 connectedTableLayout.removeAllViewsInLayout()
-                for (i in 0 until peers.length()) {
+                for (peer in peers) {
-                    val peer = peers.getJSONObject(i)
                     val view = inflater.inflate(R.layout.peers_connected, null)
                     val ip = peer.getString("IP")
                     view.findViewById<TextView>(R.id.addressLabel).text = ip
@@ -139,4 +153,23 @@ class PeersActivity : AppCompatActivity() {
             }
         }
     }
+
+    private val receiver: BroadcastReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context: Context?, intent: Intent) {
+            when (intent.getStringExtra("type")) {
+                "state" -> {
+                    if (intent.hasExtra("peers")) {
+                        val peersArray = JSONArray(intent.getStringExtra("peers") ?: "[]")
+                        val array = Array(peersArray.length()) { i ->
+                            peersArray.getJSONObject(i)
+                        }
+                        array.sortWith(compareBy { it.getString("IP") })
+                        peers = array
+
+                        updateConnectedPeers()
+                    }
+                }
+            }
+        }
+    }
 }

app/src/main/java/eu/neilalexander/yggdrasil/SettingsActivity.kt

@@ -8,7 +8,6 @@ import android.os.Bundle
 import android.view.ContextThemeWrapper
 import android.view.LayoutInflater
 import android.widget.*
-import androidx.core.view.setPadding
 import androidx.core.widget.doOnTextChanged
 import org.json.JSONObject
 
@@ -33,7 +32,7 @@ class SettingsActivity : AppCompatActivity() {
 
         deviceNameEntry.doOnTextChanged { text, _, _, _ ->
             config.updateJSON { cfg ->
-                var nodeinfo = cfg.optJSONObject("NodeInfo")
+                val nodeinfo = cfg.optJSONObject("NodeInfo")
                 if (nodeinfo == null) {
                     cfg.put("NodeInfo", JSONObject("{}"))
                 }
@@ -42,16 +41,16 @@ class SettingsActivity : AppCompatActivity() {
         }
 
         resetConfigurationRow.setOnClickListener {
-            var view = inflater.inflate(R.layout.dialog_resetconfig, null)
+            val view = inflater.inflate(R.layout.dialog_resetconfig, null)
             val builder: AlertDialog.Builder = AlertDialog.Builder(ContextThemeWrapper(this, R.style.Theme_MaterialComponents_DayNight_Dialog))
-            builder.setTitle("Warning")
+            builder.setTitle(getString(R.string.settings_warning_title))
             builder.setView(view)
-            builder.setPositiveButton("Reset") { dialog, _ ->
+            builder.setPositiveButton(getString(R.string.settings_reset)) { dialog, _ ->
                 config.resetJSON()
                 updateView()
                 dialog.dismiss()
             }
-            builder.setNegativeButton("Cancel") { dialog, _ ->
+            builder.setNegativeButton(getString(R.string.cancel)) { dialog, _ ->
                 dialog.cancel()
             }
             builder.show()
@@ -68,7 +67,7 @@ class SettingsActivity : AppCompatActivity() {
         updateView()
     }
 
-    fun updateView() {
+    private fun updateView() {
         val nodeinfo = config.getJSON().optJSONObject("NodeInfo")
         if (nodeinfo != null) {
             deviceNameEntry.setText(nodeinfo.getString("name"), TextView.BufferType.EDITABLE)

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

@@ -18,4 +18,24 @@
     <string name="dns_fix_chrome_based_browsers">Fix Chrome-based browsers</string>
     <string name="dns_fix_chrome_based_browsers_hint">If you do not have IPv6 internet connectivity, this option should help Chrome-based browsers to resolve Yggdrasil domain names correctly.</string>
     <string name="dns_fixes">DNS fixes</string>
+    <string name="dns_no_servers">No servers</string>
+    <string name="dns_one_server">1 server</string>
+    <string name="dns_many_servers">%d server</string>
+    <string name="dns_remove_title">Remove %s?</string>
+    <string name="main_no_connectivity">No connectivity</string>
+    <string name="main_enabled">Enabled</string>
+    <string name="main_disabled">Not enabled</string>
+    <string name="main_no_peers">No peers</string>
+    <string name="main_one_peer">1 peer</string>
+    <string name="main_many_peers">%d peers</string>
+    <string name="peers_add_peer">Add Configured Peer</string>
+    <string name="peers_add">Add</string>
+    <string name="peers_remove_title">Remove %s?</string>
+    <string name="peers_remove">Remove</string>
+    <string name="peers_no_configured_title">No peers currently configured</string>
+    <string name="peers_configured_title">Configured Peers</string>
+    <string name="peers_no_connected_title">No peers currently connected</string>
+    <string name="peers_connected_title">Connected Peers</string>
+    <string name="settings_warning_title">Warning</string>
+    <string name="settings_reset">Reset</string>
 </resources>