Add IpAddressCallbacks

Refactor Flowable using Interval
Shift Flowable code to WebServerHelper

app/src/main/java/org/kiwix/kiwixmobile/di/modules/ServiceModule.kt

@@ -13,6 +13,7 @@ import org.kiwix.kiwixmobile.di.ServiceScope
 import org.kiwix.kiwixmobile.webserver.WebServerHelper
 import org.kiwix.kiwixmobile.wifi_hotspot.HotspotNotificationManager
 import org.kiwix.kiwixmobile.wifi_hotspot.HotspotStateListener
+import org.kiwix.kiwixmobile.wifi_hotspot.IpAddressCallbacks
 import org.kiwix.kiwixmobile.wifi_hotspot.WifiHotspotManager
 
 @Module
@@ -22,8 +23,9 @@ class ServiceModule {
   @ServiceScope
   fun providesWebServerHelper(
     jniKiwixLibrary: JNIKiwixLibrary,
-    kiwixServer: JNIKiwixServer
+    kiwixServer: JNIKiwixServer,
-  ): WebServerHelper = WebServerHelper(jniKiwixLibrary, kiwixServer)
+    ipAddressCallbacks: IpAddressCallbacks
+  ): WebServerHelper = WebServerHelper(jniKiwixLibrary, kiwixServer, ipAddressCallbacks)
 
   @Provides
   @ServiceScope
@@ -38,6 +40,11 @@ class ServiceModule {
   fun providesHotspotStateListener(service: Service): HotspotStateListener =
     service as HotspotStateListener
 
+  @Provides
+  @ServiceScope
+  fun providesIpAddressCallbacks(service: Service): IpAddressCallbacks =
+    service as IpAddressCallbacks
+
   @Provides
   @ServiceScope
   fun providesJNIKiwixLibrary(): JNIKiwixLibrary = JNIKiwixLibrary()

app/src/main/java/org/kiwix/kiwixmobile/utils/ServerUtils.java

@@ -1,6 +1,7 @@
 package org.kiwix.kiwixmobile.utils;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import java.net.InetAddress;
 import java.net.NetworkInterface;
 import java.net.SocketException;
@@ -9,9 +10,10 @@ import java.util.Enumeration;
 public class ServerUtils {
   public static int port;
   public static boolean isServerStarted;
+  public static final String INVALID_IP = "-1";
 
   // get Ip address of the device's wireless access point i.e. wifi hotspot OR wifi network
-  public static String getIpAddress() {
+  @Nullable public static String getIpAddress() {
     String ip = "";
     try {
       Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface
@@ -51,10 +53,10 @@ public class ServerUtils {
     return address;
   }
 
-  public static String getIp() {
+  @Nullable public static String getIp() {
     String ip = getIpAddress();
     ip = ip.replaceAll("\n", "");
-    if (ip.length() == 0) throw new IllegalStateException();
+    if (ip.length() == 0) return INVALID_IP;
     return ip;
   }
 }

app/src/main/java/org/kiwix/kiwixmobile/webserver/WebServerHelper.java

@@ -2,12 +2,18 @@ package org.kiwix.kiwixmobile.webserver;
 
 import android.util.Log;
 import androidx.annotation.NonNull;
+import io.reactivex.Flowable;
+import io.reactivex.android.schedulers.AndroidSchedulers;
 import java.util.ArrayList;
+import java.util.concurrent.TimeUnit;
 import javax.inject.Inject;
 import org.kiwix.kiwixlib.JNIKiwixException;
 import org.kiwix.kiwixlib.JNIKiwixLibrary;
 import org.kiwix.kiwixlib.JNIKiwixServer;
 import org.kiwix.kiwixmobile.utils.ServerUtils;
+import org.kiwix.kiwixmobile.wifi_hotspot.IpAddressCallbacks;
+
+import static org.kiwix.kiwixmobile.utils.ServerUtils.INVALID_IP;
 
 /**
  * WebServerHelper class is used to set up the suitable environment i.e. getting the
@@ -19,11 +25,13 @@ public class WebServerHelper {
   private static final String TAG = "WebServerHelper";
   private JNIKiwixLibrary kiwixLibrary;
   private JNIKiwixServer kiwixServer;
+  private IpAddressCallbacks ipAddressCallbacks;
 
   @Inject public WebServerHelper(@NonNull JNIKiwixLibrary kiwixLibrary,
-      @NonNull JNIKiwixServer kiwixServer) {
+      @NonNull JNIKiwixServer kiwixServer, @NonNull IpAddressCallbacks ipAddressCallbacks) {
     this.kiwixLibrary = kiwixLibrary;
     this.kiwixServer = kiwixServer;
+    this.ipAddressCallbacks = ipAddressCallbacks;
   }
 
   public boolean startServerHelper(@NonNull ArrayList<String> selectedBooksPath) {
@@ -63,4 +71,25 @@ public class WebServerHelper {
     }
     return ServerUtils.isServerStarted;
   }
+
+  //Keeps checking if hotspot has been turned using the ip address with an interval of 1 sec
+  //If no ip is found after 15 seconds, dismisses the progress dialog
+  public void pollForValidIpAddress() {
+    Flowable.interval(1, TimeUnit.SECONDS)
+        .map(__ -> ServerUtils.getIp())
+        .filter(s -> s != INVALID_IP)
+        .timeout(15, TimeUnit.SECONDS)
+        .take(1)
+        .observeOn(AndroidSchedulers.mainThread())
+        .subscribe(
+            s -> {
+              ipAddressCallbacks.onIpAddressValid();
+              Log.d(TAG, "onSuccess:  " + s);
+            },       //success stuff
+            e -> {
+              Log.d(TAG, "Unable to turn on server", e);
+              ipAddressCallbacks.onIpAddressInvalid();
+            }       //failure stuff
+        );
+  }
 }

app/src/main/java/org/kiwix/kiwixmobile/webserver/ZimHostActivity.java

@@ -22,14 +22,9 @@ import androidx.core.app.ActivityCompat;
 import androidx.core.content.ContextCompat;
 import androidx.recyclerview.widget.RecyclerView;
 import butterknife.BindView;
-import io.reactivex.Flowable;
-import io.reactivex.SingleObserver;
-import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.Disposable;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.TimeUnit;
 import javax.inject.Inject;
 import kotlin.Unit;
 import kotlin.jvm.functions.Function0;
@@ -44,6 +39,7 @@ import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BookOnDiskDeleg
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskAdapter;
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem;
 
+import static org.kiwix.kiwixmobile.wifi_hotspot.HotspotService.ACTION_CHECK_IP_ADDRESS;
 import static org.kiwix.kiwixmobile.wifi_hotspot.HotspotService.ACTION_LOCATION_ACCESS_GRANTED;
 import static org.kiwix.kiwixmobile.wifi_hotspot.HotspotService.ACTION_START_SERVER;
 import static org.kiwix.kiwixmobile.wifi_hotspot.HotspotService.ACTION_STOP_SERVER;
@@ -70,15 +66,15 @@ public class ZimHostActivity extends BaseActivity implements
 
   private static final String TAG = "ZimHostActivity";
   private static final int MY_PERMISSIONS_ACCESS_FINE_LOCATION = 102;
-  public static final String SELECTED_ZIM_PATHS_KEY = "selected_zim_paths";
   private static final String IP_STATE_KEY = "ip_state_key";
-  private ProgressDialog progressDialog;
+  public static final String SELECTED_ZIM_PATHS_KEY = "selected_zim_paths";
 
   private BooksOnDiskAdapter booksAdapter;
   private BookOnDiskDelegate.BookDelegate bookDelegate;
   private HotspotService hotspotService;
   private String ip;
   private ServiceConnection serviceConnection;
+  private ProgressDialog progressDialog;
 
   @Override
   protected void onCreate(@Nullable Bundle savedInstanceState) {
@@ -280,43 +276,15 @@ public class ZimHostActivity extends BaseActivity implements
         null,
         () -> {
           progressDialog =
-              ProgressDialog.show(ZimHostActivity.this,
+              ProgressDialog.show(this,
                   getString(R.string.progress_dialog_starting_server), "",
                   true);
-          pollForValidIpAddress();
+          startService(createHotspotIntent(ACTION_CHECK_IP_ADDRESS));
           return Unit.INSTANCE;
         }
     );
   }
 
-  //Keeps checking if hotspot has been turned using the ip address with an interval of 1 sec
-  //If no ip is found after 15 seconds, dismisses the progress dialog
-  private void pollForValidIpAddress() {
-    Flowable.fromCallable(ServerUtils::getIp)
-        .retryWhen(error -> error.delay(1, TimeUnit.SECONDS))
-        .timeout(15, TimeUnit.SECONDS)
-        .firstOrError()
-        .observeOn(AndroidSchedulers.mainThread())
-        .subscribe(new SingleObserver<String>() {
-          @Override public void onSubscribe(Disposable d) {
-          }
-
-          @Override public void onSuccess(String s) {
-            progressDialog.dismiss();
-            startService(createHotspotIntent(ACTION_START_SERVER).putStringArrayListExtra(
-                SELECTED_ZIM_PATHS_KEY, getSelectedBooksPath()));
-            Log.d(TAG, "onSuccess:  " + s);
-          }
-
-          @Override public void onError(Throwable e) {
-            progressDialog.dismiss();
-            Toast.makeText(ZimHostActivity.this, R.string.server_failed_message, Toast.LENGTH_SHORT)
-                .show();
-            Log.d(TAG, "Unable to turn on server", e);
-          }
-        });
-  }
-
   private Intent createHotspotIntent(String action) {
     return new Intent(this, HotspotService.class).setAction(action);
   }
@@ -338,10 +306,10 @@ public class ZimHostActivity extends BaseActivity implements
     alertDialogShower.show(new KiwixDialog.ShowHotspotDetails(wifiConfiguration),
         (Function0<Unit>) () -> {
           progressDialog =
-              ProgressDialog.show(ZimHostActivity.this,
+              ProgressDialog.show(this,
                   getString(R.string.progress_dialog_starting_server), "",
                   true);
-          pollForValidIpAddress();
+          startService(createHotspotIntent(ACTION_CHECK_IP_ADDRESS));
           return Unit.INSTANCE;
         });
   }
@@ -383,4 +351,16 @@ public class ZimHostActivity extends BaseActivity implements
   @Override public void onLocationSet() {
     startService(createHotspotIntent(ACTION_LOCATION_ACCESS_GRANTED));
   }
+
+  @Override public void provideBooksAndStartServer() {
+    startService(createHotspotIntent(ACTION_START_SERVER).putStringArrayListExtra(
+        SELECTED_ZIM_PATHS_KEY, getSelectedBooksPath()));
+  }
+
+  @Override public void dismissProgressDialog() {
+    progressDialog.dismiss();
+    Toast.makeText(this, R.string.server_failed_message,
+        Toast.LENGTH_SHORT)
+        .show();
+  }
 }

app/src/main/java/org/kiwix/kiwixmobile/webserver/ZimHostCallbacks.java

@@ -16,4 +16,8 @@ public interface ZimHostCallbacks {
   void onHotspotFailedToStart();
 
   void requestLocationAccess();
+
+  void provideBooksAndStartServer();
+
+  void dismissProgressDialog();
 }

app/src/main/java/org/kiwix/kiwixmobile/wifi_hotspot/HotspotService.java

@@ -27,12 +27,13 @@ import static org.kiwix.kiwixmobile.wifi_hotspot.HotspotNotificationManager.HOTS
  * Created by Adeel Zafar on 07/01/2019.
  */
 
-public class HotspotService extends Service implements HotspotStateListener {
+public class HotspotService extends Service implements HotspotStateListener, IpAddressCallbacks {
 
   public static final String ACTION_TOGGLE_HOTSPOT = "toggle_hotspot";
   public static final String ACTION_LOCATION_ACCESS_GRANTED = "location_access_granted";
   public static final String ACTION_START_SERVER = "start_server";
   public static final String ACTION_STOP_SERVER = "stop_server";
+  public static final String ACTION_CHECK_IP_ADDRESS = "check_ip_address";
 
   public static final String ACTION_STOP = "hotspot_stop";
   private static final String TAG = "HotspotService";
@@ -111,6 +112,11 @@ public class HotspotService extends Service implements HotspotStateListener {
       case ACTION_STOP_SERVER:
         stopHotspotAndDismissNotification();
         break;
+
+      case ACTION_CHECK_IP_ADDRESS:
+        webServerHelper.pollForValidIpAddress();
+        break;
+
       default:
         break;
     }
@@ -169,6 +175,15 @@ public class HotspotService extends Service implements HotspotStateListener {
     hotspotNotificationManager.dismissNotification();
   }
 
+  @Override public void onIpAddressValid() {
+    zimHostCallbacks.dismissProgressDialog();
+    zimHostCallbacks.provideBooksAndStartServer();
+  }
+
+  @Override public void onIpAddressInvalid() {
+    zimHostCallbacks.dismissProgressDialog();
+  }
+
   public class HotspotBinder extends Binder {
 
     @NonNull public HotspotService getService() {

app/src/main/java/org/kiwix/kiwixmobile/wifi_hotspot/IpAddressCallbacks.java

@@ -0,0 +1,8 @@
+package org.kiwix.kiwixmobile.wifi_hotspot;
+
+public interface IpAddressCallbacks {
+
+  void onIpAddressValid();
+
+  void onIpAddressInvalid();
+}

app/src/main/java/org/kiwix/kiwixmobile/wifi_hotspot/WifiHotspotManager.java

@@ -17,15 +17,13 @@ import javax.inject.Inject;
 
 public class WifiHotspotManager {
   private static final String TAG = "WifiHotspotManager";
+  private WifiManager wifiManager;
   private WifiManager.LocalOnlyHotspotReservation hotspotReservation;
   private HotspotStateListener hotspotStateListener;
 
-  @Inject
-  WifiManager wifiManager;
-
   @Inject
   public WifiHotspotManager(@NonNull WifiManager wifiManager,
-      HotspotStateListener hotspotStateListener) {
+      @NonNull HotspotStateListener hotspotStateListener) {
     this.wifiManager = wifiManager;
     this.hotspotStateListener = hotspotStateListener;
   }