Add logout

app/src/main/java/com/testapp/AppUtils.java

@@ -39,6 +39,10 @@ public class AppUtils {
         userId = -1;
     }
 
+    public static boolean isLoggedIn() {
+        return userId != -1;
+    }
+
     public static String getUsername() {
         return username;
     }

app/src/main/java/com/testapp/LoginActivity.java

@@ -116,6 +116,7 @@ public class LoginActivity extends AppCompatActivity {
         } else {
             showProgress(true);
 
+            AppUtils.login(username, password, -1);
             Call<Token> call = AppUtils.service.getToken();
             call.enqueue(new Callback<Token>() {
                 @Override
@@ -126,7 +127,7 @@ public class LoginActivity extends AppCompatActivity {
                         mPasswordView.setError("");
                         Toast.makeText(LoginActivity.this, "Invalid credentials!", Toast.LENGTH_LONG).show();
                     } else {
-                        Toast.makeText(LoginActivity.this, "Logged in as " + username + " successfully.", Toast.LENGTH_LONG).show();
+                        Toast.makeText(LoginActivity.this, "Logged in as " + AppUtils.getUsername() + " successfully.", Toast.LENGTH_LONG).show();
                         AppUtils.login(username, password, response.body().getId());
                         Intent intent = new Intent(LoginActivity.this, NavDrawerActivity.class);
                         startActivity(intent);

app/src/main/java/com/testapp/NavDrawerActivity.java

 package com.testapp;
 
+import android.app.Activity;
+import android.app.AlertDialog;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.design.widget.FloatingActionButton;
@@ -17,9 +20,13 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.AdapterView;
+import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.LinearLayout;
 import android.widget.ListView;
+import android.widget.RelativeLayout;
+import android.widget.TextView;
+import android.widget.Toast;
 
 import com.testapp.entities.Dish;
 import com.testapp.entities.Filter;
@@ -27,6 +34,7 @@ import com.testapp.entities.Filter;
 import java.util.ArrayList;
 import java.util.List;
 
+import okhttp3.ResponseBody;
 import retrofit2.Call;
 import retrofit2.Callback;
 import retrofit2.Response;
@@ -88,7 +96,32 @@ public class NavDrawerActivity extends AppCompatActivity implements NavigationVi
             }
         });
 
-
+        RelativeLayout loggedInHeader = (RelativeLayout)findViewById(R.id.logged_in_header);
+        if(AppUtils.isLoggedIn()) {
+            loggedInHeader.setVisibility(View.VISIBLE);
+            ((TextView)findViewById(R.id.greeting)).setText("Hello, " + AppUtils.getUsername());
+            findViewById(R.id.logout_button).setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    final Activity context = NavDrawerActivity.this;
+                    new AlertDialog.Builder(context)
+                            .setTitle("Logout")
+                            .setMessage("Are you sure you want to log out?")
+                            .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
+                                @Override
+                                public void onClick(DialogInterface dialog, int which) {
+                                    AppUtils.logout();
+                                    Intent i = new Intent(context, LoginActivity.class);
+                                    context.startActivity(i);
+                                }
+                            })
+                            .setNegativeButton(R.string.no, null)
+                            .show();
+                }
+            });
+        } else {
+            loggedInHeader.setVisibility(View.GONE);
+        }
     }
 
     public <T extends Filter> void populateFilter(Call<List<T>> call, int layout_id) {