Enabling a little more kiosk security

app/src/main/AndroidManifest.xml

@@ -30,9 +30,10 @@
             </intent-filter>
         </receiver>
     </application>
+
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.REORDER_TASKS" />
-
+    <uses-permission android:name="android.permission.EXPAND_STATUS_BAR" />
     <uses-permission android:name="android.permission.INTERNET" />
 
 </manifest>

app/src/main/java/org/denhac/kiosk/KioskActivity.java

@@ -0,0 +1,116 @@
+package org.denhac.kiosk;
+
+import android.annotation.SuppressLint;
+import android.app.ActivityManager;
+import android.content.Context;
+import android.os.Build;
+import android.os.Handler;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public abstract class KioskActivity extends AppCompatActivity {
+    // To keep track of activity's window focus
+    boolean currentFocus;
+
+    // To keep track of activity's foreground/background status
+    boolean isPaused;
+
+    Handler collapseNotificationHandler;
+    @Override
+    public void onWindowFocusChanged(boolean hasFocus) {
+        super.onWindowFocusChanged(hasFocus);
+
+        currentFocus = hasFocus;
+
+        if (!hasFocus) {
+
+            // Method that handles loss of window focus
+            collapseNow();
+        }
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+
+        isPaused = true;
+
+        ActivityManager activityManager = (ActivityManager) getApplicationContext()
+                .getSystemService(Context.ACTIVITY_SERVICE);
+
+        activityManager.moveTaskToFront(getTaskId(), 0);
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        isPaused = false;
+    }
+
+    public void collapseNow() {
+
+        // Initialize 'collapseNotificationHandler'
+        if (collapseNotificationHandler == null) {
+            collapseNotificationHandler = new Handler();
+        }
+
+        // If window focus has been lost && activity is not in a paused state
+        // Its a valid check because showing of notification panel
+        // steals the focus from current activity's window, but does not
+        // 'pause' the activity
+        if (!currentFocus && !isPaused) {
+
+            // Post a Runnable with some delay - currently set to 300 ms
+            collapseNotificationHandler.postDelayed(new Runnable() {
+
+                @Override
+                public void run() {
+
+                    // Use reflection to trigger a method from 'StatusBarManager'
+
+                    @SuppressLint("WrongConstant") Object statusBarService = getSystemService("statusbar");
+                    Class<?> statusBarManager = null;
+
+                    try {
+                        statusBarManager = Class.forName("android.app.StatusBarManager");
+                    } catch (ClassNotFoundException e) {
+                        e.printStackTrace();
+                    }
+
+                    Method collapseStatusBar = null;
+
+                    try {
+
+                        // Prior to API 17, the method to call is 'collapse()'
+                        // API 17 onwards, the method to call is `collapsePanels()`
+
+                        collapseStatusBar = statusBarManager.getMethod("collapsePanels");
+                    } catch (NoSuchMethodException e) {
+                        e.printStackTrace();
+                    }
+
+                    collapseStatusBar.setAccessible(true);
+
+                    try {
+                        collapseStatusBar.invoke(statusBarService);
+                    } catch (IllegalArgumentException | IllegalAccessException | InvocationTargetException e) {
+                        e.printStackTrace();
+                    }
+
+                    // Check if the window focus has been returned
+                    // If it hasn't been returned, post this Runnable again
+                    // Currently, the delay is 100 ms. You can change this
+                    // value to suit your needs.
+                    if (!currentFocus && !isPaused) {
+                        collapseNotificationHandler.postDelayed(this, 100L);
+                    }
+
+                }
+            }, 300L);
+        }
+    }
+}

app/src/main/java/org/denhac/kiosk/MainActivity.java

@@ -5,12 +5,11 @@
 import android.view.View;
 import android.widget.Toast;
 
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.constraintlayout.widget.ConstraintLayout;
 
 import org.denhac.kiosk.events.EventsActivity;
 
-public class MainActivity extends AppCompatActivity {
+public class MainActivity extends KioskActivity {
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {

app/src/main/java/org/denhac/kiosk/WebViewActivity.java

@@ -20,7 +20,6 @@
 import android.widget.TextView;
 import android.widget.Toast;
 
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.core.widget.ContentLoadingProgressBar;
 
@@ -37,7 +36,7 @@
 import io.reactivex.functions.Consumer;
 
 
-public class WebViewActivity extends AppCompatActivity implements WebAppInterface.Callback {
+public class WebViewActivity extends KioskActivity implements WebAppInterface.Callback {
     private static final String EXTRA_URL = "ExtraUrl";
 
     private ConstraintLayout loadingScreen;

app/src/main/java/org/denhac/kiosk/WifiActivity.java

@@ -6,14 +6,12 @@
 import android.view.View;
 import android.widget.ImageView;
 
-import androidx.appcompat.app.AppCompatActivity;
-
 import com.google.zxing.WriterException;
 
 import androidmads.library.qrgenearator.QRGContents;
 import androidmads.library.qrgenearator.QRGEncoder;
 
-public class WifiActivity extends AppCompatActivity {
+public class WifiActivity extends KioskActivity {
 
     private ImageView qrCodeView;
 

app/src/main/java/org/denhac/kiosk/events/EventsActivity.java

@@ -6,9 +6,9 @@
 import android.widget.ImageView;
 import android.widget.TextView;
 
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.recyclerview.widget.GridLayoutManager;
 
+import org.denhac.kiosk.KioskActivity;
 import org.denhac.kiosk.R;
 import org.denhac.kiosk.events.meetup.MeetupRepository;
 import org.denhac.kiosk.events.popup.PopupView;
@@ -24,7 +24,7 @@
 import io.reactivex.functions.Consumer;
 import io.reactivex.schedulers.Schedulers;
 
-public class EventsActivity extends AppCompatActivity implements MeetupRepository.NetworkStatus, PopupWindow.Callback {
+public class EventsActivity extends KioskActivity implements MeetupRepository.NetworkStatus, PopupWindow.Callback {
 
     private TextView monthText;
     private Calendar currentDay;