Bug fix and lock screen feature added

app/src/main/AndroidManifest.xml

@@ -21,6 +21,19 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+         <receiver
+            android:name=".Admin"
+            android:permission="android.permission.BIND_DEVICE_ADMIN">
+            <meta-data
+                android:name="android.app.device_admin"
+                android:resource="@xml/policies" />
+
+            <intent-filter>
+                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
+            </intent-filter>
+
+        </receiver>
     </application>
 
 </manifest>

app/src/main/java/com/beautycoder/applicationlockscreenexample/Admin.java

@@ -0,0 +1,20 @@
+package com.beautycoder.applicationlockscreenexample;
+
+import android.app.admin.DeviceAdminReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.widget.Toast;
+
+public class Admin extends DeviceAdminReceiver {
+    @Override
+    public void onEnabled(Context context, Intent intent) {
+        Toast.makeText(context, "Enabled Permission", Toast.LENGTH_SHORT).show();
+        super.onEnabled(context, intent);
+    }
+
+    @Override
+    public void onDisabled(Context context, Intent intent) {
+        Toast.makeText(context, "Disabled Permission", Toast.LENGTH_SHORT).show();
+        super.onDisabled(context, intent);
+    }
+}

app/src/main/java/com/beautycoder/applicationlockscreenexample/MainActivity.java

@@ -55,6 +55,9 @@ public void onFingerprintSuccessful() {
                 @Override
                 public void onPinLoginFailed() {
                     Toast.makeText(MainActivity.this, "Pin failed", Toast.LENGTH_SHORT).show();
+                    PFCodeView pfCodeView;
+                    pfCodeView = findViewById(R.id.code_view);
+                    pfCodeView.clearCode();
                 }
 
                 @Override
@@ -120,5 +123,11 @@ private void showMainFragment() {
                 .replace(R.id.container_view, fragment).commit();
     }
 
-
-}
+    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
+    @Override
+    public void onBackPressed() {
+        super.onBackPressed();
+        finishAffinity();
+        finish();
+    }
+}

app/src/main/java/com/beautycoder/applicationlockscreenexample/MainFragment.java

@@ -12,12 +12,71 @@
  */
 
 public class MainFragment extends Fragment {
+    ComponentName componentName;
+    DevicePolicyManager devicePolicyManager;
+    Button lock, enable;
+    public static final int RESULT_ENABLE = 11;
+    private ActivityManager activityManager;
+
 
     @Nullable
     @Override
     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                              @Nullable Bundle savedInstanceState) {
         final View view = inflater.inflate(R.layout.fragment_main, container, false);
+
+        devicePolicyManager = (DevicePolicyManager) getActivity().getSystemService(Context.DEVICE_POLICY_SERVICE);
+        activityManager = (ActivityManager) getActivity().getSystemService(Context.ACTIVITY_SERVICE);
+        componentName = new ComponentName(getActivity(), Admin.class);
+
+        lock = view.findViewById(R.id.lock);
+        enable = view.findViewById(R.id.enable);
+
+        lock.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                boolean active = devicePolicyManager.isAdminActive(componentName);
+                if (active) {
+                    startActivity(new Intent(getContext(), MainActivity.class));
+                    devicePolicyManager.lockNow();
+                } else {
+                    Toast.makeText(getContext(), "You need to enable the Admin Device Features", Toast.LENGTH_SHORT).show();
+                }
+            }
+        });
+
+        enable.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
+                intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);
+                intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION, "Required Permission");
+                startActivityForResult(intent, RESULT_ENABLE);
+            }
+        });
         return view;
     }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        boolean isActive = devicePolicyManager.isAdminActive(componentName);
+        enable.setVisibility(isActive ? View.GONE : View.VISIBLE);
+    }
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
+        switch (requestCode) {
+            case RESULT_ENABLE:
+                if (resultCode == getActivity().RESULT_OK) {
+                    Toast.makeText(getContext(), "You have enabled the Admin Device features", Toast.LENGTH_SHORT).show();
+                } else if (resultCode == getActivity().RESULT_FIRST_USER) {
+                    Toast.makeText(getContext(), "Enabled Permission", Toast.LENGTH_SHORT).show();
+                } else {
+                    Toast.makeText(getContext(), "Problem to enable the Admin Device features", Toast.LENGTH_SHORT).show();
+                }
+                break;
+        }
+        super.onActivityResult(requestCode, resultCode, data);
+    }
 }

app/src/main/res/layout/fragment_main.xml

@@ -1,12 +1,37 @@
 <?xml version="1.0" encoding="utf-8"?>
-<FrameLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
-    <TextView
-        android:layout_height="match_parent"
+    <RelativeLayout
         android:layout_width="match_parent"
-        android:text="You logged In!!!"
-        android:gravity="center"/>
+        android:layout_height="match_parent">
+
+        <TextView
+            android:id="@+id/tvLoggedIn"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_centerHorizontal="true"
+            android:layout_centerVertical="true"
+            android:gravity="center"
+            android:text="You logged In!!!" />
+
+        <Button
+            android:id="@+id/lock"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_below="@+id/tvLoggedIn"
+            android:layout_centerHorizontal="true"
+            android:layout_marginTop="30dp"
+            android:text="lock" />
+
+        <Button
+            android:id="@+id/enable"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_below="@+id/lock"
+            android:layout_centerHorizontal="true"
+            android:layout_marginTop="30dp"
+            android:text="Enable" />
+    </RelativeLayout>
 </FrameLayout>