Create Custom Lock Screen to get username/ password to authenticate user in our android application

Question

I have device tracker application, where user needs to login so that devices is assigned to it.

But, now I want user should not able to use that devices until user have authenticated and should be available until user sing-out from that device ?

I want to retrieve password entered by user when he unlocks the screen and want to use it for my application authentication it's self and if password do not match I will unlock screen again.

I'm trying following code but still not basically able to lock and unlock screens using password.

public class AdminSettingsActivity extends Activity {
  private EditText baseURLEditText;
  private Button saveBaseURL;
  private TextView tv;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_admin);
    saveBaseURL = (Button) findViewById(R.id.saveBaseURLBtn);
    baseURLEditText = (EditText) findViewById(R.id.base_url_edit);

    tv = (TextView) findViewById(R.id.text_admin_message);
    tv.append(" " + DeviceTrackerApp.DEFAULT_BASE_URL);
    saveBaseURL.setOnClickListener(new OnClickListener() {

      @SuppressLint("NewApi")
      @Override
      public void onClick(View v) {
        String url = baseURLEditText.getText().toString().trim();
        if (!url.isEmpty()) {
          try {
            if (URLUtil.isValidUrl(url)) {
              new ValidateServerURL(AdminSettingsActivity.this).execute(url);
            } else {
              showInvalidURLToast();
            }
          } catch (Exception e) {
            e.printStackTrace();
          }
        }
      }
    });
  }

  protected void showInvalidURLToast() {
    // get your custom_toast.xml ayout
    LayoutInflater inflater = getLayoutInflater();

    View layout = inflater.inflate(R.layout.toast_layout,
        (ViewGroup) findViewById(R.id.toast_layout_root));

    // set a dummy image
    ImageView image = (ImageView) layout.findViewById(R.id.image_invalid_pwd);
    image.setImageResource(R.drawable.invalid_pwd);

    // set a message
    TextView text = (TextView) layout.findViewById(R.id.text_invalid_password);
    text.setText("Invalid URL! Can't Save.");

    // Toast...
    Toast toast = new Toast(getApplicationContext());
    toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
    toast.setDuration(Toast.LENGTH_LONG);
    toast.setView(layout);
    toast.show();
  }

  public void setURLStatus(int statusCode) {
    if (statusCode == 200) {
      DeviceTrackerApp.setBaseURL(baseURLEditText.getText().toString());
      Toast.makeText(getApplicationContext(), "Valid URL Saved Successful",
          Toast.LENGTH_LONG).show();
      tv.setText("\nYour Setting saved successfuly. Press back button to go home screen\n");
    } else {
      showInvalidURLToast();
      baseURLEditText.setText("");
    }
  }
}

and My DeviceTrackerAdmin class is

public class DeviceTrackerAdmin extends DeviceAdminReceiver {

  static SharedPreferences getSamplePreferences(Context context) {
    return context.getSharedPreferences(DeviceAdminReceiver.class.getName(), 0);
  }

  static String PREF_PASSWORD_QUALITY = "password_quality";
  static String PREF_PASSWORD_LENGTH = "password_length";
  static String PREF_MAX_FAILED_PW = "max_failed_pw";

  void showToast(Context context, CharSequence msg) {
    Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
  }

  @Override
  public void onEnabled(Context context, Intent intent) {
    showToast(context, "Sample Device Admin: enabled");
  }

  @Override
  public CharSequence onDisableRequested(Context context, Intent intent) {
    return "This is an optional message to warn the user about disabling.";
  }

  @Override
  public void onDisabled(Context context, Intent intent) {
    showToast(context, "Sample Device Admin: disabled");
  }

  @Override
  public void onPasswordChanged(Context context, Intent intent) {
    showToast(context, "Sample Device Admin: pw changed");
  }

  @Override
  public void onPasswordFailed(Context context, Intent intent) {
    showToast(context, "Sample Device Admin: pw failed");
  }

  @Override
  public void onPasswordSucceeded(Context context, Intent intent) {
    showToast(context, "Sample Device Admin: pw succeeded");
  }

}

I also defined reciever in AndroidMenifest.xml

   <receiver
        android:name=".DeviceTrackerAdmin"
        android:permission="android.permission.BIND_DEVICE_ADMIN" >
        <meta-data
            android:name="com.abc.devicetracker.DeviceTrackerApp"
            android:resource="@layout/policies" >
            <intent-filter>
                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" >
                </action>
            </intent-filter>
        </meta-data>
    </receiver>

But, every time onActivityResult() on

 `if (resultCode == RESULT_OK)`  **OR** `if (resultCode == Activity.RESULT_OK)` condition fails as `resultCode is 0 only` So for Device locking I need to root my mobile.

Answer 1

when u got password is correct or incorrect the password then use following code

 //Get the window from the context

 WindowManager wm = Context.getSystemService(Context.WINDOW_SERVICE);

 //Unlock if password is incorrect

http://developer.android.com/reference/android/app/Activity.html#getWindow()

Window window = getWindow();  
window.addFlags(wm.LayoutParams.FLAG_DISMISS_KEYGUARD);  



//Lock device if password is correct 

DevicePolicyManager mDPM;
mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);

Answer 2

I have found a github project and I'm modifying it as per my requirements. Thanks to All for your efforts.

• https://github.com/wordpress-mobile/Android-PasscodeLock
• https://github.com/swapnilvkotwal/LockScreenApp

And found this answer helpful Creating an Android Lock Screen App.