Popup.java

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.util.DisplayMetrics;
import android.view.Window;
import android.view.WindowManager;
import android.widget.TextView;

public class Popup extends AppCompatActivity {
TextView stateChangeSucc;
Intent intent;

@Override
protected void onCreate(Bundle savedInstanceState) {

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_popup);

    stateChangeSucc = (TextView) findViewById(R.id.stateChangeSucc);

    intent = getIntent();
    if (intent.getStringExtra("state").equals("login")){
        stateChangeSucc.setText(R.string.loginSucc);
    }
    else if (intent.getStringExtra("state").equals("register")) {
        stateChangeSucc.setText(R.string.RegisterSucc);
    }
    else {
        stateChangeSucc.setText(getString(R.string.Error) + intent.getStringExtra("state"));
    }

    DisplayMetrics dm = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(dm);

    int width = dm.widthPixels;
    int height = dm.heightPixels;

    // popup window size setting
    getWindow().setLayout((int) (width * 0.8), (int) (height * 0.6));

    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            startActivity(new Intent(Popup.this,Home.class));
            finish();
        }
    }, 500);
}
}

public class Login extends AppCompatActivity implements View.OnClickListener      {
Button bLogin,bRegister;
EditText etUsername,etPassword;

@Override
protected void onCreate(Bundle savedInstanceState) {
// set to full screen
requestWindowFeature(Window.FEATURE_NO_TITLE);              getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);

etUsername = (EditText) findViewById(R.id.etUsername);
etPassword = (EditText) findViewById(R.id.etPassword);
bLogin = (Button) findViewById(R.id.bLogin);
bRegister = (Button) findViewById(R.id.bRegister);

bLogin.setOnClickListener(this);
bRegister.setOnClickListener(this);

}


@Override
public void onClick(View v) {
switch (v.getId()) {
    case R.id.bLogin:
        // * 1.check if the username exist
        // * 2.check if the username and pw is match in database
        // give popup
        Intent intent = new Intent(getApplicationContext(),Popup.class);
        intent.putExtra("state", "login");
        startActivity(intent);
        break;
    case R.id.bRegister:
        startActivity(new Intent(this, Register.class));
        break;
    }
    }

-28 01:29:12.778 2521-2521/? D/AndroidRuntime: >>>>>> START com.android.internal.os.RuntimeInit uid 0 <<<<<<
01-28 01:29:12.779 2521-2521/? D/AndroidRuntime: CheckJNI is ON
01-28 01:29:12.792 2521-2521/? I/art: JIT created with code_cache_capacity=2MB compile_threshold=1000
01-28 01:29:12.795 2521-2521/? D/ICU: No timezone override file found: /data/misc/zoneinfo/current/icu/icu_tzdata.dat
01-28 01:29:12.811 2521-2521/? E/memtrack: Couldn't load memtrack module (No such file or directory)
01-28 01:29:12.811 2521-2521/? E/android.os.Debug: failed to load memtrack module: -2
01-28 01:29:12.812 2521-2521/? I/Radio-JNI: register_android_hardware_Radio DONE
01-28 01:29:12.821 2521-2521/? D/AndroidRuntime: Calling main entry com.android.commands.wm.Wm
01-28 01:29:12.822 2521-2521/? D/AndroidRuntime: Shutting down VM
01-28 01:29:12.827 2521-2532/? E/art: Thread attaching while runtime is shutting down: Binder_1
01-28 01:29:12.827 2521-2532/? I/AndroidRuntime: NOTE: attach of thread 'Binder_1' failed
01-28 01:38:26.973 1298-1311/system_process I/UsageStatsService: User[0] Flushing usage stats to disk