MyLoginScreen

Utl.java
===================
public class Utl {
    public static boolean checkUser(String userName,String userPass,String myUser,String myPass)
    {
        return (userName.equals(myUser) && userPass.equals(myPass));
    }
}


LoginActivity.java
============================

public class LoginActivity extends AppCompatActivity {

    final String TAG="LoginScreen";

    EditText txtUser,txtPass;
    Button btnLogin;
    TextView txtLogo;
    final String USER_NAME="Firas",USER_PASS="12345";
    Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        setPointer();
    }

    private void setPointer()
    {
        this.context=this;
        txtUser=(EditText) findViewById(R.id.txtUser);
        txtPass=(EditText)findViewById(R.id.txtPass);
        txtLogo=(TextView)findViewById(R.id.txtLogo);
        final int orgHintColor=txtLogo.getCurrentHintTextColor();
        btnLogin=(Button)findViewById(R.id.btnLogin);
        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View roni) {
                String userName=txtUser.getText().toString();
                String userPass=txtPass.getText().toString();
                //validation for user name
                if (userName.length()<1)
                {
                    txtUser.setText("");
                    txtUser.setHintTextColor(Color.RED);
                    return;
                }
                if (userPass.length()<1)
                {
                    txtPass.setText("");
                    txtPass.setHintTextColor(Color.RED);
                    return;
                }
                //check user
                if (Utl.checkUser(userName,userPass,USER_NAME,USER_PASS))
                {
                    //user is correct -true
                    Toast.makeText(context, "Hello my Master", Toast.LENGTH_SHORT).show();
                    txtPass.setText("");
                    txtPass.setHintTextColor(orgHintColor);
                    txtUser.setText("");
                    txtUser.setHintTextColor(orgHintColor);
                    Log.i(TAG, "onClick: User OK");
                }
                else
                {
                    //user is incorrect -false
                    txtPass.setText("");
                    Toast.makeText(context, "You are not allowed!!", Toast.LENGTH_LONG).show();
                    Log.e(TAG, "onClick: Incorrect User" );
                }
            }
        });
    }
}


activity_main.xml
==========================
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <!-- my logo layout -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_weight="1"
        >
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="@string/myLogo"
            android:textSize="90sp"
            android:gravity="center"
            android:id="@+id/txtLogo"
            />
    </LinearLayout>

    <!-- my Edit text box -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_weight="1">
        <EditText
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:hint="@string/hintUserName"
            android:textSize="25sp"
            android:layout_weight="1"
            android:id="@+id/txtUser"/>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="5px"
            android:orientation="vertical"
            android:background="#000"/>
        <EditText
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:hint="@string/hintPassword"
            android:textSize="25sp"
            android:inputType="numberPassword"
            android:layout_weight="1"
            android:id="@+id/txtPass"
            />

    </LinearLayout>

    <!-- my Login Button -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_weight="1">
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#009fff"
            android:textColor="#ffffff"
            android:text="@string/btnLogin"
            android:textSize="26sp"
            android:id="@+id/btnLogin"/>
    </LinearLayout>
</LinearLayout>


strings.xml
=====================
<resources>
    <string name="app_name">MyLogin</string>
    <string name="myLogo">LOGO</string>
    <string name="hintUserName">Enter user name...</string>
    <string name="hintPassword">Enter user password...</string>
    <string name="btnLogin">Login</string>
</resources>