package com.icetea09.demoespresso;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

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

@@ -108,226 +108,1354 @@
 le;%0A
-%0Apublic class MainActivity extends AppCompatActivity %7B%0A%0A    @Override%0A    protected void onCreate(Bundle savedInstanceState) %7B%0A        super.onCreate(savedInstanceState);%0A        setContentView(R.layout.activity_main);
+import android.text.TextUtils;%0Aimport android.view.View;%0Aimport android.widget.EditText;%0Aimport android.widget.TextView;%0A%0Apublic class MainActivity extends AppCompatActivity implements View.OnClickListener %7B%0A%0A    private EditText mEtUsername;%0A    private EditText mEtPassword;%0A    private TextView mTvMessage;%0A%0A    @Override%0A    protected void onCreate(Bundle savedInstanceState) %7B%0A        super.onCreate(savedInstanceState);%0A        setContentView(R.layout.activity_main);%0A%0A        mEtUsername = (EditText) findViewById(R.id.et_username);%0A        mEtPassword = (EditText) findViewById(R.id.et_password);%0A        mTvMessage = (TextView) findViewById(R.id.tv_message);%0A        findViewById(R.id.btn_login).setOnClickListener(this);%0A    %7D%0A%0A    @Override%0A    public void onClick(View v) %7B%0A        switch (v.getId()) %7B%0A            case R.id.btn_login:%0A                String username = mEtUsername.getText().toString();%0A                String password = mEtPassword.getText().toString();%0A                if (TextUtils.isEmpty(username) %7C%7C TextUtils.isEmpty(password)) %7B%0A                    mTvMessage.setText(%22You must enter both username and password!%22);%0A                %7D else %7B%0A                    mTvMessage.setText(%22Login successfully!%22);%0A                %7D%0A                mTvMessage.setVisibility(View.VISIBLE);%0A                break;%0A        %7D
 %0A   

Implement MainActivity to make it passes all the tests