Login

edit.xml

 <?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"   >

    <solid
        android:color="#fff" >
    </solid>

    <stroke
        android:width="1dp"
        android:color="#e0e6f1" >
    </stroke>

    <padding
        android:left="5dp"
        android:top="5dp"
        android:right="5dp"
        android:bottom="5dp"    >
    </padding>

    <corners
        android:radius="3dp"   >
    </corners>

</shape>

Login.java

public class MainActivity extends AppCompatActivity {

    Button login,register,forgot;
    EditText emailText,passwordText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        emailText = (EditText)findViewById(R.id.email);
        passwordText = (EditText)findViewById(R.id.password);

        login  = (Button)findViewById(R.id.login);
        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                validate();
            }
        });
        register = (Button)findViewById(R.id.register);
        register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                 Intent createAccount = new Intent(MainActivity.this,Register.class);
                 startActivity(createAccount);
            }
        });
        
        forgot = (Button)findViewById(R.id.forgot);
        forgot.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent forgotAccount = new Intent(MainActivity.this,ForgotPassword.class);
                startActivity(forgotAccount);

            }
        });
    }
    public void validate(){
        String email = emailText.getText().toString().trim();
        String emailRegex = "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@" + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
        String password = passwordText.getText().toString().trim();
        if (emailText.getText().toString().isEmpty()) {
            Toast toast = Toast.makeText( this, R.string.please_enter_email, Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            emailText.requestFocus();
        } else if (email.matches("")) {
            Toast toast = Toast.makeText( this, R.string.no_matches, Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            emailText.requestFocus();
        } else if (!email.matches(emailRegex)) {

            Toast toast = Toast.makeText(this, R.string.no_matches, Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            emailText.requestFocus();
        } else if (passwordText.getText().toString().isEmpty()) {

            Toast toast = Toast.makeText(this, R.string.please_enter_Password, Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            passwordText.requestFocus();
        } else if (password.matches("")) {
            Toast toast = Toast.makeText(this, R.string.no_spaces_allowed, Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            passwordText.requestFocus();
        } else if (passwordText.getText().toString().length() < 5) {
            Toast toast = Toast.makeText(this, R.string.required_minimum_three_characters, Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
            passwordText.requestFocus();
        } else {
            login(email,password);
        }

    }
    private  void login(String email,String password){

        Log.d(email, "login: email");
        Log.d(password, "login: password");
        
    }
}

Login.xml

<EditText

            android:textColor="@color/colorAccent"
            android:textStyle="normal"
            android:hint="@string/e_posta"
            android:textColorHint="@color/light_text"
            android:layout_width="match_parent"
            android:layout_marginLeft="30dp"
            android:layout_marginRight="30dp"
            android:background="@drawable/edit"
            android:layout_height="50dp">
 </EditText>

<EditText
            android:textColor="@color/colorAccent"
            android:textStyle="normal"
            android:hint="@string/password"
            android:textColorHint="@color/light_text"
            android:layout_width="match_parent"
            android:layout_marginLeft="30dp"
            android:layout_marginRight="30dp"
            android:layout_marginTop="5dp"
            android:background="@drawable/edit"
            android:layout_height="50dp">

 </EditText>

<Button
            android:id="@+id/login"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/colorAccent"
            android:layout_marginLeft="30dp"
            android:textColor="@color/white"
            android:layout_marginRight="30dp"
            android:layout_marginTop="20dp"
            android:textAlignment="center"
            android:textAllCaps="true"
            android:text="Giriş"
            android:fontFamily="@font/roboto_medium"
            />