import java.util.Formattable;
import java.util.Formatter;
import java.util.Locale;

import static java.util.FormattableFlags.ALTERNATE;
import static java.util.FormattableFlags.LEFT_JUSTIFY;
import static java.util.FormattableFlags.UPPERCASE;

public class FormatterTest5 {
    public static void main(String[] args) {
        Formatter formatter = new Formatter((Appendable)System.out);
        
        Name name = new Name("Yuichi", "Sakuraba");
        
        formatter.format("%%s [%1$s] %%#s [%1$#s]%n", name);
        formatter.format("%%5s [%1$5s] %%10s [%1$10s]%n", name);
        formatter.format("%%20s [%1$20s] %%-20s [%1$-20s]%n", name);
    }
}

class Name implements Formattable {
    private String firstName;
    private String lastName;

    public Name(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public String toString() {
        return firstName + " " + lastName;
    }

    public void formatTo(Formatter formatter, int flags, int width, int precision) {
        StringBuilder builder = new StringBuilder();

        boolean hasLimit = width != -1;

        if (hasLimit && width < lastName.length()) {
            createLimittedLastName(builder, width);
        } else if (hasLimit && width < firstName.length() + lastName.length()) {
            createLastName(builder);
        } else {
            createFullName(builder, flags, formatter.locale());
        }

        // 幅に足りない分のスペースを入れる
        if (hasLimit && builder.length() < width) {
            if ((flags & LEFT_JUSTIFY) != LEFT_JUSTIFY) {
                int num = width - builder.length();
                for (int i = 0; i < num; i++) {
                    builder.insert(0, ' ');
                }
            }
        }

        if ((flags & UPPERCASE) == UPPERCASE) {
            formatter.format(builder.toString().toUpperCase());
        } else {
            formatter.format(builder.toString());
        }
    }

    private void createLimittedLastName(StringBuilder builder, int width) {
        builder.append(lastName.substring(0, width - 1));
        builder.append('*');
    }

    private void createLastName(StringBuilder builder) {
        builder.append(lastName);
    }

    private void createFullName(StringBuilder builder, int flags, Locale locale) {
        if ((flags & ALTERNATE) == ALTERNATE 
            && Character.getType(firstName.charAt(0)) == Character.UPPERCASE_LETTER) {
            builder.append(firstName.substring(0, 1));
        } else {
            builder.append(firstName);
        }
        
        builder.append(' ');
        builder.append(lastName);
    }
}