명품자바 programming 실습문제 10장

2.

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
 
import javax.swing.JFrame;
 
public class Ex2 extends JFrame {
	
	public Ex2() {
		super("드래깅 동안 Yellow");
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
		Container c = getContentPane();
		c.setLayout(null);
		c.setBackground(Color.GREEN);
		
		c.addMouseListener(new MyMouse());
		c.addMouseMotionListener(new MyMouse());
		
		setSize(300,300);
		setVisible(true);
	}
	
	class MyMouse extends MouseAdapter {
		public void mouseDragged(MouseEvent e) {
			Component co = (Component)e.getSource();
			co.setBackground(Color.YELLOW);
		}
		
		public void mouseReleased(MouseEvent e) {
			Component co = (Component)e.getSource();
			co.setBackground(Color.GREEN);
		}
		
	}
	
	public static void main(String[] args) {
		new Ex2();
	}
 
}

 

3.

import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
 
import javax.swing.JFrame;
import javax.swing.JLabel;
 
public class Ex3 extends JFrame {
	
	JLabel label = null;
	
	public Ex3() {
		super("Left 키로 문자열 교체");
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
		Container c = getContentPane();
		c.setLayout(new FlowLayout());
		
		label = new JLabel("Love Java");
		c.add(label);
		
		c.addKeyListener(new MyKey());
		c.setFocusable(true);
		c.requestFocus();
		
		setSize(400,200);
		setVisible(true);
	}
	
	class MyKey extends KeyAdapter{
		public void keyPressed(KeyEvent e) {
			Component c = (Component)e.getSource();
			
			if (e.getKeyCode() == KeyEvent.VK_LEFT) { 
				StringBuffer sb = new StringBuffer(label.getText());
				sb = sb.reverse();
				label.setText(sb.toString());
				
				c.setFocusable(true);
				c.requestFocus();
			}
			
		}
	}
	
	public static void main(String[] args) {
		new Ex3();
	}
 
}

 

4.

import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
 
import javax.swing.JFrame;
import javax.swing.JLabel;
 
public class Ex3 extends JFrame {
	
	JLabel label = null;
	
	public Ex3() {
		super("Left 키로 문자열 교체");
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
		Container c = getContentPane();
		c.setLayout(new FlowLayout());
		
		label = new JLabel("Love Java");
		c.add(label);
		
		c.addKeyListener(new MyKey());
		c.setFocusable(true);
		c.requestFocus();
		
		setSize(400,200);
		setVisible(true);
	}
	
	class MyKey extends KeyAdapter{
		public void keyPressed(KeyEvent e) {
			Component c = (Component)e.getSource();
			
			if (e.getKeyCode() == KeyEvent.VK_LEFT) { 
				StringBuffer sb = new StringBuffer(label.getText());
				char temp;
				
				temp = sb.charAt(0);
				sb.append(temp);
				sb.delete(0, 1);
				label.setText(sb.toString());
				
				c.setFocusable(true);
				c.requestFocus();
			}
			
		}
	}
	
	public static void main(String[] args) {
		new Ex3();
	}
 
}

 

5. +누르면 안되는 이유 아직 해결 x

import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
 
import javax.swing.JFrame;
import javax.swing.JLabel;
 
public class Ex5 extends JFrame {
	
	JLabel label = null;
	
	public Ex5() {
		super("+,- 키로 폰트 크기 조절");
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
		Container c = getContentPane();
		c.setLayout(new FlowLayout());
		
		label = new JLabel("Love Java");
		c.add(label);
		
		c.addKeyListener(new MyKey());
		c.setFocusable(true);
		c.requestFocus();
		
		setSize(400,200);
		setVisible(true);
	}
	
	public class MyKey extends KeyAdapter {
		public void keyPressed(KeyEvent e) {
			Component c = (Component)e.getSource();
			Font f = label.getFont();
			int size = f.getSize();
			if (e.getKeyCode() == KeyEvent.VK_PLUS) {
				size += 5;
			}
			if (e.getKeyCode() == KeyEvent.VK_MINUS){
				size -= 5;
				if (size < 5) size += 5;
				
			}
			label.setFont(new Font("Arial", Font.PLAIN, (int)size));
			c.setFocusable(true);
			c.requestFocus();
		}
	}
 
	public static void main(String[] args) {
		new Ex5();
	}
 
}