Week8) Java Programming Lab : More on Grapical User Interface (GUI)

Java-Lecture8.pdf

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1. More on GUI 

 

• JButton example 1

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class FirstGUI extends JFrame {
	private JButton button1;
	private JButton button2;
	private JButton button3;
	private JButton button4;
	private JButton button5;
    
    // constructor
	public FirstGUI() {
    	// Jframe을 상속받았기 때문에 set.., add 등의 메소드를 객체 선언 없이 사용 가능 
		super.setSize(300, 300);
		super.setTitle("First GUI");
		super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        // Jbutton 객체 만드는 일반적인 방식 
		button1 = new JButton();
		button2 = new JButton();
        // JButton('title') 버튼 객체 선언 
		button3 = new JButton("Explore");
		button4 = new JButton("Cancel");
		button5 = new JButton("Send");
        
        // 버튼 setting 
		button1.setText("Back");
		button1.setBackground(Color.CYAN);
		button2.setText("Next");
		button2.setBackground(Color.RED);
		super.setLayout(new BorderLayout());
		super.add(button1, BorderLayout.EAST);
		super.add(button2, BorderLayout.WEST);
		super.add(button3, BorderLayout.CENTER);
		super.add(button4, BorderLayout.NORTH);
		super.add(button5, BorderLayout.SOUTH);
        
        // 액션리스너
		button1.addActionListener(new changeColor());
		button2.addActionListener(new  anotherAction());
		button3.addActionListener(new  changeColor());
		button4.addActionListener(new  anotherAction());
		button5.addActionListener(new  anotherAction());
		super.setVisible(true);
		
	}
	
	public static void main(String[] args) {
    	// 호출시 위 constructor에 있는 모든 객체 생성 
		FirstGUI gui = new FirstGUI();
	}

	private class changeColor implements ActionListener {
		

		@Override
		public void actionPerformed(ActionEvent e) {
			// code to do when you click a button
			// change();
			System.out.println("Red Color");

		}

	}

	private class anotherAction implements ActionListener {
		
		@Override
		public void actionPerformed(ActionEvent e) {
			// code to do when you click a button
			// change();
			System.out.println("KNock!!");

		}

	}

}

 

• JButton example2

// Creating JButtons.
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

import javax.swing.AbstractButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
import javax.swing.JRadioButton;
import javax.swing.JToggleButton;

public class ButtonFrame extends JFrame implements ActionListener {
	private AbstractButton plainJButton; // button with just text
	private JButton fancyJButton; // button with icons

	// ButtonFrame adds JButtons to JFrame
	public ButtonFrame() {
		super("Testing Buttons");
		setLayout(new FlowLayout()); // set frame layout

		plainJButton = new JRadioButton("Plain Button"); // button with text
		add(plainJButton); // add plainJButton to JFrame

		// 이미지 접근을 위해 getResource('자원이 위치한 경로');
		Icon bug1 = new ImageIcon(getClass().getResource("bug1.gif"));
		Icon bug2 = new ImageIcon(getClass().getResource("bug2.gif"));
		fancyJButton = new JButton("RollOver Button", bug1); // set image
		fancyJButton.setRolloverIcon(bug2); // set rollover image
		add(fancyJButton); // add fancyJButton to JFrame

		// 액션 추가 
		fancyJButton.addActionListener(this);
		plainJButton.addActionListener(this);
	} // end ButtonFrame constructor

	@Override
	public void actionPerformed(ActionEvent e) {
		if (e.getSource() == fancyJButton) {

			// 팝업 메시지 보여줌 
            // showMessageDialog(); : 첫번째 인자로 부모 컴포넌트 전달하는 것 중요! 
			JOptionPane.showMessageDialog(ButtonFrame.this, "fancyJButton", "fancyJButton action",
					JOptionPane.INFORMATION_MESSAGE);
		} 
		
		else if (e.getSource() == plainJButton) {
			JOptionPane.showMessageDialog(ButtonFrame.this, "Plain button", "Plain button action",
					JOptionPane.INFORMATION_MESSAGE);

		}

	}

} // end class ButtonFrame

 

• 위 example2를 실행시키기 위한 main method 

import javax.swing.JFrame;

public class ButtonTest 
{
   public static void main( String[] args )
   { 
      ButtonFrame buttonFrame = new ButtonFrame(); // create ButtonFrame
      buttonFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
      buttonFrame.setSize( 300, 200 ); // set frame size
      buttonFrame.setVisible( true ); // display frame
   } // end main
} // end class ButtonTest

 

2. MVC model

백엔드 배경지식 Backend Background) MVC (Model-View-Controller) 프레임워크 : Java Spring, Python Django, Javascript

3. Converter Apllication 

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

public class ConverterFrame extends JFrame implements ActionListener {
	JLabel distanceLabel;// = new JLabel("Distance in Km");
	JTextField inputKm;
	JButton calculateButton;
	JLabel displayLabel;

	// constructor start
	public ConverterFrame() {
		setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		setSize(300, 100);
		setLayout(new GridLayout(2, 2));
		setTitle("Converter");
		distanceLabel = new JLabel("Distance in Km");
		inputKm = new JTextField();
		calculateButton = new JButton("Calculate");
		displayLabel = new JLabel();

		// JFrame에 요소 추가 
		add(distanceLabel); 
		add(inputKm);
		add(calculateButton);
		add(displayLabel);
        // view 완성
        
        // controller = actionlistener
		calculateButton.addActionListener(this);
        
		setVisible(true);
	}

	// controller 
	@Override
	public void actionPerformed(ActionEvent e) {
    	// inputKm = textField 니까 getText -> inputValue 저장 
		String inputValue = inputKm.getText();
        
		//convert string into Double
		double inputkm = Double.parseDouble(inputValue);
		double result = inputkm *0.621;
        
        // set displayLabel to result value.
		displayLabel.setText(String.format("%f miles(s)", result));
		
		
		
	}
}



// convertor 실행을 위한 메인 메소드 클래스
public class TestConverter {

	public static void main(String[] args) {
		 ConverterFrame frame = new ConverterFrame();

	}

}

 

4. WINDOWBUILDER 

tool to create Java GUI application

• help -> eclipse marketplace에서 windowbuilder 플러그인 설치 후 이클립스 재시작 
  (설치하는데 시간이 몇 분 정도 소요되고, 설치가 다 되면 restart 여부를 묻는 팝업창이 뜸)
• java project 생성 -> src에 new -> other -> windowbuilder -> Swing Designer -> JFrame -> finish 
• GUI로 프레임에 컴포넌트를 드래그하고 속성을 변경하기만 하면 코드 자동 생성!!
• window -> references -> window builder -> swing -> code generation -> field 선택 (no local!!!) 설정 

 

• example - score board

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import java.awt.Color;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.JRadioButton;
import javax.swing.JList;
import javax.swing.JFormattedTextField;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JLabel;
import javax.swing.SwingConstants;

public class application extends JFrame implements ActionListener {

	private JPanel contentPane;
	private JButton ResetButton;
	private JPanel panel;
	private JLabel lblNewLabel;
	private JLabel lblNewLabel_1;
	private JLabel RedScoreLabel;
	private JLabel BlueScoreLabel;
	private JButton RedScoreButton;
	private JButton BlueScoreButton;
	private int redCounter = 0;
	private int blueCounter = 0;
	/**
	 * Create the frame.
	 */
	public application() {
		setTitle("This is the title");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 305, 205);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		contentPane.setLayout(new BorderLayout(0, 0));
		setContentPane(contentPane);
		
		ResetButton = new JButton("Reset Score");
		contentPane.add(ResetButton, BorderLayout.SOUTH);
		
		panel = new JPanel();
		contentPane.add(panel, BorderLayout.CENTER);
		panel.setLayout(new GridLayout(3, 2, 0, 0));
		
		lblNewLabel = new JLabel("Red Team");
		lblNewLabel.setHorizontalAlignment(SwingConstants.CENTER);
		lblNewLabel.setForeground(Color.RED);
		panel.add(lblNewLabel);
		
		lblNewLabel_1 = new JLabel("Bluee Team");
		lblNewLabel_1.setHorizontalAlignment(SwingConstants.CENTER);
		lblNewLabel_1.setForeground(Color.BLUE);
		panel.add(lblNewLabel_1);
		
		RedScoreLabel = new JLabel("0");
		RedScoreLabel.setHorizontalAlignment(SwingConstants.CENTER);
		panel.add(RedScoreLabel);
		
		BlueScoreLabel = new JLabel("0");
		BlueScoreLabel.setHorizontalAlignment(SwingConstants.CENTER);
		panel.add(BlueScoreLabel);
		
		RedScoreButton = new JButton("Red Score");
		panel.add(RedScoreButton);
		
		BlueScoreButton = new JButton("Blue Score");
		panel.add(BlueScoreButton);
        
        // 액션 리스터 연결 필요 
		RedScoreButton.addActionListener(this);
		BlueScoreButton.addActionListener(this);
		ResetButton.addActionListener(this);
	}
	
    // gui 생성후 직접 구현한 액션리스너 
	@Override
	public void actionPerformed(ActionEvent e) {
    	// 레드 스코어 버튼 클릭하면 레드 스코어 1 증가 후 display 
		if (e.getSource() == RedScoreButton ) {
			redCounter++;
			RedScoreLabel.setText(redCounter+"");
		}
		else if(e.getSource() == BlueScoreButton) {
			blueCounter++;
			BlueScoreLabel.setText(blueCounter+"");
		}
        
        // reset 버튼을 클릭하면 모든 스코어 값 0 으로 초기화 
		else if(e.getSource() == ResetButton) {
			blueCounter = 0;
			redCounter = 0;
			BlueScoreLabel.setText("0");
			RedScoreLabel.setText("0");
		}
	}
	
	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					application frame = new application();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}
	

	

}

 

 

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References

• 성균관대학교 소프트웨어학과 타메르 교수님 2021-1 <자바 프로그래밍 실습> 수업