java/71_KeyBindings at main · PeiHui369/java · GitHub

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// Key Bindings = bind an Action to a KeyStroke
//                don't require you to click a component to give it focus
//                all Swing components use Key Bindings
//                increased flexibility compared to KeyListeners
//                can assign key strokes to individual Swing components
//                more difficult to utilize and set up

<Main.java>
public class Main {
    public static void main(String[] args){

        Game game = new Game();
    }
}

<Game.java>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Game {
    JFrame frame;
    JLabel label;
    Action upAction;
    Action downAction;
    Action leftAction;
    Action rightAction;
    Game(){
        frame = new JFrame("KeyBinding Demo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(420,420);
        frame.setLayout(null);

        label = new JLabel();
        label.setBackground(Color.RED);
        label.setBounds(100,100,100,100);
        label.setOpaque(true);

        upAction = new UpAction();
        downAction = new DownAction();
        leftAction = new LeftAction();
        rightAction = new RightAction();

        label.getInputMap().put(KeyStroke.getKeyStroke("UP"),"upAction");//keyStroke, actionMapKey
        label.getActionMap().put("upAction",upAction);//key, action
        label.getInputMap().put(KeyStroke.getKeyStroke("DOWN"),"downAction");
        label.getActionMap().put("downAction",downAction);
        label.getInputMap().put(KeyStroke.getKeyStroke("LEFT"),"leftAction");
        label.getActionMap().put("leftAction",leftAction);
        label.getInputMap().put(KeyStroke.getKeyStroke("RIGHT"),"rightAction");
        label.getActionMap().put("rightAction",rightAction);


        frame.add(label);
        frame.setVisible(true);

    }

    public class UpAction extends AbstractAction {

        @Override
        public void actionPerformed(ActionEvent e) {
            label.setLocation(label.getX(), label.getY()-10);
        }
    }
    public class DownAction extends AbstractAction {

        @Override
        public void actionPerformed(ActionEvent e) {
            label.setLocation(label.getX(), label.getY()+10);
        }
    }
    public class LeftAction extends AbstractAction {

        @Override
        public void actionPerformed(ActionEvent e) {
            label.setLocation(label.getX()-10, label.getY());
        }
    }
    public class RightAction extends AbstractAction {

        @Override
        public void actionPerformed(ActionEvent e) {
            label.setLocation(label.getX()+10, label.getY());
        }
    }
}