Java 十字キーで図形を移動させたい

Javaでシューティングゲームをつくっている者です。今自機の移動をするためのプログラムを書いています。↓

Java
1import java.awt.*;
2import java.awt.event.KeyEvent;
3import java.awt.event.KeyListener;
4import javax.swing.*;
5
6public class ShootingGame{
7
8    public static void main(String[] args) {
9        ShootingFrame f = new ShootingFrame("ShootingGame",400,300);
10        f.add(new Draw());
11        f.repaint();
12    }
13}
14
15class ShootingFrame extends JFrame implements KeyListener{
16    public ShootingFrame(String title, int width, int height) {
17        super(title);
18        setDefaultCloseOperation(EXIT_ON_CLOSE);
19        setSize(width,height);
20        setLocationRelativeTo(null);
21        setResizable(false);
22        setVisible(true);
23        addKeyListener(this);
24        setBackground(Color.WHITE);
25    }
26
27    @Override
28    public void keyPressed(KeyEvent e) {
29        switch (e.getKeyCode()) {　　//ここで自機の座標を変更したい➀
30            case KeyEvent.VK_UP:
31                break;
32            case KeyEvent.VK_DOWN:
33                break;
34            case KeyEvent.VK_LEFT:
35                break;
36            case KeyEvent.VK_RIGHT:
37                break;
38            case KeyEvent.VK_SPACE:
39                break;
40        }
41
42    }
43    @Override
44    public void keyTyped(KeyEvent e) {}
45    @Override
46    public void keyReleased(KeyEvent e) {}
47}
48
49
50class Draw extends JPanel{
51    public void paint(Graphics g){
52        g.setColor(Color.BLACK);
53　　　　//ここで自機を描画したい
54　　　　//➁
55    }
56}

そこで質問なのですが、➀で自機の座標を変更して➁で描画するにはどのようにすればよいでしょうか？アドバイスをください。よろしくお願いします。

行動規範の内容に同意します

回答1件

ベストアンサー

案１ `Draw`を内部クラスにする

Javaっぽい感じがする。

Java
1import java.awt.Color;
2import java.awt.Graphics;
3import java.awt.event.KeyEvent;
4import java.awt.event.KeyListener;
5import javax.swing.JFrame;
6import javax.swing.JPanel;
7
8public class ShootingGame {
9    public static void main(String[] args) {
10        new ShootingFrame("ShootingGame", 400, 300);
11    }
12}
13
14class ShootingFrame extends JFrame implements KeyListener {
15    private int playerX;
16    private int playerY;
17
18    public ShootingFrame(String title, int width, int height) {
19        super(title);
20        setDefaultCloseOperation(EXIT_ON_CLOSE);
21        setSize(width, height);
22        setLocationRelativeTo(null);
23        setResizable(false);
24        setVisible(true);
25        addKeyListener(this);
26
27        add(new Draw());
28
29        // setVisible後でないとサイズが取れないので注意
30        playerX = getContentPane().getWidth() / 2;
31        playerY = getContentPane().getHeight() / 2;
32    }
33
34    @Override public void keyPressed(KeyEvent e) {
35        switch (e.getKeyCode()) {
36            case KeyEvent.VK_LEFT: playerX -= 5; break;
37            case KeyEvent.VK_RIGHT: playerX += 5; break;
38            case KeyEvent.VK_UP: playerY -= 5; break;
39            case KeyEvent.VK_DOWN: playerY += 5; break;
40            case KeyEvent.VK_SPACE: break;
41        }
42        repaint();
43    }
44
45    @Override public void keyTyped(KeyEvent e) {}
46
47    @Override public void keyReleased(KeyEvent e) {}
48
49
50    class Draw extends JPanel {
51        public Draw() {
52            setBackground(Color.WHITE);
53        }
54
55        @Override public void paintComponent(Graphics g) {
56            super.paintComponent(g);
57
58            g.setColor(Color.BLACK);
59            g.fillRect(playerX - 50 / 2, playerY - 50 / 2, 50, 50);
60        }
61    }
62}

案２ `Draw`で`KeyListener`する

ボタン等がなくパネルだけならこれでいい気もする。

Java
1import java.awt.Color;
2import java.awt.Dimension;
3import java.awt.Graphics;
4import java.awt.event.KeyEvent;
5import java.awt.event.KeyListener;
6import javax.swing.JFrame;
7import javax.swing.JPanel;
8
9public class ShootingGame {
10    public static void main(String[] args) {
11        new ShootingFrame("ShootingGame");
12    }
13}
14
15class ShootingFrame extends JFrame {
16    public ShootingFrame(String title) {
17        super(title);
18        setDefaultCloseOperation(EXIT_ON_CLOSE);
19        setResizable(false);
20
21        add(new Draw());
22        pack();
23        setLocationRelativeTo(null);
24        setVisible(true);
25    }
26}
27
28class Draw extends JPanel implements KeyListener {
29    private int playerX = 400 / 2;
30    private int playerY = 300 / 2;
31
32    public Draw() {
33        setBackground(Color.WHITE);
34        setFocusable(true);
35        setPreferredSize(new Dimension(400, 300));
36        addKeyListener(this);
37//        requestFocusInWindow();
38    }
39
40    @Override public void paintComponent(Graphics g) {
41        super.paintComponent(g);
42
43        g.setColor(Color.BLACK);
44        g.fillRect(playerX - 50 / 2, playerY - 50 / 2, 50, 50);
45    }
46
47    @Override public void keyPressed(KeyEvent e) {
48        switch (e.getKeyCode()) {
49            case KeyEvent.VK_LEFT: playerX -= 5; break;
50            case KeyEvent.VK_RIGHT: playerX += 5; break;
51            case KeyEvent.VK_UP: playerY -= 5; break;
52            case KeyEvent.VK_DOWN: playerY += 5; break;
53            case KeyEvent.VK_SPACE: break;
54        }
55        repaint();
56    }
57
58    @Override public void keyTyped(KeyEvent e) {}
59
60    @Override public void keyReleased(KeyEvent e) {}
61}

案３ `ShootingFrame`と`Draw`で共通の何かを持つ

なんにしろPlayerクラス的なものは作ることになる気はする。

Java
1import java.awt.Color;
2import java.awt.Graphics;
3import java.awt.event.KeyEvent;
4import java.awt.event.KeyListener;
5import javax.swing.JFrame;
6import javax.swing.JPanel;
7
8public class ShootingGame {
9    public static void main(String[] args) {
10        new ShootingFrame("ShootingGame", 400, 300);
11    }
12}
13
14class Player {
15    public int X;
16    public int Y;
17}
18
19class ShootingFrame extends JFrame implements KeyListener {
20    private Player player = new Player();
21
22    public ShootingFrame(String title, int width, int height) {
23        super(title);
24        setDefaultCloseOperation(EXIT_ON_CLOSE);
25        setSize(width, height);
26        setLocationRelativeTo(null);
27        setResizable(false);
28        setVisible(true);
29        addKeyListener(this);
30
31        add(new Draw(player));
32
33        // setVisible後でないとサイズが取れないので注意
34        player.X = getContentPane().getWidth() / 2;
35        player.Y = getContentPane().getHeight() / 2;
36    }
37
38    @Override public void keyPressed(KeyEvent e) {
39        switch (e.getKeyCode()) {
40            case KeyEvent.VK_LEFT: player.X -= 5; break;
41            case KeyEvent.VK_RIGHT: player.X += 5; break;
42            case KeyEvent.VK_UP: player.Y -= 5; break;
43            case KeyEvent.VK_DOWN: player.Y += 5; break;
44            case KeyEvent.VK_SPACE: break;
45        }
46        repaint();
47    }
48
49    @Override public void keyTyped(KeyEvent e) {}
50
51    @Override public void keyReleased(KeyEvent e) {}
52}
53
54class Draw extends JPanel {
55    private Player player;
56
57    public Draw(Player player) {
58        this.player = player;
59        setBackground(Color.WHITE);
60    }
61
62    @Override public void paintComponent(Graphics g) {
63        super.paintComponent(g);
64
65        g.setColor(Color.BLACK);
66        g.fillRect(player.X - 50 / 2, player.Y - 50 / 2, 50, 50);
67    }
68}