カウント変数を使用して配列またはコレクションを反復処理し、インデックス ラベルの右側のラベルを背景色に設定し、インデックス ラベルをアクティブな色に設定し、インデックスを進めます。例えば:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
@SuppressWarnings("serial")
public class LarsonScanner extends JPanel {
private static final int PANEL_COUNT = 50;
private static final int TIMER_DELAY = 30;
private static final Color BACKGROUND = Color.BLACK;
private static final Color ACTIVE_COLOR = Color.GREEN;
private static final Color PARTIAL_COLOR = new Color(0, 90, 0);
private static final Dimension RIGID_AREA = new Dimension(14, 1);
private JPanel[] panels = new JPanel[PANEL_COUNT];
public LarsonScanner() {
setLayout(new GridLayout(1, 0));
for (int i = 0; i < panels.length; i++) {
panels[i] = new JPanel();
panels[i].add(Box.createRigidArea(RIGID_AREA));
panels[i].setBackground(BACKGROUND);
add(panels[i]);
}
new Timer(TIMER_DELAY, new TimerListener()).start();
}
private class TimerListener implements ActionListener {
private int count = 0;
@Override
public void actionPerformed(ActionEvent e) {
int index = (count - 2 + panels.length) % panels.length;
panels[index].setBackground(BACKGROUND);
int prior = (count - 1 + panels.length) % panels.length;
int next = (count + 1) % panels.length;
panels[count].setBackground(ACTIVE_COLOR);
panels[prior].setBackground(PARTIAL_COLOR);
panels[next].setBackground(PARTIAL_COLOR);
count++;
count %= panels.length;
}
}
private static void createAndShowGui() {
LarsonScanner mainPanel = new LarsonScanner();
JFrame frame = new JFrame("LarsonScanner");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
プログラムの編集 2
反復 2:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
@SuppressWarnings("serial")
public class LarsonScanner extends JPanel {
private static final int PANEL_COUNT = 40;
private static final int TIMER_DELAY = 20;
private static final Color BACKGROUND = Color.BLACK;
private static final Color ACTIVE_COLOR = Color.GREEN;
private static final Color PARTIAL_COLOR = new Color(0, 90, 0);
private static final Dimension RIGID_AREA = new Dimension(14, 1);
private JPanel[] panels = new JPanel[PANEL_COUNT];
public LarsonScanner() {
setLayout(new GridLayout(1, 0));
for (int i = 0; i < panels.length; i++) {
panels[i] = new JPanel();
panels[i].add(Box.createRigidArea(RIGID_AREA));
panels[i].setBackground(BACKGROUND);
add(panels[i]);
}
new Timer(TIMER_DELAY, new TimerListener()).start();
}
private class TimerListener implements ActionListener {
private int count = 0;
private boolean goingRight = true;
@Override
public void actionPerformed(ActionEvent e) {
if (goingRight) {
int index = (count - 2 + panels.length) % panels.length;
panels[index].setBackground(BACKGROUND);
int prior = Math.max((count - 1) % panels.length, 0);
int next = Math.min(count + 1, panels.length - 1);
panels[prior].setBackground(PARTIAL_COLOR);
panels[next].setBackground(PARTIAL_COLOR);
panels[count].setBackground(ACTIVE_COLOR);
count++;
if (count == panels.length) {
count--;
goingRight = false;
}
} else {
int index = (count + 2) % panels.length;
panels[index].setBackground(BACKGROUND);
int prior = Math.max((count - 1) % panels.length, 0);
int next = Math.min(count + 1, panels.length - 1);
panels[prior].setBackground(PARTIAL_COLOR);
panels[next].setBackground(PARTIAL_COLOR);
panels[count].setBackground(ACTIVE_COLOR);
count--;
if (count == -1) {
count++;
goingRight = true;
}
}
}
}
private static void createAndShowGui() {
LarsonScanner mainPanel = new LarsonScanner();
JFrame frame = new JFrame("LarsonScanner");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}