这不是一个完整的答案，但这是一个滑动 JPanel 的工作示例。可以修改此代码以在问题中创建显示。
这是完整的可运行示例。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class SlidingDigitGUI implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new SlidingDigitGUI());
}
private SlidingPanel secondPanel;
@Override
public void run() {
JFrame frame = new JFrame("Sliding Digit");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createSlidingPanel(), BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
Animation animation = new Animation();
new Thread(animation).start();
}
public JPanel createSlidingPanel() {
String[] digitValues = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" };
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY, 4, false));
panel.setPreferredSize(new Dimension(300, 100));
Font font = panel.getFont();
Font derivedFont = font.deriveFont(Font.BOLD, 48F);
secondPanel = new SlidingPanel(digitValues, derivedFont);
secondPanel.setPanelValue("0");
panel.add(secondPanel);
return panel;
}
public class SlidingPanel extends JPanel {
private static final long serialVersionUID = 661553022861652947L;
private static final int MARGIN = 4;
private int imageY;
private BufferedImage slidingImage;
private Dimension characterDimension;
private final Font font;
private String currentValue;
private final String[] panelValues;
public SlidingPanel(String[] panelValues, Font font) {
this.panelValues = panelValues;
this.font = font;
this.characterDimension = calculateFontSize();
this.slidingImage = generateSlidingImage();
this.setPreferredSize(characterDimension);
}
private Dimension calculateFontSize() {
int maxWidth = 0;
int maxHeight = 0;
FontRenderContext frc = new FontRenderContext(null, true, true);
for (String s : panelValues) {
Rectangle2D r2D = font.getStringBounds(s, frc);
int rWidth = (int) Math.round(r2D.getWidth());
int rHeight = (int) Math.round(r2D.getHeight());
maxWidth = Math.max(maxWidth, rWidth);
maxHeight = Math.max(maxHeight, rHeight);
}
return new Dimension(maxWidth, maxHeight);
}
private BufferedImage generateSlidingImage() {
int height = calculateStringHeight() * (panelValues.length + 1);
BufferedImage slidingImage = new BufferedImage(characterDimension.width,
height, BufferedImage.TYPE_INT_RGB);
Graphics g = slidingImage.getGraphics();
g.setColor(Color.WHITE);
g.fillRect(0, 0, characterDimension.width, height);
g.setColor(Color.BLACK);
g.setFont(font);
int y = characterDimension.height - MARGIN;
for (String s : panelValues) {
g.drawString(s, 0, y);
y += calculateStringHeight();
}
g.drawString(panelValues[0], 0, y);
g.dispose();
return slidingImage;
}
public void setPanelValue(String value) {
int index = getValueIndex(value);
this.currentValue = value;
this.imageY = calculateStringHeight() * index;
repaint();
}
public void updatePanelValue(String value) {
if (!currentValue.equals(value)) {
int index = getValueIndex(value);
int finalY = calculateStringHeight() * index;
SliderAnimation sliderAnimation = new SliderAnimation(imageY, finalY);
new Thread(sliderAnimation).start();
this.currentValue = value;
}
}
private int getValueIndex(String value) {
for (int index = 0; index < panelValues.length; index++) {
if (value.equals(panelValues[index])) {
return index;
}
}
return -1;
}
private int calculateStringHeight() {
return characterDimension.height + MARGIN;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
BufferedImage subImage = slidingImage.getSubimage(0, imageY,
characterDimension.width,
characterDimension.height);
g.drawImage(subImage, 0, 0, this);
}
public class SliderAnimation implements Runnable {
private int originalY;
private int finalY;
public SliderAnimation(int originalY, int finalY) {
this.originalY = originalY;
this.finalY = finalY;
}
@Override
public void run() {
int differenceY = finalY - originalY;
if (finalY == 0) {
differenceY = characterDimension.height + MARGIN;
}
int steps = 10;
double difference = (double) differenceY / steps;
for (int index = 1; index <= steps; index++) {
imageY = (int) Math.round(difference * index + originalY);
update();
sleep(120L);
}
if (finalY == 0) {
imageY = 0;
update();
} else {
imageY = finalY;
}
}
private void update() {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
SlidingPanel.this.repaint();
}
});
}
private void sleep(long duration) {
try {
Thread.sleep(duration);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public class Animation implements Runnable {
@Override
public void run() {
while (true) {
update("3");
sleep(2000L);
update("8");
sleep(2000L);
}
}
private void update(final String value) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
secondPanel.updatePanelValue(value);
}
});
}
private void sleep(long duration) {
try {
Thread.sleep(duration);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}