credit.java

书籍"Java_面向事件编程"的附带光盘代码

import objectdraw.*;
import java.awt.*;

public class Credit extends ActiveObject {

    private static final int Y_SPEED = 4;
    private static final int DELAY_TIME = 100;
    
    private Text roleAndName; // information to be displayed
    
    public Credit(String scrollingLine, DrawingCanvas canvas) {
        // create the line to be displayed
        roleAndName = new Text(scrollingLine, 0, canvas.getHeight(), canvas);
        // center it on the canvas
        roleAndName.move((canvas.getWidth() - roleAndName.getWidth())/2, 0);
        // start the movement
        start();
    }
    
    public void run() {
        // move up while any part of the credit line is visible
        while (roleAndName.getY() > -roleAndName.getHeight()) {
            roleAndName.move(0, -Y_SPEED);
            pause(DELAY_TIME);
        }
        roleAndName.removeFromCanvas();
    }
}