scrollingsun.java

书籍"Java_面向事件编程"的附带光盘代码

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

    // A program that produces an animation of the sun rising and setting.
    // The animation is driven by dragging the mouse.
public class ScrollingSun extends WindowController {

    private FilledOval sun;  // Circle that represents the sun

        // Place the sun and some brief instructions on the screen
    public void begin() {
        sun = new FilledOval( 50, 150, 100, 100, canvas);
        new Text( "Drag the mouse up or down", 20, 30, canvas );
    }

        // Move the sun to follow the mouse's vertical motion
    public void onMouseDrag( Location mousePosition ) {
        sun.moveTo( 50, mousePosition.getY() );
    }

}