Java动画模板

《看的见的算法》视频中写的Java动画模板，很容易理解，记个笔记：
Model：

public class Circle {    int x;    int y;    int r = 0;    int direction = 1;    public Circle(int x, int y) {        this.x = x;        this.y = y;    }    public int getY() {        return y;    }    public void setY(int y) {        this.y = y;    }    public int getX() {        return x;    }    public void setX(int x) {        this.x = x;    }    public int getR() {        return r;    }    public void changeSize(int min, int max) {        if(r<min || r>max) //初始化是让r在这个范围内            r = min;        r = r + direction;        if(r==max || r==min) {            direction = - direction;        }    }}

View：

public class ViewFrame extends JFrame{    private int canvasWidth;    private int canvasHeight;    public ViewFrame(String title, int canvasWidth, int canvasHeight){        super(title);        this.canvasWidth = canvasWidth;        this.canvasHeight = canvasHeight;       Canvas canvas = new Canvas();        setContentPane(canvas);        pack();//frame可以随着JPanel自动伸缩        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        setResizable(false);        setVisible(true);    }    public int getCanvasWidth(){return canvasWidth;}    public int getCanvasHeight(){return canvasHeight;}    private Object data; //直接改变这里的类型，可以在后面避免进行类型转换    public void render(Object data){        this.data = data;        repaint();    }    private class Canvas extends JPanel{        public Canvas(){            // 双缓存            super(true);        }        @Override        public void paintComponent(Graphics g) {            super.paintComponent(g);            Graphics2D g2d = (Graphics2D)g;            // 抗锯齿            RenderingHints hints = new RenderingHints(                    RenderingHints.KEY_ANTIALIASING,                    RenderingHints.VALUE_ANTIALIAS_ON);            hints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);            g2d.addRenderingHints(hints);            // 将data在这里具体绘制,例如：            VisHelper.setColor(g2d, VisHelper.Red);            if(data!=null) {                Circle circle = (Circle) data;                VisHelper.drawCircle(g2d, circle.getX(), circle.getY(), circle.getR());            }        }        @Override  //通过实现此方法让JPanel可以设置我们需要的大小        public Dimension getPreferredSize(){            return new Dimension(canvasWidth, canvasHeight);        }    }}

Controller:

public class Visualizer {    private Object data;        // 数据    private ViewFrame frame;    // 视图    public Visualizer(int sceneWidth, int sceneHeight){        // 初始化数据,例如：        data = new Circle(sceneWidth/2, sceneHeight/2);        // 初始化视图        EventQueue.invokeLater(() -> {            frame = new ViewFrame("xxx's frame", sceneWidth, sceneHeight);            //添加事件            //frame.add*Listener(new *Listener());            new Thread(() -> {    //因为EventQueue.invokeLater                run();            //不放在线程里可能会阻碍后续的绘画过程            }).start();           //除非运行代码可以很快结束        });    }    // 动画逻辑    private void run(){        //编写动画逻辑，例如：        while(true) {            Circle circle = (Circle)data;            frame.render(circle);            circle.changeSize(0,200);            VisHelper.pause(10);        }    }    // 事件监听器类//    private class *Listener extends *Adapter{ }    //启动代码    public static void main(String[] args) {        int sceneWidth = 500;        int sceneHeight = 500;        // 初始化visualizer        Visualizer visualizer = new Visualizer(sceneWidth, sceneHeight);    }}

工具类：

//helper类public class VisHelper {    private VisHelper(){}    //颜色    public static final Color Red = new Color(0xF44336);    public static final Color Pink = new Color(0xE91E63);    public static final Color Purple = new Color(0x9C27B0);    //等等颜色...    //绘制空心圆    public static void drawCircle(Graphics2D g, int x, int y, int r){        Ellipse2D circle = new Ellipse2D.Double(x-r, y-r, 2*r, 2*r);        g.draw(circle);    }    //绘制实心圆    public static void fillCircle(Graphics2D g, int x, int y, int r){        Ellipse2D circle = new Ellipse2D.Double(x-r, y-r, 2*r, 2*r);        g.fill(circle);    }    //设置颜色    public static void setColor(Graphics2D g, Color color){        g.setColor(color);    }    //设置线条宽度    public static void setStrokeWidth(Graphics2D g, int w){        int strokeWidth = w;        g.setStroke(new BasicStroke(strokeWidth, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));//参数使拐弯处圆润    }    //线程暂停    public static void pause(int t) {        try {            Thread.sleep(t);        }        catch (InterruptedException e) {            System.out.println("error");        }    }    //等等方法...}

运行后，写在代码中小例子运行结果会是一个从小变大，在从大变小的空心圆