如何缩放基本图纸？

Question

我想要一个显示在我的窗口中的形状列表。每当我改变窗口的大小时，我都想缩放我的所有图纸。

我已经准备好了类，这些类将关于随机形状的信息存储在一个列表中（矩形、椭圆形等）。我把它们都画出来没有问题，但我无法处理缩放问题。我的解决方案不会改变任何东西，或者使所有形状都消失。

public class Shape extends JPanel{
    int x, y,width,height,red,green,blue;
    double scX, scY; //scale x and y

    public Shape(int x, int y, int width, int height, int red, int green, int blue) {
//...long constructor
        scX=1;
        scY=1;
    }
    void randomizeValues(){...}

        void setScale(double x, double y) {
        this.scX = x;
        this.scY = y;
    }
}

public class Rectangle extends Shape{

    public Rectangle(int x, int y, int width, int height, int red, int green, int blue) {
        super(x, y, width, height, red, green, blue);
    }

    @Override
    protected void paintComponent(Graphics graphics) {
        super.paintComponent(graphics);
        graphics.fillRect((int)(x*scX), (int)(y*scY), (int)(width*scX), (int)(height*scY));
    }
}


class Window extends JFrame {

    int defaultWidth = 768;
    int defaultHeight = 512;
    List<Shape> paintList = new ArrayList<>();

 public Window() {
        setTitle("Shape");
        add(new DrawShape);
        setSize(defaultWidth, defaultHeight);
        setVisible(true);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }

class DrawShape extends JPanel {
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            for (int i = 0; i< paintList.size(); i++) {
                Shape s = paintList.get(i);
                s.setScale(this.getWidth()/defaultWidth, this.getHeight()/defaultHeight);
                s.paintComponent(g);
            }
   }
}

如何制作适当的比例技巧？我应该在哪里乘以值，以使一切正常运行？

Answer 1

首先，您不应该将 JPanel 添加到窗口中，而是将其设置为 ContentPane：setContentPane(new DrawShape());。接下来，您不应该在循环内部重绘，而是在外部重绘（例如在 paintComponent(Graphics g) 方法的末尾）。这样，JPanel 应该被永久地再次绘制。 如果您需要根据窗口尺寸更改形状的大小，请在您的 JPanel paintComponent(Graphics g) 方法中执行此操作：

//fill it with the shapes base sizes (index 0 = width, index 1 = height)
Map<Shape,int[]> shapeSizes = new HashMap<Shape,int[]>();
public void paintComponent(Graphics g) {
double widthCoeff = this.getWidth()/(double)Window.this.defaultWidth;
double heightCoeff = this.getHeight()/(double)Window.this.defaultHeight;
for (int i = 0; i< paintList.size(); i++) {
Shape s = paintList.get(i);
int[] baseSize = shapeSizes.get(s);
int oldWidth = baseSize[0], oldHeight = baseSize[1];
int width = oldWidth*widthCoeff, height = oldHeight*heightCoeff;
//you can now give the shape its new width and height
}
}