交替随机大小圆的生成序列

Question

需要帮忙解决这个问题。

我应该得到多个不同随机大小的可区分的圆圈，但是我的程序似乎只是做了太多的圆圈，直到它被填满。

以下是人们的期望：

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下面是我的程序输出的内容：

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我有输入(例如askDouble)将输入保存到变量中。高度必须小于PATTERN_SIZE，即300。

代码:常量：

public static final double PATTERN_LEFT = 50.0;   // Left side of the pattern
public static final double PATTERN_TOP = 50.0;    // Top of the pattern
public static final double PATTERN_SIZE = 300.0;  // The size of the pattern on the window

绘制圆圈的方法：

/**
 * Drawing a sequence of circles.
 */
public void drawRandomCircles(){
    double height = 0;
    boolean validHeight = false;

    while(!validHeight){
        height = UI.askDouble("Enter height below 300px: ");

        if(height < PATTERN_SIZE && height > 0){
            validHeight = true;
            UI.setColor(Color.black);
            UI.drawRect(PATTERN_LEFT,PATTERN_TOP,PATTERN_SIZE,height);

        }

    }

    while(validHeight){
        double circleSize = (3 * Math.random() * (height-3));
        UI.setColor(Color.blue);
        for(int i = 0; i < circleSize; i++){
            if(circleSize < height){
                UI.fillOval(PATTERN_LEFT + i,PATTERN_TOP,circleSize,circleSize);
            }
        }

    }
}

我知道我必须至少有两个while循环来回答这个问题，我已经被告知了。任何正确方向的帮助都将不胜感激。我猜想它可能需要为第二个循环的条件新的变量，因为它只是不断地绘制一堆圆圈lol。

Answer 1

您的代码使用了我们无法访问的UI类。

此解决方案是用通用Java Swing编写的。甲骨文有一个有用的教程，用Swing创建GUI。跳过NetBeans IDE部分的学习Swing。

这是我想出的GUI。

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我做的第一件事是创建一个Circle类。Circle类是一个普通的Java /setter类，它包含一个半径和一个中心点。在绘制圆圈时，我更喜欢处理中间点，而不是边框的左上角。我使用一个java.awt.Point实例来保存中心点。

接下来，我创建了一个RandomCirclesModel类。RandomCirclesModel类是一个普通的Java /setter类，它包含java.util.List of Circle实例、绘图JPanel的维度和边距。当我创建一个绘图JPanel时，我喜欢在绘图区域周围有一个边距。由于圆的数目是随机的，所以我使用List来存储所有的圆。

在绘制任何东西之前，我计算所有的Circle实例。最后一个“随机”圆必须有一个半径，使其适合于包围矩形。

我不打算讨论Java Swing代码，因为您有那个秘密UI类。

Circle实例是在ButtonListener类中计算的。actionPerformed方法确定最大直径是否在此范围内。我设定的最小直径为50像素，而您的最大直径为300像素。calculateRandomCircles方法计算随机圆。命名方法就那么简单。动词-名词组合。

这是完整的可运行代码。我在内部创建了额外的类，这样我就可以将这段代码作为一个块发布。

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;

public class RandomCirclesGUI implements Runnable {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new RandomCirclesGUI());
    }

    private final RandomCirclesModel model;

    private final DrawingPanel drawingPanel;

    private JTextField validHeightField;

    public RandomCirclesGUI() {
        this.model = new RandomCirclesModel();
        this.drawingPanel = new DrawingPanel(model);
    }

    @Override
    public void run() {
        JFrame frame = new JFrame("Random Circles");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.add(createEntryPanel(), BorderLayout.NORTH);
        frame.add(drawingPanel, BorderLayout.CENTER);

        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private JPanel createEntryPanel() {
        JPanel panel = new JPanel(new FlowLayout());
        panel.setBorder(BorderFactory.createEmptyBorder(0, 5, 5, 5));

        JLabel label = new JLabel("Enter height below 300px:");
        panel.add(label);

        validHeightField = new JTextField(10);
        panel.add(validHeightField);

        panel.add(Box.createHorizontalStrut(30));

        JButton button = new JButton("Submit");
        button.addActionListener(new ButtonListener(this, model));
        panel.add(button);

        return panel;
    }

    public String getValidHeightField() {
        return validHeightField.getText();
    }

    public void repaint() {
        drawingPanel.repaint();
    }

    public class DrawingPanel extends JPanel {

        private static final long serialVersionUID = 1L;

        private final RandomCirclesModel model;

        public DrawingPanel(RandomCirclesModel model) {
            this.model = model;
            this.setPreferredSize(model.getDrawingPanelDimension());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);

            Graphics2D g2d = (Graphics2D) g;

            int width = getWidth();
            int height = model.getValidHeight();
            int margin = model.getMargin();

            paintBorder(g2d, width, height, margin);
            paintCircles(g2d);
        }

        private void paintBorder(Graphics2D g2d, int width, int height,
                int margin) {
            g2d.setColor(Color.BLACK);
            g2d.setStroke(new BasicStroke(3f));
            g2d.drawLine(margin, margin, width - margin, margin);
            g2d.drawLine(margin, margin, margin, height - margin);
            g2d.drawLine(width - margin, margin, width - margin,
                    height - margin);
            g2d.drawLine(margin, height - margin, width - margin,
                    height - margin);
        }

        private void paintCircles(Graphics2D g2d) {
            g2d.setColor(Color.blue);
            for (Circle circle : model.getCircles()) {
                Point centerPoint = circle.getCenterPoint();
                int radius = circle.getRadius();
                int diameter = radius + radius;
                g2d.fillOval(centerPoint.x - radius, centerPoint.y - radius,
                        diameter, diameter);
            }
        }
    }

    public class ButtonListener implements ActionListener {

        private final RandomCirclesGUI view;

        private final RandomCirclesModel model;

        public ButtonListener(RandomCirclesGUI view, RandomCirclesModel model) {
            this.view = view;
            this.model = model;
        }

        @Override
        public void actionPerformed(ActionEvent event) {
            String text = view.getValidHeightField();
            double validHeightD;
            try {
                validHeightD = Double.valueOf(text);
            } catch (NumberFormatException e) {
                // Invalid value, return
                return;
            }

            int validHeight = (int) Math.round(validHeightD);
            int margin = model.getMargin();
            int width = model.getDrawingPanelDimension().width;
            int height = model.getDrawingPanelDimension().height;
            if (validHeight > 50 && validHeight <= height - margin - margin) {
                model.clearCircles();
                model.setValidHeight(validHeight);
                calculateRandomCircles(margin, width, validHeight);
                view.repaint();
            }
        }

        private void calculateRandomCircles(int margin, int width,
                int validHeight) {
            Random random = new Random();
            int x = margin;
            int y = validHeight / 2;
            while (x < (width - margin)) {
                int radius = random
                        .nextInt((validHeight - margin - margin) / 2);
                if (x > (width - margin - radius - radius)) {
                    radius = (width - margin - x) / 2;
                }
                x += radius;
                model.addCircle(new Circle(new Point(x, y), radius));
                x += radius;
            }
        }

    }

    public class RandomCirclesModel {

        private final int margin;
        private int validHeight;

        private final Dimension drawingPanelDimension;

        private final List<Circle> circles;

        public RandomCirclesModel() {
            this.margin = 10;
            this.validHeight = 320;
            this.drawingPanelDimension = new Dimension(820, validHeight);
            this.circles = new ArrayList<>();
        }

        public void clearCircles() {
            this.circles.clear();
        }

        public void addCircle(Circle circle) {
            this.circles.add(circle);
        }

        public void setValidHeight(int validHeight) {
            this.validHeight = validHeight;
        }

        public int getValidHeight() {
            return validHeight;
        }

        public int getMargin() {
            return margin;
        }

        public Dimension getDrawingPanelDimension() {
            return drawingPanelDimension;
        }

        public List<Circle> getCircles() {
            return circles;
        }

    }

    public class Circle {

        private final int radius;

        private final Point centerPoint;

        public Circle(Point centerPoint, int radius) {
            this.centerPoint = centerPoint;
            this.radius = radius;
        }

        public int getRadius() {
            return radius;
        }

        public Point getCenterPoint() {
            return centerPoint;
        }

    }

}