Java swing 图形绘制并用颜色填充选定的矩形

问题描述 投票：0回答：3

我是 Java swing 桌面图形应用程序的新手，我遇到了一个问题，请建议我需要选择一些矩形并填充矩形，我们是否有任何预定义的概念，例如橡皮筋（如果有），请建议我开始绘图 

import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Stroke;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.util.ArrayList;

import javax.swing.JFrame;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class Exam extends JPanel implements MouseMotionListener {

    private static final int recW = 50;
    private static final int MAX = 100;
    private Rectangle[] rect = new Rectangle[MAX];
    private int numOfRecs = 0;
    private int currentSquareIndex = -1;
    private Point startPoint = new Point();
    private Point currentPoint = new Point();
    private int x, y, width, height;
    private Stroke dashedStroke = new BasicStroke(0.0f, BasicStroke.CAP_ROUND,
            BasicStroke.CAP_SQUARE, 5.0f, new float[] { 5f, 5f, 5f, 5f }, 5.0f);

    ArrayList list = new ArrayList();

    public Exam() {

        addRect(50, 50);
        addRect(100, 50);
        addRect(150, 50);
        addRect(200, 50);
        addRect(250, 50);
        addRect(300, 50);
        addRect(350, 50);
        addRect(400, 50);
        addRect(450, 50);
        addRect(500, 50);
        //
        addRect(50, 100);
        addRect(100, 100);
        addRect(150, 100);
        addRect(200, 100);
        addRect(250, 100);
        addRect(300, 100);
        addRect(350, 100);
        addRect(400, 100);
        addRect(450, 100);
        addRect(500, 100);
        //
        addRect(50, 150);
        addRect(100, 150);
        addRect(150, 150);
        addRect(200, 150);
        addRect(250, 150);
        addRect(300, 150);
        addRect(350, 150);
        addRect(400, 150);
        addRect(450, 150);
        addRect(500, 150);
        //
        addRect(50, 200);
        addRect(100, 200);
        addRect(150, 200);
        addRect(200, 200);
        addRect(250, 200);
        addRect(300, 200);
        addRect(350, 200);
        addRect(400, 200);
        addRect(450, 200);
        addRect(500, 200);

        addMouseListener(new MouseAdapter() {

            @Override
            public void mousePressed(MouseEvent evt) {
                startPoint = evt.getPoint();
            }

            public void mouseReleased(MouseEvent e) {

                System.out.println(" mouseReleased is " + e.getX() + " y i s "
                        + e.getY());
                Graphics g = getGraphics();
                Graphics2D g2 = (Graphics2D) g;
                g2.setComposite(AlphaComposite.SrcOver.derive(0.8f));
                Color myColour = new Color(255, 0, 0);
                g.setColor(myColour);
                x = Math.min(startPoint.x, currentPoint.x);
                y = Math.min(startPoint.y, currentPoint.y);
                width = Math.abs(startPoint.x - currentPoint.x);
                height = Math.abs(startPoint.y - currentPoint.y);
                rect[numOfRecs] = new Rectangle(x, y, width, height);
                // System.out.println("list size is:"+list.size());
                 Rectangle ggg=new Rectangle(x, y, width, height);
            for(Rectangle rect3d: rect){
                if(ggg.intersects(rect3d)){
                g2.fill(rect3d);
                }
                else
                    System.out.println("doesn't contains");
                }
repaint();
            }

        });

        addMouseMotionListener(this);
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        for (int i = 0; i < numOfRecs; i++) {
            ((Graphics2D) g).draw(rect[i]);
            list.add(rect[i]);
        }

        x = Math.min(startPoint.x, currentPoint.x);
        y = Math.min(startPoint.y, currentPoint.y);
        width = Math.abs(startPoint.x - currentPoint.x);
        height = Math.abs(startPoint.y - currentPoint.y);
        ((Graphics2D) g).setStroke(dashedStroke);
        g.setColor(Color.BLACK);
        g.drawRect(x, y, width, height);
        // Rectangle dashedRec=new Rectangle(x, y, width, height);

    }

    public void addRect(int x, int y) {
        if (numOfRecs < MAX) {
            rect[numOfRecs] = new Rectangle(x, y, recW, recW);
            currentSquareIndex = numOfRecs;
            numOfRecs++;
            repaint();
        }
    }

    @Override
    public void mouseMoved(MouseEvent event) {
    }

    @Override
    public void mouseDragged(MouseEvent event) {

        currentPoint = event.getPoint();
        repaint();
    }

    public static void main(String[] args) {
        JFrame jFrame = new JFrame();
        jFrame.setTitle("");
        jFrame.setSize(600, 300);
        Container cPane = jFrame.getContentPane();
        cPane.add(new Exam());
        jFrame.setVisible(true);
    }
}
java swing graphics mouselistener mousemotionlistener
3个回答
1
投票

你应该从改变开始 导入 java.awt.event.MouseMotionListener;

到

导入java.awt.event.MouseListener;

mousePressed 不与 MouseMotionListener 一起使用

1
投票

我看到班级名称是

Exam
，所以因为这是学校的，所以我不会给你代码解决方案。只是用一些合乎逻辑的方式来看待它。

我注意到，当您拖动鼠标时，您只是获得一个点并根据该点进行绘制。相反，您应该做的是，当第一次按下鼠标时，创建一个 

Rectangle
（并绘制矩形），然后在拖动鼠标时，使用 
setRect()
增加矩形的大小。你可以在这里看到一个很好的例子。

如果您希望颜色变化是动态的（拖动时或拖动完成时），您有两种选择：

  1. 拖动时遍历矩形列表，并检查列表中的每个矩形是否相交或包含在拖动的矩形中。 

    Rectangle
    从 Shape
     继承方法 
    intersects()
     和 
    contains()
    2. 

  2. 如果您只想在拖动完成时改变颜色，则在释放鼠标时执行与上述相同的操作。
    3. 







另请注意，您不应该以任何方式使用 
getGraphics()
 进行自定义绘画。所有绘画都应该在 
paintComponent
 方法
中提供的 Graphics 对象的上下文中完成





更新



这是一个基于我上面提出的观点的例子。该示例扩展了上面链接中提供的示例



enter image description here



import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

@SuppressWarnings("serial")
public class RectangleDrawWithDrag extends JPanel{

    private static final int D_W = 400;
    private static final int D_H = 400;
    private static final Color DEFAULT_COLOR = Color.GRAY;
    private static final Color SELECT_COLOR = Color.BLUE;
    private static final Color CURSOR_COLOR = new Color(100, 100, 100, 100);

    private Point p1;
    private Point p2;
    private Rectangle2D rectangle;
    private List<ColoredRectangle> rectangles;

    public RectangleDrawWithDrag() {
        rectangles = createRectangleList();
        addMouseListener(new MouseAdapter(){
            public void mousePressed(MouseEvent e) {
                p1 = e.getPoint();
                rectangle = new Rectangle2D.Double(p1.x, p1.y, p1.x - p1.x, p1.y - p1.y);
            }
        });
        addMouseMotionListener(new MouseMotionAdapter(){
            public void mouseDragged(MouseEvent e) {
                p2 = e.getPoint();
                if (isPointTwoInQuadOne(p1, p2)) {
                    rectangle.setRect(p2.x, p2.y, p1.x - p2.x, p1.y - p2.y);
                } else {
                    rectangle.setRect(p1.x, p1.y, p2.x - p1.x, p2.y - p1.y);  
                }
                checkRectangleContainment();
                repaint();
            }
        });
    }

    public void checkRectangleContainment() {
        for (ColoredRectangle rects: rectangles) {
            if (rectangle.contains(rects.getRectangle())) {
                rects.setColor(SELECT_COLOR);
            } else {
                rects.setColor(DEFAULT_COLOR);
            }
        }
    }

    public boolean isPointTwoInQuadOne(Point p1, Point p2) {
        return p1.x >= p2.x && p1.y >= p2.y;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        for (ColoredRectangle rect: rectangles) {
            rect.draw(g2);
        }
        if (rectangle != null) {
            g2.setColor(CURSOR_COLOR);
            g2.fill(rectangle);
        }
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(D_W, D_H);
    }

    private List<ColoredRectangle> createRectangleList() {
        List<ColoredRectangle> rects = new ArrayList<>();
        Random rand= new Random();
        for (int i = 0; i < 20; i++) {
            rects.add(new ColoredRectangle(rand.nextInt(D_W), rand.nextInt(D_H)));
        }
        return rects;
    }

    public class ColoredRectangle {
        Rectangle2D rectangle;
        Color color = DEFAULT_COLOR;
        double size = 20;

        public ColoredRectangle(double x, double y) {
            rectangle = new Rectangle2D.Double(x, y, size, size);
        }

        public ColoredRectangle(double x, double y, double size) {
            this.size = size;
            rectangle = new Rectangle2D.Double(x, y, size, size);
        }

        public void setColor(Color color) {
            this.color = color;
        }

        public Rectangle2D getRectangle() {
            return rectangle;
        }

        public void draw(Graphics2D g2) {
            g2.setColor(color);
            g2.fill(rectangle);
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new RectangleDrawWithDrag());
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
}


    

    

    
    
    

    

        

            

                

                    
-1
投票

                    
                

            

        

        


我在寻找我需要的类似内容时遇到了你的问题。我根据我的要求对保罗的代码进行了更多的定制。我写在这里是因为我不被允许发表评论这里
my version


import java.awt.Color;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Rectangle2D;
import java.util.HashSet;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingConstants;

public class TimetableFrame extends javax.swing.JFrame {

Point p1, p2;
Rectangle2D rectangle;
int mode = 0;
HashSet<JLabel> all = new HashSet<JLabel>();
HashSet<JLabel> selected = new HashSet<JLabel>();
HashSet<JLabel> current_selection = new HashSet<JLabel>();
Color empty_color = Color.WHITE;
Color fill_color = Color.RED;
Color empty_select = Color.GRAY;
Color fill_select = Color.PINK;

JPanel grid;
JPanel jPanel1;
JScrollPane jScrollPane1;

public TimetableFrame() {
    initComponents();
    setTitle("Swing grid selector example halimoglu.com");
    String[] col_titles = new String[]{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};

    String[] row_titles = new String[24];
    for (int i = 0; i < row_titles.length; i++) {
        row_titles[i] = (i) + "-" + (i + 1);
    }

    for (int y = 0; y < row_titles.length + 1; y++) {
        for (int x = 0; x < col_titles.length + 1; x++) {
            if (y == 0 && x == 0) {
                grid.add(new JLabel(""));
            } else if (y == 0) {
                JLabel col = new JLabel(col_titles[x - 1]);
                col.setHorizontalAlignment(SwingConstants.CENTER);
                grid.add(col);
            } else if (x == 0) {
                grid.add(new JLabel(row_titles[y - 1]));
            } else {
                JLabel mylabel = new JLabel(" ");

                mylabel.setOpaque(true);
                mylabel.setBackground(empty_color);
                all.add(mylabel);
                grid.add(mylabel);
            }
        }
    }

    grid.addMouseListener(new MouseListener() {
        @Override
        public void mouseClicked(MouseEvent me) {
            for (JLabel j : all) {
                if (j.getBounds().contains(me.getPoint())) {

                    if (selected.contains(j)) {
                        selected.remove(j);
                        j.setBackground(empty_color);
                    } else {
                        selected.add(j);
                        j.setBackground(fill_color);
                    }
                }
            }
        }

        @Override
        public void mousePressed(MouseEvent me) {
            p1 = me.getPoint();
            rectangle = new Rectangle2D.Double(p1.x, p1.y, p1.x - p1.x, p1.y - p1.y);
        }

        @Override
        public void mouseReleased(MouseEvent me) {

            if (mode == 1) {
                selected.addAll(current_selection);

            } else if (mode == -1) {
                selected.removeAll(current_selection);

            }
            for (JLabel j : all) {
                if (selected.contains(j)) {
                    j.setBackground(fill_color);
                } else {
                    j.setBackground(empty_color);
                }
            }
            current_selection.clear();
            mode = 0;
        }

        @Override
        public void mouseEntered(MouseEvent me) {
        }

        @Override
        public void mouseExited(MouseEvent me) {
        }

    });

    grid.addMouseMotionListener(new MouseMotionListener() {
        @Override
        public void mouseDragged(MouseEvent me) {
            p2 = me.getPoint();

            Point lu;

            int minx = Math.min(p1.x, p2.x);
            int miny = Math.min(p1.y, p2.y);
            int maxx = Math.max(p1.x, p2.x);
            int maxy = Math.max(p1.y, p2.y);

            lu = new Point(minx, miny);// left upper point

            rectangle.setRect(lu.x, lu.y, maxx - minx, maxy - miny);

            //set mode 
            //1 = if first selected cell is empty set mode to fill
            //-1 = otherwise clear 
            if (mode == 0) {
                for (JLabel j : all) {
                    if (j.getBounds().intersects(rectangle)) {
                        if (selected.contains(j)) {
                            mode = -1;
                        } else {
                            mode = 1;
                        }
                        break;
                    }
                }
            }

            for (JLabel j : all) {

                if (selected.contains(j) == (mode != 1)) {
                    if (j.getBounds().intersects(rectangle)) {
                        current_selection.add(j);
                    } else {
                        if (current_selection.contains(j)) {
                            current_selection.remove(j);
                            if (mode == 1) {
                                if (selected.contains(j) == false) {
                                    j.setBackground(empty_color);
                                }
                            } else {
                                if (selected.contains(j) == true) {
                                    j.setBackground(fill_color);
                                }
                            }
                        }
                    }
                }
            }

            for (JLabel j : current_selection) {
                if (mode == 1) {
                    j.setBackground(fill_select);
                } else if (mode == -1) {
                    j.setBackground(empty_select);
                }
            }

        }

        @Override
        public void mouseMoved(MouseEvent me) {
        }
    });
}

private void initComponents() {

    jScrollPane1 = new javax.swing.JScrollPane();
    jPanel1 = new javax.swing.JPanel();
    grid = new javax.swing.JPanel();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jPanel1.setLayout(new java.awt.BorderLayout());

    grid.setLayout(new java.awt.GridLayout(25, 0, 2, 2));
    jPanel1.add(grid, java.awt.BorderLayout.CENTER);

    jScrollPane1.setViewportView(jPanel1);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 399, Short.MAX_VALUE)
    );
    layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 465, Short.MAX_VALUE)
    );

    pack();
}

public static void main(String args[]) {

    new TimetableFrame().setVisible(true);

}



}

    

    

    


  

  

    
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