通过单击并拖动其外边缘来调整Path2D圆的大小 [英] Resizing Path2D circle by clicking and dragging its outer edge

查看：115
本文介绍了通过单击并拖动其外边缘来调整Path2D圆的大小的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

因此，当我在JPanel上单击并拖动Path2D圈时，它正在调整大小。问题是，当我最初点击并拖动它时，圆圈跳转到较小的尺寸，但随后单击并拖动时正确调整大小。最简单的演示方法是运行下面的可运行代码。

So, when I click and drag a Path2D circle on my JPanel, it is resizing. The problem is that when I initially click-and-drag it, the circle jumps to a smaller size, but then resized correctly as you click and drag. The easiest way to demonstrate is to run the runnable code below.

我知道我需要修复此代码：

I know I need to fix this code:

@Override
public void mouseDragged(MouseEvent e) {
    int mouseX = e.getX();
    int mouseY = e.getY();
    if (resizing) {
        System.out.println("resizing");
        Rectangle bounds = shapes.get(currentIndex).getBounds();
        int shapeX = bounds.x;
        int shapeY = bounds.y;
        shapes.get(currentIndex).reset();
        shapes.get(currentIndex).append(
                new Ellipse2D.Double(shapeX, shapeY, mouseX
                        - shapeX, mouseX - shapeX), true);
        repaint();
    }
}

我不确定如何长度和宽度设置为新鼠标点的位置......但我需要做的是圆的外边缘坐标到新的鼠标点。关于如何计算正确点的任何想法？

I'm not sure how, though. I am clicking on the outer edge of the circle, and then I am setting the length and width of the bounds of the circle to where the new mouse point is...but what I need to do is the the outer edge of the circle's coordinates to the new mouse points. Any ideas on how to compute the correct point?

完整代码 

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Panel;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Editor {

    public static void main(String[] args) {
        new Editor();
    }

    public Editor() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager
                            .getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException
                        | IllegalAccessException
                        | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new UMLWindow();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setBounds(30, 30, 1000, 700);
                frame.getContentPane().setBackground(Color.white);
                frame.setVisible(true);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public static class UMLWindow extends JFrame {

        Shapes shapeList = new Shapes();
        Panel panel;

        private static final long serialVersionUID = 1L;

        public UMLWindow() {
            addMenus();
            panel = new Panel();
        }

        public void addMenus() {

            getContentPane().add(shapeList);

            setSize(300, 200);
            setLocationRelativeTo(null);
            setDefaultCloseOperation(EXIT_ON_CLOSE);

            shapeList.addCircle(100, 100);
        }
    }

    // Shapes class, used to draw the shapes on the panel
    // as well as implements the MouseListener for dragging
    public static class Shapes extends JPanel {

        private static final long serialVersionUID = 1L;

        private List<Path2D> shapes = new ArrayList<Path2D>();
        int currentIndex;

        private Point mousePoint;

        public Shapes() {
            MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
            addMouseListener(myMouseAdapter);
            addMouseMotionListener(myMouseAdapter);
        }

        public void addCircle(int width, int height) {
            Path2D circ = new Path2D.Double();
            circ.append(new Ellipse2D.Double(442, 269, width, height), true);
            shapes.add(circ);
            repaint();
        }

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

            Graphics2D g2 = (Graphics2D) g;
            g2.setStroke(new BasicStroke(2));
            for (Path2D shape : shapes) {
                g2.setColor(Color.BLACK);
                g2.draw(shape);
            }
        }

        public Rectangle2D getActiveBounds(float angel, Rectangle bounds) {

            Point2D p = getPointOnEdge(angel, bounds);

            return new Rectangle2D.Double(p.getX() - 4, p.getY() - 4, 8, 8);

        }

        public Point2D getPointOnEdge(float angel, Rectangle bounds) {

            float radius = Math.max(bounds.width, bounds.height) / 2;

            float x = radius;
            float y = radius;

            double rads = Math.toRadians((angel + 90));

            // Calculate the outter point of the line
            float xPosy = (float) (x + Math.cos(rads) * radius);
            float yPosy = (float) (y + Math.sin(rads) * radius);

            return new Point2D.Float(xPosy + bounds.x, yPosy + bounds.y);

        }

        class MyMouseAdapter extends MouseAdapter {
            Boolean hovering = false;
            Boolean resizing = true;

            @Override
            public void mouseMoved(MouseEvent e) {
                mousePoint = e.getPoint();
                for (int i = 0; i < shapes.size(); i++) {
                    Path2D shape = shapes.get(i);
                    Rectangle2D bottomRight = getActiveBounds(-45,
                            shape.getBounds());

                    if (mousePoint != null) {

                        if (bottomRight.contains(mousePoint)) {
                            Cursor cursor = Cursor
                                    .getPredefinedCursor(Cursor.SE_RESIZE_CURSOR);
                            setCursor(cursor);
                            hovering = true;
                        } else {
                            Cursor cursor = Cursor
                                    .getPredefinedCursor(Cursor.DEFAULT_CURSOR);
                            setCursor(cursor);
                            hovering = false;
                        }
                    }
                }

                repaint();
            }

            @Override
            public void mousePressed(MouseEvent e) {
                if (hovering) {
                    resizing = true;
                    System.out.println("Starting to resize");
                }
            }

            @Override
            public void mouseDragged(MouseEvent e) {
                int mouseX = e.getX();
                int mouseY = e.getY();
                if (resizing) {
                    System.out.println("resizing");
                    Rectangle bounds = shapes.get(currentIndex).getBounds();
                    int shapeX = bounds.x;
                    int shapeY = bounds.y;
                    shapes.get(currentIndex).reset();
                    shapes.get(currentIndex).append(
                            new Ellipse2D.Double(shapeX, shapeY, mouseX
                                    - shapeX, mouseX - shapeX), true);
                    repaint();
                }
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                if (resizing) {
                    System.out.println("Done resizing");
                    resizing = false;
                }
            }

        }
    }

}


推荐答案

你需要知道两件事，你需要知道按下鼠标的原始点和形状的原始边界

You need to know two things, you need to know the original point that the mouse was pressed and the original bounds of the shape

private Point clickPoint;
private Rectangle originalBounds;
//...
@Override
public void mousePressed(MouseEvent e) {
    if (hovering) {
        resizing = true;
        System.out.println("Starting to resize");
        clickPoint = e.getPoint();
        originalBounds = new Rectangle(shapes.get(currentIndex).getBounds());
    }
}

使用此信息，您可以计算原始值之间的差值点击点和拖动点，有这些信息，您可以通过将差异添加到 originalBounse

With this information you can calculate the delta between the original click point and the drag point, armed with this information, you can modify the the shape by adding the difference to the originalBounse

@Override
public void mouseDragged(MouseEvent e) {
    if (resizing && clickPoint != null) {

        int mouseX = e.getX();
        int mouseY = e.getY();

        int xDelta = mouseX - clickPoint.x;
        int yDelta = mouseY - clickPoint.y;

        int delta = Math.max(xDelta, yDelta);

        Rectangle bounds = shapes.get(currentIndex).getBounds();
        int shapeX = bounds.x;
        int shapeY = bounds.y;

        int shapeWidth = originalBounds.width + delta;
        int shapeHeight = originalBounds.height + delta;

        if (shapeWidth < 0) {
            shapeWidth *= -1;
            shapeX = originalBounds.x - shapeWidth;
        }
        if (shapeHeight < 0) {
            shapeHeight *= -1;
            shapeY = originalBounds.y - shapeHeight;
        }

        System.out.printf("%d %dx%dx%dx%d%n", delta, shapeX, shapeY, shapeWidth, shapeHeight);

        shapes.get(currentIndex).reset();
        shapes.get(currentIndex).append(
                        new Ellipse2D.Double(shapeX, shapeY, shapeWidth, shapeHeight), true);
        repaint();
    }
}

不要忘记重置<$ c当用户释放按钮时，$ c> clickPoint 和 originalBounds ;）

< img src =https://i.stack.imgur.com/NFRhg.gifalt =调整大小> 

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Panel;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Editor {

    public static void main(String[] args) {
        new Editor();
    }

    public Editor() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager
                                    .getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new UMLWindow();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setBounds(30, 30, 1000, 700);
                frame.getContentPane().setBackground(Color.white);
                frame.setVisible(true);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public static class UMLWindow extends JFrame {

        Shapes shapeList = new Shapes();
        Panel panel;

        private static final long serialVersionUID = 1L;

        public UMLWindow() {
            addMenus();
            panel = new Panel();
        }

        public void addMenus() {

            getContentPane().add(shapeList);

            setSize(300, 200);
            setLocationRelativeTo(null);
            setDefaultCloseOperation(EXIT_ON_CLOSE);

            shapeList.addCircle(100, 100);
        }
    }

    // Shapes class, used to draw the shapes on the panel
    // as well as implements the MouseListener for dragging
    public static class Shapes extends JPanel {

        private static final long serialVersionUID = 1L;

        private List<Path2D> shapes = new ArrayList<Path2D>();
        int currentIndex;

        private Point mousePoint;

        public Shapes() {
            MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
            addMouseListener(myMouseAdapter);
            addMouseMotionListener(myMouseAdapter);
        }

        public void addCircle(int width, int height) {
            Path2D circ = new Path2D.Double();
            circ.append(new Ellipse2D.Double(442, 269, width, height), true);
            shapes.add(circ);
            repaint();
        }

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

            Graphics2D g2 = (Graphics2D) g;
            g2.setStroke(new BasicStroke(2));
            for (Path2D shape : shapes) {
                g2.setColor(Color.BLACK);
                g2.draw(shape);
            }
        }

        public Rectangle2D getActiveBounds(float angel, Rectangle bounds) {

            Point2D p = getPointOnEdge(angel, bounds);

            return new Rectangle2D.Double(p.getX() - 4, p.getY() - 4, 8, 8);

        }

        public Point2D getPointOnEdge(float angel, Rectangle bounds) {

            float radius = Math.max(bounds.width, bounds.height) / 2;

            float x = radius;
            float y = radius;

            double rads = Math.toRadians((angel + 90));

            // Calculate the outter point of the line
            float xPosy = (float) (x + Math.cos(rads) * radius);
            float yPosy = (float) (y + Math.sin(rads) * radius);

            return new Point2D.Float(xPosy + bounds.x, yPosy + bounds.y);

        }

        class MyMouseAdapter extends MouseAdapter {

            Boolean hovering = false;
            Boolean resizing = true;

            private Point clickPoint;
            private Rectangle originalBounds;

            @Override
            public void mouseMoved(MouseEvent e) {
                mousePoint = e.getPoint();
                for (int i = 0; i < shapes.size(); i++) {
                    Path2D shape = shapes.get(i);
                    Rectangle2D bottomRight = getActiveBounds(-45,
                                    shape.getBounds());

                    if (mousePoint != null) {

                        if (bottomRight.contains(mousePoint)) {
                            Cursor cursor = Cursor
                                            .getPredefinedCursor(Cursor.SE_RESIZE_CURSOR);
                            setCursor(cursor);
                            hovering = true;
                        } else {
                            Cursor cursor = Cursor
                                            .getPredefinedCursor(Cursor.DEFAULT_CURSOR);
                            setCursor(cursor);
                            hovering = false;
                        }
                    }
                }

                repaint();
            }

            @Override
            public void mousePressed(MouseEvent e) {
                if (hovering) {
                    resizing = true;
                    System.out.println("Starting to resize");
                    clickPoint = e.getPoint();
                    originalBounds = new Rectangle(shapes.get(currentIndex).getBounds());
                }
            }

            @Override
            public void mouseDragged(MouseEvent e) {
                if (resizing && clickPoint != null) {

                    int mouseX = e.getX();
                    int mouseY = e.getY();

                    int xDelta = mouseX - clickPoint.x;
                    int yDelta = mouseY - clickPoint.y;

                    int delta = Math.max(xDelta, yDelta);

                    Rectangle bounds = shapes.get(currentIndex).getBounds();
                    int shapeX = bounds.x;
                    int shapeY = bounds.y;

                    int shapeWidth = originalBounds.width + delta;
                    int shapeHeight = originalBounds.height + delta;

                    if (shapeWidth < 0) {
                        shapeWidth *= -1;
                        shapeX = originalBounds.x - shapeWidth;
                    }
                    if (shapeHeight < 0) {
                        shapeHeight *= -1;
                        shapeY = originalBounds.y - shapeHeight;
                    }

                    System.out.printf("%d %dx%dx%dx%d%n", delta, shapeX, shapeY, shapeWidth, shapeHeight);

                    shapes.get(currentIndex).reset();
                    shapes.get(currentIndex).append(
                                    new Ellipse2D.Double(shapeX, shapeY, shapeWidth, shapeHeight), true);
                    repaint();
                }
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                if (resizing) {
                    System.out.println("Done resizing");
                    resizing = false;
                    clickPoint = null;
                    originalBounds = null;
                }
            }

        }
    }

}

这篇关于通过单击并拖动其外边缘来调整Path2D圆的大小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

查看全文
相关文章
Java开发最新文章
热门教程
热门工具
登录 关闭
扫码关注1秒登录
发送“验证码”获取 | 15天全站免登陆