使用动态形状获取鼠标检测 [英] Get mouse detection with a dynamic shape

问题描述

基本上我正在构建一个世界地图。我知道如何有一个方形的点击区域。但我想让它，所以我可以把国家在一起，并能点击国家。现在很明显，我不能使用方形点击区域，因为我会有重叠的点击区域。我可以通过查看每个像素的透明度吗？即使这样，我不知道该怎么做？

解决方案

使用 Shape.contains（Point2D） - 像这样：

如何包含（..）方法将准确识别鼠标点击在哪些椭圆内。但你所指的地图类型可能会由一些

pre> import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.BasicStroke;
import java.awt.RenderingHints;
import java.awt.event。*;
import java.awt.geom。*;
import java.awt.image.BufferedImage;
import javax.swing。*;
import java.io.File;
import java.util。*;
import javax.imageio.ImageIO;

public class ShapeContainment {

List< Ellipse2D> shapes = new ArrayList< Ellipse2D>（）;
int w = 400;
int h = 100;
BufferedImage img = new BufferedImage（w，h，BufferedImage.TYPE_INT_RGB）;
Point2D mouse = new Point2D.Double（0，0）;
JLabel l;

ShapeContainment（）{
Random r = new Random（）;
for（int ii = 0; ii <10; ii ++）{
int x = r.nextInt（w / 2）;
int y = r.nextInt（h / 2）;
int wE = r.nextInt（w - x）;
int hE = r.nextInt（h-y）;
Ellipse2D ellipse = new Ellipse2D.Double（x，y，wE，hE）;
shapes.add（ellipse）;
}
l = new JLabel（new ImageIcon（img））;
MouseAdapter listener = new MouseAdapter（）{

@Override
public void mouseClicked（MouseEvent me）{
mouse = me.getPoint（）;
drawImage（）;
}
};
l.addMouseListener（listener）;
drawImage（）;

JOptionPane.showMessageDialog（null，l）;
}

public void drawImage（）{
Graphics2D g = img.createGraphics（）;
g.setColor（Color.WHITE）;
g.fillRect（0，0，w，h）;

RenderingHints hints = new RenderingHint（
RenderingHints.KEY_ANTIALIASING，
RenderingHints.VALUE_ANTIALIAS_ON）;
g.setRenderingHints（hints）;

颜色bg =新颜色（0，128，0，60）;
color inside = new Color（0，0，255，120）;
颜色outside = new颜色（255，0，0，120）;
g.setStroke（new BasicStroke（4））;
for（Ellipse2D shape：shapes）{
g.setColor（bg）;
g.fill（shape）;
if（shape.contains（mouse））{
g.setColor（inside）;
} else {
g.setColor（outside）;
}
g.draw（shape）;
}
g.setColor（Color.RED）;
int x =（int）mouse.getX（）;
int y =（int）mouse.getY（）;
g.setStroke（new BasicStroke（2））;
int s = 3;
g.drawLine（x-s，y，x + s，y）;
g.drawLine（x，y-s，x，y + s）
l.setIcon（new ImageIcon（img））;

g.dispose（）;

try {
ImageIO.write（
img，
png，
new File（System.currentTimeMillis（）+.png） ）;
} catch（Exception e）{
e.printStackTrace（）;
}
}

public static void main（String [] args）{
Runnable run = new Runnable（）{

@覆盖
public void run（）{
new ShapeContainment（）;
}
};
// Swing GUI应该在EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater上创建和更新（跑）;
}
}


Basically I'm constructing a world map. I know how to have a square click area. But I'd like to make it so I can put the countries together and be able to click on the country. Now it's pretty obvious that I can't use square click areas for that because I'd have overlapping click areas. Could I do it by looking at the transparency of each pixel? Even so I don't know how to do that?

解决方案

Use Shape.contains(Point2D) - something like this:

This example uses overlapping ellipses to show how the contains(..) method will accurately identify which ovals the mouse click falls inside. But the kind of map you are referring to will probably be made of a number of GeneralPath objects (one for each country) that do not overlap.

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.BasicStroke;
import java.awt.RenderingHints;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.io.File;
import java.util.*;
import javax.imageio.ImageIO;

public class ShapeContainment {

    List<Ellipse2D> shapes = new ArrayList<Ellipse2D>();
    int w = 400;
    int h = 100;
    BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    Point2D mouse = new Point2D.Double(0, 0);
    JLabel l;

    ShapeContainment() {
        Random r = new Random();
        for (int ii = 0; ii < 10; ii++) {
            int x = r.nextInt(w / 2);
            int y = r.nextInt(h / 2);
            int wE = r.nextInt(w - x);
            int hE = r.nextInt(h - y);
            Ellipse2D ellipse = new Ellipse2D.Double(x, y, wE, hE);
            shapes.add(ellipse);
        }
        l = new JLabel(new ImageIcon(img));
        MouseAdapter listener = new MouseAdapter() {

            @Override
            public void mouseClicked(MouseEvent me) {
                mouse = me.getPoint();
                drawImage();
            }
        };
        l.addMouseListener(listener);
        drawImage();

        JOptionPane.showMessageDialog(null, l);
    }

    public void drawImage() {
        Graphics2D g = img.createGraphics();
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, w, h);

        RenderingHints hints = new RenderingHints(
                RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
        g.setRenderingHints(hints);

        Color bg = new Color(0, 128, 0, 60);
        Color inside = new Color(0, 0, 255, 120);
        Color outside = new Color(255, 0, 0, 120);
        g.setStroke(new BasicStroke(4));
        for (Ellipse2D shape : shapes) {
            g.setColor(bg);
            g.fill(shape);
            if (shape.contains(mouse)) {
                g.setColor(inside);
            } else {
                g.setColor(outside);
            }
            g.draw(shape);
        }
        g.setColor(Color.RED);
        int x = (int) mouse.getX();
        int y = (int) mouse.getY();
        g.setStroke(new BasicStroke(2));
        int s = 3;
        g.drawLine(x-s, y, x+s, y);
        g.drawLine(x, y-s, x, y+s);
        l.setIcon(new ImageIcon(img));

        g.dispose();

        try {
            ImageIO.write(
                    img,
                    "png",
                    new File(System.currentTimeMillis() + ".png"));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Runnable run = new Runnable() {

            @Override
            public void run() {
                new ShapeContainment();
            }
        };
        // Swing GUIs should be created and updated on the EDT
        // http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
        SwingUtilities.invokeLater(run);
    }
}

这篇关于使用动态形状获取鼠标检测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！