我想完成与矩形(带有选择线)相似的图像。
基本上,我有一个矩形,我想在其周围有一条选择线。 为此,我想创建一个额外的JComponent。
目前,我只能绘制矩形。如何在Rectangle类中获取parentPanel JPanel,以便添加选择器?
public class TestPanel extends JFrame {
public class Rectangle extends JComponent {
public Rectangle(){
setBounds(x1, y1, x2, y2);
JPanel Selector = new JPanel();
//Adds Selector to parentPanel within Rectangle
//setBounds(x1-1, y1-1, x2+1, y2+1)
//!Problem parent is initially null! cant even a use property
//Life hacks?
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawRect(0, 0, getWidth(), getHeight());
}
}
public TestPanel() {
Rectangle Rectangle = new Rectangle();
JPanel parentFrame = new JPanel();
parentFrame.add(Rectangle);
setSize(200, 200);
setVisible(true);
}
public static void main(String[] args) {
new TestPanel();
}
}
如果我尝试将选择器添加到矩形内,它将退出绘图区域。如果我调整绘图区域的大小,它将无法扩展以用于以后的开发。
如果可能的话,我会避免双重绑定:
public TestPanel() {
Rectangle Rectangle = new Rectangle();
JPanel parentPanel = new JPanel();
parentPanel.add(Rectangle);
Rectangle.addParent(parentPanel)
...
}
答案 0 :(得分:1)
同样,我不清楚您要达到的目标。如果要创建的是用户创建的虚线(可以随鼠标按下/拖动/释放而改变的虚线),则无需创建新组件,而可以将MouseAdapter用作MouseListener和MouseMotionListener,所有这些帮助您创建Rectangle,然后根据this answer使用适当的Stroke用虚线绘制Rectangle。
例如,类似的操作将创建用户可选择的虚线:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
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 javax.swing.*;
public class SelectorPanel extends JPanel {
private static final int PREF_W = 800;
private static final int PREF_H = 650;
private static final Stroke DASHED_STROKE = new BasicStroke(2, BasicStroke.CAP_BUTT,
BasicStroke.JOIN_BEVEL, 0, new float[] { 5 }, 0);
private static final Color DASHED_COLOR = Color.LIGHT_GRAY;
private Rectangle rectangle = null;
public SelectorPanel() {
MyMouse myMouse = new MyMouse();
addMouseListener(myMouse);
addMouseMotionListener(myMouse);
}
private class MyMouse extends MouseAdapter {
private Point p1 = null;
@Override
public void mousePressed(MouseEvent e) {
p1 = e.getPoint();
rectangle = null;
}
@Override
public void mouseDragged(MouseEvent e) {
if (p1 != null) {
createRectangle(e);
}
}
@Override
public void mouseReleased(MouseEvent e) {
if (p1 != null) {
createRectangle(e);
p1 = null;
}
}
private void createRectangle(MouseEvent e) {
Point p2 = e.getPoint();
int x = Math.min(p1.x, p2.x);
int y = Math.min(p1.y, p2.y);
int width = Math.abs(p1.x - p2.x);
int height = Math.abs(p1.y - p2.y);
rectangle = new Rectangle(x, y, width, height);
repaint();
}
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (rectangle != null) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setColor(DASHED_COLOR);
g2.setStroke(DASHED_STROKE);
g2.draw(rectangle);
g2.dispose();
}
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
SelectorPanel mainPanel = new SelectorPanel();
JFrame frame = new JFrame("SelectorPanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}