如何将所有 JButton 的默认鼠标按下背景颜色覆盖为当前背景颜色的深色阴影？

Question

假设我有 10 个 JButtons，每个都明确设置了自己的背景颜色。现在，它们都获得了默认的鼠标按下背景颜色，但我如何才能将其设置为比各自背景颜色更暗的阴影，而不是一个一个地设置？

我知道我可以覆盖 UIManager 中的颜色 :

UIManager.put("Button.select", Color.RED);

我在这里找到的 How to change a JButton color on mouse pressed?

但这只会将其更改为单一颜色。我所有的按钮在按下时都会变成红色背景。

有没有办法让它变成这样：

UIManager.put("Button.select", JButton.getBackground().darker());

我正在努力学习java挥杆，请原谅我的无知。

Answer 1

实现此目的的一种方法是创建您自己的 ButtonUI。为了避免重新发明轮子的麻烦，您可以扩展 ButtonUI.

的子类

例如BasicButtonUI像这样：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.util.Objects;
import java.util.Random;
import javax.swing.AbstractButton;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicButtonUI;

public class MainWithBasicButtonUI {
    
    public static class SelectButtonUI extends BasicButtonUI {
        protected Color selectColor;
        
        public void setSelectColor(final Color selectColor) {
            this.selectColor = Objects.requireNonNull(selectColor);
        }
        
        public Color getSelectColor() {
            return selectColor;
        }
        
        @Override
        protected void paintButtonPressed(final Graphics g,
                                          final AbstractButton b){
            if (b.isContentAreaFilled()) {
                Dimension size = b.getSize();
                g.setColor(getSelectColor());
                g.fillRect(0, 0, size.width, size.height);
            }
        }
    }
    
    private static void createAndShowGUI() {
        final int rows = 3, cols = 3;
        final Color[] colors = new Color[]{Color.RED.brighter(), Color.GREEN.brighter(), Color.CYAN};
        final JPanel buttons = new JPanel(new GridLayout(rows, cols, 2, 2));
        final Random rand = new Random();
        for (int i = 0; i < rows * cols; ++i) {
            final JButton b = new JButton("Button");
            b.setBackground(colors[rand.nextInt(colors.length)]);
            final SelectButtonUI ui = new SelectButtonUI();
            ui.setSelectColor(b.getBackground().darker());
            b.setUI(ui);
            buttons.add(b);
        }
        final JFrame frame = new JFrame("App");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(buttons);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
    
    public static void main(final String[] args) {
        SwingUtilities.invokeLater(MainWithBasicButtonUI::createAndShowGUI);
    }
}

或者，更好的是，MetalButtonUI 像这样：

import java.awt.Color;
import java.awt.GridLayout;
import java.util.Objects;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.plaf.metal.MetalButtonUI;

public class MainWithMetalButtonUI {
    
    public static class SelectButtonUI extends MetalButtonUI {
        public SelectButtonUI() {
            selectColor = super.getSelectColor();
        }
        
        public void setSelectColor(final Color selectColor) {
            this.selectColor = Objects.requireNonNull(selectColor);
        }
        
        @Override
        protected Color getSelectColor() {
            return selectColor;
        }
    }
    
    private static void createAndShowGUI() {
        final int rows = 3, cols = 3;
        final Color[] colors = new Color[]{Color.RED.brighter(), Color.GREEN.brighter(), Color.CYAN};
        final JPanel buttons = new JPanel(new GridLayout(rows, cols, 2, 2));
        final Random rand = new Random();
        for (int i = 0; i < rows * cols; ++i) {
            final JButton b = new JButton("Button");
            b.setBackground(colors[rand.nextInt(colors.length)]);
            final SelectButtonUI ui = new SelectButtonUI();
            ui.setSelectColor(b.getBackground().darker());
            b.setUI(ui);
            buttons.add(b);
        }
        final JFrame frame = new JFrame("App");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(buttons);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
    
    public static void main(final String[] args) {
        SwingUtilities.invokeLater(MainWithMetalButtonUI::createAndShowGUI);
    }
}

唯一的问题是，您所有的按钮总是看起来像金属 L&F。

如何将所有 JButton 的默认鼠标按下背景颜色覆盖为当前背景颜色的深色阴影？

How can I override the default mousepressed background color of all JButtons into a darker shade of its current background color?

java

swing

overriding

jbutton

background-color