与色的项目和焦点的色的jcombobox [英] Colored jcombobox with colored items and focus

问题描述

我想用彩色项目制作彩色下拉列表（请参阅下面的代码）。在combobox失去焦点后颜色被应用。

这是正确的行为吗？

如何获得前景和/或背景颜色

  import java.awt 。*; 
 import java.awt.event。*; 
 import java.util。*; 
 import javax.swing。*; 
 import javax.swing.border。*; 
 public class DropDown {
 enum颜色{
 red（Color.red），orange（Color.orange），green（Color.green），yellow（Color.yellow），blue 。蓝色）; 
颜色（颜色）{
 this.color = color; 
} 
 static String [] listModel（）{
 java.util.List< Colors> values = Arrays.asList（values（））; 
 String s = values.toString（）。replaceAll（，）; 
 return s.substring（1，s.length（） -  1）.split（，）; 
} 
 final颜色颜色; 
} 
 static class ColoredCellRenderer实现ListCellRenderer {
 protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer（）; 
 private final static Dimension preferredSize = new Dimension（0，20）; 
 public Component getListCellRendererComponent（JList list，Object value，int index，boolean isSelected，
 boolean cellHasFocus）{
 JLabel renderer =（JLabel）defaultRenderer.getListCellRendererComponent（list，value，index，isSelected， 
 cellHasFocus）; 
 if（index！= -1）if（value instanceof String）renderer.setForeground（Colors.valueOf（（String）value）.color）; 
 else 
 System.out.println（not a string）; 
 else 
 System.out.println（in getListCellRendererComponent，index = -1）; 
 renderer.setPreferredSize（preferredSize）; 
 return renderer; 
} 
} 
 private static JComboBox addLabeledComboBox（Container c，String label，String [] model）{
 JPanel panel = new JPanel 
 panel.setLayout（new BoxLayout（panel，BoxLayout.Y_AXIS））; 
边框border = BorderFactory.createLineBorder（Color.green，1）; 
 panel.setBorder（border）; 
 JLabel l = new JLabel（label）; 
 panel.add（l）; 
 final JComboBox comboBox = new JComboBox（model）; 
 comboBox.setName（label）; 
 l.setLabelFor（comboBox）; 
 comboBox.setRenderer（new ColoredCellRenderer（））; 
 panel.add（comboBox）; 
 c.add（panel）; 
 return comboBox; 
} 
 private static void addContent（Container c）{
 c.setLayout（new BoxLayout（c，BoxLayout.Y_AXIS））; 
 ActionListener actionListener = new ActionListener（）{
 @Override public void actionPerformed（ActionEvent e）{
 if（e.getSource（）JComboBox的实例）{
 final JComboBox comboBox = JComboBox）e.getSource（）; 
 Object selected = comboBox.getSelectedItem（）; 
 String string =（String）selected; 
颜色color = Colors.valueOf（string）.color; 
 int i = comboBox.getSelectedIndex（）; 
 if（i！= -1）{
 System.out.println（comboBox+ comboBox.getName（）++ color）; 
 comboBox.setForeground（color）; 
 System.out.println（comboBox.hasFocus（））; 
 // comboBox.repaint（）; 
} else 
 System.out.println（in actionListener selected =+ selected）; 
} else 
 System.out.println（在actionListener中选择不是一个comboBox）; 
} 
}; 
 c.add（new JButton（button））; 
 for（int i = 0; i <2; i ++）{
 JPanel panel = new JPanel（）; 
边框border = BorderFactory.createLineBorder（Color.red，1）; 
 panel.setBorder（border）; 
 panel.setLayout（new BoxLayout（panel，BoxLayout.Y_AXIS））; 
 panel.add（new JLabel（label+（i + 1）））; 
 JComboBox comboBox = addLabeledComboBox（panel，+（i + 1），Colors.listModel（））; 
 comboBox.addActionListener（actionListener）; 
 comboBox.setSelectedIndex（0）; // select something 
 c.add（panel）; 
} 
} 
 private static void createAndShowGUI（）{
 JFrame frame = new JFrame（Colored JComboBox）; 
 frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）; 
 addContent（frame.getContentPane（））; 
 frame.pack（）; 
 frame.setVisible（true）; 
} 
 public static void main（String [] args）{
 javax.swing.SwingUtilities.invokeLater（new Runnable（）{
 @SuppressWarnings（synthetic-access） public void run（）{
 createAndShowGUI（）; 
} 
}）; 
} 
} 
  

解决方案

是另一种方法：

  // JList＃setSelectionForeground（...）version 
 static class ColoredCellRenderer implements ListCellRenderer {
 protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer（）; 
 private final颜色selectionBackground =新颜色（240,200,200）; 
 public Component getListCellRendererComponent（
 JList list，Object value，int index，boolean isSelected，boolean cellHasFocus）{
 Color fgc = Colors.valueOf（（String）value）.color; 
 if（index< 0）{
 //comboBox.setForeground(fgc）; // Windows，CDE / Motif Look&感觉
 list.setSelectionForeground（fgc）; 
 list.setSelectionBackground（selectionBackground）; 
} 
 JLabel renderer =（JLabel）defaultRenderer.getListCellRendererComponent（
 list，value，index，isSelected，cellHasFocus）; 
 if（index！=  -  1）{
 renderer.setForeground（fgc）; 
} 
 return renderer; 
} 
} 
 
 // html version 
 static class ComboHtmlRenderer extends DefaultListCellRenderer {
 private final Color selectionBackground = new Color（240,200,200）; 
 @Override public Component getListCellRendererComponent（
 JList list，Object value，int index，boolean isSelected，boolean hasFocus）{
 Color fgc = Colors.valueOf（（String）value）.color; 
 if（index< 0）{
 list.setSelectionBackground（selectionBackground）; 
} 
 JLabel l =（JLabel）super.getListCellRendererComponent（
 list，value，index，isSelected，hasFocus）; 
 l.setText（< html>< font color =+ hex（fgc）+>+ value）; 
 l.setBackground（isSelected？selectionBackground：list.getBackground（））; 
 return l; 
} 
 private static String hex（Color c）{
 return String.format（＃％06x，c.getRGB（）& 0xffffff）; 
} 
} 
  

i am trying to make a colored dropdown list with colored items (please see code below). The color is getting applied after the combobox loses focus.

is this correct behaviour?

how can i get the foreground and/or the background color to change when the combobox has the focus?

thanks

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.*;
public class DropDown {
    enum Colors {
        red(Color.red), orange(Color.orange), green(Color.green), yellow(Color.yellow), blue(Color.blue);
        Colors(Color color) {
            this.color = color;
        }
        static String[] listModel() {
            java.util.List<Colors> values = Arrays.asList(values());
            String s = values.toString().replaceAll(" ", "");
            return s.substring(1, s.length() - 1).split(",");
        }
        final Color color;
    }
    static class ColoredCellRenderer implements ListCellRenderer {
        protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
        private final static Dimension preferredSize = new Dimension(0, 20);
        public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected,
                boolean cellHasFocus) {
            JLabel renderer = (JLabel) defaultRenderer.getListCellRendererComponent(list, value, index, isSelected,
                    cellHasFocus);
            if (index != -1) if (value instanceof String) renderer.setForeground(Colors.valueOf((String) value).color);
            else
                System.out.println("not a string");
            else
                System.out.println("in getListCellRendererComponent, index=-1");
            renderer.setPreferredSize(preferredSize);
            return renderer;
        }
    }
    private static JComboBox addLabeledComboBox(Container c, String label, String[] model) {
        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        Border border = BorderFactory.createLineBorder(Color.green, 1);
        panel.setBorder(border);
        JLabel l = new JLabel(label);
        panel.add(l);
        final JComboBox comboBox = new JComboBox(model);
        comboBox.setName(label);
        l.setLabelFor(comboBox);
        comboBox.setRenderer(new ColoredCellRenderer());
        panel.add(comboBox);
        c.add(panel);
        return comboBox;
    }
    private static void addContent(Container c) {
        c.setLayout(new BoxLayout(c, BoxLayout.Y_AXIS));
        ActionListener actionListener = new ActionListener() {
            @Override public void actionPerformed(ActionEvent e) {
                if (e.getSource() instanceof JComboBox) {
                    final JComboBox comboBox = (JComboBox) e.getSource();
                    Object selected = comboBox.getSelectedItem();
                    String string = (String) selected;
                    Color color = Colors.valueOf(string).color;
                    int i = comboBox.getSelectedIndex();
                    if (i != -1) {
                        System.out.println("comboBox " + comboBox.getName() + " " + color);
                        comboBox.setForeground(color);
                        System.out.println(comboBox.hasFocus());
                        // comboBox.repaint();
                    } else
                        System.out.println("in actionListener selected=" + selected);
                } else
                    System.out.println("in actionListener selected is not a comboBox");
            }
        };
        c.add(new JButton("button"));
        for (int i = 0; i < 2; i++) {
            JPanel panel = new JPanel();
            Border border = BorderFactory.createLineBorder(Color.red, 1);
            panel.setBorder(border);
            panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
            panel.add(new JLabel("label " +(i+1)));
            JComboBox comboBox = addLabeledComboBox(panel, "" + (i + 1), Colors.listModel());
            comboBox.addActionListener(actionListener);
            comboBox.setSelectedIndex(0); // select something
            c.add(panel);
        }
    }
    private static void createAndShowGUI() {
        JFrame frame = new JFrame("Colored JComboBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        addContent(frame.getContentPane());
        frame.pack();
        frame.setVisible(true);
    }
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            @SuppressWarnings("synthetic-access") public void run() {
                createAndShowGUI();
            }
        });
    }
}

解决方案

Here is another approach:

//JList#setSelectionForeground(...) version
static class ColoredCellRenderer implements ListCellRenderer {
  protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
  private final Color selectionBackground = new Color(240,200,200);
  public Component getListCellRendererComponent(
      JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
    Color fgc = Colors.valueOf((String)value).color;
    if(index<0) {
      //comboBox.setForeground(fgc); //Windows, CDE/Motif Look & Feel
      list.setSelectionForeground(fgc);
      list.setSelectionBackground(selectionBackground);
    }
    JLabel renderer = (JLabel) defaultRenderer.getListCellRendererComponent(
        list, value, index, isSelected, cellHasFocus);
    if (index != -1) {
      renderer.setForeground(fgc);
    }
    return renderer;
  }
}

//html version
static class ComboHtmlRenderer extends DefaultListCellRenderer {
  private final Color selectionBackground = new Color(240,200,200);
  @Override public Component getListCellRendererComponent(
      JList list, Object value, int index, boolean isSelected, boolean hasFocus) {
    Color fgc = Colors.valueOf((String)value).color;
    if(index<0) {
      list.setSelectionBackground(selectionBackground);
    }
    JLabel l = (JLabel)super.getListCellRendererComponent(
                 list, value, index, isSelected, hasFocus);
    l.setText("<html><font color="+hex(fgc)+">"+value);
    l.setBackground(isSelected?selectionBackground:list.getBackground());
    return l;
  }
  private static String hex(Color c) {
    return String.format("#%06x", c.getRGB()&0xffffff);
  }
}

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