Como retiro a borda da seta do JComboBox

Programação Java
#1

Olá, através de muitos exemplos na internet eu elaborei esta classe:
`

package Pacote;

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.Area;
import java.awt.geom.Path2D;
import java.awt.geom.Rectangle2D;
import java.awt.geom.RoundRectangle2D;
import java.util.ArrayList;
import java.util.Objects;

import javax.accessibility.Accessible;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPopupMenu;
import javax.swing.JTextField;
import javax.swing.JWindow;
import javax.swing.ListCellRenderer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.AbstractBorder;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;
import javax.swing.plaf.ColorUIResource;
import javax.swing.plaf.basic.BasicComboBoxUI;
import javax.swing.plaf.basic.BasicComboPopup;

public class Teste {
 private static final Color BACKGROUND = Color.GREEN;
  private static final Color FOREGROUND = Color.BLUE;
  private static final Color SELECTIONFOREGROUND = Color.RED;
public Teste() {
    UIManager.put("ComboBox.border", new borda());
    UIManager.put("ComboBox.foreground", FOREGROUND);
    UIManager.put("ComboBox.background", BACKGROUND);
    UIManager.put("ComboBox.selectionForeground", SELECTIONFOREGROUND);
    UIManager.put("ComboBox.selectionBackground", BACKGROUND);

    UIManager.put("ComboBox.buttonDarkShadow", BACKGROUND);
    UIManager.put("ComboBox.buttonBackground", FOREGROUND);
    UIManager.put("ComboBox.buttonHighlight",  FOREGROUND);
    UIManager.put("ComboBox.buttonShadow",     FOREGROUND);
    UIManager.put("ComboBox.font",new Font("Comic Sans MS",Font.BOLD,30));
    
	JComboBox<String> combo1 = new JComboBox<>();
	combo1.addItem("Thallysson");
	combo1.addItem("Kein");
	combo1.addItem("Flor");
	
    combo1.setUI(new BasicComboBoxUI());
    Object o = combo1.getAccessibleContext().getAccessibleChild(0);
    if (o instanceof JComponent) {
      JComponent c = (JComponent) o;
      c.setBorder(new RoundedCornerBorder());
      c.setFont(new Font("Comic Sans MS",Font.BOLD,30));
      c.setForeground(FOREGROUND);
      c.setBackground(BACKGROUND);
    }
    combo1.addPopupMenuListener(new HeavyWeightContainerListener());
	
  JFrame j = new JFrame("Combo");
  j.setLayout(new FlowLayout());
  String[] s = {"Thallysson","Kein","Flor"};

  j.add(combo1);
  j.setSize(500,500);
  j.setVisible(true);
  j.setLocationRelativeTo(null);
  j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public static void main(String[] args) {
	Teste s = new Teste();
}
}

class borda extends AbstractBorder {
@Override public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    int r = 12;
    int w = width  - 1;
    int h = height - 1;

    Area round = new Area(new RoundRectangle2D.Double(x, y, w, h, r, r));

    Container parent = c.getParent();
    if (Objects.nonNull(parent)) {
        g2.setPaint(parent.getBackground());
        Area corner = new Area(new Rectangle2D.Double(x, y, width, height));
        corner.subtract(round);
        g2.fill(corner);
    }
    g2.setPaint(c.getForeground());
    g2.draw(round);
    g2.dispose();
}
@Override public Insets getBorderInsets(Component c) {
    return new Insets(4, 8, 4, 8);
}
@Override public Insets getBorderInsets(Component c, Insets insets) {
    insets.set(4, 8, 4, 8);
    return insets;
}


public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected,
	boolean cellHasFocus) {
return null;
}
}
class HeavyWeightContainerListener implements PopupMenuListener {
  @Override public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        JComboBox combo = (JComboBox) e.getSource();
        Accessible a = combo.getUI().getAccessibleChild(combo, 0);
        if (a instanceof BasicComboPopup) {
          BasicComboPopup pop = (BasicComboPopup) a;
          Container top = pop.getTopLevelAncestor();
          if (top instanceof JWindow) {
            //http://ateraimemo.com/Swing/DropShadowPopup.html
            System.out.println("HeavyWeightContainer");
            ((JWindow) top).setBackground(new Color(0x0, true));
          }
        }
      }
    });
  }
  @Override public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {}
  @Override public void popupMenuCanceled(PopupMenuEvent e) {}
}
class RoundedCornerBorder extends AbstractBorder {
  protected static final int ARC = 12;
  @Override public void paintBorder(
      Component c, Graphics g, int x, int y, int width, int height) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    int r = ARC;
    int w = width  - 1;
    int h = height - 1;

    Area round = new Area(new RoundRectangle2D.Float(x, y, w, h, r, r));
    if (c instanceof JPopupMenu) {
      g2.setPaint(c.getBackground());
      g2.fill(round);
    } else {
      Container parent = c.getParent();
      if (Objects.nonNull(parent)) {
        g2.setPaint(parent.getBackground());
        Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
        corner.subtract(round);
        g2.fill(corner);
      }
    }
    g2.setPaint(c.getForeground());
    g2.draw(round);
    g2.dispose();
  }
  @Override public Insets getBorderInsets(Component c) {
    return new Insets(4, 8, 4, 8);
  }
  @Override public Insets getBorderInsets(Component c, Insets insets) {
    insets.set(4, 8, 4, 8);
    return insets;
  }
}

class RoundedCornerBorder1 extends RoundedCornerBorder {
  //http://ateraimemo.com/Swing/RoundedComboBox.html
  @Override public void paintBorder(
      Component c, Graphics g, int x, int y, int width, int height) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    int r = ARC;
    int w = width  - 1;
    int h = height - 1;

    Area round = new Area(new RoundRectangle2D.Float(x, y, w, h, r, r));
    Rectangle b = round.getBounds();
    b.setBounds(b.x, b.y + r, b.width, b.height - r);
    round.add(new Area(b));

    Container parent = c.getParent();
    if (Objects.nonNull(parent)) {
      g2.setPaint(parent.getBackground());
      Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
      corner.subtract(round);
      g2.fill(corner);
    }

    g2.setPaint(c.getForeground());
    g2.draw(round);
    g2.dispose();
  }
}

class RoundedCornerBorder2 extends RoundedCornerBorder {
  @Override public void paintBorder(
      Component c, Graphics g, int x, int y, int width, int height) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    int r = ARC;
    int w = width  - 1;
    int h = height - 1;

    Path2D.Float p = new Path2D.Float();
    p.moveTo(x, y);
    p.lineTo(x, y + h - r);
    p.quadTo(x, y + h, x + r, y + h);
    p.lineTo(x + w - r, y + h);
    p.quadTo(x + w, y + h, x + w, y + h - r);
    p.lineTo(x + w, y);
    p.closePath();
    Area round = new Area(p);

    g2.setPaint(c.getBackground());
    g2.fill(round);

    g2.setPaint(c.getForeground());
    g2.draw(round);
    g2.setPaint(c.getBackground());
    g2.drawLine(x + 1, y, x + width - 2, y);
    g2.dispose();
  }
}

`
E o meu JComboBox ficou assim:

Porém eu queria retirar do JComboBox esse negócio azul e deixar somente a seta da cor preta, então eu mudei essa parte:
’

            UIManager.put("ComboBox.buttonDarkShadow", BACKGROUND);
    	    UIManager.put("ComboBox.buttonBackground", FOREGROUND);
    	    UIManager.put("ComboBox.buttonHighlight",  FOREGROUND);
    	    UIManager.put("ComboBox.buttonShadow",     FOREGROUND);'

E deixei assim:
’

UIManager.put("ComboBox.buttonDarkShadow", Color.BLACK);
    UIManager.put("ComboBox.buttonBackground", BACKGROUND);

’
Porém ficou com essa borda:

É possível retirar essa borda ou fazer de outra maneira que fique como eu quero?

1 curtida
#2

Consegui resolver eu só mudei o ui do combo:
`

combo1.setUI(new BasicComboBoxUI() {
	    @Override
	    protected JButton createArrowButton() {
	        JButton b = new JButton(getTriangulo());
	        b.setContentAreaFilled(false);
	        b.setBorderPainted(false);
	        return b; 
	   }
	});

`
Ficou assim: