Re: Controlling the scroll pane in JComboBox

Use the setUI() method
and an extended BasicComboBoxUI class.

also import javax.swing.plaf.basic.*;

regards

Chinthaka Weerasinghe - Your friendly java tutor
cherry.x+nntp@gmail.com

package pmg;

import java.awt.*;

import javax.swing.*;
import javax.swing.event.*;

import java.awt.event.*;
import java.util.ArrayList;

import javax.swing.plaf.basic.*;

public class ChoiceGui extends JComboBox {
 private ArrayList<String> myList = new ArrayList<String>();
 private boolean mySettingItem = false;
 private boolean myRespondingToChangedQuery = false;

 public static void main(String[] args) {

  ArrayList<String> choices = new ArrayList<String>();
  choices.addAll(java.util.Arrays.asList("Hello;Hello, World!;A very
looooooooooooooong String;Very Slow;Bad dog, bad!".split(";")));

  JFrame frame = new JFrame("Choice");
  frame.getContentPane().add(new ChoiceGui(choices));
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.pack();
  frame.setVisible(true);
 }

 public ChoiceGui(ArrayList<String> choices) {

  myList = choices;

  setEditor(new Editor());
  setRenderer(new Renderer3());
  setBackground(Color.getHSBColor(1f/6, .2f, 1f));

  this.setPreferredSize(new Dimension(150, 22));

  for (int s = 0; s < myList.size(); s++)
   this.addItem(myList.get(s));

  this.setSelectedIndex(-1);

  this.setEditable(true); // This is when the first setItem() is
called!
  setUI(new myComboUI());
 }

 public class myComboUI extends BasicComboBoxUI{
  protected ComboPopup createPopup(){
   BasicComboPopup popup = new BasicComboPopup(comboBox){
    protected JScrollPane createScroller() {
     return new JScrollPane( list,
ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
       ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED );
    }// end of method createScroller
   };
   return popup;
  }// end of method createPopup
 }// end of inner class myComboUI

 public class Editor implements ComboBoxEditor {
  private JTextField myTextField = new JTextField();

  public void addActionListener(ActionListener l)
{ myTextField.addActionListener(l); }
  public void removeActionListener(ActionListener l) { }
  public void setItem(Object item) {
   if (myRespondingToChangedQuery)
    return;

   System.out.println("setItem called!!!");
   mySettingItem = true;
   if (item != null) {
    myTextField.setText(item.toString());
    myTextField.setCaretPosition(0);
   }
   else if (!myRespondingToChangedQuery) // The value of SuperChoice
changed
    // for a different reason, so the
    // query must be reset.
    myTextField.setText("");

   mySettingItem = false;
  }
  public void selectAll() { myTextField.selectAll(); }
  public Object getItem() { return null; }
  public Component getEditorComponent() { return myTextField; }

  public Editor() {
   myTextField.getDocument().addDocumentListener(new
DocumentListener() {
    public void dodo() {

     javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
       myRespondingToChangedQuery = true;

       String q =
((JTextField)getEditor().getEditorComponent()).getText();
       removeAllItems();
       for (int i = 0; i < myList.size(); i++)
        if (myList.get(i).toUpperCase().contains(q.toUpperCase()))
         addItem(myList.get(i));

       setPopupVisible(true);

       myRespondingToChangedQuery = false;

      }
     });
    }

    public void changedUpdate(DocumentEvent e) {
     if (mySettingItem)
      return;
     dodo();
    }
    public void insertUpdate(DocumentEvent e) {
     if (mySettingItem)
      return;
     dodo();
    }
    public void removeUpdate(DocumentEvent e) {
     if (mySettingItem)
      return;

     dodo();
    }
   });

  }
 }
 class Renderer3 implements ListCellRenderer {
  JPanel panel = new JPanel();
  JLabel label = new JLabel();
  JLabel label1 = new JLabel();
  JLabel label2 = new JLabel();
  JLabel label3 = new JLabel();

  public Renderer3() {
   panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));

   panel.add(label1);
   panel.add(label2);
   panel.add(label3);

   panel.setOpaque(true);
   panel.setBackground(Color.RED);
   Font font = label1.getFont();
   label.setFont(new Font(font.getName(),
Font.PLAIN,font.getSize()-2));
   label1.setFont(new Font(font.getName(),
Font.PLAIN,font.getSize()));
   label2.setFont(new Font(font.getName(), Font.BOLD,font.getSize()));
   label3.setFont(new Font(font.getName(),
Font.PLAIN,font.getSize()));
   label.setOpaque(true);
   panel.setBackground(Color.getHSBColor(1f/6, .2f, 1f));
  }

  public Component getListCellRendererComponent(JList list, Object
value, int index, boolean isSelected, boolean cellHasFocus) {
   String str = (value!=null)?value.toString():"null";
   String q =
((JTextField)getEditor().getEditorComponent()).getText();
   if (q.length() != 0 && str.toUpperCase().indexOf(q.toUpperCase()) !
= -1) {
    int start = str.toUpperCase().indexOf(q.toUpperCase());
    label1.setText(str.substring(0, start));
    label2.setText(str.substring(start, start + q.length()));
    label3.setText(str.substring(start + q.length()));
    panel.setBackground(isSelected?
list.getSelectionBackground():list.getBackground());
    panel.setForeground(isSelected?
list.getSelectionForeground():list.getForeground());

    return panel;
   }
   else {
    Font font = label.getFont();
    label.setFont(new Font("Dialog", Font.PLAIN, 12));
    label.setBackground(isSelected?
list.getSelectionBackground():list.getBackground());
    label.setForeground(isSelected?
list.getSelectionForeground():list.getForeground());
    label.setText(" " + str);
    return label;
   }
  }
 }
}

On Jun 10, 9:26 am, Aaron Fude <aaronf...@gmail.com> wrote: