gcc/libjava/classpath/javax/swing/plaf/basic/BasicComboBoxEditor.java

/* BasicComboBoxEditor.java --
   Copyright (C) 2004, 2005, 2006  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

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permission to link this library with independent modules to produce an
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package javax.swing.plaf.basic;

import java.awt.Component;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

import javax.swing.ComboBoxEditor;
import javax.swing.JTextField;

/**
 * An editor used by the {@link BasicComboBoxUI} class.  This editor uses a
 * {@link JTextField} as the editor component.
 *
 * @author Olga Rodimina
 */
public class BasicComboBoxEditor extends Object implements ComboBoxEditor,
                                                           FocusListener
{
  /** The editor component. */
  protected JTextField editor;

  /**
   * Creates a new <code>BasicComboBoxEditor</code> instance.
   */
  public BasicComboBoxEditor()
  {
    editor = new JTextField();
    editor.setBorder(null);
    editor.setColumns(9);
  }

  /**
   * Returns the component that will be used by the combo box to display and
   * edit the currently selected item in the combo box.
   *
   * @return The editor component, which is a {@link JTextField} in this case.
   */
  public Component getEditorComponent()
  {
    return editor;
  }

  /**
   * Sets item that should be edited when any editing operation is performed
   * by the user. The value is always equal to the currently selected value
   * in the combo box. Thus whenever a different value is selected from the
   * combo box list then this method should be  called to change editing
   * item to the new selected item.
   *
   * @param item item that is currently selected in the combo box
   */
  public void setItem(Object item)
  {
     if (item == null)
        editor.setText("");
     else
        editor.setText(item.toString());
  }

  /**
   * Returns the text from the editor component.
   *
   * @return The text from the editor component.
   */
  public Object getItem()
  {
    return editor.getText();
  }

  /**
   * Selects all the text in the editor component.
   */
  public void selectAll()
  {
    editor.selectAll();
  }

  /**
   * This method is called when textfield gains focus. This will enable
   * editing of the selected item.
   *
   * @param e the FocusEvent describing change in focus.
   */
  public void focusGained(FocusEvent e)
  {
    // FIXME: Need to implement
  }

  /**
   * This method is called when textfield loses focus. If during this time any
   * editting operation was performed by the user, then it will be cancelled
   * and selected item will not be changed.
   *
   * @param e the FocusEvent describing change in focus
   */
  public void focusLost(FocusEvent e)
  {
    // FIXME: Need to implement
  }

  /**
   * Adds an {@link ActionListener} to the editor component.  If the user will
   * edit currently selected item in the textfield and pressEnter, then action
   * will be performed. The actionPerformed of this ActionListener should
   * change the selected item of the comboBox to the newly editted  selected
   * item.
   *
   * @param l the ActionListener responsible for changing selected item of the
   *        combo box when it is editted by the user.
   */
  public void addActionListener(ActionListener l)
  {
    editor.addActionListener(l);
  }

  /**
   * Removes the {@link ActionListener} from the editor component.
   *
   * @param l the listener to remove.
   */
  public void removeActionListener(ActionListener l)
  {
    editor.removeActionListener(l);
  }

  /**
   * A subclass of {@link BasicComboBoxEditor} that implements the
   * {@link UIResource} interface.
   */
  public static class UIResource extends BasicComboBoxEditor
    implements javax.swing.plaf.UIResource
  {
    /**
     * Creates a new <code>BasicComboBoxEditor.UIResource</code> instance.
     */
    public UIResource()
    {
      // Nothing to do here.
    }
  }

}