JcheckboxField.java

/*
   JcheckboxField.java

   Created: 12 Jul 1996


   Module By: Navin Manohar

   -----------------------------------------------------------------------

   Ganymede Directory Management System

   Copyright (C) 1996-2013
   The University of Texas at Austin

   Ganymede is a registered trademark of The University of Texas at Austin

   Contact information

   Author Email: ganymede_author@arlut.utexas.edu
   Email mailing list: ganymede@arlut.utexas.edu

   US Mail:

   Computer Science Division
   Applied Research Laboratories
   The University of Texas at Austin
   PO Box 8029, Austin TX 78713-8029

   Telephone: (512) 835-3200

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

package arlut.csd.JDataComponent;

import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.JCheckBox;
import javax.swing.JComponent;

/*------------------------------------------------------------------------------
                                                                           class
                                                                  JcheckboxField

------------------------------------------------------------------------------*/

/**
 * <p>Subclass of JCheckBox used to connect a checkbox to the standard
 * {@link arlut.csd.JDataComponent.JsetValueCallback JsetValueCallback}
 * callback.</p>
 *
 * <p>Note that like all other uses of JsetValueCallback, this GUI component
 * will revert its state if a call to JsetValueCallback is rejected.</p>
 */

public class JcheckboxField extends JCheckBox implements ItemListener, FocusListener {

  private boolean allowCallback = false;
  private boolean changed = false;

  private boolean isEditable = true;

  private JsetValueCallback callback = null;

  private boolean value;
  private boolean oldvalue;

  private String label;

  /* -- */

  /**
   * Constructor that can create a JcheckboxField with a label, a particular state,
   * and with the specified font/foreground/background value
   *
   * @param label the label to use for this JcheckboxField
   * @param state the state to which this JcheckboxField is to be set
   */

  public JcheckboxField(String label, boolean state, boolean editable)
  {
    super(label);

    value = state;
    oldvalue = state;

    setSelected(state);

    setEnabled(editable);
    isEditable = editable;

    addItemListener(this);
    addFocusListener(this);
  }

  /**
   * Constructor that creates a basic checkbox with default foreground and background
   */

  public JcheckboxField()
  {
    this(null, false, true);
  }

  /**
   * @param label the label to use for this JcheckboxField
   * @param state the state to which this JcheckboxField is to be set
   * @param callback the component which can use the value of this JcheckboxField
   */

  public JcheckboxField(String label, boolean state, boolean editable, JsetValueCallback callback)
  {
    this(label,state,editable);

    setCallback(callback);
  }

  /**
   *  sets the parent of this component for callback purposes
   */

  public void setCallback(JsetValueCallback callback)
  {
    if (callback == null)
      {
        throw new IllegalArgumentException("Invalid Parameter: callback cannot be null");
      }

    this.callback = callback;
    allowCallback = true;
  }

  /**
   * sets the value back to what it was before it was
   * changed
   */

  public void resetValue()
  {
    setValue(oldvalue);
  }

  /**
   * sets the value of this JcheckboxField to the boolean
   * value of state.
   */

  public void setValue(boolean state)
  {
    setSelected(state);
  }

  /**
   * returns the value represented by this JcheckboxField
   */

  public boolean getValue()
  {
    return isSelected();
  }

  /**
   * returns true if the value of this JcheckboxField has changed
   * since it was initiallly created.
   */

  public boolean getChanged()
  {
    return changed;
  }

  /**
   * sets the label of this JcheckboxField
   */

  public void setText(String label)
  {
    this.label = label;

    super.setText(label);
  }

  /**
   * sets the state of this JcheckboxField
   */

  public void setSelected(boolean state)
  {
    setSelected(state, true);
  }

  /**
   * sets the state of this JcheckboxField
   */

  public void setSelected(boolean state, boolean sendCallback)
  {
    if (value != state)
      {
        changed = true;
      }

    this.value = state;
    super.setSelected(state);
  }

  public void itemStateChanged(ItemEvent e)
  {
    notify(e.getStateChange() == ItemEvent.SELECTED);
  }

  public void focusLost(FocusEvent e)
  {
  }

  public void focusGained(FocusEvent e)
  {
    System.err.println("JcheckboxField gained focus");

    scrollRectToVisible(this.getBounds());
  }

  private void notify(boolean value)
  {
    Boolean bval = Boolean.valueOf(value);

    if (allowCallback)
      {
        // do a callback to talk to the server

        boolean b = false;

        try
          {
            b = callback.setValuePerformed(new JSetValueObject(this,bval));
          }
        catch (java.rmi.RemoteException ex)
          {
            throw new RuntimeException("notify caught remote exception: " + ex);
          }

        if (b==false)
          {
            resetValue();
          }
        else
          {
            oldvalue = value;
          }
      }
  }
}