/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.ui.swing.components;

import java.awt.Component;

import javax.swing.AbstractButton;
import javax.swing.ButtonGroup;
import javax.swing.JRadioButton;
import javax.swing.border.EmptyBorder;

/**
 * RadioButtonPanel is a simple extension of ButtonPanel. Differences are that
 * it uses radio buttons and the default alignment is vertical. The radio
 * buttons are placed in a ButtonGroup and the panel defaults to having no
 * buttons selected.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 904 $ $Date: 2006-02-18 18:19:05 -0500 (Sat, 18 Feb 2006)
 *          $
 */
public class RadioButtonPanel extends ButtonPanel {
	/**
	 * A ButtonGroup to help manage button state.
	 */
	protected ButtonGroup buttonGroup;

	/**
	 * ButtonGroup does not make it easy to unselect all buttons. The preferred way
	 * to do it is actually to create a hidden button.
	 */
	protected JRadioButton hiddenButton;

	/**
	 * Constructs a RadioButtonPanel. Three buttons are created so the panel is
	 * filled when used in a GUI-builder environment.
	 */
	public RadioButtonPanel() {
		super();
	}

	/**
	 * Constructs a ButtonPanel using specified buttons.
	 * 
	 * @param buttonList An array containing the strings to be used in labeling the
	 *                   buttons.
	 */
	public RadioButtonPanel(String[] buttonList) {
		super(buttonList);
	}

	/**
	 * Overridden to set vertical-center alignment and 2-pixel vgap.
	 */
	protected void initLayout() {
		super.initLayout();
		buttonPanelLayout.setAlignment(BetterFlowLayout.CENTER_VERTICAL);
		buttonPanelLayout.setVgap(2); // looks nicer than java l&f recommendation (imho)
	}

	/**
	 * Overridden to return a JRadioButton.
	 * 
	 * @param aLabel The label for the component that will be created.
	 * @return The newly created component.
	 */
	protected Component createComponentWithLabel(String aLabel) {
		String buttonLabel = aLabel;
		JRadioButton newButton = new JRadioButton();
		newButton.setName(aLabel);
		newButton.setText(buttonLabel);
		newButton.setActionCommand(aLabel);
		newButton.addActionListener(this);

		// reduce insets per java l&f guidelines (was 4 on each side)
		newButton.setBorder(new EmptyBorder(0, 4, 0, 4));

		if (buttonGroup == null) {
			buttonGroup = new ButtonGroup();

			// cheesy hack to allow a buttongroup to have no items selected.
			// note that the button is not added to container or buttonList.
			hiddenButton = new JRadioButton("Hidden Button");
			buttonGroup.add(hiddenButton);
		}
		buttonGroup.add(newButton);

		return newButton;
	}

	/**
	 * Selects the button whose name matches the given text value.
	 * 
	 * @param newText A String matching the name of one of the buttons. If null,
	 *                empty, or not matching, all buttons are deselected.
	 */
	public void setValue(String aName) {
		if (aName != null) {
			Component c = null;
			int count = buttonContainer.getComponentCount();
			for (int i = 0; i < count; i++) {
				c = buttonContainer.getComponent(i);
				if (c instanceof AbstractButton) {
					if (c.getName().equals(aName)) {
						((AbstractButton) c).setSelected(true);
						return;
					}
				}
			}
		}

		// null, empty, or not matching - deselect all
		hiddenButton.setSelected(true);
	}

	/**
	 * Gets the name of the currently selected button.
	 * 
	 * @return A string matching the name of the currently selected button, or null
	 *         of no button is selected.
	 */
	public String getValue() {
		String result = null;
		Component c = null;
		int count = buttonContainer.getComponentCount();
		for (int i = 0; i < count; i++) {
			c = buttonContainer.getComponent(i);
			if ((c instanceof AbstractButton) && (((AbstractButton) c).isSelected())) {
				return c.getName();
			}
		}
		return result;
	}

	/**
	 * Tests whether the specified value is checked.
	 * 
	 * @param aValue A value to be tested.
	 * @return True if the specified value is checked, otherwise false.
	 */
	public boolean getValue(String aValue) {
		if (aValue == null)
			return false;
		return aValue.equals(getValue());
	}

}