/**
* Copyright (c) 2008-2012 Ardor Labs, Inc.
*
* This file is part of Ardor3D.
*
* Ardor3D is free software: you can redistribute it and/or modify it
* under the terms of its license which may be found in the accompanying
* LICENSE file or at <http://www.ardor3d.com/LICENSE>.
*/
package com.ardor3d.extension.ui.util;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import com.ardor3d.extension.ui.UIButton;
/**
* Defines a group of buttons. This is generally used with radio or toggle buttons to indicate a group wherein only one
* button should be pressed at a time.
*/
public class ButtonGroup {
/** The list of buttons participating in this group. */
private final List<UIButton> _buttons = new ArrayList<UIButton>();
/** The currently selected button. */
private UIButton _selected;
public ButtonGroup() {}
/**
* Add a button to this button group if not already present.
*
* @param button
* the button to be added
* @throws NullPointerException
* if button is null
*/
public void add(final UIButton button) {
// Make sure the button has the right group set.
if (button.getGroup() != this) {
button.setGroup(this);
}
// Proceed if the button is not already part of the this.
if (!_buttons.contains(button)) {
// Add to list
_buttons.add(button);
// See if we're selected...
if (button.isSelected()) {
// ..if we are and nothing else is selected in this group, then this is our "selected" value.
if (_selected == null) {
_selected = button;
}
// ..otherwise, the existing "selected" takes priority, so turn off this button.
else {
button.setSelected(false);
}
}
}
}
/**
* Removes the button from the group.
*
* @param button
* the button to remove. no-op if null.
*/
public void remove(final UIButton button) {
if (button == null) {
return;
}
_buttons.remove(button);
if (button == _selected) {
_selected = null;
}
button.setGroup(null);
}
/**
* @return an Iterator of buttons currently in this group
*/
public Iterator<UIButton> getButtons() {
return _buttons.iterator();
}
/**
* @return the currently selected button or null if none have been selected yet.
*/
public UIButton getSelection() {
return _selected;
}
/**
* Sets the selected value for the given button. Only one button in the group may be selected at a time.
*
* @param button
* the button we are changing
* @param selected
* true if this button is to be selected and all others in the group should be de-selected.
*/
public void setSelected(final UIButton button, final boolean selected) {
if (selected && button != null && button != _selected) {
final UIButton oldSelection = _selected;
_selected = button;
if (oldSelection != null) {
oldSelection.setSelected(false);
}
button.setSelected(true);
}
}
/**
* @return true if the button is the currently selected button
*/
public boolean isSelected(final UIButton button) {
return button == _selected;
}
/**
* @return the number of buttons currently in the group.
*/
public int getButtonCount() {
return _buttons.size();
}
}