/*
* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores
* CA 94065 USA or visit www.oracle.com if you need additional information or
* have any questions.
*/
package com.sun.lwuit;
/**
* This class is used to create a multiple-exclusion scope for a set of
* RadioButtons. Creating a set of RadioButtons with the same ButtonGroup object
* means that only one RadioButton can be selected amoung the ButtonGroup.
* Initialy all RadioButtons are unselected.
*
* @author Nir Shabi
*/
public class ButtonGroup {
private java.util.Vector buttons = new java.util.Vector();
private int selectedIndex=-1;
/**
* Creates a new instance of ButtonsGroup
*/
public ButtonGroup() {
}
/**
* Adds a RadioButton to the group
*
* @param rb a RadioButton to add
*/
public void add(RadioButton rb){
if(rb==null)
return;
if(!buttons.contains(rb)) {
buttons.addElement(rb);
if(rb.isSelected()) {
setSelected(buttons.indexOf(rb));
}
rb.setButtonGroup(this);
}
}
/**
* removes a RadioButton from the group
*
* @param rb a RadioButton to remove
*/
public void remove(RadioButton rb){
if(rb==null)
return;
buttons.removeElement(rb);
if(rb.isSelected())
clearSelection();
rb.setButtonGroup(null);
}
/**
* Clears the selection such that none of the buttons in the ButtonGroup are selected.
*/
public void clearSelection() {
if(selectedIndex!=-1) {
if(selectedIndex < buttons.size()) {
((RadioButton)buttons.elementAt(selectedIndex)).setSelected(false);
}
selectedIndex=-1;
}
}
/**
* Returns the number of buttons in the group.
*
* @return number of radio buttons in the group
*/
public int getButtonCount() {
return buttons.size();
}
/**
* Returns whether a radio button in the group is selected.
*
* @return true if a selection was made in the radio button group
*/
public boolean isSelected() {
if(selectedIndex!= -1)
return true;
return false;
}
/**
* Return the index of the selected button within the group
*
* @return the index of the selected button within the group
*/
public int getSelectedIndex() {
return selectedIndex;
}
/**
* Returns the radio button at the given group index
*
* @param index offset within the group starting with 0 and no larger than getButtonCount()
* @return the radio button instance
*/
public RadioButton getRadioButton(int index) {
if(index >=0 && index < getButtonCount())
return ((RadioButton)buttons.elementAt(index));
return null;
}
/**
* Selects the given radio button
*
* @param rb the radio button to set as selected
*/
public void setSelected(RadioButton rb) {
if (rb != null) {
int index = buttons.indexOf(rb);
if(index < 0) {
add(rb);
index = buttons.indexOf(rb);
}
setSelected(index);
} else {
clearSelection();
}
}
/**
* Sets the selected Radio button by index
*
* @param index the index of the radio button to mark as selected
*/
public void setSelected(int index) {
if(index < 0 || index >= getButtonCount() )
throw new IllegalArgumentException("Index out of bounds");
if(selectedIndex == index) {
return;
}
if(selectedIndex!=-1) {
//unselect last selected Radio button
((RadioButton)buttons.elementAt(selectedIndex)).setSelectedImpl(false);
}
((RadioButton)buttons.elementAt(index)).setSelectedImpl(true);
selectedIndex=index;
}
}