FlxRadioButtonGroup.java

package org.flixel.ui;

import org.flixel.ui.event.IFlxRadioButtonGroup;

import com.badlogic.gdx.utils.Array;

/**
 * A group that holds <code>FlxRadioButton</code>s.
 * 
 * @author Ka Wing Chin
 */
public class FlxRadioButtonGroup
{
	/**
	 * Array of all the <code>FlxBasic</code>s that exist in this group.
	 */
	public Array<FlxRadioButton> members;
	/**
	 * The current radiobutton that is selected.
	 */
	private FlxRadioButton _current;
	/**
	 * The callback will be fired when there is a change made.
	 */
	public IFlxRadioButtonGroup onChange;
	/**
	 * The number of entries in the members array. For performance and safety
	 * you should check this variable instead of members.length unless you
	 * really know what you're doing!
	 */
	public int length;
	/**
	 * Internal tracker for the maximum capacity of the group. Default is 0, or
	 * no max capacity.
	 */
	protected int _maxSize;

	/**
	 * Creates a new <code>FlxRadioButtonGroup</code> object.
	 * 
	 * @param MaxSize The max size the group is allowed.
	 */
	public FlxRadioButtonGroup(int MaxSize)
	{
		members = new Array<FlxRadioButton>(MaxSize);
		length = 0;
		_maxSize = MaxSize;
	}

	/**
	 * Creates a new <code>FlxRadioButtonGroup</code> object.
	 */
	public FlxRadioButtonGroup()
	{
		this(0);
	}

	/**
	 * Adds a new <code>FlxRadioButton</code> to the group. FlxRadioButtonGroup
	 * will try to replace a null member of the array first. Failing that,
	 * FlxRadioButtonGroup will add it to the end of the member array, assuming
	 * there is room for it, and doubling the size of the array if necessary.
	 * 
	 * <p>
	 * WARNING: If the group has a maxSize that has already been met, the object
	 * will NOT be added to the group!
	 * </p>
	 * 
	 * @param Object The object you want to add to the group.
	 * 
	 * @return The same <code>FlxRadioButton</code> object that was passed in.
	 */
	public FlxRadioButton add(FlxRadioButton Object)
	{
		// Don't bother adding an object twice.
		if(members.indexOf(Object, true) >= 0)
			return Object;

		// First, look for a null entry where we can add the object.
		int i = 0;
		int l = members.size;
		while(i < l)
		{
			if(members.get(i) == null)
			{
				members.set(i, Object);
				if(i >= length)
					length = i + 1;
				return Object;
			}
			i++;
		}

		// Failing that, expand the array (if we can) and add the object.
		if(_maxSize > 0)
		{
			if(members.size >= _maxSize)
				return Object;
		}

		// If we made it this far, then we successfully grew the group,
		// and we can go ahead and add the object at the first open slot.
		members.add(Object);
		length = i + 1;
		return Object;
	}

	/**
	 * Change all status of the radio button.
	 * 
	 * @param RadioButton
	 */
	protected void onChange(FlxRadioButton RadioButton)
	{
		// Break if it's already selected.
		if(_current == RadioButton)
		{
			RadioButton.setActive(true);
			return;
		}

		FlxRadioButton object;
		for(int i = 0; i < members.size; i++)
		{
			object = members.get(i);
			object.setActive(false);
		}
		RadioButton.setActive(true);
		_current = RadioButton;
		if(onChange != null)
			onChange.callback();
	}

	/**
	 * Select a radio button at the given index.
	 * 
	 * @param Index
	 */
	public void setCheck(int Index)
	{
		if(Index < members.size)
			onChange((FlxRadioButton) members.get(Index));
	}

	/**
	 * Select a radio button.
	 * 
	 * @param RadioButton
	 */
	public void setCheck(FlxRadioButton RadioButton)
	{
		onChange(RadioButton);
	}

	/**
	 * Clean up memory.
	 */
	public void destroy()
	{
		_current = null;
		if(members != null)
		{
			FlxRadioButton radioButton;
			int i = 0;
			while(i < members.size)
			{
				radioButton = members.pop();
				if(radioButton != null)
					radioButton.destroy();
				++i;
			}
			members = null;
		}
	}

	/**
	 * Get the ID of the selected radio button.
	 * 
	 * @return
	 */
	public String getSelected()
	{
		return _current.ID;
	}

	/**
	 * Get the text of label from the selected radio button.
	 * 
	 * @return
	 */
	public CharSequence getSelectedLabel()
	{
		return _current.label.getText();
	}
}