/**
 * Copyright 2010, 2011 Jingjing Li.
 *
 * This file is part of jplot2d.
 *
 * jplot2d 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 3 of the
 * License, or any later version.
 *
 * jplot2d 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 Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with jplot2d. If not, see .
 */
package org.jplot2d.element;

import org.jplot2d.annotation.Hierarchy;
import org.jplot2d.annotation.HierarchyOp;
import org.jplot2d.annotation.Property;
import org.jplot2d.annotation.PropertyGroup;

/**
 * An item in legend to show a short line and a text. It will be hosted by the legend of the plot which host the Graph.
 * If the hosting legend is disabled, it will be hosted by legend of parent plot.
 * 
 * @author Jingjing Li
 * 
 */
@PropertyGroup("Legend Item")
public interface LegendItem extends Element {

	@Hierarchy(HierarchyOp.GET)
	public Graph getParent();

	/**
	 * Returns the legend who show this item
	 * 
	 * @return the legend who show this item
	 */
	@Hierarchy(HierarchyOp.GET)
	public Legend getLegend();

	/**
	 * returns true if this item is displayed in legend; otherwise, returns false.
	 * 
	 * @return the flag
	 */
	@Property(order = 0, styleable = false)
	public boolean isVisible();

	/**
	 * Sets a flag indicating whether this item should be displayed in the legend. The default value is
	 * true, even if the Graph is invisible.
	 * 
	 * @param show
	 *            the flag
	 */
	public void setVisible(boolean show);

	/**
	 * Returns the size of the symbol draw in legend. The default symbol size is Float.NaN, means the same
	 * size as the symbol size of XYGraph.
	 * 
	 * @return the size of the symbol draw in legend
	 */
	@Property(order = 1)
	public float getSymbolSize();

	/**
	 * Set the size of symbol draw in legend. Setting to Float.NaN means the same size as the symbol size
	 * of XYGraph.
	 * 
	 * @param size
	 *            the size of symbols draw in legend
	 */
	public void setSymbolSize(float size);

}