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/*
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package org.jdesktop.swingx.painter;

import java.awt.AlphaComposite;
import java.awt.Graphics2D;

import org.jdesktop.beans.JavaBean;

/**
 * Applies an alpha value to an entire stack of painters.
 *
 * @author joshy
 */
@JavaBean
//@SuppressWarnings("nls")
public class AlphaPainter extends CompoundPainter {
	
    private float alpha = 1.0f;

    /**
     * {@inheritDoc}
     */
    @Override
    protected void doPaint(Graphics2D g, T component, int width, int height) {
		Graphics2D g2 = (Graphics2D) g.create();

		try {
			if (getTransform() != null) {
				g2.setTransform(getTransform());
			}
			if (alpha < 1) {
				g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
			}

			super.doPaint(g2, component, width, height);
		} finally {
			g2.dispose();
		}
    }

    /**
     * Returns the current alpha value for this painter. This is the alpha value that will be applied 
     * to all painters set inside this painter. Alpha values will be multiplied. This means if you set an
     * alpha of 0.5 on this painter and you nest a painter inside which uses an alpha of 0.5 then the final
     * pixels drawn will have an alpha of 0.25.
     * @return the current value of alpha property
     */
    public float getAlpha() {
        return alpha;
    }

    /**
     * Sets the current alpha value for this painter. This is the alpha value that will be applied 
     * to all painters set inside this painter. Alpha values will be multiplied. This means if you set an
     * alpha of 0.5 on this painter and you nest a painter inside which uses an alpha of 0.5 then the final
     * pixels drawn will have an alpha of 0.25.
     * @param alpha the new value of the alpha property
     */
    public void setAlpha(float alpha) {
        float old = getAlpha();
        this.alpha = alpha;
        firePropertyChange("alpha", old, getAlpha());
    }
}