BlurLayer.java

/*
 * ATLauncher - https://github.com/ATLauncher/ATLauncher
 * Copyright (C) 2013 ATLauncher
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package com.atlauncher.gui.layer;

import javax.swing.JComponent;
import javax.swing.JLayer;
import javax.swing.JPanel;
import javax.swing.plaf.LayerUI;
import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.beans.PropertyChangeEvent;

public final class BlurLayer extends LayerUI<JPanel> {
    private boolean blur = false;

    public void setBlur(boolean b) {
        this.firePropertyChange("blur", this.blur, b);
    }

    @Override
    public void applyPropertyChange(PropertyChangeEvent pce, JLayer l) {
        if (pce.getPropertyName().equalsIgnoreCase("blur")) {
            this.blur = (Boolean) pce.getNewValue();
            l.repaint();
        }
    }

    @Override
    public void paint(Graphics g, JComponent comp) {
        Graphics2D g2 = (Graphics2D) g;
        super.paint(g2, comp);

        if (this.blur) {
            g2.setComposite(alpha(0.5F));
            g2.fillRect(0, 0, comp.getWidth(), comp.getHeight());
        }
    }

    private Composite alpha(float f) {
        return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, f);
    }
}