com.anrisoftware.prefdialog.miscswing.lists.RubberBandingList.java Source code

Introduction

Here is the source code for com.anrisoftware.prefdialog.miscswing.lists.RubberBandingList.java

Source

/*
 * Copyright 2013-2016 Erwin Mller <erwin.mueller@deventm.org>
 *
 * This file is part of prefdialog-misc-swing.
 *
 * prefdialog-misc-swing 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 (at your
 * option) any later version.
 *
 * prefdialog-misc-swing 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 Lesser General Public License
 * along with prefdialog-misc-swing. If not, see <http://www.gnu.org/licenses/>.
 */
package com.anrisoftware.prefdialog.miscswing.lists;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Path2D;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;

import javax.swing.JList;
import javax.swing.ListModel;

import org.apache.commons.lang3.builder.ToStringBuilder;

/**
 * Using rubber band selection in a swing list.
 * 
 * @author <a
 *         href=http://java-swing-tips.blogspot.de/2008/10/using-rubber-band-selection
 *         -in-jlist.html">2008/10/09 using rubber band selection in JList
 *         Posted by TERAI Atsuhiro </a>
 * @author Erwin Mueller, erwin.mueller@deventm.org
 * @since 1.0
 */
@SuppressWarnings("serial")
public class RubberBandingList<E> extends JList<E> {

    private static final AlphaComposite ALPHA = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.1f);

    private Path2D rubberBand;

    private Color selectionColor;

    private Point srcPoint;

    private MouseAdapter rubberBandMouseListener;

    private MouseMotionAdapter rubberBandMouseMotionListener;

    /**
     * @see JList#JList()
     */
    public RubberBandingList() {
        super();
        init();
    }

    /**
     * @see JList#JList(Object[])
     */
    public RubberBandingList(E[] listData) {
        super(listData);
        init();
    }

    /**
     * @see JList#JList(ListModel)
     */
    public RubberBandingList(ListModel<E> dataModel) {
        super(dataModel);
        init();
    }

    /**
     * @see JList#JList(Vector)
     */
    public RubberBandingList(Vector<? extends E> listData) {
        super(listData);
        init();
    }

    private void init() {
        this.srcPoint = new Point();
        this.selectionColor = createSelectionColor();
        this.rubberBandMouseListener = new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                int index = locationToIndex(e.getPoint());
                Rectangle rect = getCellBounds(index, index);
                if (!rect.contains(e.getPoint())) {
                    clearSelection();
                    getSelectionModel().setAnchorSelectionIndex(-1);
                    getSelectionModel().setLeadSelectionIndex(-1);
                    setFocusable(false);
                } else {
                    setFocusable(true);
                }
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                setFocusable(true);
                rubberBand = null;
                repaint();
            }
        };
        this.rubberBandMouseMotionListener = new MouseMotionAdapter() {
            @Override
            public void mouseDragged(MouseEvent e) {
                setFocusable(true);
                if (rubberBand == null) {
                    srcPoint.setLocation(e.getPoint());
                }
                Point destPoint = e.getPoint();
                rubberBand = new Path2D.Double();
                rubberBand.moveTo(srcPoint.x, srcPoint.y);
                rubberBand.lineTo(destPoint.x, srcPoint.y);
                rubberBand.lineTo(destPoint.x, destPoint.y);
                rubberBand.lineTo(srcPoint.x, destPoint.y);
                rubberBand.closePath();
                setSelectedIndices(getIntersectsIdices(rubberBand));
                repaint();
            }
        };
        addMouseListener(rubberBandMouseListener);
        addMouseMotionListener(rubberBandMouseMotionListener);
    }

    private int[] getIntersectsIdices(Shape shape) {
        ListModel<E> model = getModel();
        List<Integer> list = new ArrayList<Integer>(model.getSize());
        for (int i = 0; i < model.getSize(); i++) {
            Rectangle r = getCellBounds(i, i);
            if (shape.intersects(r)) {
                list.add(i);
            }
        }
        int[] indices = new int[list.size()];
        for (int i = 0; i < list.size(); i++) {
            indices[i] = list.get(i);
        }
        return indices;
    }

    @Override
    public void setSelectionBackground(Color selectionBackground) {
        super.setSelectionBackground(selectionBackground);
        this.selectionColor = createSelectionColor();
    }

    private Color createSelectionColor() {
        Color c = getSelectionBackground();
        int r = c.getRed(), g = c.getGreen(), b = c.getBlue();
        return r > g ? r > b ? new Color(r, 0, 0) : new Color(0, 0, b)
                : g > b ? new Color(0, g, 0) : new Color(0, 0, b);
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (rubberBand != null) {
            drawSelectionRubberBand((Graphics2D) g);
        }
    }

    private void drawSelectionRubberBand(Graphics2D g) {
        g.setPaint(getSelectionBackground());
        g.draw(rubberBand);
        g.setComposite(ALPHA);
        g.setPaint(selectionColor);
        g.fill(rubberBand);
    }

    @Override
    public String toString() {
        return new ToStringBuilder(this).appendSuper(super.toString()).toString();
    }
}