src/share/demo/jfc/SampleTree/SampleTreeCellRenderer.java

/*
 * Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 */

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JTree;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.DefaultMutableTreeNode;
import java.awt.Component;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;

public class SampleTreeCellRenderer extends JLabel implements TreeCellRenderer
{
    /** Font used if the string to be displayed isn't a font. */
    static protected Font             defaultFont;
    /** Icon to use when the item is collapsed. */
    static protected ImageIcon        collapsedIcon;
    /** Icon to use when the item is expanded. */
    static protected ImageIcon        expandedIcon;

    /** Color to use for the background when selected. */
    static protected final Color SelectedBackgroundColor = Color.yellow;//new Color(0, 0, 128);

    static
    {
        try {
            defaultFont = new Font("SansSerif", 0, 12);
        } catch (Exception e) {}
        try {
            collapsedIcon = new ImageIcon(SampleTreeCellRenderer.class.getResource("/resources/images/collapsed.gif"));
            expandedIcon = new ImageIcon(SampleTreeCellRenderer.class.getResource("/resources/images/expanded.gif"));
        } catch (Exception e) {
            System.out.println("Couldn't load images: " + e);
        }
    }

    /** Whether or not the item that was last configured is selected. */
    protected boolean            selected;

    /**
      * This is messaged from JTree whenever it needs to get the size
      * of the component or it wants to draw it.
      * This attempts to set the font based on value, which will be
      * a TreeNode.
      */
    public Component getTreeCellRendererComponent(JTree tree, Object value,
                                          boolean selected, boolean expanded,
                                          boolean leaf, int row,
                                                  boolean hasFocus) {
        Font            font;
        String          stringValue = tree.convertValueToText(value, selected,
                                           expanded, leaf, row, hasFocus);

        /* Set the text. */
        setText(stringValue);
        /* Tooltips used by the tree. */
        setToolTipText(stringValue);

        /* Set the image. */
        if(expanded)
            setIcon(expandedIcon);
        else if(!leaf)
            setIcon(collapsedIcon);
        else
            setIcon(null);

        /* Set the color and the font based on the SampleData userObject. */
        SampleData         userObject = (SampleData)((DefaultMutableTreeNode)value)
                                        .getUserObject();
        if(hasFocus)
            setForeground(Color.cyan);
        else
            setForeground(userObject.getColor());
        if(userObject.getFont() == null)
            setFont(defaultFont);
        else
            setFont(userObject.getFont());

        /* Update the selected flag for the next paint. */
        this.selected = selected;

        return this;
    }

    /**
      * paint is subclassed to draw the background correctly.  JLabel
      * currently does not allow backgrounds other than white, and it
      * will also fill behind the icon.  Something that isn't desirable.
      */
    public void paint(Graphics g) {
        Color            bColor;
        Icon             currentI = getIcon();

        if(selected)
            bColor = SelectedBackgroundColor;
        else if(getParent() != null)
            /* Pick background color up from parent (which will come from
               the JTree we're contained in). */
            bColor = getParent().getBackground();
        else
            bColor = getBackground();
        g.setColor(bColor);
        if(currentI != null && getText() != null) {
            int          offset = (currentI.getIconWidth() + getIconTextGap());

            if (getComponentOrientation().isLeftToRight()) {
                g.fillRect(offset, 0, getWidth() - 1 - offset,
                           getHeight() - 1);
            }
            else {
                g.fillRect(0, 0, getWidth() - 1 - offset, getHeight() - 1);
            }
        }
        else
            g.fillRect(0, 0, getWidth()-1, getHeight()-1);
        super.paint(g);
    }
}