biz.wolschon.finance.jgnucash.widgets.MultiLineToolTip.java Source code

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Here is the source code for biz.wolschon.finance.jgnucash.widgets.MultiLineToolTip.java

Source

/**
 * MultiLineToolTip.java
 * created: 2008-08-03
 * (c) ${year} by <a href="http://Wolschon.biz">Wolschon Softwaredesign und Beratung</a>
 * This file is part of ${project_name} by Marcus Wolschon <a href="mailto:Marcus@Wolscon.biz">Marcus@Wolscon.biz</a>.
 * You can purchase support for a sensible hourly rate or
 * a commercial license of this file (unless modified by others) by contacting him directly.
 *
 *  ${project_name} 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.
 *
 *  jGnucashLib 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 ${project_name}.  If not, see <http://www.gnu.org/licenses/>.
 *
 ***********************************
 * Editing this file:
 *  -For consistent code-quality this file should be checked with the
 *   checkstyle-ruleset enclosed in this project.
 *  -After the design of this file has settled it should get it's own
 *   JUnit-Test that shall be executed regularly. It is best to write
 *   the test-case BEFORE writing this class and to run it on every build
 *   as a regression-test.
 */
package biz.wolschon.finance.jgnucash.widgets;

import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.StringReader;
import java.util.LinkedList;
import java.util.List;

import javax.swing.JComponent;
import javax.swing.JToolTip;
import javax.swing.SwingUtilities;
import javax.swing.plaf.metal.MetalToolTipUI;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Usage:
 * <pre>
 * public JToolTip createToolTip() {
 *               MultiLineToolTip tip = new MultiLineToolTip();
 *               tip.setComponent(this);
 *               return tip;
 *            }
 *   </pre>
 * @author fox
 *
 */
public class MultiLineToolTip extends JToolTip {
    public MultiLineToolTip() {
        setUI(new MultiLineToolTipUI());
    }

    private static class MultiLineToolTipUI extends MetalToolTipUI {
        /**
         * Automatically created logger for debug and error-output.
         */
        private final Log LOGGER = LogFactory.getLog(MultiLineToolTipUI.class);

        private String[] myStrings;

        private int maxWidth = 0;

        public void paint(final Graphics g, final JComponent c) {
            // Font.getStringBounds() cannot be used here because we have
            FontMetrics metrics = Toolkit.getDefaultToolkit().getFontMetrics(g.getFont());
            Dimension size = c.getSize();
            g.setColor(c.getBackground());
            g.fillRect(0, 0, size.width, size.height);
            g.setColor(c.getForeground());

            if (myStrings != null) {
                for (int i = 0; i < myStrings.length; i++) {
                    String str = myStrings[i];
                    if (str == null) {
                        str = "";
                    }
                    g.drawString(str, 3, (metrics.getHeight()) * (i + 1));
                }
            }
        }

        public Dimension getPreferredSize(final JComponent c) {
            // Font.getStringBounds() cannot be used here because we have no Graphics2D-object
            FontMetrics metrics = Toolkit.getDefaultToolkit().getFontMetrics(c.getFont());
            String tipText = ((JToolTip) c).getTipText();
            if (tipText == null) {
                tipText = "";
            }

            // read Tooltip-Text
            BufferedReader br = new BufferedReader(new StringReader(tipText));
            String line;
            int maxWidth = 0;
            List<String> lines = new LinkedList<String>();
            try {
                while ((line = br.readLine()) != null) {
                    int width = SwingUtilities.computeStringWidth(metrics, line);
                    maxWidth = (maxWidth < width) ? width : maxWidth;
                    if (line != null) {
                        lines.add(line);
                    }
                }
            } catch (IOException ex) {
                LOGGER.error("Cannot read Tooltip-Text", ex);
            }

            myStrings = lines.toArray(new String[lines.size()]);

            int height = metrics.getHeight() * lines.size();
            this.maxWidth = maxWidth;
            return new Dimension(maxWidth + 6, height + 4);
        }
    }
}