com.anrisoftware.prefdialog.miscswing.filetextfield.FileDisplayFormatter.java Source code

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Here is the source code for com.anrisoftware.prefdialog.miscswing.filetextfield.FileDisplayFormatter.java

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/*
 * 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.filetextfield;

import static java.io.File.separatorChar;

import java.awt.FontMetrics;
import java.io.File;
import java.text.ParseException;

import javax.swing.JFormattedTextField;
import javax.swing.text.DefaultFormatter;

import org.apache.commons.lang3.StringUtils;

/**
 * Custom display formatter for a file field. It will trim the file path
 * according to the current viewable characters of the text field.
 * <p>
 * The text field need to set the {@link FontMetrics} by calling the
 * {@link FileDisplayFormatter#setFontMetrics(FontMetrics, int)} method.
 * 
 * @author Erwin Mueller, erwin.mueller@deventm.org
 * @since 3.0
 */
@SuppressWarnings("serial")
class FileDisplayFormatter extends DefaultFormatter {

    private String absolutePath;

    private String text;

    private int maxWidth;

    private FontMetrics fontMetrics;

    private String oldAbsolutePath;

    private String[] splitAbsolutePath;

    @Override
    public boolean getOverwriteMode() {
        return false;
    }

    @Override
    public String valueToString(Object value) throws ParseException {
        if (value == null) {
            return "";
        }
        absolutePath = asAbsolutePath((File) value);
        splitAbsolutePath = StringUtils.split(absolutePath, separatorChar);
        text = createShortPath(getFormattedTextField().getWidth());
        return text;
    }

    private String asAbsolutePath(File file) {
        return file.getAbsolutePath();
    }

    @Override
    public Object stringToValue(String string) throws ParseException {
        return new File(absolutePath);
    }

    /**
     * Updates the new maximum width of the {@link JFormattedTextField}. It will
     * trim the path with the help of the previously set {@link FontMetrics}.
     */
    public void updatePathMaxWidth(int newMaxWidth) {
        text = createShortPath(newMaxWidth);
        getFormattedTextField().setValue(getFormattedTextField().getValue());
    }

    private String createShortPath(int newMaxWidth) {
        newMaxWidth = newMaxWidth - 100;
        if (maxWidth == newMaxWidth && oldAbsolutePath == absolutePath) {
            return text;
        }
        oldAbsolutePath = absolutePath;
        maxWidth = newMaxWidth;
        return createShortPath();
    }

    private String createShortPath() {
        StringBuilder builder = new StringBuilder();
        int i;
        for (i = splitAbsolutePath.length - 1; i >= 0 && isInMaxWidth(builder); i--) {
            builder.insert(0, splitAbsolutePath[i]);
            builder.insert(0, separatorChar);
        }
        if (i > 0) {
            builder.insert(0, "..");
        }
        return builder.toString();
    }

    private boolean isInMaxWidth(StringBuilder builder) {
        return pixelsWidth(builder.toString()) < maxWidth;
    }

    private int pixelsWidth(String string) {
        if (fontMetrics == null) {
            return string.length() * 6;
        } else {
            return fontMetrics.stringWidth(string);
        }
    }

    /**
     * Sets the {@link FontMetrics} from the {@link JFormattedTextField}. The
     * font metrics is used to calculate the currently viewable characters in
     * the text field.
     * 
     * @param fm
     *            the {@link FontMetrics}.
     * 
     * @param maxWidth
     *            the current width of the {@link JFormattedTextField}.
     */
    public void setFontMetrics(FontMetrics fm, int maxWidth) {
        if (fontMetrics == null) {
            this.fontMetrics = fm;
            updatePathMaxWidth(maxWidth);
        }
    }
}