Java Image checkLosslessImageExt(Component parent, File f)

Description

Optionally validate the file name to have an extension of a lossless image format.

License

Open Source License

Parameter

Parameter	Description
parent	the parent component
f	the file

Return

the optionally changed file reference

Declaration

public static File checkLosslessImageExt(Component parent, File f)

Method Source Code


//package com.java2s;
/*/*from   w ww  . jav  a 2 s  .  c o  m*/
 * ArikTools
 * Copyright (C) Arik Z.Lakritz, Peter Macko, and David K. Wittenberg
 * 
 * This file is part of ArikTools.
 *
 * ArikTools 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.
 *
 * ArikTools 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 ArikTools.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.awt.*;

import java.io.*;

import javax.swing.*;

public class Main {
    private static final String[] SUPPORTED_IMAGE_FORMATS = { "png", "jpg", "jpeg", "gif" };
    private static final String[] SUPPORTED_IMAGE_LOSSLESS_FORMATS = { "png" };

    /**
     * Optionally validate the file name to have an extension of a lossless image format.
     * If the initial file name does not have such extension, ask the user.
     *
     * @param parent the parent component
     * @param f the file
     * @return the optionally changed file reference
     */
    public static File checkLosslessImageExt(Component parent, File f) {

        if (f == null)
            return null;

        String ext = getExtension(f);

        // No extension

        if (ext == null) {

            Object[] options = { "Use .png", "No Extension" };
            String msg = "<html><body><b>Are you sure to not use a file extension?</b><br><br>"
                    + "An image file without a proper extension<br>may not be opened correctly by other programs.</body></html>";

            int n = JOptionPane.showOptionDialog(parent, msg, "Save Image", JOptionPane.YES_NO_OPTION,
                    JOptionPane.WARNING_MESSAGE, null, options, options[0]);

            if (n == 0)
                f = new File(f.getAbsolutePath() + ".png");

            return f;
        }

        // Unsupported extension

        ext = ext.toLowerCase();
        boolean unsupported = true;

        for (int i = 0; i < SUPPORTED_IMAGE_FORMATS.length; i++) {
            if (ext.equals(SUPPORTED_IMAGE_FORMATS[i])) {
                unsupported = false;
                break;
            }
        }

        if (unsupported) {

            Object[] options = { "Use .png", "Cancel" };
            String msg = "<html><body><b>The image format \"" + ext + "\" is not supported.</b><br><br>"
                    + "Would you like to save the image as \"png\" instead?</body></html>";

            int n = JOptionPane.showOptionDialog(parent, msg, "Save Image", JOptionPane.YES_NO_OPTION,
                    JOptionPane.ERROR_MESSAGE, null, options, options[0]);

            if (n == 0) {
                String str = f.getAbsolutePath();
                return new File(str.substring(0, str.lastIndexOf('.')) + ".png");
            } else {
                return null;
            }
        }

        // Not recommended extension

        ext = ext.toLowerCase();
        boolean notRecommended = true;

        for (int i = 0; i < SUPPORTED_IMAGE_LOSSLESS_FORMATS.length; i++) {
            if (ext.equals(SUPPORTED_IMAGE_LOSSLESS_FORMATS[i])) {
                notRecommended = false;
                break;
            }
        }

        if (notRecommended) {

            Object[] options = { "Use .png", "Keep ." + ext };
            String msg = "<html><body><b>Are you sure to save the file as \"" + ext + "\"?</b><br><br>"
                    + "The file format you have selected is not recommended,<br>"
                    + "because it does not employ lossless compression on<br>"
                    + "RGB images with 24-bit color depth.</body></html>";

            int n = JOptionPane.showOptionDialog(parent, msg, "Save Image", JOptionPane.YES_NO_OPTION,
                    JOptionPane.WARNING_MESSAGE, null, options, options[0]);

            if (n == 0) {
                String str = f.getAbsolutePath();
                return new File(str.substring(0, str.lastIndexOf('.')) + ".png");
            }

            return f;
        }

        // It's okay

        return f;
    }

    /**
      * Get the extension of a file.
     * The code is based on http://java.sun.com/docs/books/tutorial/uiswing/components/examples/Utils.java
     *
     * @param f the file
     * @return the file extension
      */
    public static String getExtension(File f) {
        String ext = null;
        String s = f.getName();
        int i = s.lastIndexOf('.');

        if ((i > 0) && (i < s.length() - 1)) {
            ext = s.substring(i + 1);
        }

        return ext;
    }
}

Java Image checkLosslessImageExt(Component parent, File f)

Description

License

Parameter

Return

Declaration

Method Source Code

Related