/*
* This file is part of Caliph & Emir.
*
* Caliph & Emir 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 2 of the License, or
* (at your option) any later version.
*
* Caliph & Emir 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 Caliph & Emir; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright statement:
* --------------------
* (c) 2005 by Werner Klieber (werner@klieber.info)
* http://caliph-emir.sourceforge.net
*/
package at.wklieber.tools;
import javax.swing.filechooser.FileFilter;
import java.io.File;
import java.util.Enumeration;
import java.util.Hashtable;
/**
* A convenience implementation of FileFilter that filters out
* all files except for those type extensions that it knows about.
* <p/>
* Extensions are of the type ".foo", which is typically found on
* Windows and Unix boxes, but not on Macinthosh. Case is ignored.
* <p/>
* Example - create a new filter that filerts out all files
* but gif and jpg image files:
* <p/>
* JFileChooser chooser = new JFileChooser();
* ExampleFileFilter filter = new ExampleFileFilter(
* new String{"gif", "jpg"}, "JPEG & GIF Images")
* chooser.addChoosableFileFilter(filter);
* chooser.showOpenDialog(this);
*
* @author Jeff Dinkins
* @version 1.9 04/23/99
*/
public class ExampleFileFilter extends FileFilter {
private static String TYPE_UNKNOWN = "Type Unknown";
private static String HIDDEN_FILE = "Hidden File";
private Hashtable filters = null;
private String description = null;
private String fullDescription = null;
private boolean useExtensionsInDescription = true;
/**
* Creates a file filter. If no filters are added, then all
* files are accepted.
*
* @see #addExtension
*/
public ExampleFileFilter() {
this.filters = new Hashtable();
}
/**
* Creates a file filter that accepts files with the given extension.
* Example: new ExampleFileFilter("jpg");
*
* @see #addExtension
*/
public ExampleFileFilter(String extension) {
this(extension, null);
}
/**
* Creates a file filter that accepts the given file type.
* Example: new ExampleFileFilter("jpg", "JPEG Image Images");
* <p/>
* Note that the "." before the extension is not needed. If
* provided, it will be ignored.
*
* @see #addExtension
*/
public ExampleFileFilter(String extension, String description) {
this();
if (extension != null) addExtension(extension);
if (description != null) setDescription(description);
}
/**
* Creates a file filter from the given string array.
* Example: new ExampleFileFilter(String {"gif", "jpg"});
* <p/>
* Note that the "." before the extension is not needed adn
* will be ignored.
*
* @see #addExtension
*/
public ExampleFileFilter(String[] filters) {
this(filters, null);
}
/**
* Creates a file filter from the given string array and description.
* Example: new ExampleFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
* <p/>
* Note that the "." before the extension is not needed and will be ignored.
*
* @see #addExtension
*/
public ExampleFileFilter(String[] filters, String description) {
this();
for (int i = 0; i < filters.length; i++) {
// add filters one by one
addExtension(filters[i]);
}
if (description != null) setDescription(description);
}
/**
* Return true if this file should be shown in the directory pane,
* false if it shouldn't.
* <p/>
* Files that begin with "." are ignored.
*
* @see #getExtension
* @see FileFilter
*/
public boolean accept(File f) {
if (f != null) {
if (f.isDirectory()) {
return true;
}
String extension = getExtension(f);
if (extension != null && filters.get(getExtension(f)) != null) {
return true;
}
;
}
return false;
}
/**
* Return the extension portion of the file's name .
*
* @see #getExtension
* @see FileFilter#accept
*/
public String getExtension(File f) {
if (f != null) {
String filename = f.getName();
int i = filename.lastIndexOf('.');
if (i > 0 && i < filename.length() - 1) {
return filename.substring(i + 1).toLowerCase();
}
;
}
return null;
}
/**
* Adds a filetype "dot" extension to filter against.
* <p/>
* For example: the following code will create a filter that filters
* out all files except those that end in ".jpg" and ".tif":
* <p/>
* ExampleFileFilter filter = new ExampleFileFilter();
* filter.addExtension("jpg");
* filter.addExtension("tif");
* <p/>
* Note that the "." before the extension is not needed and will be ignored.
*/
public void addExtension(String extension) {
if (filters == null) {
filters = new Hashtable(5);
}
filters.put(extension.toLowerCase(), this);
fullDescription = null;
}
/**
* Returns the human readable description of this filter. For
* example: "JPEG and GIF Image Files (*.jpg, *.gif)"
*/
public String getDescription() {
if (fullDescription == null) {
if (description == null || isExtensionListInDescription()) {
fullDescription = description == null ? "(" : description + " (";
// build the description from the extension list
Enumeration extensions = filters.keys();
if (extensions != null) {
fullDescription += "." + (String) extensions.nextElement();
while (extensions.hasMoreElements()) {
fullDescription += ", " + (String) extensions.nextElement();
}
}
fullDescription += ")";
} else {
fullDescription = description;
}
}
return fullDescription;
}
/**
* Sets the human readable description of this filter. For
* example: filter.setDescription("Gif and JPG Images");
*/
public void setDescription(String description) {
this.description = description;
fullDescription = null;
}
/**
* Determines whether the extension list (.jpg, .gif, etc) should
* show up in the human readable description.
* <p/>
* Only relevent if a description was provided in the constructor
* or using setDescription();
*/
public void setExtensionListInDescription(boolean b) {
useExtensionsInDescription = b;
fullDescription = null;
}
/**
* Returns whether the extension list (.jpg, .gif, etc) should
* show up in the human readable description.
* <p/>
* Only relevent if a description was provided in the constructor
* or using setDescription();
*/
public boolean isExtensionListInDescription() {
return useExtensionsInDescription;
}
}