/*
* @(#)ExtensionFileFilter.java 1.7 99/04/23
*
* Copyright (c) 1998, 1999 by Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
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* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
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*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/
package com.hackerdude.lib;
import java.io.File;
import java.util.Enumeration;
import java.util.Hashtable;
import javax.swing.filechooser.FileFilter;
/**
* A convenience implementation of FileFilter that filters out
* all files except for those type extensions that it knows about.
*
* Extensions are of the type ".foo", which is typically found on
* Windows and Unix boxes, but not on Macinthosh. Case is ignored.
*
* Example - create a new filter that filerts out all files
* but gif and jpg image files:
*
* JFileChooser chooser = new JFileChooser();
* ExtensionFileFilter filter = new ExtensionFileFilter(
* new String{"gif", "jpg"}, "JPEG & GIF Images")
* chooser.addChoosableFileFilter(filter);
* chooser.showOpenDialog(this);
*
* @version 1.7 04/23/99
* @author Jeff Dinkins
*/
public class ExtensionFileFilter 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(String)
*/
public ExtensionFileFilter() {
this((String) null, (String) null);
}
/**
* Creates a file filter that accepts files with the given extension.
* Example: new ExtensionFileFilter("jpg");
*
* @see #addExtension(String)
*/
public ExtensionFileFilter(String extension) {
this(extension,null);
}
/**
* Creates a file filter that accepts the given file type.
* Example: new ExtensionFileFilter("jpg", "JPEG Image Images");
*
* Note that the "." before the extension is not needed. If
* provided, it will be ignored.
*
* @see #addExtension(String)
*/
public ExtensionFileFilter(String extension, String description) {
this(new String[] {extension}, description);
}
/**
* Creates a file filter from the given string array.
* Example: new ExtensionFileFilter(String {"gif", "jpg"});
*
* Note that the "." before the extension is not needed adn
* will be ignored.
*
* @see #addExtension(String)
*/
public ExtensionFileFilter(String[] filters) {
this(filters, null);
}
/**
* Creates a file filter from the given string array and description.
* Example: new ExtensionFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
*
* Note that the "." before the extension is not needed and will be ignored.
*
* @see #addExtension(String)
*/
public ExtensionFileFilter(String[] filters, String description) {
this.filters = new Hashtable(filters.length);
for (int i = 0; i < filters.length; i++) {
// add filters one by one
addExtension(filters[i]);
}
setDescription(description);
}
/**
* Return true if this file should be shown in the directory pane,
* false if it shouldn't.
*
* Files that begin with "." are ignored.
*
* @see #getExtension(File)
* @see FileFilter#accept(java.io.File)
*/
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(File)
* @see FileFilter#accept(java.io.File)
*/
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.
*
* For example: the following code will create a filter that filters
* out all files except those that end in ".jpg" and ".tif":
*
* ExtensionFileFilter filter = new ExtensionFileFilter();
* filter.addExtension("jpg");
* filter.addExtension("tif");
*
* 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)"
*
* @see ExtensionFileFilter#setDescription(String)
* @see ExtensionFileFilter#setExtensionListInDescription(boolean)
* @see ExtensionFileFilter#isExtensionListInDescription()
* @see FileFilter#getDescription()
*/
public String getDescription() {
if(fullDescription == null) {
if(description == null || isExtensionListInDescription()) {
if(description != null) {
fullDescription = description;
}
fullDescription += " (";
// 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");
*
* @see ExtensionFileFilter#setExtensionListInDescription(boolean)
* @see ExtensionFileFilter#isExtensionListInDescription()
*/
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.
*
* Only relevent if a description was provided in the constructor
* or using setDescription();
*
* @see ExtensionFileFilter#getDescription()
* @see ExtensionFileFilter#setDescription(String)
* @see ExtensionFileFilter#isExtensionListInDescription()
*/
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.
*
* Only relevent if a description was provided in the constructor
* or using setDescription();
*
* @see ExtensionFileFilter#getDescription()
* @see ExtensionFileFilter#setDescription(String)
* @see ExtensionFileFilter#setExtensionListInDescription(boolean)
*/
public boolean isExtensionListInDescription() {
return useExtensionsInDescription;
}
}