jffilefilter.java

来自「用Java开发的、实现类似Visio功能的应用程序源码」· Java 代码 · 共 288 行

/**
 *    $Id:JFFileFilter.java $
 *
 *    Copyright 2004 ~ 2005  JingFei International Cooperation LTD. All rights reserved. *
 */
package com.jfimagine.jfgraph.transfer;

import java.io.File;
import java.util.Hashtable;
import java.util.Enumeration;

import javax.swing.filechooser.FileFilter;

 
/**
 * A convenience implementation of FileFilter that filters out
 * all files except for those type extensions that it knows about.
 *
 * Example - create a new filter that filerts out all files
 * but gif and jpg image files:
 *
 *     JFileChooser chooser = new JFileChooser();
 *     JFFileFilter filter = new JFFileFilter(
 *                   new String{"gif", "jpg"}, "JPEG & GIF Images")
 *     chooser.addChoosableFileFilter(filter);
 *     chooser.showOpenDialog(this);
 *
 * @author     CookieMaker    
 *
 * @version $Revision: 1.00 $
 */ 
 
public class JFFileFilter extends FileFilter { 
	
	
    /** default binary file extension for JFDraw*/	    		
    public static final String FILEEXT_DRAW		="jfd";
    public static final String FILEDESC_DRAW		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.jfd");
    
    /** default xml file extension for JFDraw*/	    		
    public static final String FILEEXT_DRAW_XML		="jfx";
    public static final String FILEDESC_DRAW_XML	=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.jfx");
    
    /** default library extension for JFDraw*/	    		
    public static final String FILEEXT_DRAW_LIBRARY	="lib";
    public static final String FILEDESC_DRAW_LIBRARY	=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.lib");

    /** default template extension for JFDraw*/	    		
    public static final String FILEEXT_DRAW_TEMPLATE	="tpl";
    public static final String FILEDESC_DRAW_TEMPLATE	=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.tpl");

    /** gif extension for JFDraw*/	    		
    public static final String FILEEXT_GIF		="gif";
    public static final String FILEDESC_GIF		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.gif");

    /** jpg extension for JFDraw*/	    		
    public static final String FILEEXT_JPG		="jpg";
    public static final String FILEDESC_JPG		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.jpg");

    /** png extension for JFDraw*/	    		
    public static final String FILEEXT_PNG		="png";
    public static final String FILEDESC_PNG		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.png");

    /** eps extension for JFDraw*/	    		
    public static final String FILEEXT_EPS		="eps";
    public static final String FILEDESC_EPS		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.eps");

    /** svg extension for JFDraw*/	    		
    public static final String FILEEXT_SVG		="svg";
    public static final String FILEDESC_SVG		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.svg");

    /** swf extension for JFDraw*/	    		
    public static final String FILEEXT_SWF		="swf";
    public static final String FILEDESC_SWF		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.swf");

    /** cgm extension for JFDraw*/	    		
    public static final String FILEEXT_CGM		="cgm";
    public static final String FILEDESC_CGM		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.cgm");

    /** emf extension for JFDraw*/	    		
    public static final String FILEEXT_EMF		="emf";
    public static final String FILEDESC_EMF		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.emf");

    /** pdf extension for JFDraw*/	    		
    public static final String FILEEXT_PDF		="pdf";
    public static final String FILEDESC_PDF		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.pdf");

    /** ppm extension for JFDraw*/	    		
    public static final String FILEEXT_PPM		="ppm";
    public static final String FILEDESC_PPM		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.ppm");

    /** tiff extension for JFDraw*/	    		
    public static final String FILEEXT_TIFF		="tiff";
    public static final String FILEDESC_TIFF		=com.jfimagine.jfdraw.gui.resource.CADResource.getString("label.filetype.tiff");


    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 JFFileFilter() {
	this.filters = new Hashtable();
    }

    /**
     * Creates a file filter that accepts files with the given extension.
     * Example: new JFFileFilter("jpg");
     *
     * @see #addExtension
     */
    public JFFileFilter(String extension) {
	this(extension,null);
    }

    /**
     * Creates a file filter that accepts the given file type.
     * Example: new JFFileFilter("jpg", "JPEG Image Images");
     *
     * Note that the "." before the extension is not needed. If
     * provided, it will be ignored.
     *
     * @see #addExtension
     */
    public JFFileFilter(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 JFFileFilter(String {"gif", "jpg"});
     *
     * Note that the "." before the extension is not needed adn
     * will be ignored.
     *
     * @see #addExtension
     */
    public JFFileFilter(String[] filters) {
	this(filters, null);
    }

    /**
     * Creates a file filter from the given string array and description.
     * Example: new JFFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
     *
     * Note that the "." before the extension is not needed and will be ignored.
     *
     * @see #addExtension
     */
    public JFFileFilter(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.
     *
     * Files that begin with "." are ignored.
     */
    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.
     *
     * For example: the following code will create a filter that filters
     * out all files except those that end in ".jpg" and ".tif":
     *
     *   JFFileFilter filter = new JFFileFilter();
     *   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)"
     *
     */
    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.
     *
     * 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.
     *
     * Only relevent if a description was provided in the constructor
     * or using setDescription();
     *
     */
    public boolean isExtensionListInDescription() {
	return useExtensionsInDescription;
    }
}