File Menu - sample applications

Samples Index

Demonstrates how to get the FileChooser and change the properties of it. This sample sets the File filters to the following FileChooser

Sample 8:- It contains two files

File 1:- FileChooserFileFilter.java

File 2:- HandleFileChooserExample.java



/*
* @(#)HandleFileChooserExample.java
*
*Product Of : MakeLogic
* URL : http://www.makelogic.com
* Author : R.Venkatesh
* Date : 20 June, 2003
* email : venkat@makelogicmldb.com

* Please feel free to use this Sample Code in your Applications.
*/

/*
* This sample Application Demonstrates how to get the
* FileChooser and make Changes to the FileChooser.
*/





import java.io.File;
import java.util.Hashtable;
import java.util.Enumeration;
import javax.swing.*;

import javax.swing.filechooser.*;

/**
* 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();
* MyFileFilter filter = new MyFileFilter(
* new String{"gif", "jpg"}, "JPEG & GIF Images")
* chooser.addChoosableFileFilter(filter);
* chooser.showOpenDialog(this);
*
*/
public class FileChooserFileFilter 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 FileChooserFileFilter() {
this.filters = new Hashtable();
}

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

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

/**
* Creates a file filter from the given string array and description.
* Example: new MyFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
*
* Note that the "." before the extension is not needed and will be ignored.
*
* @see #addExtension
*/
public FileChooserFileFilter(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.
*
* @see #getExtension
* @see FileFilter#accepts
*/
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":
*
* MyFileFilter filter = new MyFileFilter();
* 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 setDescription
* @see setExtensionListInDescription
* @see isExtensionListInDescription
* @see FileFilter#getDescription
*/
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");
*
* @see setDescription
* @see setExtensionListInDescription
* @see 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 getDescription
* @see setDescription
* @see 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 getDescription
* @see setDescription
* @see setExtensionListInDescription
*/
public boolean isExtensionListInDescription() {
return useExtensionsInDescription;
}
}



import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;


import javax.swing.JDesktopPane;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenuBar;
import javax.swing.JOptionPane;
import javax.swing.KeyStroke;

import com.makeLogic.utils.FileMenu;

class HandleFileChooser extends JFrame implements PropertyChangeListener
{
JDesktopPane desktop;
JMenuBar menuBar;

HandleFileChooser(String title)
{
//..calls the super class constructor
super(title);

//..creates a JMenuBar to Place Menus
menuBar=new JMenuBar();

//..container
desktop=new JDesktopPane();

//..gets the ContentPane of the JFrame
getContentPane().add("Center",desktop);


//..Creates the FileMenu Object
FileMenu fileMenu=new FileMenu(desktop);

//..Adds fileMenu to the MenuBar
menuBar.add(fileMenu);

//..Adds the JMenuBar to the JFrame
setJMenuBar(menuBar);

//..adds the PropertyChange Listeners
fileMenu.getOpenMenuItem().addPropertyChangeListener(this);
fileMenu.getSaveMenuItem().addPropertyChangeListener(this);
fileMenu.getSaveAsMenuItem().addPropertyChangeListener(this);

//.. exit when window closed
addWindowListener(fileMenu.getDefaultClosingListener());

}

//..PropertyChangeListener
//..it gets the FileChooser and changes the FileChooser properties
public void propertyChange(PropertyChangeEvent propertyChangeEvent)
{
//..checks the property Name as FileChooserOpend which is set by the developer
if(propertyChangeEvent.getPropertyName().equalsIgnoreCase("FileChooserOpened"))
{
//..gets the FileChooser
JFileChooser fileChooser = (JFileChooser)propertyChangeEvent.getOldValue();

if(fileChooser != null)
{
//..makes modifications to the FileChooser

//..creates the FileFilters
FileChooserFileFilter myFileFilter = new FileChooserFileFilter();

//..sets the FileFilters to the FileChooser
myFileFilter.addExtension("jpg");
myFileFilter.addExtension("gif");
myFileFilter.setDescription("JPG & GIF Images");
fileChooser.setFileFilter(myFileFilter);

//..sets the Title to the FileChooser
fileChooser.setDialogTitle("HandleFileChooser Demo");
fileChooser.validate();
}
else
{
//..do nothing

}

}
}

}

public class HandleFileChooserExample
{
public static void main(String args[]) throws Exception
{
HandleFileChooser handleFileChooser=new HandleFileChooser("Handle FileChooser Example");
handleFileChooser.show();
handleFileChooser.setSize(500,500);
handleFileChooser.validate();
}
}