Java IO.pdf - Nguyen Dang Binh

13.2.5 Custom Dialogs
Java I/O
File choosers support three dialog types: open, save, and custom. The type is indicated by one
of these three mnemonic constants:
FileChooser.OPEN_DIALOG
FileChooser.SAVE_DIALOG
FileChooser.CUSTOM_DIALOG
You set the type with the setDialogType() method or, less commonly, retrieve it with
getDialogType():
public int getDialogType()
public void setDialogType(int dialogType)
If you use a custom dialog, you should also set the dialog title, the text of the Approve
button's label, the text of the Approve button's tooltip, and the Approve button mnemonic
(shortcut key). Setting the Approve button's text automatically sets the dialog to custom type.
There are five set and four get methods to handle these tasks:
public void setDialogTitle(String dialogTitle)
public String getDialogTitle()
public void setApproveButtonToolTipText(String toolTipText)
public String getApproveButtonToolTipText()
public int getApproveButtonMnemonic()
public void setApproveButtonMnemonic(int mnemonic)
public void setApproveButtonMnemonic(char mnemonic)
public void setApproveButtonText(String approveButtonText)
public String getApproveButtonText()
Use these methods sparingly. If you use them, you'll probably want to store the exact strings
you use in a resource bundle so your code is easily localizable.
When you're showing a custom dialog, you'll simply use the showDialog() method rather
than showOpenDialog() or showSaveDialog() (since a custom dialog is neither):
public int showDialog(Component parent, String approveButtonText)
Suppose you want a file chooser that allows you to gzip files, then exit when the user presses
the Cancel button. You can set the Approve button text to "GZIP," the Approve button tooltip
to "Select a file, then press this button to gzip it," the Approve button mnemonic to the letter
"g" (for gzip), and the dialog title to "Please choose a file to gzip:," as Example 13.5
demonstrates. The chosen file is read from a file input stream. StreamCopier.copy() copies
this file onto a file output stream chained to a gzip output stream that compresses the data.
After both input and output streams are closed, the directory is rescanned so the compressed
file will appear in the list.
Example 13.5. GUIGZipper
import java.io.*;
import java.util.zip.*;
import javax.swing.*;
import com.macfaq.io.*;
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