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package javax.swing.filechooser;
import java.io.File;
import javax.swing.*;
FileView defines an abstract class that can be implemented
to provide the filechooser with UI information for a File.
Each L&F JFileChooserUI object implements this
class to pass back the correct icons and type descriptions specific to
that L&F. For example, the Microsoft Windows L&F returns the
generic Windows icons for directories and generic files.
Additionally, you may want to provide your own FileView to
JFileChooser to return different icons or additional information using JFileChooser.setFileView.
JFileChooser first looks to see if there is a user defined
FileView, if there is, it gets type information from
there first. If FileView returns null for
any method, JFileChooser then uses the L&F specific
view to get the information.
So, for example, if you provide a FileView class that
returns an Icon for JPG files, and returns null
icons for all other files, the UI's FileView will provide
default icons for all other files.
For an example implementation of a simple file view, see
yourJDK/demo/jfc/FileChooserDemo/ExampleFileView.java.
For more information and examples see
How to Use File Choosers,
a section in The Java Tutorial.
Author: Jeff Dinkins See Also:
/**
* <code>FileView</code> defines an abstract class that can be implemented
* to provide the filechooser with UI information for a <code>File</code>.
* Each L&F <code>JFileChooserUI</code> object implements this
* class to pass back the correct icons and type descriptions specific to
* that L&F. For example, the Microsoft Windows L&F returns the
* generic Windows icons for directories and generic files.
* Additionally, you may want to provide your own <code>FileView</code> to
* <code>JFileChooser</code> to return different icons or additional
* information using {@link javax.swing.JFileChooser#setFileView}.
*
* <p>
*
* <code>JFileChooser</code> first looks to see if there is a user defined
* <code>FileView</code>, if there is, it gets type information from
* there first. If <code>FileView</code> returns <code>null</code> for
* any method, <code>JFileChooser</code> then uses the L&F specific
* view to get the information.
* So, for example, if you provide a <code>FileView</code> class that
* returns an <code>Icon</code> for JPG files, and returns <code>null</code>
* icons for all other files, the UI's <code>FileView</code> will provide
* default icons for all other files.
*
* <p>
*
* For an example implementation of a simple file view, see
* <code><i>yourJDK</i>/demo/jfc/FileChooserDemo/ExampleFileView.java</code>.
* For more information and examples see
* <a
href="https://docs.oracle.com/javase/tutorial/uiswing/components/filechooser.html">How to Use File Choosers</a>,
* a section in <em>The Java Tutorial</em>.
*
* @see javax.swing.JFileChooser
*
* @author Jeff Dinkins
*
*/
public abstract class FileView {
Constructor for subclasses to call.
/**
* Constructor for subclasses to call.
*/
protected FileView() {}
The name of the file. Normally this would be simply
f.getName().
Params: - f – a
File object
Returns: a String representing the name of the file
/**
* The name of the file. Normally this would be simply
* <code>f.getName()</code>.
*
* @param f a {@code File} object
* @return a {@code String} representing the name of the file
*/
public String getName(File f) {
return null;
};
A human readable description of the file. For example,
a file named jag.jpg might have a description that read:
"A JPEG image file of James Gosling's face".
Params: - f – a
File object
Returns: a String containing a description of the file or null if it is not available.
/**
* A human readable description of the file. For example,
* a file named <i>jag.jpg</i> might have a description that read:
* "A JPEG image file of James Gosling's face".
*
* @param f a {@code File} object
* @return a {@code String} containing a description of the file or
* {@code null} if it is not available.
*
*/
public String getDescription(File f) {
return null;
}
A human readable description of the type of the file. For
example, a jpg file might have a type description of:
"A JPEG Compressed Image File"
Params: - f – a
File object
Returns: a String containing a description of the type of the file or null if it is not available .
/**
* A human readable description of the type of the file. For
* example, a <code>jpg</code> file might have a type description of:
* "A JPEG Compressed Image File"
*
* @param f a {@code File} object
* @return a {@code String} containing a description of the type of the file
* or {@code null} if it is not available .
*/
public String getTypeDescription(File f) {
return null;
}
The icon that represents this file in the JFileChooser.
Params: - f – a
File object
Returns: an Icon which represents the specified File or null if it is not available.
/**
* The icon that represents this file in the <code>JFileChooser</code>.
*
* @param f a {@code File} object
* @return an {@code Icon} which represents the specified {@code File} or
* {@code null} if it is not available.
*/
public Icon getIcon(File f) {
return null;
}
Whether the directory is traversable or not. This might be
useful, for example, if you want a directory to represent
a compound document and don't want the user to descend into it.
Params: - f – a
File object representing a directory
See Also: Returns: true if the directory is traversable, false if it is not, and null if the file system should be checked.
/**
* Whether the directory is traversable or not. This might be
* useful, for example, if you want a directory to represent
* a compound document and don't want the user to descend into it.
*
* @param f a {@code File} object representing a directory
* @return {@code true} if the directory is traversable,
* {@code false} if it is not, and {@code null} if the
* file system should be checked.
* @see FileSystemView#isTraversable
*/
public Boolean isTraversable(File f) {
return null;
}
}