Download Lecture 06: More Swing Components

Lecture 05:
More Swing Components
© NIKO IBRAHIM, MIT
PROGRAM STUDI SISTEM INFORMASI
UNIVERSITAS KRISTEN MARANATHA
Text Component
 Swing offers sophisticated text components, from
plain-text entry boxes to HTML interpreters.
 It's a huge subject; we'll just scratch the surface here.
 More information:


Learning Java, Ch 18.1
O’Reilly Java Swing 2nd Ed, Ch 19
 Lots of Text Component subclasses:
 JTextField, JTextArea, JFormattedTextField, DocumentFilter,
InputVerifier, JPasswordField, HTML & RTF viewer,
JTextPane
JTextField & JTextArea: TextEntryBox App.
JFormattedTextField
 The JFormattedTextField component provides
explicit support for editing complex formatted values
such as numbers and dates.
 JFormattedTextField acts somewhat like a
JTextField, except that it accepts a format-specifying
object in its constructor and manages a complex
object type (such as Date or Integer) through its
setValue( ) and getValue( ) methods.
FormatedFields.java
Filtering Input
 JFormattedTextField does not know about all format
types itself, instead it uses AbstractFormatter objects
that know about particular format types.
 AbstractFormatter provide implementations of two
interfaces: DocumentFilter & NavigationFilter
 A DocumentFilter attaches to implementations of
Document and allows you to intercept editing
commands, modifying them as you wish.
 DocumentFilter provides a low-level, edit-by-edit
means of controlling or mapping user input.
Filtering Input Example: DocFilter.java
Validating Data
 Whereas character filtering prevents you from entering
incorrect data, field validation happens after data has
been entered.
 Normally, validation occurs when the user tries to change
focus and leave the field, either by clicking the mouse or
through keyboard navigation.
 Java 1.4 added the InputVerifier API, which allows you to
validate the contents of a component before focus is
transferred.
 Although we are going to talk about this in the context of
text fields, an InputVerifier can actually be attached to
any JComponent to validate its state in this way.
Validating Data Example: Validator.java
Password Input
 A JPasswordField behaves just like a JTextField (it's a
subclass), except every character typed is echoed as the
same, obfuscating character, typically an asterisk.
 The creation and use of JPasswordField is basically the
same as for JTextField. If you find asterisks distasteful,
you can tell the JPasswordField to use a different
character using the setEchoChar( ) method.
 Normally, you would use getText( ) to retrieve the text
typed into the JPasswordField. This method, however, is
deprecated; you should use getPassword( ) instead.
 The getPassword( ) method returns a character array
rather than a String object. This is done because
character arrays are a little less vulnerable than Strings.
Password Example: LoginDialog.java
Timer
 The Timer class provides a mechanism to generate
timed events.
 It has properties and events, and thus can be used in
application builders that understand JavaBeans.
 It fires an ActionEvent at a given time.
 The timer can be set to repeat, and an optional initial
delay can be set before the repeating event starts.
Timer Example: ClockLabel.java & ClockTest.java
Tree
 Tree components help you visualize hierarchical
information and make traversal and manipulation of
that information much more manageable.
 A tree consists of nodes, which can contain either a
user-defined object along with references to other
nodes, or a user-defined object only. (Nodes with no
references to other nodes are commonly called
leaves.)
 In modern windowing environments, the directory
list is an excellent example of a tree.
 More resources about Tree nodes, event, selection:
see “O’Reilly Java Swing 2nd Ed, Ch 17”
Example of a Simple Tree: TestTree.java
More Resources…
 O’Reilly Java Swing 2nd Edition, Chapter 15-17
 Learning Java 3rd Ed, Ch 18
 JFC Swing Tutorial
Summary
 Congratulations, during the lecture you’ve learnt
many more advanced swing components!