A JTextArea
is a multi-line area that displays plain text.
It is intended to be a lightweight component that provides source
compatibility with the java.awt.TextArea
class where it can
reasonably do so.
You can find information and examples of using all the text components in
Using Text Components,
a section in The Java Tutorial.
This component has capabilities not found in the
java.awt.TextArea
class. The superclass should be
consulted for additional capabilities.
Alternative multi-line text classes with
more capabilities are JTextPane
and JEditorPane
.
The java.awt.TextArea
internally handles scrolling.
JTextArea
is different in that it doesn't manage scrolling,
but implements the swing Scrollable
interface. This allows it
to be placed inside a JScrollPane
if scrolling
behavior is desired, and used directly if scrolling is not desired.
The java.awt.TextArea
has the ability to do line wrapping.
This was controlled by the horizontal scrolling policy. Since
scrolling is not done by JTextArea
directly, backward
compatibility must be provided another way. JTextArea
has
a bound property for line wrapping that controls whether or
not it will wrap lines. By default, the line wrapping property
is set to false (not wrapped).
java.awt.TextArea
has two properties rows
and columns
that are used to determine the preferred size.
JTextArea
uses these properties to indicate the
preferred size of the viewport when placed inside a JScrollPane
to match the functionality provided by java.awt.TextArea
.
JTextArea
has a preferred size of what is needed to
display all of the text, so that it functions properly inside of
a JScrollPane
. If the value for rows
or columns
is equal to zero,
the preferred size along that axis is used for
the viewport preferred size along the same axis.
The java.awt.TextArea
could be monitored for changes by adding
a TextListener
for TextEvent
s.
In the JTextComponent
based
components, changes are broadcasted from the model via a
DocumentEvent
to DocumentListeners
.
The DocumentEvent
gives
the location of the change and the kind of change if desired.
The code fragment might look something like:
DocumentListener myListener = ??; JTextArea myArea = ??; myArea.getDocument().addDocumentListener(myListener);
Warning: Swing is not thread safe. For more information see Swing's Threading Policy.
Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing. As of 1.4, support for long term storage
of all JavaBeansTM
has been added to the java.beans
package.
Please see java.beans.XMLEncoder
.
extends
JTextPane, JEditorPane
@beaninfo
attribute: isContainer false
description: A multi-line area that displays plain text.