java.awt
Class TextField

java.lang.Object   
  java.awt.Component   
      java.awt.TextComponent   
          java.awt.TextField

All Implemented Interfaces:

ImageObserver , MenuContainer , Serializable , Accessible

public class TextField
extends TextComponent   

A TextField object is a text component that allows for the editing of a single line of text.

For example, the following image depicts a frame with four text fields of varying widths. Two of these text fields display the predefined text "Hello".

Here is the code that produces these four text fields:

 TextField tf1, tf2, tf3, tf4;
 // a blank text field
 tf1 = new TextField();
 // blank field of 20 columns
 tf2 = new TextField("", 20);
 // predefined text displayed
 tf3 = new TextField("Hello!");
 // predefined text in 30 columns
 tf4 = new TextField("Hello", 30);
 

Every time the user types a key in the text field, one or more key events are sent to the text field. A KeyEvent may be one of three types: keyPressed, keyReleased, or keyTyped. The properties of a key event indicate which of these types it is, as well as additional information about the event, such as what modifiers are applied to the key event and the time at which the event occurred.

The key event is passed to every KeyListener or KeyAdapter object which registered to receive such events using the component's addKeyListener method. (KeyAdapter objects implement the KeyListener interface.)

It is also possible to fire an ActionEvent. If action events are enabled for the text field, they may be fired by pressing the Return key.

The TextField class's processEvent method examines the action event and passes it along to processActionEvent. The latter method redirects the event to any ActionListener objects that have registered to receive action events generated by this text field.

Since:

JDK1.0

See Also:

KeyEvent , KeyAdapter , KeyListener , ActionEvent , Component.addKeyListener(java.awt.event.KeyListener) , processEvent(java.awt.AWTEvent) , processActionEvent(java.awt.event.ActionEvent) , addActionListener(java.awt.event.ActionListener) , Serialized Form

Nested Class Summary

protected class

TextField.AccessibleAWTTextField This class implements accessibility support for the TextField class.

Nested classes/interfaces inherited from class java.awt.TextComponent

TextComponent.AccessibleAWTTextComponent

Nested classes/interfaces inherited from class java.awt.Component

Component.AccessibleAWTComponent , Component.BltBufferStrategy , Component.FlipBufferStrategy

Field Summary

Fields inherited from class java.awt.TextComponent

textListener

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT , CENTER_ALIGNMENT , LEFT_ALIGNMENT , RIGHT_ALIGNMENT , TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT , ALLBITS , ERROR , FRAMEBITS , HEIGHT , PROPERTIES , SOMEBITS , WIDTH

Constructor Summary

TextField ()
Constructs a new text field.

TextField (int columns)
Constructs a new empty text field with the specified number of columns.

TextField (String text)
Constructs a new text field initialized with the specified text.

TextField (String text, int columns)
Constructs a new text field initialized with the specified text to be displayed, and wide enough to hold the specified number of columns.

Method Summary

void	addActionListener (ActionListener l) Adds the specified action listener to receive action events from this text field.
void	addNotify () Creates the TextField's peer.
boolean	echoCharIsSet () Indicates whether or not this text field has a character set for echoing.
AccessibleContext	getAccessibleContext () Gets the AccessibleContext associated with this TextField.
ActionListener []	getActionListeners () Returns an array of all the action listeners registered on this textfield.
int	getColumns () Gets the number of columns in this text field.
char	getEchoChar () Gets the character that is to be used for echoing.
<T extends EventListener > T[]	getListeners (Class <T> listenerType) Returns an array of all the objects currently registered as FooListeners upon this TextField.
Dimension	getMinimumSize () Gets the minumum dimensions for this text field.
Dimension	getMinimumSize (int columns) Gets the minumum dimensions for a text field with the specified number of columns.
Dimension	getPreferredSize () Gets the preferred size of this text field.
Dimension	getPreferredSize (int columns) Gets the preferred size of this text field with the specified number of columns.
Dimension	minimumSize () Deprecated. As of JDK version 1.1, replaced by getMinimumSize().
Dimension	minimumSize (int columns) Deprecated. As of JDK version 1.1, replaced by getMinimumSize(int).
protected String	paramString () Returns a string representing the state of this TextField.
Dimension	preferredSize () Deprecated. As of JDK version 1.1, replaced by getPreferredSize().
Dimension	preferredSize (int columns) Deprecated. As of JDK version 1.1, replaced by getPreferredSize(int).
protected void	processActionEvent (ActionEvent e) Processes action events occurring on this text field by dispatching them to any registered ActionListener objects.
protected void	processEvent (AWTEvent e) Processes events on this text field.
void	removeActionListener (ActionListener l) Removes the specified action listener so that it no longer receives action events from this text field.
void	setColumns (int columns) Sets the number of columns in this text field.
void	setEchoChar (char c) Sets the echo character for this text field.
void	setEchoCharacter (char c) Deprecated. As of JDK version 1.1, replaced by setEchoChar(char).
void	setText (String t) Sets the text that is presented by this text component to be the specified text.

Methods inherited from class java.awt.TextComponent

addTextListener , enableInputMethods , getBackground , getCaretPosition , getInputMethodRequests , getSelectedText , getSelectionEnd , getSelectionStart , getText , getTextListeners , isEditable , processTextEvent , removeNotify , removeTextListener , select , selectAll , setBackground , setCaretPosition , setEditable , setSelectionEnd , setSelectionStart

Methods inherited from class java.awt.Component

action , add , addComponentListener , addFocusListener , addHierarchyBoundsListener , addHierarchyListener , addInputMethodListener , addKeyListener , addMouseListener , addMouseMotionListener , addMouseWheelListener , addPropertyChangeListener , addPropertyChangeListener , applyComponentOrientation , areFocusTraversalKeysSet , bounds , checkImage , checkImage , coalesceEvents , contains , contains , createImage , createImage , createVolatileImage , createVolatileImage , deliverEvent , disable , disableEvents , dispatchEvent , doLayout , enable , enable , enableEvents , firePropertyChange , firePropertyChange , firePropertyChange , firePropertyChange , firePropertyChange , firePropertyChange , firePropertyChange , firePropertyChange , firePropertyChange , getAlignmentX , getAlignmentY , getBounds , getBounds , getColorModel , getComponentAt ,