java.awt
Class TextArea

java.lang.Object
  java.awt.Component
      java.awt.TextComponent
          java.awt.TextArea

All Implemented Interfaces:

javax.accessibility.Accessible, ImageObserver, MenuContainer, Serializable

public class TextArea

extends TextComponent

A TextArea object is a multi-line region that displays text. It can be set to allow editing or to be read-only.

The following image shows the appearance of a text area:

This text area could be created by the following line of code:

 new TextArea("Hello", 5, 40);
 

Since:

JDK1.0

Author:

Sami Shaio

See Also:

Serialized Form

Nested Class Summary

protected class

TextArea.AccessibleAWTTextArea This class implements accessibility support for the TextArea class.

Nested classes inherited from class java.awt.TextComponent

TextComponent.AccessibleAWTTextComponent

Nested classes inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.AWTTreeLock, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

private static Set	backwardTraversalKeys Cache the Sets of forward and backward traversal keys so we need not look them up each time.
private static String	base
(package private) int	columns The number of columns in the TextArea.
private static Set	forwardTraversalKeys Cache the Sets of forward and backward traversal keys so we need not look them up each time.
private static int	nameCounter
(package private) int	rows The number of rows in the TextArea.
static int	SCROLLBARS_BOTH Create and display both vertical and horizontal scrollbars.
static int	SCROLLBARS_HORIZONTAL_ONLY Create and display horizontal scrollbar only.
static int	SCROLLBARS_NONE Do not create or display any scrollbars for the text area.
static int	SCROLLBARS_VERTICAL_ONLY Create and display vertical scrollbar only.
private int	scrollbarVisibility Determines which scrollbars are created for the text area.
private static long	serialVersionUID
private int	textAreaSerializedDataVersion The textArea Serialized Data Version.

Fields inherited from class java.awt.TextComponent

backgroundSetByClientCode, editable, selectionEnd, selectionStart, text, textListener

Fields inherited from class java.awt.Component

accessibleContext, actionListenerK, adjustmentListenerK, appContext, background, BOTTOM_ALIGNMENT, bufferStrategy, CENTER_ALIGNMENT, componentListener, componentListenerK, componentOrientation, containerListenerK, cursor, dropTarget, enabled, eventMask, focusListener, focusListenerK, focusTraversalKeys, font, foreground, graphicsConfig, height, hierarchyBoundsListener, hierarchyBoundsListenerK, hierarchyListener, hierarchyListenerK, ignoreRepaint, incRate, inputMethodListener, inputMethodListenerK, isInc, isPacked, itemListenerK, keyListener, keyListenerK, LEFT_ALIGNMENT, locale, LOCK, metrics, minSize, mouseListener, mouseListenerK, mouseMotionListener, mouseMotionListenerK, mouseWheelListener, mouseWheelListenerK, newEventsOnly, ownedWindowK, parent, peer, peerFont, popups, prefSize, RIGHT_ALIGNMENT, textListenerK, TOP_ALIGNMENT, valid, visible, width, windowClosingException, windowFocusListenerK, windowListenerK, windowStateListenerK, x, y

Fields inherited from interface java.awt.image.ImageObserver

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

Constructor Summary

TextArea()
Constructs a new text area with the empty string as text.

TextArea(int rows, int columns)
Constructs a new text area with the specified number of rows and columns and the empty string as text.

TextArea(String text)
Constructs a new text area with the specified text.

TextArea(String text, int rows, int columns)
Constructs a new text area with the specified text, and with the specified number of rows and columns.

TextArea(String text, int rows, int columns, int scrollbars)
Constructs a new text area with the specified text, and with the rows, columns, and scroll bar visibility as specified.

Method Summary

void	addNotify() Creates the TextArea's peer.
void	append(String str) Appends the given text to the text area's current text.
void	appendText(String str) Deprecated. As of JDK version 1.1, replaced by append(String).
(package private) String	constructComponentName() Construct a name for this component.
javax.accessibility.AccessibleContext	getAccessibleContext() Returns the AccessibleContext associated with this TextArea.
int	getColumns() Returns the number of columns in this text area.
Dimension	getMinimumSize() Determines the minimum size of this text area.
Dimension	getMinimumSize(int rows, int columns) Determines the minimum size of a text area with the specified number of rows and columns.
Dimension	getPreferredSize() Determines the preferred size of this text area.
Dimension	getPreferredSize(int rows, int columns) Determines the preferred size of a text area with the specified number of rows and columns.
int	getRows() Returns the number of rows in the text area.
int	getScrollbarVisibility() Returns an enumerated value that indicates which scroll bars the text area uses.
private static void	initIDs() Initialize JNI field and method ids
void	insert(String str, int pos) Inserts the specified text at the specified position in this text area.
void	insertText(String str, int pos) Deprecated. As of JDK version 1.1, replaced by insert(String, int).
Dimension	minimumSize() Deprecated. As of JDK version 1.1, replaced by getMinimumSize().
Dimension	minimumSize(int rows, int columns) Deprecated. As of JDK version 1.1, replaced by getMinimumSize(int, int).
protected String	paramString() Returns a string representing the state of this TextArea.
Dimension	preferredSize() Deprecated. As of JDK version 1.1, replaced by getPreferredSize().
Dimension	preferredSize(int rows, int columns) Deprecated. As of JDK version 1.1, replaced by getPreferredSize(int, int).
private void	readObject(ObjectInputStream s) Read the ObjectInputStream.
void	replaceRange(String str, int start, int end) Replaces text between the indicated start and end positions with the specified replacement text.
void	replaceText(String str, int start, int end) Deprecated. As of JDK version 1.1, replaced by replaceRange(String, int, int).
void	setColumns(int columns) Sets the number of columns for this text area.
void	setRows(int rows) Sets the number of rows for this text area.

Methods inherited from class java.awt.TextComponent

addTextListener, areInputMethodsEnabled, enableInputMethods, eventEnabled, getBackground, getCaretPosition, getCharacterBounds, getIndexAtPoint, getListeners, getSelectedText, getSelectionEnd, getSelectionStart, getText, getTextListeners, isEditable, processEvent, processTextEvent, removeNotify, removeTextListener, select, selectAll, setBackground, setCaretPosition, setEditable, setSelectionEnd, setSelectionStart, setText

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addPropertyChangeListener, addPropertyChangeListener, adjustListeningChildrenOnParent, applyComponentOrientation, areFocusTraversalKeysSet, autoProcessMouseWheel, autoTransferFocus, bounds, checkGD, checkImage, checkImage, checkWindowClosingException, clearCurrentFocusCycleRootOnHide, clearMostRecentFocusOwnerOnHide, coalesceEvents, contains, contains, containsFocus, countHierarchyMembers, createBufferStrategy, createBufferStrategy, createChildHierarchyEvents, createHierarchyEvents, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, dispatchEventImpl, dispatchMouseWheelToAncestor, doLayout, enable, enable, enableEvents, eventTypeEnabled, firePropertyChange, firePropertyChange, firePropertyChange, getAccessibleIndexInParent, getAccessibleStateSet, getAlignmentX, getAlignmentY, getBackBuffer, getBounds, getBounds, getBufferStrategy, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys_NoIDCheck, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont_NoClientCode, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen_NoTreeLock, getLocationOnScreen, getMaximumSize, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getNativeContainer, getParent_NoClientCode, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getToolkitImpl, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, initializeFocusTraversalKeys, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isEnabledImpl, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFocusTraversableOverridden, isFontSet, isForegroundSet, isLightweight, isOpaque, isRecursivelyVisible, isShowing, isValid, isVisible, keyDown, keyUp, layout, lightweightPaint, lightweightPrint, list, list, list, list, list, locate, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, nextFocusHelper, numListening, paint, paintAll, paintHeavyweightComponents, postEvent, postsOldMouseEvents, prepareImage, prepareImage, print, printAll, printHeavyweightComponents, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusHelper, requestFocusInWindow, requestFocusInWindow, resetGC, reshape, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys_NoIDCheck, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setGCFromPeer, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, updateCursorImmediately, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

rows

int rows

The number of rows in the TextArea. This parameter will determine the text area's height. Guaranteed to be non-negative.

See Also:

getRows(), setRows(int)

columns

int columns

The number of columns in the TextArea. A column is an approximate average character width that is platform-dependent. This parameter will determine the text area's width. Guaranteed to be non-negative.

See Also:

setColumns(int), getColumns()

base

private static final String base

See Also:

Constant Field Values

nameCounter

private static int nameCounter

SCROLLBARS_BOTH

public static final int SCROLLBARS_BOTH

Create and display both vertical and horizontal scrollbars.

Since:

JDK1.1

See Also:

Constant Field Values

SCROLLBARS_VERTICAL_ONLY

public static final int SCROLLBARS_VERTICAL_ONLY

Create and display vertical scrollbar only.

Since:

JDK1.1

See Also:

Constant Field Values

SCROLLBARS_HORIZONTAL_ONLY

public static final int SCROLLBARS_HORIZONTAL_ONLY

Create and display horizontal scrollbar only.

Since:

JDK1.1

See Also:

Constant Field Values

SCROLLBARS_NONE

public static final int SCROLLBARS_NONE

Do not create or display any scrollbars for the text area.

Since:

JDK1.1

See Also:

Constant Field Values

scrollbarVisibility

private int scrollbarVisibility

Determines which scrollbars are created for the text area. It can be one of four values : SCROLLBARS_BOTH = both scrollbars.
SCROLLBARS_HORIZONTAL_ONLY = Horizontal bar only.
SCROLLBARS_VERTICAL_ONLY = Vertical bar only.
SCROLLBARS_NONE = No scrollbars.

See Also:

getScrollbarVisibility()

forwardTraversalKeys

private static Set forwardTraversalKeys

Cache the Sets of forward and backward traversal keys so we need not look them up each time.

backwardTraversalKeys

private static Set backwardTraversalKeys

Cache the Sets of forward and backward traversal keys so we need not look them up each time.

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

textAreaSerializedDataVersion

private int textAreaSerializedDataVersion

The textArea Serialized Data Version.

Constructor Detail

TextArea

public TextArea()
         throws HeadlessException

Constructs a new text area with the empty string as text. This text area is created with scrollbar visibility equal to SCROLLBARS_BOTH, so both vertical and horizontal scrollbars will be visible for this text area.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless returns true

See Also:

GraphicsEnvironment.isHeadless()

TextArea

public TextArea(String text)
         throws HeadlessException

Constructs a new text area with the specified text. This text area is created with scrollbar visibility equal to SCROLLBARS_BOTH, so both vertical and horizontal scrollbars will be visible for this text area.

Parameters:

text - the text to be displayed; if text is null, the empty string "" will be displayed

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless returns true

See Also:

GraphicsEnvironment.isHeadless()

TextArea

public TextArea(int rows,
                int columns)
         throws HeadlessException

Constructs a new text area with the specified number of rows and columns and the empty string as text. A column is an approximate average character width that is platform-dependent. The text area is created with scrollbar visibility equal to SCROLLBARS_BOTH, so both vertical and horizontal scrollbars will be visible for this text area.

Parameters:

rows - the number of rows

columns - the number of columns

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless returns true

See Also:

GraphicsEnvironment.isHeadless()

TextArea

public TextArea(String text,
                int rows,
                int columns)
         throws HeadlessException

Constructs a new text area with the specified text, and with the specified number of rows and columns. A column is an approximate average character width that is platform-dependent. The text area is created with scrollbar visibility equal to SCROLLBARS_BOTH, so both vertical and horizontal scrollbars will be visible for this text area.

Parameters:

text - the text to be displayed; if text is null, the empty string "" will be displayed

rows - the number of rows

columns - the number of columns

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless returns true

See Also:

GraphicsEnvironment.isHeadless()

TextArea

public TextArea(String text,
                int rows,
                int columns,
                int scrollbars)
         throws HeadlessException

Constructs a new text area with the specified text, and with the rows, columns, and scroll bar visibility as specified. All TextArea constructors defer to this one.

The TextArea class defines several constants that can be supplied as values for the scrollbars argument:

• SCROLLBARS_BOTH,
• SCROLLBARS_VERTICAL_ONLY,
• SCROLLBARS_HORIZONTAL_ONLY,
• SCROLLBARS_NONE.

Any other value for the scrollbars argument is invalid and will result in this text area being created with scrollbar visibility equal to the default value of SCROLLBARS_BOTH.

Parameters:

text - the text to be displayed; if text is null, the empty string "" will be displayed

rows - the number of rows; if rows is less than 0, rows is set to 0

columns - the number of columns; if columns is less than 0, columns is set to 0

scrollbars - a constant that determines what scrollbars are created to view the text area

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless returns true

Since:

JDK1.1

See Also:

GraphicsEnvironment.isHeadless()

Method Detail

initIDs

private static void initIDs()

Initialize JNI field and method ids

constructComponentName

String constructComponentName()

Construct a name for this component. Called by getName when the name is null.

Overrides:

constructComponentName in class Component

addNotify

public void addNotify()

Creates the TextArea's peer. The peer allows us to modify the appearance of the TextArea without changing any of its functionality.

Overrides:

addNotify in class TextComponent

See Also:

TextComponent.removeNotify()

insert

public void insert(String str,
                   int pos)

Inserts the specified text at the specified position in this text area.

Note that passing null or inconsistent parameters is invalid and will result in unspecified behavior.

Parameters:

str - the non-null text to insert

pos - the position at which to insert

Since:

JDK1.1

See Also:

TextComponent.setText(java.lang.String), replaceRange(java.lang.String, int, int), append(java.lang.String)

insertText

public void insertText(String str,
                       int pos)

Deprecated. As of JDK version 1.1, replaced by insert(String, int).

append

public void append(String str)

Appends the given text to the text area's current text.

Note that passing null or inconsistent parameters is invalid and will result in unspecified behavior.

Parameters:

str - the non-null text to append

Since:

JDK1.1

See Also:

insert(java.lang.String, int)

appendText

public void appendText(String str)

Deprecated. As of JDK version 1.1, replaced by append(String).

replaceRange

public void replaceRange(String str,
                         int start,
                         int end)

Replaces text between the indicated start and end positions with the specified replacement text. The text at the end position will not be replaced. The text at the start position will be replaced (unless the start position is the same as the end position). The text position is zero-based. The inserted substring may be of a different length than the text it replaces.

Note that passing null or inconsistent parameters is invalid and will result in unspecified behavior.

Parameters:

str - the non-null text to use as the replacement

start - the start position

end - the end position

Since:

JDK1.1

See Also:

insert(java.lang.String, int)

replaceText

public void replaceText(String str,
                        int start,
                        int end)

Deprecated. As of JDK version 1.1, replaced by replaceRange(String, int, int).

getRows

public int getRows()

Returns the number of rows in the text area.

Returns:

the number of rows in the text area

Since:

JDK1

See Also:

setRows(int), getColumns()

setRows

public void setRows(int rows)

Sets the number of rows for this text area.

Parameters:

rows - the number of rows

Throws:

IllegalArgumentException - if the value supplied for rows is less than 0

Since:

JDK1.1

See Also:

getRows(), setColumns(int)

getColumns

public int getColumns()

Returns the number of columns in this text area.

Returns:

the number of columns in the text area

See Also:

setColumns(int), getRows()

setColumns

public void setColumns(int columns)

Sets the number of columns for this text area.

Parameters:

columns - the number of columns

Throws:

IllegalArgumentException - if the value supplied for columns is less than 0

Since:

JDK1.1

See Also:

getColumns(), setRows(int)

getScrollbarVisibility

public int getScrollbarVisibility()

Returns an enumerated value that indicates which scroll bars the text area uses.

The TextArea class defines four integer constants that are used to specify which scroll bars are available. TextArea has one constructor that gives the application discretion over scroll bars.

Returns:

an integer that indicates which scroll bars are used

Since:

JDK1.1

See Also:

SCROLLBARS_BOTH, SCROLLBARS_VERTICAL_ONLY, SCROLLBARS_HORIZONTAL_ONLY, SCROLLBARS_NONE, TextArea(java.lang.String, int, int, int)

getPreferredSize

public Dimension getPreferredSize(int rows,
                                  int columns)

Determines the preferred size of a text area with the specified number of rows and columns.

Parameters:

rows - the number of rows

columns - the number of columns

Returns:

the preferred dimensions required to display the text area with the specified number of rows and columns

Since:

JDK1.1

See Also:

Component.getPreferredSize()

preferredSize

public Dimension preferredSize(int rows,
                               int columns)

Deprecated. As of JDK version 1.1, replaced by getPreferredSize(int, int).

getPreferredSize

public Dimension getPreferredSize()

Determines the preferred size of this text area.

Overrides:

getPreferredSize in class Component

Returns:

the preferred dimensions needed for this text area

Since:

JDK1.1

See Also:

Component.getPreferredSize()

preferredSize

public Dimension preferredSize()

Deprecated. As of JDK version 1.1, replaced by getPreferredSize().

Overrides:

preferredSize in class Component

getMinimumSize

public Dimension getMinimumSize(int rows,
                                int columns)

Determines the minimum size of a text area with the specified number of rows and columns.

Parameters:

rows - the number of rows

columns - the number of columns

Returns:

the minimum dimensions required to display the text area with the specified number of rows and columns

Since:

JDK1.1

See Also:

Component.getMinimumSize()

minimumSize

public Dimension minimumSize(int rows,
                             int columns)

Deprecated. As of JDK version 1.1, replaced by getMinimumSize(int, int).

getMinimumSize

public Dimension getMinimumSize()

Determines the minimum size of this text area.

Overrides:

getMinimumSize in class Component

Returns:

the preferred dimensions needed for this text area

Since:

JDK1.1

See Also:

Component.getPreferredSize()

minimumSize

public Dimension minimumSize()

Deprecated. As of JDK version 1.1, replaced by getMinimumSize().

Overrides:

minimumSize in class Component

paramString

protected String paramString()

Returns a string representing the state of this TextArea. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Overrides:

paramString in class TextComponent

Returns:

the parameter string of this text area

readObject

private void readObject(ObjectInputStream s)
                 throws ClassNotFoundException,
                        IOException,
                        HeadlessException

Read the ObjectInputStream.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true

ClassNotFoundException

IOException

See Also:

GraphicsEnvironment.isHeadless()

getAccessibleContext

public javax.accessibility.AccessibleContext getAccessibleContext()

Returns the AccessibleContext associated with this TextArea. For text areas, the AccessibleContext takes the form of an AccessibleAWTTextArea. A new AccessibleAWTTextArea instance is created if necessary.

Specified by:

getAccessibleContext in interface javax.accessibility.Accessible

Overrides:

getAccessibleContext in class TextComponent

Returns:

an AccessibleAWTTextArea that serves as the AccessibleContext of this TextArea