[Chapter 19] TextComponent

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| Chapter 19 java.awt Reference |

# TextComponent

## Name

TextComponent

##

## Description

The abstract `TextComponent` class provides the base class for the text input components, `TextArea` and `TextField`.

## Class Definition

    public abstract class java.awt.TextComponent
        extends java.awt.Component {

      // Instance Methods
      public void addTextListener (TextListener l);
      public int getCaretPosition();
      public synchronized String getSelectedText();
      public synchronized int getSelectionEnd();
      public synchronized int getSelectionStart();
      public synchronized String getText();
      public boolean isEditable();
      public void removeNotify();
      public void removeTextListener (TextListener l);
      public synchronized void select (int selectionStart, int selectionEnd);
      public synchronized void selectAll();
      public void setCaretPosition (int position);
      public synchronized void setEditable (boolean state);
      public synchronized void setSelectionEnd (int selectionEnd);
      public synchronized void setSelectionStart (int selectionStart);
      public synchronized void setText (String text);

      // Protected Instance Methods
      protected String paramString();
      protected void processEvent (AWTEvent e);
      protected void processTextEvent (TextEvent e);
    }

## Instance Methods

### addTextListener

#### public void addTextListener (TextListener l)

Parameters

  l

    An object that implements the `TextListener` interface.

Description

  Add a listener for the text events.

### getCaretPosition

#### public int getCaretPosition()

Returns

  The position, in characters, of the caret (text cursor).

### getSelectedText

#### public synchronized String getSelectedText()

Returns

  The currently selected text of the `TextComponent`.

### getSelectionEnd

#### public synchronized int getSelectionEnd()

Returns

  The ending cursor position of any selected text.

### getSelectionStart

#### public synchronized int getSelectionStart()

Returns

  The initial position of any selected text.

### getText

#### public synchronized String getText()

Returns

  Current contents of the `TextComponent`.

### isEditable

#### public boolean isEditable()

Returns

  `true` if editable, `false` otherwise.

### removeNotify

#### public void removeNotify()

Description

  Destroys the peer of the `TextComponent`.

### removeTextListener

#### public void removeTextListener (TextListener l)

Parameters

  l

    One of this `TextComponent`'s `TextListener`s.

Description

  Remove a text event listener.

### select

#### public synchronized void select (int selectionStart, int selectionEnd)

Parameters

  selectionStart

    Beginning position of text to select.

  selectionEnd

    Ending position of text to select.

Description

  Selects text in the `TextComponent`.

### selectAll

#### public synchronized void selectAll()

Description

  Selects all the text in the `TextComponent`.

### setCaretPosition

#### public void setCaretPosition (int position)

Parameters

  position

    The new character position for the caret.

Throws

  IllegalArgumentException

    If `position` is less than zero.

Description

  Allows you to change the location of the caret.

### setEditable

#### public synchronized void setEditable (boolean state)

Parameters

  state

    `true` to allow the user to edit the text in the `TextComponent`; `false` to prevent editing.

Description

  Allows you to make the `TextComponent` editable or read-only.

### setSelectionEnd

#### public synchronized void setSelectionEnd (int selectionEnd)

Parameters

  selectionEnd

    The character position of the end of the selection.

Description

  Allows you to change the location of the end of the selected text.

### setSelectionStart

#### public synchronized void setSelectionStart (int selectionStart)

Parameters

  selectionStart

    The character position of the start of the selection.

Description

  Allows you to change the location of the start of the selected text.

### setText

#### public synchronized void setText (String text)

Parameters

  text

    New text for `TextComponent`.

Description

  Sets the content of the `TextComponent`.

## Protected Instance Methods

### paramString

#### protected String paramString()

Returns

  String with current settings of `TextComponent`.

Overrides

  `Component.paramString()`

Description

  Helper method for `toString()` to generate string of current settings.

### processEvent

#### protected void processEvent (AWTEvent e)

Parameters

  e

    The event to process.

Description

  Low-level `AWTEvent`s are passed to this method for processing.

### processTextEvent

#### protected void processTextEvent (TextEvent e)

Parameters

  e

    The event to process.

Description

  Text events are passed to this method for processing. Normally, this method is called by `processEvent()`.

## See Also

`Component`, `TextArea`, `TextField`, `String`

TextArea |  | TextField