# Class JTextField

java.lang.Object
java.awt.Component
java.awt.Container
javax.swing.JComponent
javax.swing.text.JTextComponent
javax.swing.JTextField

All Implemented Interfaces:
  `ImageObserver, MenuContainer, Serializable, Accessible, Scrollable, SwingConstants`

Direct Known Subclasses:
  `DefaultTreeCellEditor.DefaultTextField, JFormattedTextField, JPasswordField`

@JavaBean(defaultProperty="UIClassID", description="A component which allows for the editing of a single line of text.") public class JTextField extends JTextComponent implements SwingConstants
`JTextField` is a lightweight component that allows the editing of a single line of text. For information on and examples of using text fields, see How to Use Text Fields in The Java Tutorial.

`JTextField` is intended to be source-compatible with `java.awt.TextField` where it is reasonable to do so. This component has capabilities not found in the `java.awt.TextField` class. The superclass should be consulted for additional capabilities.

`JTextField` has a method to establish the string used as the command string for the action event that gets fired. The `java.awt.TextField` used the text of the field as the command string for the `ActionEvent`. `JTextField` will use the command string set with the `setActionCommand` method if not `null`, otherwise it will use the text of the field as a compatibility with `java.awt.TextField`.

The method `setEchoChar` and `getEchoChar` are not provided directly to avoid a new implementation of a pluggable look-and-feel inadvertently exposing password characters. To provide password-like services a separate class `JPasswordField` extends `JTextField` to provide this service with an independently pluggable look-and-feel.

The `java.awt.TextField` 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 = ??;
         JTextField myArea = ??;
         myArea.getDocument().addDocumentListener(myListener);

The horizontal alignment of `JTextField` can be set to be left justified, leading justified, centered, right justified or trailing justified. Right/trailing justification is useful if the required size of the field text is smaller than the size allocated to it. This is determined by the `setHorizontalAlignment` and `getHorizontalAlignment` methods. The default is to be leading justified.

How the text field consumes VK_ENTER events depends on whether the text field has any action listeners. If so, then VK_ENTER results in the listeners getting an ActionEvent, and the VK_ENTER event is consumed. This is compatible with how AWT text fields handle VK_ENTER events. If the text field has no action listeners, then as of v 1.3 the VK_ENTER event is not consumed. Instead, the bindings of ancestor components are processed, which enables the default button feature of JFC/Swing to work.

Customized fields can easily be created by extending the model and changing the default model provided. For example, the following piece of code will create a field that holds only upper case characters. It will work even if text is pasted into from the clipboard or it is altered via programmatic changes.

     public class UpperCaseField extends JTextField {

         public UpperCaseField(int cols) {
             super(cols);
         }

         protected Document createDefaultModel() {
             return new UpperCaseDocument();
         }

         static class UpperCaseDocument extends PlainDocument {

             public void insertString(int offs, String str, AttributeSet a)
                 throws BadLocationException {

                 if (str == null) {
                     return;
                 }
                 char[] upper = str.toCharArray();
                 for (int i = 0; i < upper.length; i++) {
                     upper[i] = Character.toUpperCase(upper[i]);
                 }
                 super.insertString(offs, new String(upper), a);
             }
         }
     }

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 JavaBeans has been added to the `java.beans` package. Please see `XMLEncoder`.

Since:
  1.2
See Also:
  - `setActionCommand(String)`
  - `JPasswordField`
  - `addActionListener(ActionListener)`

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `protected class`
  `JTextField.AccessibleJTextField`
  This class implements accessibility support for the `JTextField` class.

  ### Nested classes/interfaces declared in class JTextComponent

  `JTextComponent.AccessibleJTextComponent, JTextComponent.DropLocation, JTextComponent.KeyBinding`

  ### Nested classes/interfaces declared in class JComponent

  `JComponent.AccessibleJComponent`

  ### Nested classes/interfaces declared in class Container

  `Container.AccessibleAWTContainer`

  ### Nested classes/interfaces declared in class Component

  `Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final String`
  `notifyAction`
  Name of the action to send notification that the contents of the field have been accepted.

  ### Fields declared in class JTextComponent

  `DEFAULT_KEYMAP, FOCUS_ACCELERATOR_KEY`

  ### Fields declared in class JComponent

  `listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW`

  ### Fields declared in class Component

  `accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT`

  ### Fields declared in interface ImageObserver

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

  ### Fields declared in interface SwingConstants

  `BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NEXT, NORTH, NORTH_EAST, NORTH_WEST, PREVIOUS, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `JTextField()`
  Constructs a new `TextField`.
  `JTextField(int columns)`
  Constructs a new empty `TextField` with the specified number of columns.
  `JTextField(String text)`
  Constructs a new `TextField` initialized with the specified text.
  `JTextField(String text, int columns)`
  Constructs a new `TextField` initialized with the specified text and columns.
  `JTextField(Document doc, String text, int columns)`
  Constructs a new `JTextField` that uses the given text storage model and the given number of columns.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected void`
  `actionPropertyChanged(Action action, String propertyName)`
  Updates the textfield's state in response to property changes in associated action.
  `void`
  `addActionListener(ActionListener l)`
  Adds the specified action listener to receive action events from this textfield.
  `protected void`
  `configurePropertiesFromAction(Action a)`
  Sets the properties on this textfield to match those in the specified `Action`.
  `protected PropertyChangeListener`
  `createActionPropertyChangeListener(Action a)`
  Creates and returns a `PropertyChangeListener` that is responsible for listening for changes from the specified `Action` and updating the appropriate properties.
  `protected Document`
  `createDefaultModel()`
  Creates the default implementation of the model to be used at construction if one isn't explicitly given.
  `protected void`
  `fireActionPerformed()`
  Notifies all listeners that have registered interest for notification on this event type.
  `AccessibleContext`
  `getAccessibleContext()`
  Gets the `AccessibleContext` associated with this `JTextField`.
  `Action`
  `getAction()`
  Returns the currently set `Action` for this `ActionEvent` source, or `null` if no `Action` is set.
  `ActionListener[]`
  `getActionListeners()`
  Returns an array of all the `ActionListener`s added to this JTextField with addActionListener().
  `Action[]`
  `getActions()`
  Fetches the command list for the editor.
  `int`
  `getColumns()`
  Returns the number of columns in this `TextField`.
  `protected int`
  `getColumnWidth()`
  Returns the column width.
  `int`
  `getHorizontalAlignment()`
  Returns the horizontal alignment of the text.
  `BoundedRangeModel`
  `getHorizontalVisibility()`
  Gets the visibility of the text field.
  `Dimension`
  `getPreferredSize()`
  Returns the preferred size `Dimensions` needed for this `TextField`.
  `int`
  `getScrollOffset()`
  Gets the scroll offset, in pixels.
  `String`
  `getUIClassID()`
  Gets the class ID for a UI.
  `boolean`
  `isValidateRoot()`
  Calls to `revalidate` that come from within the textfield itself will be handled by validating the textfield, unless the textfield is contained within a `JViewport`, in which case this returns false.
  `protected String`
  `paramString()`
  Returns a string representation of this `JTextField`.
  `void`
  `postActionEvent()`
  Processes action events occurring on this textfield by dispatching them to any registered `ActionListener` objects.
  `void`
  `removeActionListener(ActionListener l)`
  Removes the specified action listener so that it no longer receives action events from this textfield.
  `void`
  `scrollRectToVisible(Rectangle r)`
  Scrolls the field left or right.
  `void`
  `setAction(Action a)`
  Sets the `Action` for the `ActionEvent` source.
  `void`
  `setActionCommand(String command)`
  Sets the command string used for action events.
  `void`
  `setColumns(int columns)`
  Sets the number of columns in this `TextField`, and then invalidate the layout.
  `void`
  `setDocument(Document doc)`
  Associates the editor with a text document.
  `void`
  `setFont(Font f)`
  Sets the current font.
  `void`
  `setHorizontalAlignment(int alignment)`
  Sets the horizontal alignment of the text.
  `void`
  `setScrollOffset(int scrollOffset)`
  Sets the scroll offset, in pixels.

  ### Methods declared in class JTextComponent

  `addCaretListener, addKeymap, copy, cut, fireCaretUpdate, getCaret, getCaretColor, getCaretListeners, getCaretPosition, getDisabledTextColor, getDocument, getDragEnabled, getDropLocation, getDropMode, getFocusAccelerator, getHighlighter, getInputMethodRequests, getKeymap, getKeymap, getMargin, getNavigationFilter, getPreferredScrollableViewportSize, getPrintable, getScrollableBlockIncrement, getScrollableTracksViewportHeight, getScrollableTracksViewportWidth, getScrollableUnitIncrement, getSelectedText, getSelectedTextColor, getSelectionColor, getSelectionEnd, getSelectionStart, getText, getText, getToolTipText, getUI, isEditable, loadKeymap, modelToView, modelToView2D, moveCaretPosition, paste, print, print, print, read, removeCaretListener, removeKeymap, replaceSelection, restoreComposedText, saveComposedText, select, selectAll, setCaret, setCaretColor, setCaretPosition, setDisabledTextColor, setDragEnabled, setDropMode, setEditable, setFocusAccelerator, setHighlighter, setKeymap, setMargin, setNavigationFilter, setSelectedTextColor, setSelectionColor, setSelectionEnd, setSelectionStart, setText, setUI, updateUI, viewToModel, viewToModel2D, write`

  ### Methods declared in class JComponent

  `addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update`

  ### Methods declared in class Container

  `add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTree`

  ### Methods declared in class Component

  `action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setMixingCutoutShape, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle`

  ### Methods declared in class Object

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

- ## Field Details

  - ### notifyAction

    public static final String notifyAction
    Name of the action to send notification that the contents of the field have been accepted. Typically this is bound to a carriage-return.
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### JTextField

    public JTextField()
    Constructs a new `TextField`. A default model is created, the initial string is `null`, and the number of columns is set to 0.

  - ### JTextField

    public JTextField(String text)
    Constructs a new `TextField` initialized with the specified text. A default model is created and the number of columns is 0.
    Parameters:
      `text` - the text to be displayed, or `null`

  - ### JTextField

    public JTextField(int columns)
    Constructs a new empty `TextField` with the specified number of columns. A default model is created and the initial string is set to `null`.
    Parameters:
      `columns` - the number of columns to use to calculate the preferred width; if columns is set to zero, the preferred width will be whatever naturally results from the component implementation

  - ### JTextField

    public JTextField(String text, int columns)
    Constructs a new `TextField` initialized with the specified text and columns. A default model is created.
    Parameters:
      `text` - the text to be displayed, or `null`
      `columns` - the number of columns to use to calculate the preferred width; if columns is set to zero, the preferred width will be whatever naturally results from the component implementation

  - ### JTextField

    public JTextField(Document doc, String text, int columns)
    Constructs a new `JTextField` that uses the given text storage model and the given number of columns. This is the constructor through which the other constructors feed. If the document is `null`, a default model is created.
    Parameters:
      `doc` - the text storage to use; if this is `null`, a default will be provided by calling the `createDefaultModel` method
      `text` - the initial string to display, or `null`
      `columns` - the number of columns to use to calculate the preferred width >= 0; if `columns` is set to zero, the preferred width will be whatever naturally results from the component implementation
    Throws:
      `IllegalArgumentException` - if `columns` < 0

- ## Method Details

  - ### getUIClassID

    @BeanProperty(bound=false) public String getUIClassID()
    Gets the class ID for a UI.
    Overrides:
      `getUIClassID` in class `JComponent`
    Returns:
      the string "TextFieldUI"
    See Also:
      - `JComponent.getUIClassID()`
      - `UIDefaults.getUI(JComponent)`

  - ### setDocument

    @BeanProperty(expert=true, description="the text document model") public void setDocument(Document doc)
    Associates the editor with a text document. The currently registered factory is used to build a view for the document, which gets displayed by the editor after revalidation. A PropertyChange event ("document") is propagated to each listener.
    Overrides:
      `setDocument` in class `JTextComponent`
    Parameters:
      `doc` - the document to display/edit
    See Also:
      - `JTextComponent.getDocument()`

  - ### isValidateRoot

    public boolean isValidateRoot()
    Calls to `revalidate` that come from within the textfield itself will be handled by validating the textfield, unless the textfield is contained within a `JViewport`, in which case this returns false.
    Overrides:
      `isValidateRoot` in class `JComponent`
    Returns:
      if the parent of this textfield is a `JViewPort` return false, otherwise return true
    See Also:
      - `JComponent.revalidate()`
      - `JComponent.isValidateRoot()`
      - `Container.isValidateRoot()`

  - ### getHorizontalAlignment

    public int getHorizontalAlignment()
    Returns the horizontal alignment of the text. Valid keys are:
    - `JTextField.LEFT`
    - `JTextField.CENTER`
    - `JTextField.RIGHT`
    - `JTextField.LEADING`
    - `JTextField.TRAILING`
    Returns:
      the horizontal alignment

  - ### setHorizontalAlignment

    @BeanProperty(preferred=true, enumerationValues={"JTextField.LEFT","JTextField.CENTER","JTextField.RIGHT","JTextField.LEADING","JTextField.TRAILING"}, description="Set the field alignment to LEFT, CENTER, RIGHT, LEADING (the default) or TRAILING") public void setHorizontalAlignment(int alignment)
    Sets the horizontal alignment of the text. Valid keys are:
    - `JTextField.LEFT`
    - `JTextField.CENTER`
    - `JTextField.RIGHT`
    - `JTextField.LEADING`
    - `JTextField.TRAILING`
    `invalidate` and `repaint` are called when the alignment is set, and a `PropertyChange` event ("horizontalAlignment") is fired.
    Parameters:
      `alignment` - the alignment
    Throws:
      `IllegalArgumentException` - if `alignment` is not a valid key

  - ### createDefaultModel

    protected Document createDefaultModel()
    Creates the default implementation of the model to be used at construction if one isn't explicitly given. An instance of `PlainDocument` is returned.
    Returns:
      the default model implementation

  - ### getColumns

    public int getColumns()
    Returns the number of columns in this `TextField`.
    Returns:
      the number of columns >= 0

  - ### setColumns

    @BeanProperty(bound=false, description="the number of columns preferred for display") public void setColumns(int columns)
    Sets the number of columns in this `TextField`, and then invalidate the layout.
    Parameters:
      `columns` - the number of columns >= 0
    Throws:
      `IllegalArgumentException` - if `columns` is less than 0

  - ### getColumnWidth

    protected int getColumnWidth()
    Returns the column width. The meaning of what a column is can be considered a fairly weak notion for some fonts. This method is used to define the width of a column. By default this is defined to be the width of the character m for the font used. This method can be redefined to be some alternative amount
    Returns:
      the column width >= 1

  - ### getPreferredSize

    public Dimension getPreferredSize()
    Returns the preferred size `Dimensions` needed for this `TextField`. If a non-zero number of columns has been set, the width is set to the columns multiplied by the column width.
    Overrides:
      `getPreferredSize` in class `JComponent`
    Returns:
      the dimension of this textfield
    See Also:
      - `JComponent.setPreferredSize(Dimension)`
      - `ComponentUI`

  - ### setFont

    public void setFont(Font f)
    Sets the current font. This removes cached row height and column width so the new font will be reflected. `revalidate` is called after setting the font.
    Overrides:
      `setFont` in class `JComponent`
    Parameters:
      `f` - the new font
    See Also:
      - `Component.getFont()`

  - ### addActionListener

    public void addActionListener(ActionListener l)
    Adds the specified action listener to receive action events from this textfield.
    Parameters:
      `l` - the action listener to be added

  - ### removeActionListener

    public void removeActionListener(ActionListener l)
    Removes the specified action listener so that it no longer receives action events from this textfield.
    Parameters:
      `l` - the action listener to be removed

  - ### getActionListeners

    @BeanProperty(bound=false) public ActionListener[] getActionListeners()
    Returns an array of all the `ActionListener`s added to this JTextField with addActionListener().
    Returns:
      all of the `ActionListener`s added or an empty array if no listeners have been added
    Since:
      1.4

  - ### fireActionPerformed

    protected void fireActionPerformed()
    Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created. The listener list is processed in last to first order.
    See Also:
      - `EventListenerList`

  - ### setActionCommand

    public void setActionCommand(String command)
    Sets the command string used for action events.
    Parameters:
      `command` - the command string

  - ### setAction

    @BeanProperty(visualUpdate=true, description="the Action instance connected with this ActionEvent source") public void setAction(Action a)
    Sets the `Action` for the `ActionEvent` source. The new `Action` replaces any previously set `Action` but does not affect `ActionListeners` independently added with `addActionListener`. If the `Action` is already a registered `ActionListener` for the `ActionEvent` source, it is not re-registered.

    Setting the `Action` results in immediately changing all the properties described in Swing Components Supporting `Action`. Subsequently, the textfield's properties are automatically updated as the `Action`'s properties change.

    This method uses three other methods to set and help track the `Action`'s property values. It uses the `configurePropertiesFromAction` method to immediately change the textfield's properties. To track changes in the `Action`'s property values, this method registers the `PropertyChangeListener` returned by `createActionPropertyChangeListener`. The default `PropertyChangeListener` invokes the `actionPropertyChanged` method when a property in the `Action` changes.

    Parameters:
      `a` - the `Action` for the `JTextField`, or `null`
    Since:
      1.3
    See Also:
      - `Action`
      - `getAction()`
      - `configurePropertiesFromAction(Action)`
      - `createActionPropertyChangeListener(Action)`
      - `actionPropertyChanged(Action, String)`

  - ### getAction

    public Action getAction()
    Returns the currently set `Action` for this `ActionEvent` source, or `null` if no `Action` is set.
    Returns:
      the `Action` for this `ActionEvent` source, or `null`
    Since:
      1.3
    See Also:
      - `Action`
      - `setAction(Action)`

  - ### configurePropertiesFromAction

    protected void configurePropertiesFromAction(Action a)
    Sets the properties on this textfield to match those in the specified `Action`. Refer to Swing Components Supporting `Action` for more details as to which properties this sets.
    Parameters:
      `a` - the `Action` from which to get the properties, or `null`
    Since:
      1.3
    See Also:
      - `Action`
      - `setAction(Action)`

  - ### actionPropertyChanged

    protected void actionPropertyChanged(Action action, String propertyName)
    Updates the textfield's state in response to property changes in associated action. This method is invoked from the `PropertyChangeListener` returned from `createActionPropertyChangeListener`. Subclasses do not normally need to invoke this. Subclasses that support additional `Action` properties should override this and `configurePropertiesFromAction`.

    Refer to the table at Swing Components Supporting `Action` for a list of the properties this method sets.

    Parameters:
      `action` - the `Action` associated with this textfield
      `propertyName` - the name of the property that changed
    Since:
      1.6
    See Also:
      - `Action`
      - `configurePropertiesFromAction(Action)`

  - ### createActionPropertyChangeListener

    protected PropertyChangeListener createActionPropertyChangeListener(Action a)
    Creates and returns a `PropertyChangeListener` that is responsible for listening for changes from the specified `Action` and updating the appropriate properties.

    Warning: If you subclass this do not create an anonymous inner class. If you do the lifetime of the textfield will be tied to that of the `Action`.

    Parameters:
      `a` - the textfield's action
    Returns:
      a `PropertyChangeListener` that is responsible for listening for changes from the specified `Action` and updating the appropriate properties
    Since:
      1.3
    See Also:
      - `Action`
      - `setAction(Action)`

  - ### getActions

    @BeanProperty(bound=false) public Action[] getActions()
    Fetches the command list for the editor. This is the list of commands supported by the plugged-in UI augmented by the collection of commands that the editor itself supports. These are useful for binding to events, such as in a keymap.
    Overrides:
      `getActions` in class `JTextComponent`
    Returns:
      the command list

  - ### postActionEvent

    public void postActionEvent()
    Processes action events occurring on this textfield by dispatching them to any registered `ActionListener` objects. This is normally called by the controller registered with textfield.

  - ### getHorizontalVisibility

    @BeanProperty(bound=false) public BoundedRangeModel getHorizontalVisibility()
    Gets the visibility of the text field. This can be adjusted to change the location of the visible area if the size of the field is greater than the area that was allocated to the field.

    The fields look-and-feel implementation manages the values of the minimum, maximum, and extent properties on the `BoundedRangeModel`.

    Returns:
      the visibility
    See Also:
      - `BoundedRangeModel`

  - ### getScrollOffset

    public int getScrollOffset()
    Gets the scroll offset, in pixels.
    Returns:
      the offset >= 0

  - ### setScrollOffset

    public void setScrollOffset(int scrollOffset)
    Sets the scroll offset, in pixels.
    Parameters:
      `scrollOffset` - the offset >= 0

  - ### scrollRectToVisible

    public void scrollRectToVisible(Rectangle r)
    Scrolls the field left or right.
    Overrides:
      `scrollRectToVisible` in class `JComponent`
    Parameters:
      `r` - the region to scroll
    See Also:
      - `JViewport`

  - ### paramString

    protected String paramString()
    Returns a string representation of this `JTextField`. 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 `JTextComponent`
    Returns:
      a string representation of this `JTextField`

  - ### getAccessibleContext

    @BeanProperty(bound=false) public AccessibleContext getAccessibleContext()
    Gets the `AccessibleContext` associated with this `JTextField`. For `JTextFields`, the `AccessibleContext` takes the form of an `AccessibleJTextField`. A new `AccessibleJTextField` instance is created if necessary.
    Specified by:
      `getAccessibleContext` in interface `Accessible`
    Overrides:
      `getAccessibleContext` in class `JTextComponent`
    Returns:
      an `AccessibleJTextField` that serves as the `AccessibleContext` of this `JTextField`