JTextComponent (Java 2 Platform SE v1.4.1_"07")

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JavaTM 2 Platform
Std. Ed. v1.4.1_"07"

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## javax.swing.text
Class JTextComponent

    java.lang.Object
      |
      +--java.awt.Component
            |
            +--java.awt.Container
                  |
                  +--javax.swing.JComponent
                        |
                        +--javax.swing.text.JTextComponent

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

Direct Known Subclasses:
  JEditorPane, JTextArea, JTextField

public abstract class JTextComponent
extends JComponent
implements Scrollable, Accessible

`JTextComponent` is the base class for swing text components. It tries to be compatible with the `java.awt.TextComponent` class where it can reasonably do so. Also provided are other services for additional flexibility (beyond the pluggable UI and bean support). You can find information on how to use the functionality this class provides in General Rules for Using Text Components, a section in The Java Tutorial.

Caret Changes
  The caret is a pluggable object in swing text components. Notification of changes to the caret position and the selection are sent to implementations of the `CaretListener` interface that have been registered with the text component. The UI will install a default caret unless a customized caret has been set.

Commands
  Text components provide a number of commands that can be used to manipulate the component. This is essentially the way that the component expresses its capabilities. These are expressed in terms of the swing `Action` interface, using the `TextAction` implementation. The set of commands supported by the text component can be found with the `getActions()` method. These actions can be bound to key events, fired from buttons, etc.

Text Input
  The text components support flexible and internationalized text input, using keymaps and the input method framework, while maintaining compatibility with the AWT listener model.

  A `Keymap` lets an application bind key strokes to actions. In order to allow keymaps to be shared across multiple text components, they can use actions that extend `TextAction`. `TextAction` can determine which `JTextComponent` most recently has or had focus and therefore is the subject of the action (In the case that the `ActionEvent` sent to the action doesn't contain the target text component as its source).

  The input method framework lets text components interact with input methods, separate software components that preprocess events to let users enter thousands of different characters using keyboards with far fewer keys. `JTextComponent` is an active client of the framework, so it implements the preferred user interface for interacting with input methods. As a consequence, some key events do not reach the text component because they are handled by an input method, and some text input reaches the text component as committed text within an `InputMethodEvent` instead of as a key event. The complete text input is the combination of the characters in `keyTyped` key events and committed text in input method events.

  The AWT listener model lets applications attach event listeners to components in order to bind events to actions. Swing encourages the use of keymaps instead of listeners, but maintains compatibility with listeners by giving the listeners a chance to steal an event by consuming it.

  Keyboard event and input method events are handled in the following stages, with each stage capable of consuming the event:

  Stage | KeyEvent | InputMethodEvent
  1. | input methods | (generated here)
  2. | focus manager |
  3. | registered key listeners | registered input method listeners
  4. |  | input method handling in JTextComponent
  5. | keymap handling using the current keymap
  6. | keyboard handling in JComponent (e.g. accelerators, component navigation, etc.) |

  To maintain compatibility with applications that listen to key events but are not aware of input method events, the input method handling in stage 4 provides a compatibility mode for components that do not process input method events. For these components, the committed text is converted to keyTyped key events and processed in the key event pipeline starting at stage 3 instead of in the input method event pipeline.

  By default the component will create a keymap (named DEFAULT_KEYMAP) that is shared by all JTextComponent instances as the default keymap. Typically a look-and-feel implementation will install a different keymap that resolves to the default keymap for those bindings not found in the different keymap. The minimal bindings include:

  - inserting content into the editor for the printable keys.
  - removing content with the backspace and del keys.
  - caret movement forward and backward

Model/View Split
  The text components have a model-view split. A text component pulls together the objects used to represent the model, view, and controller. The text document model may be shared by other views which act as observers of the model (e.g. a document may be shared by multiple components).

  The model is defined by the `Document` interface. This is intended to provide a flexible text storage mechanism that tracks change during edits and can be extended to more sophisticated models. The model interfaces are meant to capture the capabilities of expression given by SGML, a system used to express a wide variety of content. Each modification to the document causes notification of the details of the change to be sent to all observers in the form of a `DocumentEvent` which allows the views to stay up to date with the model. This event is sent to observers that have implemented the `DocumentListener` interface and registered interest with the model being observed.

Location Information
  The capability of determining the location of text in the view is provided. There are two methods, `modelToView(int)` and `viewToModel(java.awt.Point)` for determining this information.

Undo/Redo support
  Support for an edit history mechanism is provided to allow undo/redo operations. The text component does not itself provide the history buffer by default, but does provide the `UndoableEdit` records that can be used in conjunction with a history buffer to provide the undo/redo support. The support is provided by the Document model, which allows one to attach UndoableEditListener implementations.

Thread Safety
  The swing text components provide some support of thread safe operations. Because of the high level of configurability of the text components, it is possible to circumvent the protection provided. The protection primarily comes from the model, so the documentation of `AbstractDocument` describes the assumptions of the protection provided. The methods that are safe to call asynchronously are marked with comments.

Newlines
  For a discussion on how newlines are handled, see DefaultEditorKit.

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 `XMLEncoder`.

See Also:
  `Document`, `DocumentEvent`, `DocumentListener`, `Caret`, `CaretEvent`, `CaretListener`, `TextUI`, `View`, `ViewFactory`

Nested Class Summary
`class` | `JTextComponent.AccessibleJTextComponent` This class implements accessibility support for the `JTextComponent` class.
`static class` | `JTextComponent.KeyBinding` Binding record for creating key bindings.

Nested classes inherited from class javax.swing.JComponent
``

Nested classes inherited from class java.awt.Container
``

Nested classes inherited from class java.awt.Component
`Component.BltBufferStrategy, Component.FlipBufferStrategy`

Field Summary
`static String` | `DEFAULT_KEYMAP` The default keymap that will be shared by all `JTextComponent` instances unless they have had a different keymap set.
`static String` | `FOCUS_ACCELERATOR_KEY` The bound property name for the focus accelerator.

Fields inherited from class javax.swing.JComponent
`accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW`

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
`JTextComponent()` Creates a new `JTextComponent`.

Method Summary
`void` | `addCaretListener(CaretListener listener)` Adds a caret listener for notification of any changes to the caret.
`void` | `addInputMethodListener(InputMethodListener l)` Adds the specified input method listener to receive input method events from this component.
`static Keymap` | `addKeymap(String nm, Keymap parent)` Adds a new keymap into the keymap hierarchy.
`void` | `copy()` Transfers the currently selected range in the associated text model to the system clipboard, leaving the contents in the text model.
`void` | `cut()` Transfers the currently selected range in the associated text model to the system clipboard, removing the contents from the model.
`protected void` | `fireCaretUpdate(CaretEvent e)` Notifies all listeners that have registered interest for notification on this event type.
`AccessibleContext` | `getAccessibleContext()` Gets the `AccessibleContext` associated with this `JTextComponent`.
`Action[]` | `getActions()` Fetches the command list for the editor.
`Caret` | `getCaret()` Fetches the caret that allows text-oriented navigation over the view.
`Color` | `getCaretColor()` Fetches the current color used to render the caret.
`CaretListener[]` | `getCaretListeners()` Returns an array of all the caret listeners registered on this text component.
`int` | `getCaretPosition()` Returns the position of the text insertion caret for the text component.
`Color` | `getDisabledTextColor()` Fetches the current color used to render the selected text.
`Document` | `getDocument()` Fetches the model associated with the editor.
`boolean` | `getDragEnabled()` Gets the `dragEnabled` property.
`char` | `getFocusAccelerator()` Returns the key accelerator that will cause the receiving text component to get the focus.
`Highlighter` | `getHighlighter()` Fetches the object responsible for making highlights.
`InputMethodRequests` | `getInputMethodRequests()` Gets the input method request handler which supports requests from input methods for this component.
`Keymap` | `getKeymap()` Fetches the keymap currently active in this text component.
`static Keymap` | `getKeymap(String nm)` Fetches a named keymap previously added to the document.
`Insets` | `getMargin()` Returns the margin between the text component's border and its text.
`NavigationFilter` | `getNavigationFilter()` Returns the `NavigationFilter`.
`Dimension` | `getPreferredScrollableViewportSize()` Returns the preferred size of the viewport for a view component.
`int` | `getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction)` Components that display logical rows or columns should compute the scroll increment that will completely expose one block of rows or columns, depending on the value of orientation.
`boolean` | `getScrollableTracksViewportHeight()` Returns true if a viewport should always force the height of this `Scrollable` to match the height of the viewport.
`boolean` | `getScrollableTracksViewportWidth()` Returns true if a viewport should always force the width of this `Scrollable` to match the width of the viewport.
`int` | `getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)` Components that display logical rows or columns should compute the scroll increment that will completely expose one new row or column, depending on the value of orientation.
`String` | `getSelectedText()` Returns the selected text contained in this `TextComponent`.
`Color` | `getSelectedTextColor()` Fetches the current color used to render the selected text.
`Color` | `getSelectionColor()` Fetches the current color used to render the selection.
`int` | `getSelectionEnd()` Returns the selected text's end position.
`int` | `getSelectionStart()` Returns the selected text's start position.
`String` | `getText()` Returns the text contained in this `TextComponent`.
`String` | `getText(int offs, int len)` Fetches a portion of the text represented by the component.
`String` | `getToolTipText(MouseEvent event)` Returns the string to be used as the tooltip for `event`.
`TextUI` | `getUI()` Fetches the user-interface factory for this text-oriented editor.
`boolean` | `isEditable()` Returns the boolean indicating whether this `TextComponent` is editable or not.
`static void` | `loadKeymap(Keymap map, JTextComponent.KeyBinding[] bindings, Action[] actions)` Loads a keymap with a bunch of bindings.
`Rectangle` | `modelToView(int pos)` Converts the given location in the model to a place in the view coordinate system.
`void` | `moveCaretPosition(int pos)` Moves the caret to a new position, leaving behind a mark defined by the last time `setCaretPosition` was called.
`protected String` | `paramString()` Returns a string representation of this `JTextComponent`.
`void` | `paste()` Transfers the contents of the system clipboard into the associated text model.
`protected void` | `processInputMethodEvent(InputMethodEvent e)` Processes input method events occurring on this component by dispatching them to any registered `InputMethodListener` objects.
`void` | `read(Reader in, Object desc)` Initializes from a stream.
`void` | `removeCaretListener(CaretListener listener)` Removes a caret listener.
`static Keymap` | `removeKeymap(String nm)` Removes a named keymap previously added to the document.
`void` | `removeNotify()` Notifies this component that it no longer has a parent component.
`void` | `replaceSelection(String content)` Replaces the currently selected content with new content represented by the given string.
`void` | `select(int selectionStart, int selectionEnd)` Selects the text between the specified start and end positions.
`void` | `selectAll()` Selects all the text in the `TextComponent`.
`void` | `setCaret(Caret c)` Sets the caret to be used.
`void` | `setCaretColor(Color c)` Sets the current color used to render the caret.
`void` | `setCaretPosition(int position)` Sets the position of the text insertion caret for the `TextComponent`.
`void` | `setComponentOrientation(ComponentOrientation o)` Sets the language-sensitive orientation that is to be used to order the elements or text within this component.
`void` | `setDisabledTextColor(Color c)` Sets the current color used to render the disabled text.
`void` | `setDocument(Document doc)` Associates the editor with a text document.
`void` | `setDragEnabled(boolean b)` Sets the `dragEnabled` property, which must be `true` to enable automatic drag handling (the first part of drag and drop) on this component.
`void` | `setEditable(boolean b)` Sets the specified boolean to indicate whether or not this `TextComponent` should be editable.
`void` | `setFocusAccelerator(char aKey)` Sets the key accelerator that will cause the receiving text component to get the focus.
`void` | `setHighlighter(Highlighter h)` Sets the highlighter to be used.
`void` | `setKeymap(Keymap map)` Sets the keymap to use for binding events to actions.
`void` | `setMargin(Insets m)` Sets margin space between the text component's border and its text.
`void` | `setNavigationFilter(NavigationFilter filter)` Sets the `NavigationFilter`.
`void` | `setSelectedTextColor(Color c)` Sets the current color used to render the selected text.
`void` | `setSelectionColor(Color c)` Sets the current color used to render the selection.
`void` | `setSelectionEnd(int selectionEnd)` Sets the selection end to the specified position.
`void` | `setSelectionStart(int selectionStart)` Sets the selection start to the specified position.
`void` | `setText(String t)` Sets the text of this `TextComponent` to the specified text.
`void` | `setUI(TextUI ui)` Sets the user-interface factory for this text-oriented editor.
`void` | `updateUI()` Reloads the pluggable UI.
`int` | `viewToModel(Point pt)` Converts the given place in the view coordinate system to the nearest representative location in the model.
`void` | `write(Writer out)` Stores the contents of the model into the given stream.

Methods inherited from class javax.swing.JComponent
`addAncestorListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getGraphics, getHeight, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getTopLevelAncestor, getTransferHandler, getUIClassID, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update`

Methods inherited from class java.awt.Container
`add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setLayout, transferFocusBackward, transferFocusDownCycle, validate, validateTree`

Methods inherited from class java.awt.Component
`action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, 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, processMouseEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Field Detail

### FOCUS_ACCELERATOR_KEY

    public static final String FOCUS_ACCELERATOR_KEY

  The bound property name for the focus accelerator.

  See Also:
    Constant Field Values

### DEFAULT_KEYMAP

    public static final String DEFAULT_KEYMAP

  The default keymap that will be shared by all `JTextComponent` instances unless they have had a different keymap set.

  See Also:
    Constant Field Values

Constructor Detail

### JTextComponent

    public JTextComponent()

  Creates a new `JTextComponent`. Listeners for caret events are established, and the pluggable UI installed. The component is marked as editable. No layout manager is used, because layout is managed by the view subsystem of text. The document model is set to `null`.

Method Detail

### getUI

    public TextUI getUI()

  Fetches the user-interface factory for this text-oriented editor.

  Returns:
    the factory

### setUI

    public void setUI(TextUI ui)

  Sets the user-interface factory for this text-oriented editor.

  Parameters:
    `ui` - the factory

### updateUI

    public void updateUI()

  Reloads the pluggable UI. The key used to fetch the new interface is `getUIClassID()`. The type of the UI is `TextUI`. `invalidate` is called after setting the UI.

  Overrides:
    `updateUI` in class `JComponent`
  See Also:
    `JComponent.setUI(javax.swing.plaf.ComponentUI)`, `UIManager.getLookAndFeel()`, `UIManager.getUI(javax.swing.JComponent)`

### addCaretListener

    public void addCaretListener(CaretListener listener)

  Adds a caret listener for notification of any changes to the caret.

  Parameters:
    `listener` - the listener to be added
  See Also:
    `CaretEvent`

### removeCaretListener

    public void removeCaretListener(CaretListener listener)

  Removes a caret listener.

  Parameters:
    `listener` - the listener to be removed
  See Also:
    `CaretEvent`

### getCaretListeners

    public CaretListener[] getCaretListeners()

  Returns an array of all the caret listeners registered on this text component.

  Returns:
    all of this component's `CaretListener`s or an empty array if no caret listeners are currently registered
  Since:
    1.4
  See Also:
    `addCaretListener(javax.swing.event.CaretListener)`, `removeCaretListener(javax.swing.event.CaretListener)`

### fireCaretUpdate

    protected void fireCaretUpdate(CaretEvent e)

  Notifies all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method. The listener list is processed in a last-to-first manner.

  Parameters:
    `e` - the event
  See Also:
    `EventListenerList`

### setDocument

    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.

  Parameters:
    `doc` - the document to display/edit
  See Also:
    `getDocument()`

### getDocument

    public Document getDocument()

  Fetches the model associated with the editor. This is primarily for the UI to get at the minimal amount of state required to be a text editor. Subclasses will return the actual type of the model which will typically be something that extends Document.

  Returns:
    the model

### setComponentOrientation

    public void setComponentOrientation(ComponentOrientation o)

  Description copied from class: `Component`
  Sets the language-sensitive orientation that is to be used to order the elements or text within this component. Language-sensitive `LayoutManager` and `Component` subclasses will use this property to determine how to lay out and draw components.

  At construction time, a component's orientation is set to `ComponentOrientation.UNKNOWN`, indicating that it has not been specified explicitly. The UNKNOWN orientation behaves the same as `ComponentOrientation.LEFT_TO_RIGHT`.

  To set the orientation of a single component, use this method. To set the orientation of an entire component hierarchy, use `applyComponentOrientation`.

  Overrides:
    `setComponentOrientation` in class `Component`
  See Also:
    `ComponentOrientation`

### getActions

    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.

  Returns:
    the command list

### setMargin

    public void setMargin(Insets m)

  Sets margin space between the text component's border and its text. The text component's default `Border` object will use this value to create the proper margin. However, if a non-default border is set on the text component, it is that `Border` object's responsibility to create the appropriate margin space (else this property will effectively be ignored). This causes a redraw of the component. A PropertyChange event ("margin") is sent to all listeners.

  Parameters:
    `m` - the space between the border and the text

### getMargin

    public Insets getMargin()

  Returns the margin between the text component's border and its text.

  Returns:
    the margin

### setNavigationFilter

    public void setNavigationFilter(NavigationFilter filter)

  Sets the `NavigationFilter`. `NavigationFilter` is used by `DefaultCaret` and the default cursor movement actions as a way to restrict the cursor movement.

  Since:
    1.4

### getNavigationFilter

    public NavigationFilter getNavigationFilter()

  Returns the `NavigationFilter`. `NavigationFilter` is used by `DefaultCaret` and the default cursor movement actions as a way to restrict the cursor movement. A null return value implies the cursor movement and selection should not be restricted.

  Returns:
    the NavigationFilter
  Since:
    1.4

### getCaret

    public Caret getCaret()

  Fetches the caret that allows text-oriented navigation over the view.

  Returns:
    the caret

### setCaret

    public void setCaret(Caret c)

  Sets the caret to be used. By default this will be set by the UI that gets installed. This can be changed to a custom caret if desired. Setting the caret results in a PropertyChange event ("caret") being fired.

  Parameters:
    `c` - the caret
  See Also:
    `getCaret()`

### getHighlighter

    public Highlighter getHighlighter()

  Fetches the object responsible for making highlights.

  Returns:
    the highlighter

### setHighlighter

    public void setHighlighter(Highlighter h)

  Sets the highlighter to be used. By default this will be set by the UI that gets installed. This can be changed to a custom highlighter if desired. The highlighter can be set to `null` to disable it. A PropertyChange event ("highlighter") is fired when a new highlighter is installed.

  Parameters:
    `h` - the highlighter
  See Also:
    `getHighlighter()`

### setKeymap

    public void setKeymap(Keymap map)

  Sets the keymap to use for binding events to actions. Setting to `null` effectively disables keyboard input. A PropertyChange event ("keymap") is fired when a new keymap is installed.

  Parameters:
    `map` - the keymap
  See Also:
    `getKeymap()`

### setDragEnabled

    public void setDragEnabled(boolean b)

  Sets the `dragEnabled` property, which must be `true` to enable automatic drag handling (the first part of drag and drop) on this component. The `transferHandler` property needs to be set to a non-`null` value for the drag to do anything. The default value of the `dragEnabled` property is `false`.

  When automatic drag handling is enabled, most look and feels begin a drag-and-drop operation whenever the user presses the mouse button over a selection and then moves the mouse a few pixels. Setting this property to `true` can therefore have a subtle effect on how selections behave.

  Some look and feels might not support automatic drag and drop; they will ignore this property. You can work around such look and feels by modifying the component to directly call the `exportAsDrag` method of a `TransferHandler`.

  Parameters:
    `b` - the value to set the `dragEnabled` property to
  Throws:
    `HeadlessException` - if `b` is `true` and `GraphicsEnvironment.isHeadless()` returns `true`
  Since:
    1.4
  See Also:
    `GraphicsEnvironment.isHeadless()`, `getDragEnabled()`, `JComponent.setTransferHandler(javax.swing.TransferHandler)`, `TransferHandler`

### getDragEnabled

    public boolean getDragEnabled()

  Gets the `dragEnabled` property.

  Returns:
    the value of the `dragEnabled` property
  Since:
    1.4
  See Also:
    `setDragEnabled(boolean)`

### getKeymap

    public Keymap getKeymap()

  Fetches the keymap currently active in this text component.

  Returns:
    the keymap

### addKeymap

    public static Keymap addKeymap(String nm,
                                   Keymap parent)

  Adds a new keymap into the keymap hierarchy. Keymap bindings resolve from bottom up so an attribute specified in a child will override an attribute specified in the parent.

  Parameters:
    `nm` - the name of the keymap (must be unique within the collection of named keymaps in the document); the name may be `null` if the keymap is unnamed, but the caller is responsible for managing the reference returned as an unnamed keymap can't be fetched by name
    `parent` - the parent keymap; this may be `null` if unspecified bindings need not be resolved in some other keymap
  Returns:
    the keymap

### removeKeymap

    public static Keymap removeKeymap(String nm)

  Removes a named keymap previously added to the document. Keymaps with `null` names may not be removed in this way.

  Parameters:
    `nm` - the name of the keymap to remove
  Returns:
    the keymap that was removed

### getKeymap

    public static Keymap getKeymap(String nm)

  Fetches a named keymap previously added to the document. This does not work with `null`-named keymaps.

  Parameters:
    `nm` - the name of the keymap
  Returns:
    the keymap

### loadKeymap

    public static void loadKeymap(Keymap map,
                                  JTextComponent.KeyBinding[] bindings,
                                  Action[] actions)

  Loads a keymap with a bunch of bindings. This can be used to take a static table of definitions and load them into some keymap. The following example illustrates an example of binding some keys to the cut, copy, and paste actions associated with a JTextComponent. A code fragment to accomplish this might look as follows:

         static final JTextComponent.KeyBinding[] defaultBindings = {
           new JTextComponent.KeyBinding(
             KeyStroke.getKeyStroke(KeyEvent.VK_C, InputEvent.CTRL_MASK),
             DefaultEditorKit.copyAction),
           new JTextComponent.KeyBinding(
             KeyStroke.getKeyStroke(KeyEvent.VK_V, InputEvent.CTRL_MASK),
             DefaultEditorKit.pasteAction),
           new JTextComponent.KeyBinding(
             KeyStroke.getKeyStroke(KeyEvent.VK_X, InputEvent.CTRL_MASK),
             DefaultEditorKit.cutAction),
         };

         JTextComponent c = new JTextPane();
         Keymap k = c.getKeymap();
         JTextComponent.loadKeymap(k, defaultBindings, c.getActions());

  The sets of bindings and actions may be empty but must be non-`null`.

  Parameters:
    `map` - the keymap
    `bindings` - the bindings
    `actions` - the set of actions

### getCaretColor

    public Color getCaretColor()

  Fetches the current color used to render the caret.

  Returns:
    the color

### setCaretColor

    public void setCaretColor(Color c)

  Sets the current color used to render the caret. Setting to `null` effectively restores the default color. Setting the color results in a PropertyChange event ("caretColor") being fired.

  Parameters:
    `c` - the color
  See Also:
    `getCaretColor()`

### getSelectionColor

    public Color getSelectionColor()

  Fetches the current color used to render the selection.

  Returns:
    the color

### setSelectionColor

    public void setSelectionColor(Color c)

  Sets the current color used to render the selection. Setting the color to `null` is the same as setting `Color.white`. Setting the color results in a PropertyChange event ("selectionColor").

  Parameters:
    `c` - the color
  See Also:
    `getSelectionColor()`

### getSelectedTextColor

    public Color getSelectedTextColor()

  Fetches the current color used to render the selected text.

  Returns:
    the color

### setSelectedTextColor

    public void setSelectedTextColor(Color c)

  Sets the current color used to render the selected text. Setting the color to `null` is the same as `Color.black`. Setting the color results in a PropertyChange event ("selectedTextColor") being fired.

  Parameters:
    `c` - the color
  See Also:
    `getSelectedTextColor()`

### getDisabledTextColor

    public Color getDisabledTextColor()

  Fetches the current color used to render the selected text.

  Returns:
    the color

### setDisabledTextColor

    public void setDisabledTextColor(Color c)

  Sets the current color used to render the disabled text. Setting the color fires off a PropertyChange event ("disabledTextColor").

  Parameters:
    `c` - the color
  See Also:
    `getDisabledTextColor()`

### replaceSelection

    public void replaceSelection(String content)

  Replaces the currently selected content with new content represented by the given string. If there is no selection this amounts to an insert of the given text. If there is no replacement text this amounts to a removal of the current selection.

  This is the method that is used by the default implementation of the action for inserting content that gets bound to the keymap actions.

  This method is thread safe, although most Swing methods are not. Please see Threads and Swing for more information.

  Parameters:
    `content` - the content to replace the selection with

### getText

    public String getText(int offs,
                          int len)
                   throws BadLocationException

  Fetches a portion of the text represented by the component. Returns an empty string if length is 0.

  Parameters:
    `offs` - the offset >= 0
    `len` - the length >= 0
  Returns:
    the text
  Throws:
    `BadLocationException` - if the offset or length are invalid

### modelToView

    public Rectangle modelToView(int pos)
                          throws BadLocationException

  Converts the given location in the model to a place in the view coordinate system. The component must have a positive size for this translation to be computed (i.e. layout cannot be computed until the component has been sized). The component does not have to be visible or painted.

  Parameters:
    `pos` - the position >= 0
  Returns:
    the coordinates as a rectangle, with (r.x, r.y) as the location in the coordinate system, or null if the component does not yet have a positive size.
  Throws:
    `BadLocationException` - if the given position does not represent a valid location in the associated document
  See Also:
    `TextUI.modelToView(javax.swing.text.JTextComponent, int)`

### viewToModel

    public int viewToModel(Point pt)

  Converts the given place in the view coordinate system to the nearest representative location in the model. The component must have a positive size for this translation to be computed (i.e. layout cannot be computed until the component has been sized). The component does not have to be visible or painted.

  Parameters:
    `pt` - the location in the view to translate
  Returns:
    the offset >= 0 from the start of the document, or -1 if the component does not yet have a positive size.
  See Also:
    `TextUI.viewToModel(javax.swing.text.JTextComponent, java.awt.Point)`

### cut

    public void cut()

  Transfers the currently selected range in the associated text model to the system clipboard, removing the contents from the model. The current selection is reset. Does nothing for `null` selections.

  See Also:
    `Toolkit.getSystemClipboard()`, `Clipboard`

### copy

    public void copy()

  Transfers the currently selected range in the associated text model to the system clipboard, leaving the contents in the text model. The current selection remains intact. Does nothing for `null` selections.

  See Also:
    `Toolkit.getSystemClipboard()`, `Clipboard`

### paste

    public void paste()

  Transfers the contents of the system clipboard into the associated text model. If there is a selection in the associated view, it is replaced with the contents of the clipboard. If there is no selection, the clipboard contents are inserted in front of the current insert position in the associated view. If the clipboard is empty, does nothing.

  See Also:
    `replaceSelection(java.lang.String)`, `Toolkit.getSystemClipboard()`, `Clipboard`

### moveCaretPosition

    public void moveCaretPosition(int pos)

  Moves the caret to a new position, leaving behind a mark defined by the last time `setCaretPosition` was called. This forms a selection. If the document is `null`, does nothing. The position must be between 0 and the length of the component's text or else an exception is thrown.

  Parameters:
    `pos` - the position
  Throws:
    `IllegalArgumentException` - if the value supplied for `position` is less than zero or greater than the component's text length
  See Also:
    `setCaretPosition(int)`

### setFocusAccelerator

    public void setFocusAccelerator(char aKey)

  Sets the key accelerator that will cause the receiving text component to get the focus. The accelerator will be the key combination of the alt key and the character given (converted to upper case). By default, there is no focus accelerator key. Any previous key accelerator setting will be superseded. A '\0' key setting will be registered, and has the effect of turning off the focus accelerator. When the new key is set, a PropertyChange event (FOCUS_ACCELERATOR_KEY) will be fired.

  Parameters:
    `aKey` - the key
  See Also:
    `getFocusAccelerator()`

### getFocusAccelerator

    public char getFocusAccelerator()

  Returns the key accelerator that will cause the receiving text component to get the focus. Return '\0' if no focus accelerator has been set.

  Returns:
    the key

### read

    public void read(Reader in,
                     Object desc)
              throws IOException

  Initializes from a stream. This creates a model of the type appropriate for the component and initializes the model from the stream. By default this will load the model as plain text. Previous contents of the model are discarded.

  Parameters:
    `in` - the stream to read from
    `desc` - an object describing the stream; this might be a string, a File, a URL, etc. Some kinds of documents (such as html for example) might be able to make use of this information; if non-`null`, it is added as a property of the document
  Throws:
    `IOException` - as thrown by the stream being used to initialize
  See Also:
    `EditorKit.createDefaultDocument()`, `setDocument(javax.swing.text.Document)`, `PlainDocument`

### write

    public void write(Writer out)
               throws IOException

  Stores the contents of the model into the given stream. By default this will store the model as plain text.

  Parameters:
    `out` - the output stream
  Throws:
    `IOException` - on any I/O error

### removeNotify

    public void removeNotify()

  Description copied from class: `JComponent`
  Notifies this component that it no longer has a parent component. When this method is invoked, any `KeyboardAction`s set up in the the chain of parent components are removed.

  Overrides:
    `removeNotify` in class `JComponent`
  See Also:
    `JComponent.registerKeyboardAction(java.awt.event.ActionListener, java.lang.String, javax.swing.KeyStroke, int)`

### setCaretPosition

    public void setCaretPosition(int position)

  Sets the position of the text insertion caret for the `TextComponent`. Note that the caret tracks change, so this may move if the underlying text of the component is changed. If the document is `null`, does nothing. The position must be between 0 and the length of the component's text or else an exception is thrown.

  Parameters:
    `position` - the position
  Throws:
    `IllegalArgumentException` - if the value supplied for `position` is less than zero or greater than the component's text length

### getCaretPosition

    public int getCaretPosition()

  Returns the position of the text insertion caret for the text component.

  Returns:
    the position of the text insertion caret for the text component >= 0

### setText

    public void setText(String t)

  Sets the text of this `TextComponent` to the specified text. If the text is `null` or empty, has the effect of simply deleting the old text. When text has been inserted, the resulting caret location is determined by the implementation of the caret class.

  This method is thread safe, although most Swing methods are not. Please see Threads and Swing for more information.

  Parameters:
    `t` - the new text to be set
  See Also:
    `getText(int, int)`, `DefaultCaret`

### getText

    public String getText()

  Returns the text contained in this `TextComponent`. If the underlying document is `null`, will give a `NullPointerException`.

  Returns:
    the text
  Throws:
    `NullPointerException` - if the document is `null`
  See Also:
    `setText(java.lang.String)`

### getSelectedText

    public String getSelectedText()

  Returns the selected text contained in this `TextComponent`. If the selection is `null` or the document empty, returns `null`.

  Returns:
    the text
  Throws:
    `IllegalArgumentException` - if the selection doesn't have a valid mapping into the document for some reason
  See Also:
    `setText(java.lang.String)`

### isEditable

    public boolean isEditable()

  Returns the boolean indicating whether this `TextComponent` is editable or not.

  Returns:
    the boolean value
  See Also:
    `setEditable(boolean)`

### setEditable

    public void setEditable(boolean b)

  Sets the specified boolean to indicate whether or not this `TextComponent` should be editable. A PropertyChange event ("editable") is fired when the state is changed.

  Parameters:
    `b` - the boolean to be set
  See Also:
    `isEditable()`

### getSelectionStart

    public int getSelectionStart()

  Returns the selected text's start position. Return 0 for an empty document, or the value of dot if no selection.

  Returns:
    the start position >= 0

### setSelectionStart

    public void setSelectionStart(int selectionStart)

  Sets the selection start to the specified position. The new starting point is constrained to be before or at the current selection end.

  This is available for backward compatibility to code that called this method on `java.awt.TextComponent`. This is implemented to forward to the `Caret` implementation which is where the actual selection is maintained.

  Parameters:
    `selectionStart` - the start position of the text >= 0

### getSelectionEnd

    public int getSelectionEnd()

  Returns the selected text's end position. Return 0 if the document is empty, or the value of dot if there is no selection.

  Returns:
    the end position >= 0

### setSelectionEnd

    public void setSelectionEnd(int selectionEnd)

  Sets the selection end to the specified position. The new end point is constrained to be at or after the current selection start.

  This is available for backward compatibility to code that called this method on `java.awt.TextComponent`. This is implemented to forward to the `Caret` implementation which is where the actual selection is maintained.

  Parameters:
    `selectionEnd` - the end position of the text >= 0

### select

    public void select(int selectionStart,
                       int selectionEnd)

  Selects the text between the specified start and end positions.

  This method sets the start and end positions of the selected text, enforcing the restriction that the start position must be greater than or equal to zero. The end position must be greater than or equal to the start position, and less than or equal to the length of the text component's text.

  If the caller supplies values that are inconsistent or out of bounds, the method enforces these constraints silently, and without failure. Specifically, if the start position or end position is greater than the length of the text, it is reset to equal the text length. If the start position is less than zero, it is reset to zero, and if the end position is less than the start position, it is reset to the start position.

  This call is provided for backward compatibility. It is routed to a call to `setCaretPosition` followed by a call to `moveCaretPosition`. The preferred way to manage selection is by calling those methods directly.

  Parameters:
    `selectionStart` - the start position of the text
    `selectionEnd` - the end position of the text
  See Also:
    `setCaretPosition(int)`, `moveCaretPosition(int)`

### selectAll

    public void selectAll()

  Selects all the text in the `TextComponent`. Does nothing on a `null` or empty document.

### getToolTipText

    public String getToolTipText(MouseEvent event)

  Returns the string to be used as the tooltip for `event`. This will return one of:
  1. If `setToolTipText` has been invoked with a non-`null` value, it will be returned, otherwise
  2. The value from invoking `getToolTipText` on the UI will be returned.
  By default `JTextComponent` does not register itself with the `ToolTipManager`. This means that tooltips will NOT be shown from the `TextUI` unless `registerComponent` has been invoked on the `ToolTipManager`.

  Overrides:
    `getToolTipText` in class `JComponent`
  Parameters:
    `event` - the event in question
  Returns:
    the string to be used as the tooltip for `event`
  See Also:
    `JComponent.setToolTipText(java.lang.String)`, `TextUI.getToolTipText(javax.swing.text.JTextComponent, java.awt.Point)`, `ToolTipManager.registerComponent(javax.swing.JComponent)`

### getPreferredScrollableViewportSize

    public Dimension getPreferredScrollableViewportSize()

  Returns the preferred size of the viewport for a view component. This is implemented to do the default behavior of returning the preferred size of the component.

  Specified by:
    `getPreferredScrollableViewportSize` in interface `Scrollable`
  Returns:
    the `preferredSize` of a `JViewport` whose view is this `Scrollable`
  See Also:
    `JComponent.getPreferredSize()`

### getScrollableUnitIncrement

    public int getScrollableUnitIncrement(Rectangle visibleRect,
                                          int orientation,
                                          int direction)

  Components that display logical rows or columns should compute the scroll increment that will completely expose one new row or column, depending on the value of orientation. Ideally, components should handle a partially exposed row or column by returning the distance required to completely expose the item.

  The default implementation of this is to simply return 10% of the visible area. Subclasses are likely to be able to provide a much more reasonable value.

  Specified by:
    `getScrollableUnitIncrement` in interface `Scrollable`
  Parameters:
    `visibleRect` - the view area visible within the viewport
    `orientation` - either `SwingConstants.VERTICAL` or `SwingConstants.HORIZONTAL`
    `direction` - less than zero to scroll up/left, greater than zero for down/right
  Returns:
    the "unit" increment for scrolling in the specified direction
  Throws:
    `IllegalArgumentException` - for an invalid orientation
  See Also:
    `JScrollBar.setUnitIncrement(int)`

### getScrollableBlockIncrement

    public int getScrollableBlockIncrement(Rectangle visibleRect,
                                           int orientation,
                                           int direction)

  Components that display logical rows or columns should compute the scroll increment that will completely expose one block of rows or columns, depending on the value of orientation.

  The default implementation of this is to simply return the visible area. Subclasses will likely be able to provide a much more reasonable value.

  Specified by:
    `getScrollableBlockIncrement` in interface `Scrollable`
  Parameters:
    `visibleRect` - the view area visible within the viewport
    `orientation` - either `SwingConstants.VERTICAL` or `SwingConstants.HORIZONTAL`
    `direction` - less than zero to scroll up/left, greater than zero for down/right
  Returns:
    the "block" increment for scrolling in the specified direction
  Throws:
    `IllegalArgumentException` - for an invalid orientation
  See Also:
    `JScrollBar.setBlockIncrement(int)`

### getScrollableTracksViewportWidth

    public boolean getScrollableTracksViewportWidth()

  Returns true if a viewport should always force the width of this `Scrollable` to match the width of the viewport. For example a normal text view that supported line wrapping would return true here, since it would be undesirable for wrapped lines to disappear beyond the right edge of the viewport. Note that returning true for a `Scrollable` whose ancestor is a `JScrollPane` effectively disables horizontal scrolling.

  Scrolling containers, like `JViewport`, will use this method each time they are validated.

  Specified by:
    `getScrollableTracksViewportWidth` in interface `Scrollable`
  Returns:
    true if a viewport should force the `Scrollable`s width to match its own

### getScrollableTracksViewportHeight

    public boolean getScrollableTracksViewportHeight()

  Returns true if a viewport should always force the height of this `Scrollable` to match the height of the viewport. For example a columnar text view that flowed text in left to right columns could effectively disable vertical scrolling by returning true here.

  Scrolling containers, like `JViewport`, will use this method each time they are validated.

  Specified by:
    `getScrollableTracksViewportHeight` in interface `Scrollable`
  Returns:
    true if a viewport should force the Scrollables height to match its own

### getAccessibleContext

    public AccessibleContext getAccessibleContext()

  Gets the `AccessibleContext` associated with this `JTextComponent`. For text components, the `AccessibleContext` takes the form of an `AccessibleJTextComponent`. A new `AccessibleJTextComponent` instance is created if necessary.

  Specified by:
    `getAccessibleContext` in interface `Accessible`
  Overrides:
    `getAccessibleContext` in class `JComponent`
  Returns:
    an `AccessibleJTextComponent` that serves as the `AccessibleContext` of this `JTextComponent`

### paramString

    protected String paramString()

  Returns a string representation of this `JTextComponent`. 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`.

  Overriding `paramString` to provide information about the specific new aspects of the JFC components.

  Overrides:
    `paramString` in class `JComponent`
  Returns:
    a string representation of this `JTextComponent`

### processInputMethodEvent

    protected void processInputMethodEvent(InputMethodEvent e)

  Description copied from class: `Component`
  Processes input method events occurring on this component by dispatching them to any registered `InputMethodListener` objects.

  This method is not called unless input method events are enabled for this component. Input method events are enabled when one of the following occurs:

  - An `InputMethodListener` object is registered via `addInputMethodListener`.
  - Input method events are enabled via `enableEvents`.

  Note that if the event parameter is `null` the behavior is unspecified and may result in an exception.

  Overrides:
    `processInputMethodEvent` in class `Component`
  Parameters:
    `e` - the input method event
  See Also:
    `InputMethodEvent`, `InputMethodListener`, `Component.addInputMethodListener(java.awt.event.InputMethodListener)`, `Component.enableEvents(long)`

### getInputMethodRequests

    public InputMethodRequests getInputMethodRequests()

  Description copied from class: `Component`
  Gets the input method request handler which supports requests from input methods for this component. A component that supports on-the-spot text input must override this method to return an `InputMethodRequests` instance. At the same time, it also has to handle input method events.

  Overrides:
    `getInputMethodRequests` in class `Component`
  Returns:
    the input method request handler for this component, `null` by default
  See Also:
    `Component.addInputMethodListener(java.awt.event.InputMethodListener)`

### addInputMethodListener

    public void addInputMethodListener(InputMethodListener l)

  Description copied from class: `Component`
  Adds the specified input method listener to receive input method events from this component. A component will only receive input method events from input methods if it also overrides `getInputMethodRequests` to return an `InputMethodRequests` instance. If listener `l` is `null`, no exception is thrown and no action is performed.

  Overrides:
    `addInputMethodListener` in class `Component`
  Parameters:
    `l` - the input method listener
  See Also:
    `InputMethodEvent`, `InputMethodListener`, `Component.removeInputMethodListener(java.awt.event.InputMethodListener)`, `Component.getInputMethodListeners()`, `Component.getInputMethodRequests()`

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