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Java™ Platform Standard Ed. 6 |
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java.lang.Objectjava.awt.Component
java.awt.Container
javax.swing.JComponent
javax.swing.text.JTextComponent
public abstract class JTextComponent
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.
CaretListener
interface that have been registered with the text component.
The UI will install a default caret unless a customized caret
has been set. DefaultCaret
tries to make itself visible which may lead to scrolling
of a text component within JScrollPane. The default caret
behavior can be changed by the DefaultCaret.setUpdatePolicy(int) method.
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.
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:

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.
modelToView(int)
and viewToModel(java.awt.Point) for determining this information.
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.
AbstractDocument
describes the assumptions of the protection provided.
The methods that are safe to call asynchronously are marked
with comments.
print methods are provided for basic
document printing. If more advanced printing is needed, use the
getPrintable(java.text.MessageFormat, java.text.MessageFormat) method.
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.
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.DropLocation
Represents a drop location for JTextComponents. |
static class |
JTextComponent.KeyBinding
Binding record for creating key bindings. |
| Nested classes/interfaces inherited from class javax.swing.JComponent |
|---|
JComponent.AccessibleJComponent |
| Nested classes/interfaces inherited from class java.awt.Container |
|---|
Container.AccessibleAWTContainer |
| Nested classes/interfaces inherited from class java.awt.Component |
|---|
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, 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 disabled text. |
Document |
getDocument()
Fetches the model associated with the editor. |
boolean |
getDragEnabled()
Returns whether or not automatic drag handling is enabled. |
JTextComponent.DropLocation |
getDropLocation()
Returns the location that this component should visually indicate as the drop location during a DnD operation over the component, or null if no location is to currently be shown. |
DropMode |
getDropMode()
Returns the drop mode for this component. |
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. |
Printable |
getPrintable(MessageFormat headerFormat,
MessageFormat footerFormat)
Returns a Printable to use for printing the content of this
JTextComponent. |
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. |
boolean |
print()
A convenience print method that displays a print dialog, and then prints this JTextComponent in interactive mode with no
header or footer text. |
boolean |
print(MessageFormat headerFormat,
MessageFormat footerFormat)
A convenience print method that displays a print dialog, and then prints this JTextComponent in interactive mode with
the specified header and footer text. |
boolean |
print(MessageFormat headerFormat,
MessageFormat footerFormat,
boolean showPrintDialog,
PrintService service,
PrintRequestAttributeSet attributes,
boolean interactive)
Prints the content of this JTextComponent. |
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)
Turns on or off automatic drag handling. |
void |
setDropMode(DropMode dropMode)
Sets the drop mode for 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 java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
| Field Detail |
|---|
public static final String FOCUS_ACCELERATOR_KEY
public static final String DEFAULT_KEYMAP
JTextComponent instances unless they
have had a different keymap set.
| Constructor Detail |
|---|
public JTextComponent()
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 |
|---|
public TextUI getUI()
public void setUI(TextUI ui)
ui - the factorypublic void updateUI()
getUIClassID(). The type of
the UI is TextUI. invalidate
is called after setting the UI.
updateUI in class JComponentJComponent.setUI(javax.swing.plaf.ComponentUI),
UIManager.getLookAndFeel(),
UIManager.getUI(javax.swing.JComponent)public void addCaretListener(CaretListener listener)
listener - the listener to be addedCaretEventpublic void removeCaretListener(CaretListener listener)
listener - the listener to be removedCaretEventpublic CaretListener[] getCaretListeners()
CaretListeners
or an empty
array if no caret listeners are currently registeredaddCaretListener(javax.swing.event.CaretListener),
removeCaretListener(javax.swing.event.CaretListener)protected void fireCaretUpdate(CaretEvent e)
e - the eventEventListenerListpublic void setDocument(Document doc)
doc - the document to display/editgetDocument()public Document getDocument()
public void setComponentOrientation(ComponentOrientation o)
ComponentLayoutManager 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.
setComponentOrientation in class ComponentComponentOrientationpublic Action[] getActions()
public void setMargin(Insets m)
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.
m - the space between the border and the textpublic Insets getMargin()
public void setNavigationFilter(NavigationFilter filter)
NavigationFilter. NavigationFilter
is used by DefaultCaret and the default cursor movement
actions as a way to restrict the cursor movement.
public NavigationFilter getNavigationFilter()
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.
public Caret getCaret()
public void setCaret(Caret c)
c - the caretgetCaret()public Highlighter getHighlighter()
public void setHighlighter(Highlighter h)
null to disable it.
A PropertyChange event ("highlighter") is fired
when a new highlighter is installed.
h - the highlightergetHighlighter()public void setKeymap(Keymap map)
null effectively disables
keyboard input.
A PropertyChange event ("keymap") is fired when a new keymap
is installed.
map - the keymapgetKeymap()public void setDragEnabled(boolean b)
true, and the
component's TransferHandler needs to be non-null.
The default value of the dragEnabled property is false.
The job of honoring this property, and recognizing a user drag gesture,
lies with the look and feel implementation, and in particular, the component's
TextUI. When automatic drag handling is enabled, most look and
feels (including those that subclass BasicLookAndFeel) 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.
If a look and feel is used that ignores this property, you can still
begin a drag and drop operation by calling exportAsDrag on the
component's TransferHandler.
b - whether or not to enable automatic drag handling
HeadlessException - if
b is true and
GraphicsEnvironment.isHeadless()
returns trueGraphicsEnvironment.isHeadless(),
getDragEnabled(),
JComponent.setTransferHandler(javax.swing.TransferHandler),
TransferHandlerpublic boolean getDragEnabled()
dragEnabled propertysetDragEnabled(boolean)public final void setDropMode(DropMode dropMode)
DropMode.USE_SELECTION.
Usage of DropMode.INSERT is recommended, however,
for an improved user experience. It offers similar behavior of dropping
between text locations, but does so without affecting the actual text
selection and caret location.
JTextComponents support the following drop modes:
DropMode.USE_SELECTIONDropMode.INSERT
The drop mode is only meaningful if this component has a
TransferHandler that accepts drops.
dropMode - the drop mode to use
IllegalArgumentException - if the drop mode is unsupported
or nullgetDropMode(),
getDropLocation(),
JComponent.setTransferHandler(javax.swing.TransferHandler),
TransferHandlerpublic final DropMode getDropMode()
setDropMode(javax.swing.DropMode)public final JTextComponent.DropLocation getDropLocation()
null if no location is to currently be shown.
This method is not meant for querying the drop location
from a TransferHandler, as the drop location is only
set after the TransferHandler's canImport
has returned and has allowed for the location to be shown.
When this property changes, a property change event with name "dropLocation" is fired by the component.
setDropMode(javax.swing.DropMode),
TransferHandler.canImport(TransferHandler.TransferSupport)public Keymap getKeymap()
public static Keymap addKeymap(String nm,
Keymap parent)
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 nameparent - the parent keymap; this may be null if
unspecified bindings need not be resolved in some other keymap
public static Keymap removeKeymap(String nm)
null names may not be removed in this way.
nm - the name of the keymap to remove
public static Keymap getKeymap(String nm)
null-named keymaps.
nm - the name of the keymap
pub