Class com.sun.java.swing.text.JTextComponent
java.lang.Object
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+----java.awt.Component
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+----java.awt.Container
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+----com.sun.java.swing.JComponent
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+----com.sun.java.swing.text.JTextComponent
- 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).
- 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 it's 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.
- Keymaps
-
To facilitate flexible use of the keyboard, support for
creating keymaps and binding various keystrokes to some kind of
action is provided. 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 it's source).
The use of the keymap is encouraged, but backward compatibilty
with the awt mechanism is provided by giving the
listeners a chance to steal the event by consuming it.
Keyboard event distribution is handled the following order, with
each distribution capable of consuming the event.
- focus manager
- registered KeyListener's
- keymap handling using the current keymap
- keyboard handling in JComponent (eg accelerators,
component navigation, etc).
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 (eg. 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. Changes to the model are sent in the form of a
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 and
viewToModel for determining
this information.
- Undo/Redo support
-
Support of 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.
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 Swing1.0 applications. It will
not be possible to load serialized Swing1.0 objects with future releases
of Swing. The JDK1.2 release of Swing will be the compatibility
baseline for the serialized form of Swing objects.
- See Also:
- Document, DocumentEvent, DocumentListener, Caret, CaretEvent, CaretListener, TextUI, View, ViewFactory
Variable Index
- DEFAULT_KEYMAP
- This is the name of the default keymap that will be shared by all
JTextComponent instances unless they have had a different
keymap set.
- FOCUS_ACCELERATOR_KEY
- The bound property name for the focus accelerator.
Constructor Index
- JTextComponent()
- Creates a new JTextComponent.
Method Index
- addCaretListener(CaretListener)
- Adds a caret listener for notification of any changes
to the caret.
- addKeymap(String, Keymap)
- Adds a new keymap into the keymap hierarchy.
- copy()
- Transfers the currently selected range in the associated
text model to the system clipboard, leaving the contents
in the text model.
- cut()
- Transfers the currently selected range in the associated
text model to the system clipboard, removing the contents
from the model.
- fireCaretUpdate(CaretEvent)
- Notifies all listeners that have registered interest for
notification on this event type.
- getAccessibleContext()
- Get the AccessibleContext associated with this JComponent
- getActions()
- Fetches the command list for the editor.
- getCaret()
- Fetches the cursor that allows text-oriented navigation over
the view.
- getCaretColor()
- Fetches the current color used to render the
caret.
- getCaretPosition()
- Returns the position of the text insertion caret for the
text component.
- getDisabledTextColor()
- Fetches the current color used to render the
selected text.
- getDocument()
- Fetches the model associated with the editor.
- getFocusAccelerator()
- Returns the key accelerator that will cause the receiving
text component to get the focus.
- getHighlighter()
- Fetches the object responsible for making highlights.
- getKeymap()
- Fetches the keymap being used by the controller
- getKeymap(String)
- Fetches a named keymap previously added to the document.
- getMargin()
- Returns the margin between the text component's border and
its text.
- getPreferredScrollableViewportSize()
- Returns the preferred size of the viewport for a view component.
- getScrollableBlockIncrement(Rectangle, int, int)
- 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.
- getScrollableTracksViewportHeight()
- Return true if a viewport should always force the height of this
Scrollable to match the height of the viewport.
- getScrollableTracksViewportWidth()
- Return true if a viewport should always force the width of this
Scrollable to match the width of the viewport.
- getScrollableUnitIncrement(Rectangle, int, int)
- 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.
- getSelectedText()
- Returns the selected text contained in this TextComponent.
- getSelectedTextColor()
- Fetches the current color used to render the
selected text.
- getSelectionColor()
- Fetches the current color used to render the
selection.
- getSelectionEnd()
- Returns the selected text's end position.
- getSelectionStart()
- Returns the selected text's start position.
- getText()
- Returns the text contained in this TextComponent.
- getText(int, int)
- Fetches a portion of the text represented by the
component.
- getUI()
- Fetches the user-interface factory for this text-oriented editor.
- isEditable()
- Returns the boolean indicating whether this TextComponent is
editable or not.
- isFocusTraversable()
- Returns true if the focus can be traversed.
- isOpaque()
- Returns true if this component is completely opaque.
- loadKeymap(Keymap, JTextComponent. KeyBinding[], Action[])
-
Loads a keymap with a bunch of
bindings.
- modelToView(int)
- Converts the given location in the model to a place in
the view coordinate system.
- moveCaretPosition(int)
- Moves the caret to a new position, leaving behind a
mark defined by the last time setCaretPosition was
called.
- paste()
- Transfers the contents of the system clipboard into the
associated text model.
- processComponentKeyEvent(KeyEvent)
- Process any key events that the component itself
recognizes.
- read(Reader, Object)
- Initialize from a stream.
- removeCaretListener(CaretListener)
- Removes a caret listener.
- removeKeymap(String)
- Removes a named keymap previously added to the document.
- replaceSelection(String)
- Replaces the currently selected content with new content
represented by the given string.
- select(int, int)
- Selects the text found between the specified start and end
locations.
- selectAll()
- Selects all the text in the TextComponent.
- setCaret(Caret)
- Sets the caret to be used.
- setCaretColor(Color)
- Sets the current color used to render the
caret.
- setCaretPosition(int)
- Sets the position of the text insertion caret for the TextComponent.
- setDisabledTextColor(Color)
- Sets the current color used to render the
disabled text.
- setDocument(Document)
- Associates the editor with a text document.
- setEditable(boolean)
- Sets the specified boolean to indicate whether or not this
TextComponent should be editable.
- setFocusAccelerator(char)
- Sets the key accelerator that will cause the receiving text
component to get the focus.
- setHighlighter(Highlighter)
- Sets the highlighter to be used.
- setKeymap(Keymap)
- Sets the keymap to use for binding events to
actions.
- setMargin(Insets)
- Sets margin space between the text component's border
and its text.
- setOpaque(boolean)
- Sets whether or not the UI should render a background.
- setSelectedTextColor(Color)
- Sets the current color used to render the
selected text.
- setSelectionColor(Color)
- Sets the current color used to render the
selection.
- setSelectionEnd(int)
- Sets the selection end to the specified position.
- setSelectionStart(int)
- Sets the selection start to the specified position.
- setText(String)
- Sets the text of this TextComponent to the specified text.
- setUI(TextUI)
- Sets the user-interface factory for this text-oriented editor
- updateUI()
- Reloads the pluggable UI.
- viewToModel(Point)
- Converts the given place in the view coordinate system
to the nearest representative location in the model.
- write(Writer)
- Stores the contents of the model into the given
stream.
Variables
FOCUS_ACCELERATOR_KEY
public static final String FOCUS_ACCELERATOR_KEY
- The bound property name for the focus accelerator.
DEFAULT_KEYMAP
public static final String DEFAULT_KEYMAP
- This is the name of the default keymap that will be shared by all
JTextComponent instances unless they have had a different
keymap set.
Constructors
JTextComponent
public JTextComponent()
- Creates a new JTextComponent.
Methods
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.
- Overrides:
- updateUI in class JComponent
isOpaque
public boolean isOpaque()
- Returns true if this component is completely opaque.
- Returns:
- true if this component is completely opaque.
- Overrides:
- isOpaque in class JComponent
setOpaque
public void setOpaque(boolean o)
- Sets whether or not the UI should render a background.
- Parameters:
- o - true if should render a background
- Overrides:
- setOpaque in class JComponent
addCaretListener
public void addCaretListener(CaretListener listener)
- Adds a caret listener for notification of any changes
to the caret.
- Parameters:
- listener - the listener
- See Also:
- CaretEvent
removeCaretListener
public void removeCaretListener(CaretListener listener)
- Removes a caret listener.
- Parameters:
- listener - the listener
- See Also:
- CaretEvent
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.
- 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.
- 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
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. Setting it to null will cause the text component
to use a default margin. 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).
- 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
getCaret
public Caret getCaret()
- Fetches the cursor that allows text-oriented navigation over
the view.
- Returns:
- the cursor
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.
- 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.
- Parameters:
- h - the highlighter
- See Also:
- getHighlighter
setKeymap
public void setKeymap(Keymap map)
- Sets the keymap to use for binding events to
actions.
- Parameters:
- map - the keymap
- See Also:
- getKeymap
getKeymap
public Keymap getKeymap()
- Fetches the keymap being used by the controller
- 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.
- Parameters:
- nm - the name of the keymap to remove
- Returns:
- the keymap
getKeymap
public static Keymap getKeymap(String nm)
- Fetches a named keymap previously added to the document.
- 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. It also binds tab to insert the tab
into the text component. A code fragment to accomplish
this might look as follows:
JTextComponent c = new JTextPane();
Keymap k = c.getKeymap();
JTextComponent.loadKeymap(k, c.getActions(), defaultBindings);
static final JTextComponent.KeyBinding[] defaultBindings = {
new JTextComponent.KeyBinding(
KeyStroke.getKeyStroke(KeyEvent.VK_C, InputEvent.CTRL_MASK),
JTextComponent.copyAction),
new JTextComponent.KeyBinding(
KeyStroke.getKeyStroke(KeyEvent.VK_V, InputEvent.CTRL_MASK),
JTextComponent.pasteAction),
new JTextComponent.KeyBinding(
KeyStroke.getKeyStroke(KeyEvent.VK_X, InputEvent.CTRL_MASK),
JTextComponent.cutAction),
new JTextComponent.KeyBinding(
KeyStroke.getKeyStroke('\t'),
JTextComponent.insertContentAction)
};
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Parameters:
- offs - the offset
- len - the length
- Returns:
- the text
- Throws: BadLocationException
- of 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.
- Parameters:
- pos - the position
- Returns:
- the coordinates as a rectangle
- Throws: BadLocationException
- if the given position does not represent a
valid location in the associated document
- See Also:
- modelToView
viewToModel
public int viewToModel(Point pt)
- Converts the given place in the view coordinate system
to the nearest representative location in the model.
- Parameters:
- pt - the location in the view to translate
- Returns:
- the offset from the start of the document
- See Also:
- viewToModel
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.
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 is remains intact.
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.
- See Also:
- replaceSelection
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.
- Parameters:
- pos - the position
- See Also:
- setCaretPosition
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. By default, there is no focus accelerator key.
- 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
- Initialize 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.
- 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.
- Throws: IOException
- as thrown by the stream being
used to initialize.
- See Also:
- createDefaultDocument, setDocument, 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
isFocusTraversable
public boolean isFocusTraversable()
- Returns true if the focus can be traversed.
- Returns:
- true if the focus is traversable
- Overrides:
- isFocusTraversable in class JComponent
processComponentKeyEvent
protected void processComponentKeyEvent(KeyEvent e)
- Process any key events that the component itself
recognizes. This will be called after the focus
manager and any interested listeners have been
given a chance to steal away the event. This
method will only be called is the event has not
yet been consumed. This method is called prior
to the keyboard UI logic.
This is implemented to do nothing. Subclasses would
normally override this method if they process some
key events themselves. If the event is processed,
it should be consumed.
- Parameters:
- e - the event
- Overrides:
- processComponentKeyEvent in class JComponent
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.
- Parameters:
- position - the position
- Throws: IllegalArgumentException
- if position is less than 0
or greater than the length of the associated document
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
setText
public void setText(String t)
- Sets the text of this TextComponent to the specified text.
This method is thread safe, although most Swing methods
are not.
- Parameters:
- t - the new text to be set
- See Also:
- getText
getText
public String getText()
- Returns the text contained in this TextComponent.
- Returns:
- the text
- See Also:
- setText
getSelectedText
public String getSelectedText()
- Returns the selected text contained in this TextComponent.
- Returns:
- the text
- Throws: IllegalArgumentException
- if the selection doesn't
have a valid mapping into the document for some reason
- See Also:
- setText
isEditable
public boolean isEditable()
- Returns the boolean indicating whether this TextComponent is
editable or not.
- Returns:
- the boolean value
- See Also:
- setEditable
setEditable
public void setEditable(boolean b)
- Sets the specified boolean to indicate whether or not this
TextComponent should be editable.
- Parameters:
- b - the boolean to be set
- See Also:
- isEditable
getSelectionStart
public int getSelectionStart()
- Returns the selected text's start position.
- Returns:
- the start position
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 compatiblitity 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
getSelectionEnd
public int getSelectionEnd()
- Returns the selected text's end position.
- Returns:
- the end position
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 compatiblitity 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 start position of the text
select
public void select(int selectionStart,
int selectionEnd)
- Selects the text found between the specified start and end
locations. This call is provided for backward compatibility.
It is routed to a call to setCaretPosition
followed by a call to moveCaretPostion. 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, moveCaretPosition
selectAll
public void selectAll()
- Selects all the text in the TextComponent.
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.
- Returns:
- The preferredSize of a JViewport whose view is this Scrollable.
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.
- 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
- See Also:
- setUnitIncrement
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.
- 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.
- See Also:
- setBlockIncrement
getScrollableTracksViewportWidth
public boolean getScrollableTracksViewportWidth()
- Return true if a viewport should always force the width of this
Scrollable to match the width of the viewport. For example a noraml
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.
- Returns:
- True if a viewport should force the Scrollables width to match its own.
getScrollableTracksViewportHeight
public boolean getScrollableTracksViewportHeight()
- Return 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.
- Returns:
- True if a viewport should force the Scrollables height to match its own.
getAccessibleContext
public AccessibleContext getAccessibleContext()
- Get the AccessibleContext associated with this JComponent
- Returns:
- the AccessibleContext of this JComponent
- Overrides:
- getAccessibleContext in class JComponent
