javax.swing.text
Interface Caret

All Known Implementing Classes:

DefaultCaret

public abstract interface Caret

A place within a document view that represents where things can be inserted into the document model. It gives a way to navigate through the document view while abstracting away the details of how the view is arranged. This can be useful because some views may filter out portions of the associated model, and some views may not allow navigation in certain areas such as read-only areas.

Method Summary

void	addChangeListener(ChangeListener l) Adds a listener to track whenever the caret position has been changed.
void	deinstall(JTextComponent c) Called when the UI is being removed from the interface of a JTextComponent.
int	getBlinkRate() Gets the blink rate of the caret.
int	getDot() Fetches the current position of the caret.
Point	getMagicCaretPosition() Gets the current caret position.
int	getMark() Fetches the current position of the mark.
void	install(JTextComponent c) Called when the UI is being installed into the interface of a JTextComponent.
boolean	isSelectionVisible() Determines if the selection is currently visible.
boolean	isVisible() Determines if the caret is currently visible.
void	moveDot(int dot) Moves the caret position to some other position, leaving behind the mark.
void	paint(Graphics g) Renders the caret.
void	removeChangeListener(ChangeListener l) Removes a listener that was tracking caret position changes.
void	setBlinkRate(int rate) Sets the blink rate of the caret.
void	setDot(int dot) Sets the caret position to some position.
void	setMagicCaretPosition(Point p) Saves the current caret position.
void	setSelectionVisible(boolean v) Sets the visibility of the selection
void	setVisible(boolean v) Sets the visibility of the caret.

Method Detail

install

public void install(JTextComponent c)

Called when the UI is being installed into the interface of a JTextComponent. This can be used to gain access to the model that is being navigated by the implementation of this interface.

Parameters:

c - the JTextComponent

deinstall

public void deinstall(JTextComponent c)

Called when the UI is being removed from the interface of a JTextComponent. This is used to unregister any listeners that were attached.

Parameters:

c - the JTextComponent

paint

public void paint(Graphics g)

Renders the caret.

Parameters:

g - the graphics context

addChangeListener

public void addChangeListener(ChangeListener l)

Adds a listener to track whenever the caret position has been changed.

Parameters:

l - the change listener

removeChangeListener

public void removeChangeListener(ChangeListener l)

Removes a listener that was tracking caret position changes.

Parameters:

l - the change listener

isVisible

public boolean isVisible()

Determines if the caret is currently visible.

Returns:

true if the caret is visible else false

setVisible

public void setVisible(boolean v)

Sets the visibility of the caret.

Parameters:

v - true if the caret should be shown, and false if the caret should be hidden

isSelectionVisible

public boolean isSelectionVisible()

Determines if the selection is currently visible.

Returns:

true if the caret is visible else false

setSelectionVisible

public void setSelectionVisible(boolean v)

Sets the visibility of the selection

Parameters:

v - true if the caret should be shown, and false if the caret should be hidden

setMagicCaretPosition

public void setMagicCaretPosition(Point p)

Saves the current caret position. This is used when caret up or down actions occur, moving between lines that have uneven end positions.

Parameters:

p - the Point to use for the saved position

getMagicCaretPosition

public Point getMagicCaretPosition()

Gets the current caret position.

Returns:

the position

See Also:

setMagicCaretPosition(java.awt.Point)

setBlinkRate

public void setBlinkRate(int rate)

Sets the blink rate of the caret. This determines if and how fast the caret blinks, commonly used as one way to attract attention to the caret.

Parameters:

rate - the delay in milliseconds >= 0. If this is zero the caret will not blink.

getBlinkRate

public int getBlinkRate()

Gets the blink rate of the caret. This determines if and how fast the caret blinks, commonly used as one way to attract attention to the caret.

getDot

public int getDot()

Fetches the current position of the caret.

Returns:

the position >= 0

getMark

public int getMark()

Fetches the current position of the mark. If there is a selection, the mark will not be the same as the dot.

Returns:

the position >= 0

setDot

public void setDot(int dot)

Sets the caret position to some position. This causes the mark to become the same as the dot, effectively setting the selection range to zero.

Parameters:

dot - the new position to set the caret to >= 0

moveDot

public void moveDot(int dot)

Moves the caret position to some other position, leaving behind the mark. This is useful for making selections.

Parameters:

dot - the new position to move the caret to >= 0