Class BasicLabelUI

java.lang.Object

javax.swing.plaf.ComponentUI

javax.swing.plaf.LabelUI

javax.swing.plaf.basic.BasicLabelUI

All Implemented Interfaces:

PropertyChangeListener, EventListener

Direct Known Subclasses:

MetalLabelUI, SynthLabelUI

public class BasicLabelUI
extends LabelUI
implements PropertyChangeListener

A Windows L&F implementation of LabelUI. This implementation is completely static, i.e. there's only one UIView implementation that's shared by all JLabel objects.

Field Summary

Fields

Modifier and Type	Field	Description
protected static BasicLabelUI	labelUI	The default BasicLabelUI instance.

Constructor Summary

Constructors

Constructor	Description
BasicLabelUI()	Constructs a BasicLabelUI.

Method Summary

Modifier and Type	Method	Description
static ComponentUI	createUI(JComponent c)	Returns an instance of BasicLabelUI.
int	getBaseline(JComponent c, int width, int height)	Returns the baseline.
Component.BaselineResizeBehavior	getBaselineResizeBehavior(JComponent c)	Returns an enum indicating how the baseline of the component changes as the size changes.
Dimension	getMaximumSize(JComponent c)	Returns the specified component's maximum size appropriate for the look and feel.
Dimension	getMinimumSize(JComponent c)	Returns the specified component's minimum size appropriate for the look and feel.
protected void	installComponents(JLabel c)	Registers components.
protected void	installDefaults(JLabel c)	Installs default properties.
protected void	installKeyboardActions(JLabel l)	Registers keyboard actions.
protected void	installListeners(JLabel c)	Registers listeners.
protected String	layoutCL(JLabel label, FontMetrics fontMetrics, String text, Icon icon, Rectangle viewR, Rectangle iconR, Rectangle textR)	Forwards the call to SwingUtilities.layoutCompoundLabel().
void	paint(Graphics g, JComponent c)	Paints the label text with the foreground color, if the label is opaque then paints the entire background with the background color.
protected void	paintDisabledText(JLabel l, Graphics g, String s, int textX, int textY)	Paint clippedText at textX, textY with background.lighter() and then shifted down and to the right by one pixel with background.darker().
protected void	paintEnabledText(JLabel l, Graphics g, String s, int textX, int textY)	Paint clippedText at textX, textY with the labels foreground color.
void	propertyChange(PropertyChangeEvent e)	This method gets called when a bound property is changed.
protected void	uninstallComponents(JLabel c)	Unregisters components.
protected void	uninstallDefaults(JLabel c)	Uninstalls default properties.
protected void	uninstallKeyboardActions(JLabel c)	Unregisters keyboard actions.
protected void	uninstallListeners(JLabel c)	Unregisters listeners.

Methods declared in class ComponentUI

contains, getAccessibleChild, getAccessibleChildrenCount, getPreferredSize, installUI, uninstallUI, update

Modifier and Type	Method	Description
boolean	contains(JComponent c, int x, int y)	Returns true if the specified x,y location is contained within the look and feel's defined shape of the specified component.
Accessible	getAccessibleChild(JComponent c, int i)	Returns the ith Accessible child of the object.
int	getAccessibleChildrenCount(JComponent c)	Returns the number of accessible children in the object.
Dimension	getPreferredSize(JComponent c)	Returns the specified component's preferred size appropriate for the look and feel.
void	installUI(JComponent c)	Configures the specified component appropriately for the look and feel.
void	uninstallUI(JComponent c)	Reverses configuration which was done on the specified component during installUI.
void	update(Graphics g, JComponent c)	Notifies this UI delegate that it is time to paint the specified component.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Field Details

labelUI

protected static BasicLabelUI labelUI

The default BasicLabelUI instance. This field might not be used. To change the default instance use a subclass which overrides the createUI method, and place that class name in defaults table under the key "LabelUI".

Constructor Details

BasicLabelUI

public BasicLabelUI()

Constructs a BasicLabelUI.

Method Details

layoutCL

protected String layoutCL(JLabel label,
 FontMetrics fontMetrics,
 String text,
 Icon icon,
 Rectangle viewR,
 Rectangle iconR,
 Rectangle textR)

Forwards the call to SwingUtilities.layoutCompoundLabel(). This method is here so that a subclass could do Label specific layout and to shorten the method name a little.

Parameters:

label - an instance of JLabel

fontMetrics - a font metrics

text - a text

icon - an icon

viewR - a bounding rectangle to lay out label

iconR - a bounding rectangle to lay out icon

textR - a bounding rectangle to lay out text

Returns:

a possibly clipped version of the compound labels string

See Also:

• SwingUtilities.layoutCompoundLabel(JComponent, FontMetrics, String, Icon, int, int, int, int, Rectangle, Rectangle, Rectangle, int)

paintEnabledText

protected void paintEnabledText(JLabel l,
 Graphics g,
 String s,
 int textX,
 int textY)

Paint clippedText at textX, textY with the labels foreground color.

Parameters:

l - an instance of JLabel

g - an instance of Graphics

s - a text

textX - an X coordinate

textY - an Y coordinate

See Also:

• paint(Graphics, JComponent)
• paintDisabledText(JLabel, Graphics, String, int, int)

paintDisabledText

protected void paintDisabledText(JLabel l,
 Graphics g,
 String s,
 int textX,
 int textY)

Paint clippedText at textX, textY with background.lighter() and then shifted down and to the right by one pixel with background.darker().

Parameters:

l - an instance of JLabel

g - an instance of Graphics

s - a text

textX - an X coordinate

textY - an Y coordinate

See Also:

• paint(Graphics, JComponent)
• paintEnabledText(JLabel, Graphics, String, int, int)

paint

public void paint(Graphics g,
 JComponent c)

Paints the label text with the foreground color, if the label is opaque then paints the entire background with the background color. The Label text is drawn by paintEnabledText(JLabel, Graphics, String, int, int) or paintDisabledText(JLabel, Graphics, String, int, int). The locations of the label parts are computed by layoutCL(JLabel, FontMetrics, String, Icon, Rectangle, Rectangle, Rectangle).

Overrides:

paint in class ComponentUI

Parameters:

g - the Graphics context in which to paint

c - the component being painted; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components

See Also:

• paintEnabledText(JLabel, Graphics, String, int, int)
• paintDisabledText(JLabel, Graphics, String, int, int)
• layoutCL(JLabel, FontMetrics, String, Icon, Rectangle, Rectangle, Rectangle)

getMinimumSize

public Dimension getMinimumSize(JComponent c)

Description copied from class: ComponentUI

Returns the specified component's minimum size appropriate for the look and feel. If null is returned, the minimum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes getPreferredSize and returns that value.

Overrides:

getMinimumSize in class ComponentUI

Parameters:

c - the component whose minimum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components

Returns:

getPreferredSize(c)

See Also:

• JComponent.getMinimumSize()
• LayoutManager.minimumLayoutSize(Container)
• ComponentUI.getPreferredSize(JComponent)

getMaximumSize

public Dimension getMaximumSize(JComponent c)

Description copied from class: ComponentUI

Returns the specified component's maximum size appropriate for the look and feel. If null is returned, the maximum size will be calculated by the component's layout manager instead (this is the preferred approach for any component with a specific layout manager installed). The default implementation of this method invokes getPreferredSize and returns that value.

Overrides:

getMaximumSize in class ComponentUI

Parameters:

c - the component whose maximum size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components

Returns:

getPreferredSize(c)

See Also:

• JComponent.getMaximumSize()
• LayoutManager2.maximumLayoutSize(Container)

getBaseline

public int getBaseline(JComponent c,
 int width,
 int height)

Returns the baseline.

Overrides:

getBaseline in class ComponentUI

Parameters:

c - JComponent baseline is being requested for

width - the width to get the baseline for

height - the height to get the baseline for

Returns:

baseline or a value < 0 indicating there is no reasonable baseline

Throws:

NullPointerException - if c is null

IllegalArgumentException - if width or height is < 0

Since:

1.6

See Also:

• JComponent.getBaseline(int, int)

getBaselineResizeBehavior

public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c)

Returns an enum indicating how the baseline of the component changes as the size changes.

Overrides:

getBaselineResizeBehavior in class ComponentUI

Parameters:

c - JComponent to return baseline resize behavior for

Returns:

an enum indicating how the baseline changes as the component size changes

Throws:

NullPointerException - if c is null

Since:

1.6

See Also:

• JComponent.getBaseline(int, int)

installDefaults

protected void installDefaults(JLabel c)

Installs default properties.

Parameters:

c - an instance of JLabel

installListeners

protected void installListeners(JLabel c)

Registers listeners.

Parameters:

c - an instance of JLabel

installComponents

protected void installComponents(JLabel c)

Registers components.

Parameters:

c - an instance of JLabel

installKeyboardActions

protected void installKeyboardActions(JLabel l)

Registers keyboard actions.

Parameters:

l - an instance of JLabel

uninstallDefaults

protected void uninstallDefaults(JLabel c)

Uninstalls default properties.

Parameters:

c - an instance of JLabel

uninstallListeners

protected void uninstallListeners(JLabel c)

Unregisters listeners.

Parameters:

c - an instance of JLabel

uninstallComponents

protected void uninstallComponents(JLabel c)

Unregisters components.

Parameters:

c - an instance of JLabel

uninstallKeyboardActions

protected void uninstallKeyboardActions(JLabel c)

Unregisters keyboard actions.

Parameters:

c - an instance of JLabel

createUI

public static ComponentUI createUI(JComponent c)

Returns an instance of BasicLabelUI.

Parameters:

c - a component

Returns:

an instance of BasicLabelUI

propertyChange

public void propertyChange(PropertyChangeEvent e)

Description copied from interface: PropertyChangeListener

This method gets called when a bound property is changed.

Specified by:

propertyChange in interface PropertyChangeListener

Parameters:

e - A PropertyChangeEvent object describing the event source and the property that has changed.