W3cubDocs

/OpenJDK 21

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

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

Constructor Summary

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 javax.swing.plaf.ComponentUI

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

Methods declared in class java.lang.Object

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

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:

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:

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

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(javax.swing.JLabel, java.awt.Graphics, java.lang.String, int, int) or paintDisabledText(javax.swing.JLabel, java.awt.Graphics, java.lang.String, int, int). The locations of the label parts are computed by layoutCL(javax.swing.JLabel, java.awt.FontMetrics, java.lang.String, javax.swing.Icon, java.awt.Rectangle, java.awt.Rectangle, java.awt.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:

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:

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:

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:

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:

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.

© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/plaf/basic/BasicLabelUI.html