Class BasicLabelUI

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 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 `i`th `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()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

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(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:

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.

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