All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class com.sun.java.swing.JLabel

java.lang.Object
   |
   +----java.awt.Component
           |
           +----java.awt.Container
                   |
                   +----com.sun.java.swing.JComponent
                           |
                           +----com.sun.java.swing.JLabel

public class JLabel

extends JComponent

implements SwingConstants, Accessible

A JLabel object can display either text, an image, or both. You can specify where in the label's display area the label's contents are aligned by setting the vertical and horizontal alignment. By default, labels are vertically centered in their display area. Text-only labels are left-aligned, by default; image-only labels are horizontally centered, by default.

You can also specify the position of the text relative to the image. By default, text is to the right of the image, with the text and image vertically aligned.

Finally, you can use the setIconTextGap method to specify how many pixels should appear between the text and the image. The default is 4 pixels.

See How to Use Labels in The Java Tutorial for further documentation.

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.

labelFor

--- Accessibility Support ---

JLabel()

Creates a JLabel instance with no image and with an empty string for the title.

JLabel(Icon)

Creates a JLabel instance with the specified image.

JLabel(Icon, int)

Creates a JLabel instance with the specified image and horizontal alignment.

JLabel(String)

Creates a JLabel instance with the specified text.

JLabel(String, Icon, int)

Creates a JLabel instance with the specified text, image, and horizontal alignment.

JLabel(String, int)

Creates a JLabel instance with the specified text and horizontal alignment.

checkHorizontalKey(int, String)

Verify that key is a legal value for the horizontalAlignment or horizontalTextPosition properties.

checkVerticalKey(int, String)

Verify that key is a legal value for the verticalAlignment or verticalTextPosition properties.

getAccessibleContext()

Get the AccessibleContext of this object

getDisabledIcon()

Returns the value of the disabledIcon property if it's been set, If it hasn't been set and the value of the icon property is an ImageIcon, we compute a "grayed out" version of the icon and update the disabledIcon property with that.

getDisplayedMnemonic()

Return the keycode that indicates a mnemonic key.

getHorizontalAlignment()

Returns the alignment of the label's contents along the X axis.

getHorizontalTextPosition()

Returns the horizontal position of the label's text, relative to its image.

getIcon()

Returns the graphic image (glyph, icon) that the label displays.

getIconTextGap()

Returns the amount of space between the text and the icon displayed in this label.

getLabelFor()

Get the component this is labelling.

getText()

Returns the text string that the label displays.

getUI()

Returns the L&F object that renders this component.

getUIClassID()

Returns a string that specifies the name of the l&f class that renders this component.

getVerticalAlignment()

Returns the alignment of the label's contents along the Y axis.

getVerticalTextPosition()

Returns the vertical position of the label's text, relative to its image.

setDisabledIcon(Icon)

Set the icon to be displayed if this JLabel is "disabled", i.e.

setDisplayedMnemonic(char)

setDisplayedMnemonic(int)

Specify a keycode that indicates a mnemonic key.

setFont(Font)

Sets the font used to display the label's text.

setHorizontalAlignment(int)

Sets the alignment of the label's contents along the X axis.

setHorizontalTextPosition(int)

Sets the horizontal position of the label's text, relative to its image.

setIcon(Icon)

Defines the icon this component will display.

setIconTextGap(int)

If both the icon and text properties are set, this property defines the space between them.

setLabelFor(Component)

Set the component this is labelling.

setText(String)

Defines the single line of text this component will display.

setUI(LabelUI)

Sets the L&F object that renders this component.

setVerticalAlignment(int)

Sets the alignment of the label's contents along the Y axis.

setVerticalTextPosition(int)

Sets the vertical position of the label's text, relative to its image.

updateUI()

Notification from the UIFactory that the L&F has changed.

 protected Component labelFor

--- Accessibility Support ---

 public JLabel(String text,
               Icon icon,
               int horizontalAlignment)

Creates a JLabel instance with the specified text, image, and horizontal alignment. The label is centered vertically in its display area. The text is to the right of the image.

Parameters:

text - The text to be displayed by the label.

icon - The image to be displayed by the label.

horizontalAlignment - One of the following constants defined in SwingConstants: LEFT, CENTER, or RIGHT.

 public JLabel(String text,
               int horizontalAlignment)

Creates a JLabel instance with the specified text and horizontal alignment. The label is centered vertically in its display area.

Parameters:

text - The text to be displayed by the label.

horizontalAlignment - One of the following constants defined in SwingConstants: LEFT, CENTER, or RIGHT.

 public JLabel(String text)

Creates a JLabel instance with the specified text. The label is aligned against the left side of its display area, and centered vertically.

Parameters:

text - The text to be displayed by the label.

 public JLabel(Icon image,
               int horizontalAlignment)

Creates a JLabel instance with the specified image and horizontal alignment. The label is centered vertically in its display area.

Parameters:

icon - The image to be displayed by the label.

horizontalAlignment - One of the following constants defined in SwingConstants: LEFT, CENTER, or RIGHT.

 public JLabel(Icon image)

Creates a JLabel instance with the specified image. The label is centered vertically and horizontally in its display area.

Parameters:

icon - The image to be displayed by the label.

 public JLabel()

Creates a JLabel instance with no image and with an empty string for the title. The label is centered vertically in its display area. The label's contents, once set, will be displayed at the left of the label's display area.

 public LabelUI getUI()

Returns the L&F object that renders this component.

Returns:

LabelUI object

 public void setUI(LabelUI ui)

Sets the L&F object that renders this component.

Parameters:

ui - the LabelUI L&F object

See Also:

getUI

 public void updateUI()

Notification from the UIFactory that the L&F has changed.

Overrides:

updateUI in class JComponent

See Also:

updateUI

 public String getUIClassID()

Returns a string that specifies the name of the l&f class that renders this component.

Returns:

String "LabelUI"

Overrides:

getUIClassID in class JComponent

See Also:

getUIClassID, getUI

 public String getText()

Returns the text string that the label displays.

Returns:

a String

See Also:

setText

 public void setText(String text)

Defines the single line of text this component will display. If the value of text is null or empty string, nothing is displayed.

The default value of this property is null.

This is a JavaBeans bound property.

See Also:

setVerticalTextPosition, setHorizontalTextPosition, setIcon

 public Icon getIcon()

Returns the graphic image (glyph, icon) that the label displays.

Returns:

an Icon

See Also:

setIcon

 public void setIcon(Icon icon)

Defines the icon this component will display. If the value of icon is null, nothing is displayed.

The default value of this property is null.

This is a JavaBeans bound property.

See Also:

setVerticalTextPosition, setHorizontalTextPosition, getIcon

 public Icon getDisabledIcon()

Returns the value of the disabledIcon property if it's been set, If it hasn't been set and the value of the icon property is an ImageIcon, we compute a "grayed out" version of the icon and update the disabledIcon property with that.

Returns:

The value of the disabledIcon property.

See Also:

setDisabledIcon, ImageIcon

 public void setDisabledIcon(Icon disabledIcon)

Set the icon to be displayed if this JLabel is "disabled", i.e. JLabel.setEnabled(false).

The default value of this property is null.

Parameters:

disabledIcon - the Icon to display when the component is disabled

See Also:

getDisabledIcon, setEnabled

 public void setDisplayedMnemonic(int key)

Specify a keycode that indicates a mnemonic key. This property is used when the label is part of a larger component. If the labelFor property of the label is not null, the label will call the requestFocus method of the component specified by the labelFor property when the mnemonic is activated.

See Also:

getLabelFor, setLabelFor

 public void setDisplayedMnemonic(char aChar)

 public int getDisplayedMnemonic()

Return the keycode that indicates a mnemonic key. This property is used when the label is part of a larger component. If the labelFor property of the label is not null, the label will call the requestFocus method of the component specified by the labelFor property when the mnemonic is activated.

Returns:

int value for the mnemonic key

See Also:

getLabelFor, setLabelFor

 protected int checkHorizontalKey(int key,
                                  String message)

Verify that key is a legal value for the horizontalAlignment or horizontalTextPosition properties.

Parameters:

key - the property value to check

message - the IllegalArgumentException detail message

Throws: IllegalArgumentException

if key isn't LEFT, CENTER, or RIGHT.

See Also:

setHorizontalAlignment, setHorizontalTextPosition

 protected int checkVerticalKey(int key,
                                String message)

Verify that key is a legal value for the verticalAlignment or verticalTextPosition properties.

Parameters:

key - the property value to check

message - the IllegalArgumentException detail message

Throws: IllegalArgumentException

if key isn't TOP, CENTER, or BOTTOM.

See Also:

setVerticalAlignment, setVerticalTextPosition

 public int getIconTextGap()

Returns the amount of space between the text and the icon displayed in this label.

Returns:

an int equal to the number of pixels between the text and the icon.

See Also:

setIconTextGap

 public void setIconTextGap(int iconTextGap)

If both the icon and text properties are set, this property defines the space between them.

The default value of this property is 4 pixels.

This is a JavaBeans bound property.

See Also:

getIconTextGap

 public int getVerticalAlignment()

Returns the alignment of the label's contents along the Y axis.

Returns:

The value of the verticalAlignment property, one of the following constants defined in SwingConstants: TOP, CENTER, or BOTTOM.

See Also:

SwingConstants, setVerticalAlignment

 public void setVerticalAlignment(int alignment)

Sets the alignment of the label's contents along the Y axis.

The default value of this property is CENTER.

This is a JavaBeans bound property.

Parameters:

alignment - One of the following constants defined in SwingConstants: TOP, CENTER (the default), or BOTTOM.

See Also:

SwingConstants, getVerticalAlignment

 public int getHorizontalAlignment()

Returns the alignment of the label's contents along the X axis.

Returns:

The value of the horizontalAlignment property, one of the following constants defined in SwingConstants: LEFT, CENTER, or RIGHT.

See Also:

setHorizontalAlignment, SwingConstants

 public void setHorizontalAlignment(int alignment)

Sets the alignment of the label's contents along the X axis.

This is a JavaBeans bound property.

Parameters:

alignment - One of the following constants defined in SwingConstants: LEFT (the default for text-only labels), CENTER (the default for image-only labels), or RIGHT.

See Also:

SwingConstants, getHorizontalAlignment

 public int getVerticalTextPosition()

Returns the vertical position of the label's text, relative to its image.

Returns:

One of the following constants defined in SwingConstants: TOP, CENTER, or BOTTOM.

See Also:

setVerticalTextPosition, SwingConstants

 public void setVerticalTextPosition(int textPosition)

Sets the vertical position of the label's text, relative to its image.

The default value of this property is CENTER.

This is a JavaBeans bound property.

Parameters:

textPosition - One of the following constants defined in SwingConstants: TOP, CENTER (the default), or BOTTOM.

See Also:

SwingConstants, getVerticalTextPosition

 public int getHorizontalTextPosition()

Returns the horizontal position of the label's text, relative to its image.

Returns:

One of the following constants defined in SwingConstants: LEFT, CENTER, or RIGHT.

See Also:

SwingConstants

 public void setHorizontalTextPosition(int x)

Sets the horizontal position of the label's text, relative to its image.

Parameters:

x - One of the following constants defined in SwingConstants: LEFT, CENTER, or RIGHT (the default).

See Also:

SwingConstants

 public void setFont(Font font)

Sets the font used to display the label's text.

Parameters:

font - The font to use.

Overrides:

setFont in class Component

 public AccessibleContext getAccessibleContext()

Get the AccessibleContext of this object

Returns:

the AccessibleContext of this object

Overrides:

getAccessibleContext in class JComponent

 public Component getLabelFor()

Get the component this is labelling.

Returns:

the Component this is labelling. Can be null if this does not label a Component. If the displayedMnemonic property is set and the labelFor property is also set, the label will call the requestFocus method of the component specified by the labelFor property when the mnemonic is activated.

See Also:

getDisplayedMnemonic, setDisplayedMnemonic

 public void setLabelFor(Component c)

Set the component this is labelling. Can be null if this does not label a Component. If the displayedMnemonic property is set and the labelFor property is also set, the label will call the requestFocus method of the component specified by the labelFor property when the mnemonic is activated.

Parameters:

c - the Component this label is for, or null if the label is not the label for a component

See Also:

getDisplayedMnemonic, setDisplayedMnemonic

All Packages  Class Hierarchy  This Package  Previous  Next  Index