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.
Fields
Modifier and Type | Field and Description |
---|---|
protected static BasicLabelUI |
labelUI The default |
Constructors
Constructor and Description |
---|
BasicLabelUI() |
Methods
Modifier and Type | Method and Description |
---|---|
static ComponentUI |
createUI(JComponent c) Returns an instance of |
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. |
Dimension |
getPreferredSize(JComponent c) Returns the specified component's preferred 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. |
void |
installUI(JComponent c) Configures the specified component appropriately for the look and feel. |
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. |
void |
uninstallUI(JComponent c) Reverses configuration which was done on the specified component during |
Methods inherited from class javax.swing.plaf.ComponentUI
contains, getAccessibleChild, getAccessibleChildrenCount, update
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Fields
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".
Constructors
BasicLabelUI
public BasicLabelUI()
Methods
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 ofJLabel
-
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(javax.swing.JComponent, java.awt.FontMetrics, java.lang.String, javax.swing.Icon, int, int, int, int, java.awt.Rectangle, java.awt.Rectangle, java.awt.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 ofJLabel
-
g
- an instance ofGraphics
-
s
- a text -
textX
- an X coordinate -
textY
- an Y coordinate - See Also:
-
paint(java.awt.Graphics, javax.swing.JComponent)
,paintDisabledText(javax.swing.JLabel, java.awt.Graphics, java.lang.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 ofJLabel
-
g
- an instance ofGraphics
-
s
- a text -
textX
- an X coordinate -
textY
- an Y coordinate - See Also:
-
paint(java.awt.Graphics, javax.swing.JComponent)
,paintEnabledText(javax.swing.JLabel, java.awt.Graphics, java.lang.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(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 classComponentUI
- Parameters:
-
g
- theGraphics
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(javax.swing.JLabel, java.awt.Graphics, java.lang.String, int, int)
,paintDisabledText(javax.swing.JLabel, java.awt.Graphics, java.lang.String, int, int)
,layoutCL(javax.swing.JLabel, java.awt.FontMetrics, java.lang.String, javax.swing.Icon, java.awt.Rectangle, java.awt.Rectangle, java.awt.Rectangle)
getPreferredSize
public Dimension getPreferredSize(JComponent c)
Description copied from class: ComponentUI
Returns the specified component's preferred size appropriate for the look and feel. If null
is returned, the preferred 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 returns null
.
- Overrides:
-
getPreferredSize
in classComponentUI
- Parameters:
-
c
- the component whose preferred size is being queried; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components - See Also:
-
JComponent.getPreferredSize()
,LayoutManager.preferredLayoutSize(java.awt.Container)
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 classComponentUI
- 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(java.awt.Container)
,ComponentUI.getPreferredSize(javax.swing.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 classComponentUI
- 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(java.awt.Container)
getBaseline
public int getBaseline(JComponent c, int width, int height)
Returns the baseline.
- Overrides:
-
getBaseline
in classComponentUI
- 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
- ifc
isnull
-
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 classComponentUI
- Parameters:
-
c
-JComponent
to return baseline resize behavior for - Returns:
- an enum indicating how the baseline changes as the component size changes
- Throws:
-
NullPointerException
- ifc
isnull
- Since:
- 1.6
- See Also:
JComponent.getBaseline(int, int)
installUI
public void installUI(JComponent c)
Description copied from class: ComponentUI
Configures the specified component appropriately for the look and feel. This method is invoked when the ComponentUI
instance is being installed as the UI delegate on the specified component. This method should completely configure the component for the look and feel, including the following:
- Install default property values for color, fonts, borders, icons, opacity, etc. on the component. Whenever possible, property values initialized by the client program should not be overridden.
- Install a
LayoutManager
on the component if necessary. - Create/add any required sub-components to the component.
- Create/install event listeners on the component.
- Create/install a
PropertyChangeListener
on the component in order to detect and respond to component property changes appropriately. - Install keyboard UI (mnemonics, traversal, etc.) on the component.
- Initialize any appropriate instance data.
- Overrides:
-
installUI
in classComponentUI
- Parameters:
-
c
- the component where this UI delegate is being installed - See Also:
-
ComponentUI.uninstallUI(javax.swing.JComponent)
,JComponent.setUI(javax.swing.plaf.ComponentUI)
,JComponent.updateUI()
uninstallUI
public void uninstallUI(JComponent c)
Description copied from class: ComponentUI
Reverses configuration which was done on the specified component during installUI
. This method is invoked when this UIComponent
instance is being removed as the UI delegate for the specified component. This method should undo the configuration performed in installUI
, being careful to leave the JComponent
instance in a clean state (no extraneous listeners, look-and-feel-specific property objects, etc.). This should include the following:
- Remove any UI-set borders from the component.
- Remove any UI-set layout managers on the component.
- Remove any UI-added sub-components from the component.
- Remove any UI-added event/property listeners from the component.
- Remove any UI-installed keyboard UI from the component.
- Nullify any allocated instance data objects to allow for GC.
- Overrides:
-
uninstallUI
in classComponentUI
- Parameters:
-
c
- the component from which this UI delegate is being removed; this argument is often ignored, but might be used if the UI object is stateless and shared by multiple components - See Also:
-
ComponentUI.installUI(javax.swing.JComponent)
,JComponent.updateUI()
installDefaults
protected void installDefaults(JLabel c)
Installs default properties.
- Parameters:
-
c
- an instance ofJLabel
installListeners
protected void installListeners(JLabel c)
Registers listeners.
- Parameters:
-
c
- an instance ofJLabel
installComponents
protected void installComponents(JLabel c)
Registers components.
- Parameters:
-
c
- an instance ofJLabel
installKeyboardActions
protected void installKeyboardActions(JLabel l)
Registers keyboard actions.
- Parameters:
-
l
- an instance ofJLabel
uninstallDefaults
protected void uninstallDefaults(JLabel c)
Uninstalls default properties.
- Parameters:
-
c
- an instance ofJLabel
uninstallListeners
protected void uninstallListeners(JLabel c)
Unregisters listeners.
- Parameters:
-
c
- an instance ofJLabel
uninstallComponents
protected void uninstallComponents(JLabel c)
Unregisters components.
- Parameters:
-
c
- an instance ofJLabel
uninstallKeyboardActions
protected void uninstallKeyboardActions(JLabel c)
Unregisters keyboard actions.
- Parameters:
-
c
- an instance ofJLabel
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 interfacePropertyChangeListener
- Parameters:
-
e
- A PropertyChangeEvent object describing the event source and the property that has changed.
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https://docs.oracle.com/javase/8/docs/api/javax/swing/plaf/basic/BasicLabelUI.html