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/OpenJDK 21

Class SynthComboBoxUI

All Implemented Interfaces:
PropertyChangeListener, EventListener, SynthConstants, SynthUI
public class SynthComboBoxUI extends BasicComboBoxUI implements PropertyChangeListener, SynthUI
Provides the Synth L&F UI delegate for JComboBox.
Since:
1.7

Nested Class Summary

Field Summary

Fields declared in interface javax.swing.plaf.synth.SynthConstants

DEFAULT, DISABLED, ENABLED, FOCUSED, MOUSE_OVER, PRESSED, SELECTED

Constructor Summary

Constructor Description
SynthComboBoxUI()
Constructs a SynthComboBoxUI.

Method Summary

Modifier and Type Method Description
static ComponentUI createUI(JComponent c)
Creates a new UI object for the given component.
SynthContext getContext(JComponent c)
Returns the Context for the specified component.
protected Dimension getDefaultSize()
Returns the default size of an empty display area of the combo box using the current renderer and font.
Dimension getMinimumSize(JComponent c)
The minimum size is the size of the display area plus insets plus the button.
void installUI(JComponent c)
Configures the specified component appropriately for the look and feel.
void paint(Graphics g, JComponent c)
Paints the specified component according to the Look and Feel.
protected void paint(SynthContext context, Graphics g)
Paints the specified component.
void paintBorder(SynthContext context, Graphics g, int x, int y, int w, int h)
Paints the border.
void paintCurrentValue(Graphics g, Rectangle bounds, boolean hasFocus)
Paints the currently selected item.
void propertyChange(PropertyChangeEvent e)
This method gets called when a bound property is changed.
void update(Graphics g, JComponent c)
Notifies this UI delegate to repaint the specified component.

Methods declared in class java.lang.Object

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

Constructor Details

SynthComboBoxUI

public SynthComboBoxUI()
Constructs a SynthComboBoxUI.

Method Details

createUI

public static ComponentUI createUI(JComponent c)
Creates a new UI object for the given component.
Parameters:
c - component to create UI object for
Returns:
the UI object

installUI

public void installUI(JComponent c)
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:
  1. 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.
  2. Install a LayoutManager on the component if necessary.
  3. Create/add any required sub-components to the component.
  4. Create/install event listeners on the component.
  5. Create/install a PropertyChangeListener on the component in order to detect and respond to component property changes appropriately.
  6. Install keyboard UI (mnemonics, traversal, etc.) on the component.
  7. Initialize any appropriate instance data.
Overridden to ensure that ButtonHandler is created prior to any of the other installXXX methods, since several of them reference buttonHandler.
Overrides:
installUI in class ComponentUI
Parameters:
c - the component where this UI delegate is being installed
See Also:

getContext

public SynthContext getContext(JComponent c)
Returns the Context for the specified component.
Specified by:
getContext in interface SynthUI
Parameters:
c - Component requesting SynthContext.
Returns:
SynthContext describing component.

propertyChange

public void propertyChange(PropertyChangeEvent e)
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.

update

public void update(Graphics g, JComponent c)
Notifies this UI delegate to repaint the specified component. This method paints the component background, then calls the paint(SynthContext,Graphics) method.

In general, this method does not need to be overridden by subclasses. All Look and Feel rendering code should reside in the paint method.

Overrides:
update in class ComponentUI
Parameters:
g - the Graphics object used for painting
c - the component being painted
See Also:

getMinimumSize

public Dimension getMinimumSize(JComponent c)
The minimum size is the size of the display area plus insets plus the button.
Overrides:
getMinimumSize in class BasicComboBoxUI
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:
a Dimension object or null
See Also:

paint

public void paint(Graphics g, JComponent c)
Paints the specified component according to the Look and Feel.

This method is not used by Synth Look and Feel. Painting is handled by the paint(SynthContext,Graphics) method.

Overrides:
paint in class ComponentUI
Parameters:
g - the Graphics object used for painting
c - the component being painted
See Also:

paint

protected void paint(SynthContext context, Graphics g)
Paints the specified component.
Parameters:
context - context for the component being painted
g - the Graphics object used for painting
See Also:

paintBorder

public void paintBorder(SynthContext context, Graphics g, int x, int y, int w, int h)
Paints the border.
Specified by:
paintBorder in interface SynthUI
Parameters:
context - a component context
g - Graphics to paint on
x - the X coordinate
y - the Y coordinate
w - width of the border
h - height of the border

paintCurrentValue

public void paintCurrentValue(Graphics g, Rectangle bounds, boolean hasFocus)
Paints the currently selected item.
Overrides:
paintCurrentValue in class BasicComboBoxUI
Parameters:
g - an instance of Graphics
bounds - a bounding rectangle to render to
hasFocus - is focused

getDefaultSize

protected Dimension getDefaultSize()
Returns the default size of an empty display area of the combo box using the current renderer and font. This method was overridden to use SynthComboBoxRenderer instead of DefaultListCellRenderer as the default renderer when calculating the size of the combo box. This is used in the case of the combo not having any data.
Overrides:
getDefaultSize in class BasicComboBoxUI
Returns:
the size of an empty display area
See Also:

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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/plaf/synth/SynthComboBoxUI.html