# Class ComboBoxUI

java.lang.Object
javax.swing.plaf.ComponentUI
javax.swing.plaf.ComboBoxUI

Direct Known Subclasses:
  `BasicComboBoxUI, MultiComboBoxUI`

public abstract class ComboBoxUI extends ComponentUI
Pluggable look and feel interface for JComboBox.

- ## Constructor Summary

  Constructors
  Modifier
  Constructor
  Description
  `protected`
  `ComboBoxUI()`
  Constructor for subclasses to call.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `abstract boolean`
  `isFocusTraversable(JComboBox<?> c)`
  Determine whether or not the combo box itself is traversable
  `abstract boolean`
  `isPopupVisible(JComboBox<?> c)`
  Determine the visibility of the popup
  `abstract void`
  `setPopupVisible(JComboBox<?> c, boolean v)`
  Set the visibility of the popup

  ### Methods declared in class ComponentUI

  `contains, createUI, getAccessibleChild, getAccessibleChildrenCount, getBaseline, getBaselineResizeBehavior, getMaximumSize, getMinimumSize, getPreferredSize, installUI, paint, uninstallUI, update`

  ### Methods declared in class Object

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

- ## Constructor Details

  - ### ComboBoxUI

    protected ComboBoxUI()
    Constructor for subclasses to call.

- ## Method Details

  - ### setPopupVisible

    public abstract void setPopupVisible(JComboBox<?> c, boolean v)
    Set the visibility of the popup
    Parameters:
      `c` - a `JComboBox`
      `v` - a `boolean` determining the visibility of the popup

  - ### isPopupVisible

    public abstract boolean isPopupVisible(JComboBox<?> c)
    Determine the visibility of the popup
    Parameters:
      `c` - a `JComboBox`
    Returns:
      true if popup of the `JComboBox` is visible

  - ### isFocusTraversable

    public abstract boolean isFocusTraversable(JComboBox<?> c)
    Determine whether or not the combo box itself is traversable
    Parameters:
      `c` - a `JComboBox`
    Returns:
      true if the given `JComboBox` is traversable