Class BasicComboBoxUI

protected JButton arrowButton

The arrow button that is displayed in the right side of JComboBox. This button is used to hide and show combo box's list of items.

protected Dimension cachedMinimumSize

The current minimum size if isMinimumSizeDirty is false. Setup by getMinimumSize() and invalidated by the various listeners.

protected JComboBox comboBox

The combo box represented by this UI delegate.

protected CellRendererPane currentValuePane

Used to render the combo box values.

protected Component editor

The component that is responsible for displaying/editing the selected item of the combo box.

See Also:

BasicComboBoxEditor.getEditorComponent()

protected FocusListener focusListener

A listener listening to focus events occurring in the JComboBox.

protected boolean hasFocus

A flag indicating whether JComboBox currently has the focus.

protected boolean isMinimumSizeDirty

Indicates whether or not the cachedMinimumSize field is valid or not.

protected ItemListener itemListener

A listener listening to item events fired by the JComboBox.

protected KeyListener keyListener

A listener listening to key events that occur while JComboBox has the focus.

protected JList listBox

List used when rendering selected item of the combo box. The selection and foreground colors for combo box renderer are configured from this list.

protected ListDataListener listDataListener

ListDataListener listening to JComboBox model

protected ComboPopup popup

Popup list containing the combo box's menu items.

protected KeyListener popupKeyListener

protected MouseListener popupMouseListener

protected MouseMotionListener popupMouseMotionListener

protected PropertyChangeListener propertyChangeListener

Listener listening to changes in the bound properties of JComboBox

public BasicComboBoxUI()

Creates a new BasicComboBoxUI object.

public void addEditor()

Adds the current editor to the combo box.

public void configureArrowButton()

Configures the arrow button.

See Also:

configureArrowButton()

protected void configureEditor()

Configures the editor for this combo box.

protected JButton createArrowButton()

Creates an arrow button for this JComboBox. The arrow button is displayed at the right end of the combo box and is used to display/hide the drop down list of items.

Returns:

A new button.

protected ComboBoxEditor createEditor()

Creates the component that will be responsible for displaying/editing the selected item in the combo box. This editor is used only when combo box is editable.

Returns:

A new component that will be responsible for displaying/editing the selected item in the combo box.

protected FocusListener createFocusListener()

Creates the FocusListener that will listen to changes in this JComboBox's focus.

Returns:

the FocusListener.

protected ItemListener createItemListener()

Creates an ItemListener that will listen to the changes in the JComboBox's selection.

Returns:

The ItemListener

protected KeyListener createKeyListener()

Creates a KeyListener to listen to key events.

Returns:

KeyListener that listens to key events.

protected LayoutManager createLayoutManager()

Creates and returns a layout manager for the combo box. Subclasses can override this method to provide a different layout.

Returns:

a layout manager for the combo box.

protected ListDataListener createListDataListener()

Creates a ListDataListener to listen to the combo box's data model.

Returns:

The new listener.

protected ComboPopup createPopup()

Creates the popup that will contain list of combo box's items.

Returns:

popup containing list of combo box's items

protected PropertyChangeListener createPropertyChangeListener()

Creates a PropertyChangeListener to listen to the changes in the JComboBox's bound properties.

Returns:

The PropertyChangeListener

protected ListCellRenderer createRenderer()

Creates a component that will be responsible for rendering the selected component in the combo box.

Returns:

A renderer for the combo box.

public static ComponentUI createUI(JComponent c)

A factory method to create a UI delegate for the given JComponent, which should be a JComboBox.

Overrides:

createUI in interface ComponentUI

Parameters:

c - The JComponent a UI is being created for.

Returns:

A UI delegate for the JComponent.

public Accessible getAccessibleChild(JComponent c,
                                     int i)

Returns the accessible child with the specified index.

Overrides:

getAccessibleChild in interface ComponentUI

Parameters:

c - the component, this is ignored

i - the index of the accessible child to return

public int getAccessibleChildrenCount(JComponent c)

Returns the number of accessible children of the combobox.

Overrides:

getAccessibleChildrenCount in interface ComponentUI

Parameters:

c - the component (combobox) to check, ignored

Returns:

the number of accessible children of the combobox

protected Dimension getDefaultSize()

Returns the default size for the display area of a combo box that does not contain any elements. This method returns the width and height of a single space in the current font, plus a margin of 1 pixel.

Returns:

The default display size.

See Also:

getDisplaySize()

protected Dimension getDisplaySize()

Returns the size of the display area for the combo box. This size will be the size of the combo box, not including the arrowButton.

Returns:

The size of the display area for the combo box.

protected Insets getInsets()

Returns the insets of the current border.

Returns:

Insets representing space between combo box and its border

public Dimension getMaximumSize(JComponent c)

Returns the maximum size for this JComboBox for this look and feel.

Overrides:

getMaximumSize in interface ComponentUI

Parameters:

c - The JComponent to find the maximum size for

Returns:

The maximum size (Dimension(32767, 32767)).

public Dimension getMinimumSize(JComponent c)

Returns the minimum size for this JComboBox for this look and feel. Also makes sure cachedMinimimSize is setup correctly.

Overrides:

getMinimumSize in interface ComponentUI

Parameters:

c - The JComponent to find the minimum size for.

Returns:

The dimensions of the minimum size.

public Dimension getPreferredSize(JComponent c)

Returns preferred size for the combo box.

Overrides:

getPreferredSize in interface ComponentUI

Parameters:

c - comboBox for which to get preferred size

Returns:

The preferred size for the given combo box

protected void installComponents()

Installs the components for this JComboBox. ArrowButton, main part of combo box (upper part) and popup list of items are created and configured here.

protected void installDefaults()

Installs the defaults that are defined in the BasicLookAndFeel for this JComboBox.

See Also:

uninstallDefaults()

protected void installKeyboardActions()

Installs the keyboard actions for the JComboBox as specified by the look and feel.

protected void installListeners()

Creates and installs the listeners for this UI.

See Also:

uninstallListeners()

public void installUI(JComponent c)

Installs the UI for the given JComponent.

Overrides:

installUI in interface ComponentUI

Parameters:

c - the JComponent to install a UI for.

See Also:

uninstallUI(JComponent)

public boolean isFocusTraversable(JComboBox c)

JComboBox is focus traversable if it is editable and not otherwise.

Overrides:

isFocusTraversable in interface ComboBoxUI

Parameters:

c - combo box for which to check whether it is focus traversable

Returns:

true if focus tranversable and false otherwise

protected boolean isNavigationKey(int keyCode)

Returns true if the specified key is a navigation key and false otherwise

Parameters:

keyCode - a key for which to check whether it is navigation key or not.

Returns:

true if the specified key is a navigation key and false otherwis

public boolean isPopupVisible(JComboBox c)

Returns true if the popup is visible, and false otherwise.

Overrides:

isPopupVisible in interface ComboBoxUI

Parameters:

c - The JComboBox to check

Returns:

true if popup part of the JComboBox is visible and false otherwise.

public void paint(Graphics g,
                  JComponent c)

Paints given menu item using specified graphics context

Overrides:

paint in interface ComponentUI

Parameters:

g - The graphics context used to paint this combo box

c - comboBox which needs to be painted.

public void paintCurrentValue(Graphics g,
                              Rectangle bounds,
                              boolean hasFocus)

Paints currently selected value in the main part of the combo box (part without popup).

Parameters:

g - graphics context

bounds - Rectangle representing the size of the area in which selected item should be drawn

hasFocus - true if combo box has focus and false otherwise

public void paintCurrentValueBackground(Graphics g,
                                        Rectangle bounds,
                                        boolean hasFocus)

Paints the background of part of the combo box, where currently selected value is displayed. If the combo box has focus this method should also paint focus rectangle around the combo box.

Parameters:

g - graphics context

bounds - Rectangle representing the size of the largest item in the comboBox

hasFocus - true if combo box has fox and false otherwise

protected Rectangle rectangleForCurrentValue()

Returns the bounds in which comboBox's selected item will be displayed.

Returns:

rectangle bounds in which comboBox's selected Item will be displayed

public void removeEditor()

Removes the current editor from the combo box.

protected void selectNextPossibleValue()

Selects next possible item relative to the current selection to be next selected item in the combo box.

protected void selectPreviousPossibleValue()

Selects previous item relative to current selection to be next selected item.

public void setPopupVisible(JComboBox c,
                            boolean v)

Displays/hides the JComboBox's list of items on the screen.

Overrides:

setPopupVisible in interface ComboBoxUI

Parameters:

c - The combo box, for which list of items should be displayed/hidden

v - true if show popup part of the jcomboBox and false to hide.

protected void toggleOpenClose()

Displays combo box popup if the popup is not currently shown on the screen and hides it if it is currently shown

public void unconfigureArrowButton()

Unconfigures the arrow button.

See Also:

configureArrowButton()

protected void unconfigureEditor()

Unconfigures the editor for this combo box.

protected void uninstallComponents()

Uninstalls components from this JComboBox.

See Also:

installComponents()

protected void uninstallDefaults()

Uninstalls the defaults and sets any objects created during install to null.

See Also:

installDefaults()

protected void uninstallKeyboardActions()

Uninstalls the keyboard actions for the JComboBox there were installed by in installListeners().

protected void uninstallListeners()

Detaches all the listeners we attached in installListeners().

See Also:

installListeners()

public void uninstallUI(JComponent c)

Uninstalls the UI for the given JComponent.

Overrides:

uninstallUI in interface ComponentUI

Parameters:

c - The JComponent that is having this UI removed.

See Also:

installUI(JComponent)