javax.swing.plaf.basic

Class BasicComboBoxUI

java.lang.Object

javax.swing.plaf.ComponentUI

javax.swing.plaf.ComboBoxUI

javax.swing.plaf.basic.BasicComboBoxUI

public class BasicComboBoxUI
extends javax.swing.plaf.ComboBoxUI

A UI delegate for the JComboBox component.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	BasicComboBoxUI.ComboBoxLayoutManager A LayoutManager used to position the sub-components of the JComboBox.
class	BasicComboBoxUI.FocusHandler Handles focus changes occuring in the combo box.
class	BasicComboBoxUI.ItemHandler Handles ItemEvents fired by the JComboBox when its selected item changes.
class	BasicComboBoxUI.KeyHandler KeyHandler handles key events occuring while JComboBox has focus.
class	BasicComboBoxUI.ListDataHandler Handles the changes occurring in the JComboBox's data model.
class	BasicComboBoxUI.PropertyChangeHandler Handles PropertyChangeEvents fired by the JComboBox.

Field Summary

Fields

Modifier and Type	Field and Description
protected javax.swing.JButton	arrowButton The arrow button that is displayed in the right side of JComboBox.
protected java.awt.Dimension	cachedMinimumSize The current minimum size if isMinimumSizeDirty is false.
protected javax.swing.JComboBox	comboBox The combo box represented by this UI delegate.
protected javax.swing.CellRendererPane	currentValuePane Used to render the combo box values.
protected java.awt.Component	editor The component that is responsible for displaying/editing the selected item of the combo box.
protected java.awt.event.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 java.awt.event.ItemListener	itemListener A listener listening to item events fired by the JComboBox.
protected java.awt.event.KeyListener	keyListener A listener listening to key events that occur while JComboBox has the focus.
protected javax.swing.JList	listBox List used when rendering selected item of the combo box.
protected javax.swing.event.ListDataListener	listDataListener ListDataListener listening to JComboBox model
protected ComboPopup	popup Popup list containing the combo box's menu items.
protected java.awt.event.KeyListener	popupKeyListener
protected java.awt.event.MouseListener	popupMouseListener
protected java.awt.event.MouseMotionListener	popupMouseMotionListener
protected java.beans.PropertyChangeListener	propertyChangeListener Listener listening to changes in the bound properties of JComboBox

Constructor Summary

Constructors

Constructor and Description
BasicComboBoxUI() Creates a new BasicComboBoxUI object.

Method Summary

Methods

Modifier and Type	Method and Description
void	addEditor() Adds the current editor to the combo box.
void	configureArrowButton() Configures the arrow button.
protected void	configureEditor() Configures the editor for this combo box.
protected javax.swing.JButton	createArrowButton() Creates an arrow button for this JComboBox.
protected javax.swing.ComboBoxEditor	createEditor() Creates the component that will be responsible for displaying/editing the selected item in the combo box.
protected java.awt.event.FocusListener	createFocusListener() Creates the FocusListener that will listen to changes in this JComboBox's focus.
protected java.awt.event.ItemListener	createItemListener() Creates an ItemListener that will listen to the changes in the JComboBox's selection.
protected java.awt.event.KeyListener	createKeyListener() Creates a KeyListener to listen to key events.
protected java.awt.LayoutManager	createLayoutManager() Creates and returns a layout manager for the combo box.
protected javax.swing.event.ListDataListener	createListDataListener() Creates a ListDataListener to listen to the combo box's data model.
protected ComboPopup	createPopup() Creates the popup that will contain list of combo box's items.
protected java.beans.PropertyChangeListener	createPropertyChangeListener() Creates a PropertyChangeListener to listen to the changes in the JComboBox's bound properties.
protected javax.swing.ListCellRenderer	createRenderer() Creates a component that will be responsible for rendering the selected component in the combo box.
static javax.swing.plaf.ComponentUI	createUI(javax.swing.JComponent c) A factory method to create a UI delegate for the given JComponent, which should be a JComboBox.
javax.accessibility.Accessible	getAccessibleChild(javax.swing.JComponent c, int i) Returns the accessible child with the specified index.
int	getAccessibleChildrenCount(javax.swing.JComponent c) Returns the number of accessible children of the combobox.
protected java.awt.Dimension	getDefaultSize() Returns the default size for the display area of a combo box that does not contain any elements.
protected java.awt.Dimension	getDisplaySize() Returns the size of the display area for the combo box.
protected java.awt.Insets	getInsets() Returns the insets of the current border.
java.awt.Dimension	getMaximumSize(javax.swing.JComponent c) Returns the maximum size for this JComboBox for this look and feel.
java.awt.Dimension	getMinimumSize(javax.swing.JComponent c) Returns the minimum size for this JComboBox for this look and feel.
java.awt.Dimension	getPreferredSize(javax.swing.JComponent c) Returns preferred size for the combo box.
protected void	installComponents() Installs the components for this JComboBox.
protected void	installDefaults() Installs the defaults that are defined in the BasicLookAndFeel for this JComboBox.
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.
void	installUI(javax.swing.JComponent c) Installs the UI for the given JComponent.
boolean	isFocusTraversable(javax.swing.JComboBox c) JComboBox is focus traversable if it is editable and not otherwise.
protected boolean	isNavigationKey(int keyCode) Returns true if the specified key is a navigation key and false otherwise
boolean	isPopupVisible(javax.swing.JComboBox c) Returns true if the popup is visible, and false otherwise.
void	paint(java.awt.Graphics g, javax.swing.JComponent c) Paints given menu item using specified graphics context
void	paintCurrentValue(java.awt.Graphics g, java.awt.Rectangle bounds, boolean hasFocus) Paints currently selected value in the main part of the combo box (part without popup).
void	paintCurrentValueBackground(java.awt.Graphics g, java.awt.Rectangle bounds, boolean hasFocus) Paints the background of part of the combo box, where currently selected value is displayed.
protected java.awt.Rectangle	rectangleForCurrentValue() Returns the bounds in which comboBox's selected item will be displayed.
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.
void	setPopupVisible(javax.swing.JComboBox c, boolean v) Displays/hides the JComboBox's list of items on the screen.
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
void	unconfigureArrowButton() Unconfigures the arrow button.
protected void	unconfigureEditor() Unconfigures the editor for this combo box.
protected void	uninstallComponents() Uninstalls components from this JComboBox.
protected void	uninstallDefaults() Uninstalls the defaults and sets any objects created during install to null.
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().
void	uninstallUI(javax.swing.JComponent c) Uninstalls the UI for the given JComponent.

Methods inherited from class javax.swing.plaf.ComponentUI

contains, update

Methods inherited from class java.lang.Object

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

Field Detail

arrowButton

protected javax.swing.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.

comboBox

protected javax.swing.JComboBox comboBox

The combo box represented by this UI delegate.

editor

protected java.awt.Component editor

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

See Also:

BasicComboBoxEditor.getEditorComponent()

focusListener

protected java.awt.event.FocusListener focusListener

A listener listening to focus events occurring in the JComboBox.

hasFocus

protected boolean hasFocus

A flag indicating whether JComboBox currently has the focus.

itemListener

protected java.awt.event.ItemListener itemListener

A listener listening to item events fired by the JComboBox.

keyListener

protected java.awt.event.KeyListener keyListener

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

listBox

protected javax.swing.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.

listDataListener

protected javax.swing.event.ListDataListener listDataListener

ListDataListener listening to JComboBox model

popup

protected ComboPopup popup

Popup list containing the combo box's menu items.

popupKeyListener

protected java.awt.event.KeyListener popupKeyListener

popupMouseListener

protected java.awt.event.MouseListener popupMouseListener

popupMouseMotionListener

protected java.awt.event.MouseMotionListener popupMouseMotionListener

propertyChangeListener

protected java.beans.PropertyChangeListener propertyChangeListener

Listener listening to changes in the bound properties of JComboBox

currentValuePane

protected javax.swing.CellRendererPane currentValuePane

Used to render the combo box values.

cachedMinimumSize

protected java.awt.Dimension cachedMinimumSize

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

isMinimumSizeDirty

protected boolean isMinimumSizeDirty

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

Constructor Detail

BasicComboBoxUI

public BasicComboBoxUI()

Creates a new BasicComboBoxUI object.

Method Detail

createUI

public static javax.swing.plaf.ComponentUI createUI(javax.swing.JComponent c)

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

Parameters:

c - The JComponent a UI is being created for.

Returns:

A UI delegate for the JComponent.

installUI

public void installUI(javax.swing.JComponent c)

Installs the UI for the given JComponent.

Overrides:

installUI in class javax.swing.plaf.ComponentUI

Parameters:

c - the JComponent to install a UI for.

See Also:

uninstallUI(JComponent)

uninstallUI

public void uninstallUI(javax.swing.JComponent c)

Uninstalls the UI for the given JComponent.

Overrides:

uninstallUI in class javax.swing.plaf.ComponentUI

Parameters:

c - The JComponent that is having this UI removed.

See Also:

installUI(JComponent)

installDefaults

protected void installDefaults()

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

See Also:

uninstallDefaults()

installListeners

protected void installListeners()

Creates and installs the listeners for this UI.

See Also:

uninstallListeners()

uninstallDefaults

protected void uninstallDefaults()

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

See Also:

installDefaults()

uninstallListeners

protected void uninstallListeners()

Detaches all the listeners we attached in installListeners().

See Also:

installListeners()

createPopup

protected ComboPopup createPopup()

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

Returns:

popup containing list of combo box's items

createKeyListener

protected java.awt.event.KeyListener createKeyListener()

Creates a KeyListener to listen to key events.

Returns:

KeyListener that listens to key events.

createFocusListener

protected java.awt.event.FocusListener createFocusListener()

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

Returns:

the FocusListener.

createListDataListener

protected javax.swing.event.ListDataListener createListDataListener()

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

Returns:

The new listener.

createItemListener

protected java.awt.event.ItemListener createItemListener()

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

Returns:

The ItemListener

createPropertyChangeListener

protected java.beans.PropertyChangeListener createPropertyChangeListener()

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

Returns:

The PropertyChangeListener

createLayoutManager

protected java.awt.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.

createRenderer

protected javax.swing.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.

createEditor

protected javax.swing.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.

installComponents

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.

uninstallComponents

protected void uninstallComponents()

Uninstalls components from this JComboBox.

See Also:

installComponents()

addEditor

public void addEditor()

Adds the current editor to the combo box.

removeEditor

public void removeEditor()

Removes the current editor from the combo box.

configureEditor

protected void configureEditor()

Configures the editor for this combo box.

unconfigureEditor

protected void unconfigureEditor()

Unconfigures the editor for this combo box.

configureArrowButton

public void configureArrowButton()

Configures the arrow button.

See Also:

configureArrowButton()

unconfigureArrowButton

public void unconfigureArrowButton()

Unconfigures the arrow button.

See Also:

configureArrowButton()

createArrowButton

protected javax.swing.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.

isPopupVisible

public boolean isPopupVisible(javax.swing.JComboBox c)

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

Specified by:

isPopupVisible in class javax.swing.plaf.ComboBoxUI

Parameters:

c - The JComboBox to check

Returns:

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

setPopupVisible

public void setPopupVisible(javax.swing.JComboBox c,
                   boolean v)

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

Specified by:

setPopupVisible in class javax.swing.plaf.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.

isFocusTraversable

public boolean isFocusTraversable(javax.swing.JComboBox c)

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

Specified by:

isFocusTraversable in class javax.swing.plaf.ComboBoxUI

Parameters:

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

Returns:

true if focus tranversable and false otherwise

paint

public void paint(java.awt.Graphics g,
         javax.swing.JComponent c)

Paints given menu item using specified graphics context

Overrides:

paint in class javax.swing.plaf.ComponentUI

Parameters:

g - The graphics context used to paint this combo box

c - comboBox which needs to be painted.

getPreferredSize

public java.awt.Dimension getPreferredSize(javax.swing.JComponent c)

Returns preferred size for the combo box.

Overrides:

getPreferredSize in class javax.swing.plaf.ComponentUI

Parameters:

c - comboBox for which to get preferred size

Returns:

The preferred size for the given combo box

getMinimumSize

public java.awt.Dimension getMinimumSize(javax.swing.JComponent c)

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

Overrides:

getMinimumSize in class javax.swing.plaf.ComponentUI

Parameters:

c - The JComponent to find the minimum size for.

Returns:

The dimensions of the minimum size.

getMaximumSize

public java.awt.Dimension getMaximumSize(javax.swing.JComponent c)

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

Overrides:

getMaximumSize in class javax.swing.plaf.ComponentUI

Parameters:

c - The JComponent to find the maximum size for

Returns:

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

getAccessibleChildrenCount

public int getAccessibleChildrenCount(javax.swing.JComponent c)

Returns the number of accessible children of the combobox.

Overrides:

getAccessibleChildrenCount in class javax.swing.plaf.ComponentUI

Parameters:

c - the component (combobox) to check, ignored

Returns:

the number of accessible children of the combobox

getAccessibleChild

public javax.accessibility.Accessible getAccessibleChild(javax.swing.JComponent c,
                                                int i)

Returns the accessible child with the specified index.

Overrides:

getAccessibleChild in class javax.swing.plaf.ComponentUI

Parameters:

c - the component, this is ignored

i - the index of the accessible child to return

isNavigationKey

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

selectNextPossibleValue

protected void selectNextPossibleValue()

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

selectPreviousPossibleValue

protected void selectPreviousPossibleValue()

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

toggleOpenClose

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

rectangleForCurrentValue

protected java.awt.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

getInsets

protected java.awt.Insets getInsets()

Returns the insets of the current border.

Returns:

Insets representing space between combo box and its border

paintCurrentValue

public void paintCurrentValue(java.awt.Graphics g,
                     java.awt.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

paintCurrentValueBackground

public void paintCurrentValueBackground(java.awt.Graphics g,
                               java.awt.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

getDefaultSize

protected java.awt.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()

getDisplaySize

protected java.awt.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.

installKeyboardActions

protected void installKeyboardActions()

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

uninstallKeyboardActions

protected void uninstallKeyboardActions()

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