public class BasicComboBoxUI extends ComboBoxUI
The combo box is a compound component which means that it is an aggregate of many simpler components. This class creates and manages the listeners on the combo box and the combo box model. These listeners update the user interface in response to changes in the properties and state of the combo box.
All event handling is handled by listener classes created with the createxxxListener() methods and internal classes. You can change the behavior of this class by overriding the createxxxListener() methods and supplying your own event listeners or subclassing from the ones supplied in this class.
For adding specific actions, overide installKeyboardActions to add actions in response to KeyStroke bindings. See the article How to Use Key Bindings
| Modifier and Type | Class and Description |
|---|---|
class |
BasicComboBoxUI
This layout manager handles the 'standard' layout of combo boxes.
|
class |
BasicComboBoxUI
This listener hides the popup when the focus is lost.
|
class |
BasicComboBoxUI
This listener watches for changes to the selection in the combo box.
|
class |
BasicComboBoxUI
This listener checks to see if the key event isn't a navigation key.
|
class |
BasicComboBoxUI
This listener watches for changes in the
ComboBoxModel.
|
class |
BasicComboBoxUI
This listener watches for bound properties that have changed in the combo box.
|
| Modifier and Type | Field and Description |
|---|---|
protected JButton |
arrowButton
|
protected Dimension |
cachedMinimumSize
|
protected JComboBox |
comboBox
|
protected CellRendererPane |
currentValuePane
|
protected Component |
editor
|
protected FocusListener |
focusListener
This protected field is implementation specific.
|
protected boolean |
hasFocus
This protected field is implementation specific.
|
protected boolean |
isMinimumSizeDirty
|
protected ItemListener |
itemListener
This protected field is implementation specific.
|
protected KeyListener |
keyListener
This protected field is implementation specific.
|
protected JList |
listBox
|
protected ListDataListener |
listDataListener
This protected field is implementation specific.
|
protected Insets |
padding
If specified, these insets act as padding around the cell renderer when laying out and painting the "selected" item in the combo box.
|
protected ComboPopup |
popup
|
protected KeyListener |
popupKeyListener
|
protected MouseListener |
popupMouseListener
|
protected MouseMotionListener |
popupMouseMotionListener
|
protected PropertyChangeListener |
propertyChangeListener
This protected field is implementation specific.
|
protected boolean |
squareButton
Indicates whether or not the combo box button should be square.
|
| Constructor and Description |
|---|
BasicComboBoxUI()
|
| Modifier and Type | Method and Description |
|---|---|
void |
addEditor()
This public method is implementation specific and should be private.
|
void |
configureArrowButton()
This public method is implementation specific and should be private.
|
protected void |
configureEditor()
This protected method is implementation specific and should be private.
|
protected JButton |
createArrowButton()
Creates a button which will be used as the control to show or hide the popup portion of the combo box.
|
protected ComboBoxEditor |
createEditor()
Creates the default editor that will be used in editable combo boxes.
|
protected FocusListener |
createFocusListener()
Creates a
FocusListener which will be added to the combo box.
|
protected ItemListener |
createItemListener()
Creates an
ItemListener which will be added to the combo box.
|
protected KeyListener |
createKeyListener()
Creates a
KeyListener which will be added to the combo box.
|
protected LayoutManager |
createLayoutManager()
Creates a layout manager for managing the components which make up the combo box.
|
protected ListDataListener |
createListDataListener()
Creates a list data listener which will be added to the
ComboBoxModel.
|
protected ComboPopup |
createPopup()
Creates the popup portion of the combo box.
|
protected PropertyChangeListener |
createPropertyChangeListener()
Creates a
PropertyChangeListener which will be added to the combo box.
|
protected ListCellRenderer |
createRenderer()
Creates the default renderer that will be used in a non-editiable combo box.
|
static ComponentUI |
createUI(JComponent
|
Accessible |
getAccessibleChild(JComponent
Returns the
ith
Accessible child of the object.
|
int |
getAccessibleChildrenCount(JComponent
Returns the number of accessible children in the object.
|
int |
getBaseline(JComponent
Returns the baseline.
|
Component |
getBaselineResizeBehavior(JComponent
Returns an enum indicating how the baseline of the component changes as the size changes.
|
protected Dimension |
getDefaultSize()
Return the default size of an empty display area of the combo box using the current renderer and font.
|
protected Dimension |
getDisplaySize()
Returns the calculated size of the display area.
|
protected Insets |
getInsets()
Gets the insets from the JComboBox.
|
Dimension |
getMaximumSize(JComponent
Returns the specified component's maximum size appropriate for the look and feel.
|
Dimension |
getMinimumSize(JComponent
The minimum size is the size of the display area plus insets plus the button.
|
Dimension |
getPreferredSize(JComponent
Returns the specified component's preferred size appropriate for the look and feel.
|
protected Dimension |
getSizeForComponent(Component
Returns the size a component would have if used as a cell renderer.
|
protected void |
installComponents()
Creates and initializes the components which make up the aggregate combo box.
|
protected void |
installDefaults()
Installs the default colors, default font, default renderer, and default editor into the JComboBox.
|
protected void |
installKeyboardActions()
Adds keyboard actions to the JComboBox.
|
protected void |
installListeners()
Creates and installs listeners for the combo box and its model.
|
void |
installUI(JComponent
Configures the specified component appropriately for the look and feel.
|
boolean |
isFocusTraversable(JComboBox
Determines if the JComboBox is focus traversable.
|
protected boolean |
isNavigationKey(int keyCode)
Returns whether or not the supplied keyCode maps to a key that is used for navigation.
|
boolean |
isPopupVisible(JComboBox
Tells if the popup is visible or not.
|
void |
paint(Graphics
Paints the specified component appropriately for the look and feel.
|
void |
paintCurrentValue(Graphics
Paints the currently selected item.
|
void |
paintCurrentValueBackground(Graphics
Paints the background of the currently selected item.
|
protected Rectangle |
rectangleForCurrentValue()
Returns the area that is reserved for drawing the currently selected item.
|
void |
removeEditor()
This public method is implementation specific and should be private.
|
protected void |
selectNextPossibleValue()
Selects the next item in the list.
|
protected void |
selectPreviousPossibleValue()
Selects the previous item in the list.
|
void |
setPopupVisible(JComboBox
Hides the popup.
|
protected void |
toggleOpenClose()
Hides the popup if it is showing and shows the popup if it is hidden.
|
void |
unconfigureArrowButton()
This public method is implementation specific and should be private.
|
protected void |
unconfigureEditor()
This protected method is implementation specific and should be private.
|
protected void |
uninstallComponents()
The aggregate components which comprise the combo box are unregistered and uninitialized.
|
protected void |
uninstallDefaults()
Uninstalls the default colors, default font, default renderer, and default editor from the combo box.
|
protected void |
uninstallKeyboardActions()
Removes the focus InputMap and ActionMap.
|
protected void |
uninstallListeners()
Removes the installed listeners from the combo box and its model.
|
void |
uninstallUI(JComponent
Reverses configuration which was done on the specified component during
installUI.
|
contains, updateprotected JComboBoxcomboBox
protected boolean hasFocus
protected JListlistBox
protected CellRendererPanecurrentValuePane
protected ComboPopuppopup
protected Componenteditor
protected JButtonarrowButton
protected KeyListenerkeyListener
createKeyListener()
protected FocusListenerfocusListener
createFocusListener()
protected PropertyChangeListenerpropertyChangeListener
createPropertyChangeListener()
protected ItemListeneritemListener
createItemListener()
protected MouseListenerpopupMouseListener
protected MouseMotionListenerpopupMouseMotionListener
protected KeyListenerpopupKeyListener
protected ListDataListenerlistDataListener
createListDataListener()
protected boolean isMinimumSizeDirty
protected DimensioncachedMinimumSize
protected boolean squareButton
protected Insetspadding
public static ComponentUIcreateUI(JComponent c)
public void installUI(JComponentc)
ComponentUI
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:
LayoutManager on the component if necessary. PropertyChangeListener on the component in order to detect and respond to component property changes appropriately. installUI in class
ComponentUI
c - the component where this UI delegate is being installed
ComponentUI.uninstallUI(javax.swing.JComponent) ,
JComponent.setUI(javax.swing.plaf.ComponentUI) ,
JComponent.updateUI()
public void uninstallUI(JComponentc)
ComponentUI
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:
uninstallUI in class
ComponentUI
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
ComponentUI.installUI(javax.swing.JComponent) ,
JComponent.updateUI()
protected void installDefaults()
protected void installListeners()
protected void uninstallDefaults()
protected void uninstallListeners()
installListeners
protected ComboPopupcreatePopup()
ComboPopup
ComboPopup
protected KeyListenercreateKeyListener()
KeyListener which will be added to the combo box. If this method returns null then it will not be added to the combo box.
KeyListener or null
protected FocusListenercreateFocusListener()
FocusListener which will be added to the combo box. If this method returns null then it will not be added to the combo box.
FocusListener or null
protected ListDataListenercreateListDataListener()
ComboBoxModel. If this method returns null then it will not be added to the combo box model.
ListDataListener or null
protected ItemListenercreateItemListener()
ItemListener which will be added to the combo box. If this method returns null then it will not be added to the combo box.
Subclasses may override this method to return instances of their own ItemEvent handlers.
ItemListener or null
protected PropertyChangeListenercreatePropertyChangeListener()
PropertyChangeListener which will be added to the combo box. If this method returns null then it will not be added to the combo box.
PropertyChangeListener or null
protected LayoutManagercreateLayoutManager()
protected ListCellRenderercreateRenderer()
setRenderer.
ListCellRender used for the combo box
JComboBox.setRenderer(javax.swing.ListCellRenderer<? super E>)
protected ComboBoxEditorcreateEditor()
setEditor.
ComboBoxEditor used for the combo box
JComboBox.setEditor(javax.swing.ComboBoxEditor)
protected void installComponents()
protected void uninstallComponents()
public void addEditor()
ComboBoxEditor
public void removeEditor()
addEditor()
protected void configureEditor()
addEditor()
protected void unconfigureEditor()
addEditor()
public void configureArrowButton()
createArrowButton()
public void unconfigureArrowButton()
createArrowButton()
protected JButtoncreateArrowButton()
public boolean isPopupVisible(JComboBoxc)
public void setPopupVisible(JComboBoxc, boolean v)
public boolean isFocusTraversable(JComboBoxc)
public void paint(Graphicsg, JComponent c)
ComponentUI
ComponentUI.update method when the specified component is being painted. Subclasses should override this method and use the specified
Graphics object to render the content of the component.
paint in class
ComponentUI
g - the
Graphics 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
ComponentUI.update(java.awt.Graphics, javax.swing.JComponent)
public DimensiongetPreferredSize(JComponent c)
ComponentUI
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.
getPreferredSize in class
ComponentUI
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
JComponent.getPreferredSize() ,
LayoutManager.preferredLayoutSize(java.awt.Container)
public DimensiongetMinimumSize(JComponent c)
getMinimumSize in class
ComponentUI
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
Dimension object or
null
JComponent.getMinimumSize() ,
LayoutManager.minimumLayoutSize(java.awt.Container) ,
ComponentUI.getPreferredSize(javax.swing.JComponent)
public DimensiongetMaximumSize(JComponent c)
ComponentUI
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.
getMaximumSize in class
ComponentUI
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
Dimension object or
null
JComponent.getMaximumSize() ,
LayoutManager2.maximumLayoutSize(java.awt.Container)
public int getBaseline(JComponentc, int width, int height)
getBaseline in class
ComponentUI
c -
JComponent baseline is being requested for
width - the width to get the baseline for
height - the height to get the baseline for
NullPointerException - if
c is
null
IllegalArgumentException - if width or height is < 0
JComponent.getBaseline(int, int)
public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c)
getBaselineResizeBehavior in class
ComponentUI
c -
JComponent to return baseline resize behavior for
NullPointerException - if
c is
null
JComponent.getBaseline(int, int)
public int getAccessibleChildrenCount(JComponentc)
ComponentUI
Accessible, this method should return the number of children of this object. UIs might wish to override this if they present areas on the screen that can be viewed as components, but actual components are not used for presenting those areas. Note: As of v1.3, it is recommended that developers call
Component.AccessibleAWTComponent.getAccessibleChildrenCount() instead of this method.
getAccessibleChildrenCount in class
ComponentUI
ComponentUI.getAccessibleChild(javax.swing.JComponent, int)
public AccessiblegetAccessibleChild(JComponent c, int i)
ComponentUI
ith
Accessible child of the object. UIs might need to override this if they present areas on the screen that can be viewed as components, but actual components are not used for presenting those areas.
Note: As of v1.3, it is recommended that developers call Component.AccessibleAWTComponent.getAccessibleChild() instead of this method.
getAccessibleChild in class
ComponentUI
i - zero-based index of child
ith
Accessible child of the object
ComponentUI.getAccessibleChildrenCount(javax.swing.JComponent)
protected boolean isNavigationKey(int keyCode)
protected void selectNextPossibleValue()
protected void selectPreviousPossibleValue()
protected void toggleOpenClose()
protected RectanglerectangleForCurrentValue()
protected InsetsgetInsets()
public void paintCurrentValue(Graphicsg, Rectangle bounds, boolean hasFocus)
public void paintCurrentValueBackground(Graphicsg, Rectangle bounds, boolean hasFocus)
protected DimensiongetDefaultSize()
getDisplaySize()
protected DimensiongetDisplaySize()
For combo boxes with a non trivial number of items, it is recommended to use a prototype display value to significantly speed up the display size calculation.
JComboBox.setPrototypeDisplayValue(E)
protected DimensiongetSizeForComponent(Component comp)
comp - a
Component to check
protected void installKeyboardActions()
protected void uninstallKeyboardActions()