public class BasicComboBoxUI extends ComboBoxUI
The combo box is a compound component which means that it is an agregate 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 Keyboard Bindings in Swing
at The Swing Connection.
Modifier and Type | Class and Description |
---|---|
class |
BasicComboBoxUI.ComboBoxLayoutManager
This layout manager handles the 'standard' layout of combo boxes.
|
class |
BasicComboBoxUI.FocusHandler
This listener hides the popup when the focus is lost.
|
class |
BasicComboBoxUI.ItemHandler
This listener watches for changes to the selection in the
combo box.
|
class |
BasicComboBoxUI.KeyHandler
This listener checks to see if the key event isn't a navigation key.
|
class |
BasicComboBoxUI.ListDataHandler
This listener watches for changes in the
ComboBoxModel . |
class |
BasicComboBoxUI.PropertyChangeHandler
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 c) |
Accessible |
getAccessibleChild(JComponent c,
int i)
Returns the
i th Accessible child of the object. |
int |
getAccessibleChildrenCount(JComponent c)
Returns the number of accessible children in the object.
|
int |
getBaseline(JComponent c,
int width,
int height)
Returns the baseline.
|
Component.BaselineResizeBehavior |
getBaselineResizeBehavior(JComponent c)
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 c)
Returns the specified component's maximum size appropriate for
the look and feel.
|
Dimension |
getMinimumSize(JComponent c)
The minumum size is the size of the display area plus insets plus the button.
|
Dimension |
getPreferredSize(JComponent c)
Returns the specified component's preferred size appropriate for
the look and feel.
|
protected Dimension |
getSizeForComponent(Component comp)
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 c)
Configures the specified component appropriately for the look and feel.
|
boolean |
isFocusTraversable(JComboBox c)
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 c)
Tells if the popup is visible or not.
|
void |
paint(Graphics g,
JComponent c)
Paints the specified component appropriately for the look and feel.
|
void |
paintCurrentValue(Graphics g,
Rectangle bounds,
boolean hasFocus)
Paints the currently selected item.
|
void |
paintCurrentValueBackground(Graphics g,
Rectangle bounds,
boolean hasFocus)
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 c,
boolean v)
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 compise 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 c)
Reverses configuration which was done on the specified component during
installUI . |
contains, update
protected JComboBox comboBox
protected boolean hasFocus
protected JList listBox
protected CellRendererPane currentValuePane
protected ComboPopup popup
protected Component editor
protected JButton arrowButton
protected KeyListener keyListener
createKeyListener()
protected FocusListener focusListener
createFocusListener()
protected PropertyChangeListener propertyChangeListener
createPropertyChangeListener()
protected ItemListener itemListener
createItemListener()
protected MouseListener popupMouseListener
protected MouseMotionListener popupMouseMotionListener
protected KeyListener popupKeyListener
protected ListDataListener listDataListener
createListDataListener()
protected boolean isMinimumSizeDirty
protected Dimension cachedMinimumSize
protected boolean squareButton
protected Insets padding
public static ComponentUI createUI(JComponent c)
public void installUI(JComponent c)
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 installedComponentUI.uninstallUI(javax.swing.JComponent)
,
JComponent.setUI(javax.swing.plaf.ComponentUI)
,
JComponent.updateUI()
public void uninstallUI(JComponent c)
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 componentsComponentUI.installUI(javax.swing.JComponent)
,
JComponent.updateUI()
protected void installDefaults()
protected void installListeners()
protected void uninstallDefaults()
protected void uninstallListeners()
installListeners
protected ComboPopup createPopup()
ComboPopup
ComboPopup
protected KeyListener createKeyListener()
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 nullprotected FocusListener createFocusListener()
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 nullprotected ListDataListener createListDataListener()
ComboBoxModel
. If this method returns null then
it will not be added to the combo box model.ListDataListener
or nullprotected ItemListener createItemListener()
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 nullprotected PropertyChangeListener createPropertyChangeListener()
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 nullprotected LayoutManager createLayoutManager()
protected ListCellRenderer createRenderer()
setRenderer
.ListCellRender
used for the combo boxJComboBox.setRenderer(javax.swing.ListCellRenderer<? super E>)
protected ComboBoxEditor createEditor()
setEditor
.ComboBoxEditor
used for the combo boxJComboBox.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 JButton createArrowButton()
public boolean isPopupVisible(JComboBox c)
isPopupVisible
in class ComboBoxUI
public void setPopupVisible(JComboBox c, boolean v)
setPopupVisible
in class ComboBoxUI
public boolean isFocusTraversable(JComboBox c)
isFocusTraversable
in class ComboBoxUI
public void paint(Graphics g, 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 paintc
- the component being painted;
this argument is often ignored,
but might be used if the UI object is stateless
and shared by multiple componentsComponentUI.update(java.awt.Graphics, javax.swing.JComponent)
public Dimension getPreferredSize(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 componentsJComponent.getPreferredSize()
,
LayoutManager.preferredLayoutSize(java.awt.Container)
public Dimension getMinimumSize(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 componentsDimension
object or null
JComponent.getMinimumSize()
,
LayoutManager.minimumLayoutSize(java.awt.Container)
,
ComponentUI.getPreferredSize(javax.swing.JComponent)
public Dimension getMaximumSize(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 componentsDimension
object or null
JComponent.getMaximumSize()
,
LayoutManager2.maximumLayoutSize(java.awt.Container)
public int getBaseline(JComponent c, int width, int height)
getBaseline
in class ComponentUI
c
- JComponent
baseline is being requested forwidth
- the width to get the baseline forheight
- the height to get the baseline forNullPointerException
- if c
is null
IllegalArgumentException
- if width or height is < 0JComponent.getBaseline(int, int)
public Component.BaselineResizeBehavior getBaselineResizeBehavior(JComponent c)
getBaselineResizeBehavior
in class ComponentUI
c
- JComponent
to return baseline resize behavior forNullPointerException
- if c
is null
JComponent.getBaseline(int, int)
public int getAccessibleChildrenCount(JComponent c)
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 Accessible getAccessibleChild(JComponent c, int i)
ComponentUI
i
th 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 childi
th Accessible
child of the objectComponentUI.getAccessibleChildrenCount(javax.swing.JComponent)
protected boolean isNavigationKey(int keyCode)
protected void selectNextPossibleValue()
protected void selectPreviousPossibleValue()
protected void toggleOpenClose()
protected Rectangle rectangleForCurrentValue()
protected Insets getInsets()
public void paintCurrentValue(Graphics g, Rectangle bounds, boolean hasFocus)
public void paintCurrentValueBackground(Graphics g, Rectangle bounds, boolean hasFocus)
protected Dimension getDefaultSize()
getDisplaySize()
protected Dimension getDisplaySize()
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 Dimension getSizeForComponent(Component comp)
comp
- a Component
to checkprotected void installKeyboardActions()
protected void uninstallKeyboardActions()
Submit a bug or feature
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