ImageObserver
, MenuContainer
, Serializable
, Accessible
public class JRootPane extends JComponent implements Accessible
JFrame
, JDialog
, JWindow
, JApplet
, and JInternalFrame
. For task-oriented information on functionality provided by root panes see How to Use Root Panes, a section in The Java Tutorial. The following image shows the relationships between the classes that use root panes.
The "heavyweight" components (those that delegate to a peer, or native component on the host system) are shown with a darker, heavier box. The four heavyweight JFC/Swing containers (JFrame
, JDialog
, JWindow
, and JApplet
) are shown in relation to the AWT classes they extend. These four components are the only heavyweight containers in the Swing library. The lightweight container JInternalFrame
is also shown. All five of these JFC/Swing containers implement the RootPaneContainer
interface, and they all delegate their operations to a JRootPane
(shown with a little "handle" on top). Note: TheJComponent
methodgetRootPane
can be used to obtain theJRootPane
that contains a given component.
Example:
JRootPane
. A JRootpane
is made up of a glassPane
, an optional menuBar
, and a contentPane
. (The JLayeredPane
manages the menuBar
and the contentPane
.) The glassPane
sits over the top of everything, where it is in a position to intercept mouse movements. Since the glassPane
(like the contentPane
) can be an arbitrary component, it is also possible to set up the glassPane
for drawing. Lines and images on the glassPane
can then range over the frames underneath without being limited by their boundaries. Although the menuBar
component is optional, the layeredPane
, contentPane
, and glassPane
always exist. Attempting to set them to null
generates an exception.
To add components to the JRootPane
(other than the optional menu bar), you add the object to the contentPane
of the JRootPane
, like this:
rootPane.getContentPane().add(child);The same principle holds true for setting layout managers, removing components, listing children, etc. All these methods are invoked on the
contentPane
instead of on the JRootPane
. Note: The default layout manager for theIf acontentPane
is aBorderLayout
manager. However, theJRootPane
uses a customLayoutManager
. So, when you want to change the layout manager for the components you added to aJRootPane
, be sure to use code like this:rootPane.getContentPane().setLayout(new BoxLayout());
JMenuBar
component is set on the JRootPane
, it is positioned along the upper edge of the frame. The contentPane
is adjusted in location and size to fill the remaining area. (The JMenuBar
and the contentPane
are added to the layeredPane
component at the JLayeredPane.FRAME_CONTENT_LAYER
layer.) The layeredPane
is the parent of all children in the JRootPane
-- both as the direct parent of the menu and the grandparent of all components added to the contentPane
. It is an instance of JLayeredPane
, which provides the ability to add components at several layers. This capability is very useful when working with menu popups, dialog boxes, and dragging -- situations in which you need to place a component on top of all other components in the pane.
The glassPane
sits on top of all other components in the JRootPane
. That provides a convenient place to draw above all other components, and makes it possible to intercept mouse events, which is useful both for dragging and for drawing. Developers can use setVisible
on the glassPane
to control when the glassPane
displays over the other children. By default the glassPane
is not visible.
The custom LayoutManager
used by JRootPane
ensures that:
glassPane
fills the entire viewable area of the JRootPane
(bounds - insets). layeredPane
fills the entire viewable area of the JRootPane
. (bounds - insets) menuBar
is positioned at the upper edge of the layeredPane
. contentPane
fills the entire viewable area, minus the menuBar
, if present. JRootPane
view hierarchy are ignored. If you replace the LayoutManager
of the JRootPane
, you are responsible for managing all of these views. So ordinarily you will want to be sure that you change the layout manager for the contentPane
rather than for the JRootPane
itself!
The painting architecture of Swing requires an opaque JComponent
to exist in the containment hierarchy above all other components. This is typically provided by way of the content pane. If you replace the content pane, it is recommended that you make the content pane opaque by way of setOpaque(true)
. Additionally, if the content pane overrides paintComponent
, it will need to completely fill in the background in an opaque color in paintComponent
.
Warning: Swing is not thread safe. For more information see Swing's Threading Policy.
Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans has been added to the java.beans
package. Please see XMLEncoder
.
Modifier and Type | Class | Description |
---|---|---|
protected class |
JRootPane.AccessibleJRootPane |
This class implements accessibility support for the JRootPane class. |
protected class |
JRootPane.RootLayout |
A custom layout manager that is responsible for the layout of layeredPane, glassPane, and menuBar. |
JComponent.AccessibleJComponent
Container.AccessibleAWTContainer
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
Modifier and Type | Field | Description |
---|---|---|
static final int |
COLOR_CHOOSER_DIALOG |
Constant used for the windowDecorationStyle property. |
protected Container |
contentPane |
The content pane. |
protected JButton |
defaultButton |
The button that gets activated when the pane has the focus and a UI-specific action like pressing the Enter key occurs. |
static final int |
ERROR_DIALOG |
Constant used for the windowDecorationStyle property. |
static final int |
FILE_CHOOSER_DIALOG |
Constant used for the windowDecorationStyle property. |
static final int |
FRAME |
Constant used for the windowDecorationStyle property. |
protected Component |
glassPane |
The glass pane that overlays the menu bar and content pane, so it can intercept mouse movements and such. |
static final int |
INFORMATION_DIALOG |
Constant used for the windowDecorationStyle property. |
protected JLayeredPane |
layeredPane |
The layered pane that manages the menu bar and content pane. |
protected JMenuBar |
menuBar |
The menu bar. |
static final int |
NONE |
Constant used for the windowDecorationStyle property. |
static final int |
PLAIN_DIALOG |
Constant used for the windowDecorationStyle property. |
static final int |
QUESTION_DIALOG |
Constant used for the windowDecorationStyle property. |
static final int |
WARNING_DIALOG |
Constant used for the windowDecorationStyle property. |
listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW
accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
Constructor | Description |
---|---|
JRootPane() |
Creates a JRootPane , setting up its glassPane , layeredPane , and contentPane . |
Modifier and Type | Method | Description |
---|---|---|
protected void |
addImpl |
Overridden to enforce the position of the glass component as the zero child. |
protected Container |
createContentPane() |
Called by the constructor methods to create the default contentPane . |
protected Component |
createGlassPane() |
Called by the constructor methods to create the default glassPane . |
protected JLayeredPane |
createLayeredPane() |
Called by the constructor methods to create the default layeredPane . |
protected LayoutManager |
createRootLayout() |
Called by the constructor methods to create the default layoutManager . |
AccessibleContext |
getAccessibleContext() |
Gets the AccessibleContext associated with this JRootPane . |
Container |
getContentPane() |
Returns the content pane -- the container that holds the components parented by the root pane. |
JButton |
getDefaultButton() |
Returns the value of the defaultButton property. |
Component |
getGlassPane() |
Returns the current glass pane for this JRootPane . |
JMenuBar |
getJMenuBar() |
Returns the menu bar from the layered pane. |
JLayeredPane |
getLayeredPane() |
Gets the layered pane used by the root pane. |
JMenuBar |
getMenuBar() |
Deprecated. |
RootPaneUI |
getUI() |
Returns the L&F object that renders this component. |
String |
getUIClassID() |
Returns a string that specifies the name of the L&F class that renders this component. |
int |
getWindowDecorationStyle() |
Returns a constant identifying the type of Window decorations the JRootPane is providing. |
boolean |
isOptimizedDrawingEnabled() |
The glassPane and contentPane have the same bounds, which means JRootPane does not tiles its children and this should return false. |
boolean |
isValidateRoot() |
If a descendant of this JRootPane calls revalidate , validate from here on down. |
protected String |
paramString() |
Returns a string representation of this JRootPane . |
void |
setContentPane |
Sets the content pane -- the container that holds the components parented by the root pane. |
void |
setDefaultButton |
Sets the defaultButton property, which determines the current default button for this JRootPane . |
void |
setDoubleBuffered |
Sets whether this component should use a buffer to paint. |
void |
setGlassPane |
Sets a specified Component to be the glass pane for this root pane. |
void |
setJMenuBar |
Adds or changes the menu bar used in the layered pane. |
void |
setLayeredPane |
Sets the layered pane for the root pane. |
void |
setMenuBar |
Deprecated. As of Swing version 1.0.3 replaced by setJMenuBar(JMenuBar menu) . |
void |
setUI |
Sets the L&F object that renders this component. |
void |
setWindowDecorationStyle |
Sets the type of Window decorations (such as borders, widgets for closing a Window, title ...) the JRootPane should provide. |
void |
updateUI() |
Resets the UI property to a value from the current look and feel. |
addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update
add, add, add, add, add, addContainerListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTree
action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setMixingCutoutShape, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle
public static final int NONE
JRootPane
should not provide any sort of Window decorations.public static final int FRAME
JRootPane
should provide decorations appropriate for a Frame.public static final int PLAIN_DIALOG
JRootPane
should provide decorations appropriate for a Dialog.public static final int INFORMATION_DIALOG
JRootPane
should provide decorations appropriate for a Dialog used to display an informational message.public static final int ERROR_DIALOG
JRootPane
should provide decorations appropriate for a Dialog used to display an error message.public static final int COLOR_CHOOSER_DIALOG
JRootPane
should provide decorations appropriate for a Dialog used to display a JColorChooser
.public static final int FILE_CHOOSER_DIALOG
JRootPane
should provide decorations appropriate for a Dialog used to display a JFileChooser
.public static final int QUESTION_DIALOG
JRootPane
should provide decorations appropriate for a Dialog used to present a question to the user.public static final int WARNING_DIALOG
JRootPane
should provide decorations appropriate for a Dialog used to display a warning message.protected Container contentPane
protected JLayeredPane layeredPane
protected Component glassPane
protected JButton defaultButton
public JRootPane()
JRootPane
, setting up its glassPane
, layeredPane
, and contentPane
.public void setDoubleBuffered(boolean aFlag)
Component
is buffered and one of its ancestor is also buffered, the ancestor buffer will be used.setDoubleBuffered
in class JComponent
aFlag
- if true, set this component to be double bufferedpublic int getWindowDecorationStyle()
JRootPane
is providing.NONE
, FRAME
, PLAIN_DIALOG
, INFORMATION_DIALOG
, ERROR_DIALOG
, COLOR_CHOOSER_DIALOG
, FILE_CHOOSER_DIALOG
, QUESTION_DIALOG
or WARNING_DIALOG
.@BeanProperty(expert=true, visualUpdate=true, enumerationValues={"JRootPane.NONE","JRootPane.FRAME","JRootPane.PLAIN_DIALOG","JRootPane.INFORMATION_DIALOG","JRootPane.ERROR_DIALOG","JRootPane.COLOR_CHOOSER_DIALOG","JRootPane.FILE_CHOOSER_DIALOG","JRootPane.QUESTION_DIALOG","JRootPane.WARNING_DIALOG"}, description="Identifies the type of Window decorations to provide") public void setWindowDecorationStyle(int windowDecorationStyle)
JRootPane
should provide. The default is to provide no Window decorations (NONE
). This is only a hint, and some look and feels may not support this. This is a bound property.
windowDecorationStyle
- Constant identifying Window decorations to provide.IllegalArgumentException
- if style
is not one of: NONE
, FRAME
, PLAIN_DIALOG
, INFORMATION_DIALOG
, ERROR_DIALOG
, COLOR_CHOOSER_DIALOG
, FILE_CHOOSER_DIALOG
, QUESTION_DIALOG
, or WARNING_DIALOG
.public RootPaneUI getUI()
getUI
in class JComponent
LabelUI
object@BeanProperty(expert=true, hidden=true, visualUpdate=true, description="The UI object that implements the Component\'s LookAndFeel.") public void setUI(RootPaneUI ui)
ui
- the LabelUI
L&F objectpublic void updateUI()
updateUI
in class JComponent
public String getUIClassID()
getUIClassID
in class JComponent
protected JLayeredPane createLayeredPane()
layeredPane
. Bt default it creates a new JLayeredPane
.layeredPane
protected Container createContentPane()
contentPane
. By default this method creates a new JComponent
add sets a BorderLayout
as its LayoutManager
.contentPane
protected Component createGlassPane()
glassPane
. By default this method creates a new JComponent
with visibility set to false.glassPane
protected LayoutManager createRootLayout()
layoutManager
.layoutManager
.public void setJMenuBar(JMenuBar menu)
menu
- the JMenuBar
to add@Deprecated public void setMenuBar(JMenuBar menu)
setJMenuBar(JMenuBar menu)
.menu
- the JMenuBar
to add.public JMenuBar getJMenuBar()
JMenuBar
used in the pane@Deprecated public JMenuBar getMenuBar()
getJMenuBar()
.JMenuBar
used in the panepublic void setContentPane(Container content)
Swing's painting architecture requires an opaque JComponent
in the containment hierarchy. This is typically provided by the content pane. If you replace the content pane it is recommended you replace it with an opaque JComponent
.
content
- the Container
to use for component-contentsIllegalComponentStateException
- (a runtime exception) if the content pane parameter is null
public Container getContentPane()
Container
that holds the component-contentspublic void setLayeredPane(JLayeredPane layered)
JMenuBar
.layered
- the JLayeredPane
to useIllegalComponentStateException
- (a runtime exception) if the layered pane parameter is null
public JLayeredPane getLayeredPane()
JMenuBar
.JLayeredPane
currently in usepublic void setGlassPane(Component glass)
Component
to be the glass pane for this root pane. The glass pane should normally be a lightweight, transparent component, because it will be made visible when ever the root pane needs to grab input events. The new glass pane's visibility is changed to match that of the current glass pane. An implication of this is that care must be taken when you want to replace the glass pane and make it visible. Either of the following will work:
root.setGlassPane(newGlassPane); newGlassPane.setVisible(true);or:
root.getGlassPane().setVisible(true); root.setGlassPane(newGlassPane);
glass
- the Component
to use as the glass pane for this JRootPane
NullPointerException
- if the glass
parameter is null
public Component getGlassPane()
JRootPane
.public boolean isValidateRoot()
JRootPane
calls revalidate
, validate from here on down. Deferred requests to layout a component and its descendents again. For example, calls to revalidate
, are pushed upwards to either a JRootPane
or a JScrollPane
because both classes override isValidateRoot
to return true.
isValidateRoot
in class JComponent
public boolean isOptimizedDrawingEnabled()
glassPane
and contentPane
have the same bounds, which means JRootPane
does not tiles its children and this should return false. On the other hand, the glassPane
is normally not visible, and so this can return true if the glassPane
isn't visible. Therefore, the return value here depends upon the visibility of the glassPane
.isOptimizedDrawingEnabled
in class JComponent
@BeanProperty(description="The button activated by default in this root pane") public void setDefaultButton(JButton defaultButton)
defaultButton
property, which determines the current default button for this JRootPane
. The default button is the button which will be activated when a UI-defined activation event (typically the Enter key) occurs in the root pane regardless of whether or not the button has keyboard focus (unless there is another component within the root pane which consumes the activation event, such as a JTextPane
). For default activation to work, the button must be an enabled descendent of the root pane when activation occurs. To remove a default button from this root pane, set this property to null
.defaultButton
- the JButton
which is to be the default buttonpublic JButton getDefaultButton()
defaultButton
property.JButton
which is currently the default buttonprotected void addImpl(Component comp, Object constraints, int index)
protected String paramString()
JRootPane
. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null
.paramString
in class JComponent
JRootPane
.public AccessibleContext getAccessibleContext()
AccessibleContext
associated with this JRootPane
. For root panes, the AccessibleContext
takes the form of an AccessibleJRootPane
. A new AccessibleJRootPane
instance is created if necessary.getAccessibleContext
in interface Accessible
getAccessibleContext
in class Component
AccessibleJRootPane
that serves as the AccessibleContext
of this JRootPane
© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/JRootPane.html
getJMenuBar()
.