javax.swing
Class JScrollPane

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--javax.swing.JComponent
                    |
                    +--javax.swing.JScrollPane

All Implemented Interfaces:

Accessible, ImageObserver, MenuContainer, ScrollPaneConstants, Serializable

public class JScrollPane

extends JComponent

implements ScrollPaneConstants, Accessible

Provides a scrollable view of a lightweight component. A JScrollPane manages a viewport, optional vertical and horizontal scroll bars, and optional row and column heading viewports. You can find task-oriented documentation of JScrollPane in How to Use Scroll Panes, a section in The Java Tutorial. Note that JScrollPane does not support heavyweight components.

The JViewport provides a window, or "viewport" onto a data source -- for example, a text file. That data source is the "scrollable client" (aka data model) displayed by the JViewport view. A JScrollPane basically consists of JScrollBars, a JViewport, and the wiring between them, as shown in the diagram at right.

In addition to the scroll bars and viewport, a JScrollPane can have a column header and a row header. Each of these is a JViewport object that you specify with setRowHeaderView, and setColumnHeaderView. The column header viewport automatically scrolls left and right, tracking the left-right scrolling of the main viewport. (It never scrolls vertically, however.) The row header acts in a similar fashion.

By default, the corners are empty. You can put a component into a corner using setCorner, in case you there is some function or decoration you would like to add to the scroll pane. The size of corner components is entirely determined by the size of the headers and scroll bars that surround them.

To add a border around the main viewport, you can use setViewportBorder. (Of course, you can also add a border around the whole scroll pane using setBorder.)

For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the JScrollPane key assignments.

A common operation to want to do is to set the background color that will be used if the main viewport view is smaller than the viewport, or is not opaque. This can be accomplished by setting the background color of the viewport, via scrollPane.getViewport().setBackground(). The reason for setting the color of the viewport and not the scrollpane is that by default JViewport is opaque which, among other things, means it will completely fill in its background using its background color. Therefore when JScrollPane draws its background the viewport will usually draw over it.

By default JScrollPane uses ScrollPaneLayout to handle the layout of its child Components. ScrollPaneLayout determines the size to make the viewport view in one of two ways:

1. If the view implements Scrollable a combination of getPreferredScrollableViewportSize, getScrollableTracksViewportWidth and getScrollableTracksViewportHeightis used, otherwise
2. getPreferredSize is used.

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^TM has been added to the java.beans package. Please see XMLEncoder.

See Also:

JScrollBar, JViewport, ScrollPaneLayout, Scrollable, Component.getPreferredSize(), setViewportView(java.awt.Component), setRowHeaderView(java.awt.Component), setColumnHeaderView(java.awt.Component), setCorner(java.lang.String, java.awt.Component), setViewportBorder(javax.swing.border.Border)

Nested Class Summary

protected class	JScrollPane.AccessibleJScrollPane This class implements accessibility support for the JScrollPane class.
protected class	JScrollPane.ScrollBar By default JScrollPane creates scrollbars that are instances of this class.

Nested classes inherited from class javax.swing.JComponent

Nested classes inherited from class java.awt.Container

Nested classes inherited from class java.awt.Component

Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

protected JViewport	columnHeader The column header child.
protected JScrollBar	horizontalScrollBar The scrollpane's horizontal scrollbar child.
protected int	horizontalScrollBarPolicy The display policy for the horizontal scrollbar.
protected Component	lowerLeft The component to display in the lower left corner.
protected Component	lowerRight The component to display in the lower right corner.
protected JViewport	rowHeader The row header child.
protected Component	upperLeft The component to display in the upper left corner.
protected Component	upperRight The component to display in the upper right corner.
protected JScrollBar	verticalScrollBar The scrollpane's vertical scrollbar child.
protected int	verticalScrollBarPolicy The display policy for the vertical scrollbar.
protected JViewport	viewport The scrollpane's viewport child.

Fields inherited from class javax.swing.JComponent

accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface javax.swing.ScrollPaneConstants

COLUMN_HEADER, HORIZONTAL_SCROLLBAR, HORIZONTAL_SCROLLBAR_ALWAYS, HORIZONTAL_SCROLLBAR_AS_NEEDED, HORIZONTAL_SCROLLBAR_NEVER, HORIZONTAL_SCROLLBAR_POLICY, LOWER_LEADING_CORNER, LOWER_LEFT_CORNER, LOWER_RIGHT_CORNER, LOWER_TRAILING_CORNER, ROW_HEADER, UPPER_LEADING_CORNER, UPPER_LEFT_CORNER, UPPER_RIGHT_CORNER, UPPER_TRAILING_CORNER, VERTICAL_SCROLLBAR, VERTICAL_SCROLLBAR_ALWAYS, VERTICAL_SCROLLBAR_AS_NEEDED, VERTICAL_SCROLLBAR_NEVER, VERTICAL_SCROLLBAR_POLICY, VIEWPORT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

JScrollPane()
Creates an empty (no viewport view) JScrollPane where both horizontal and vertical scrollbars appear when needed.

JScrollPane(Component view)
Creates a JScrollPane that displays the contents of the specified component, where both horizontal and vertical scrollbars appear whenever the component's contents are larger than the view.

JScrollPane(Component view, int vsbPolicy, int hsbPolicy)
Creates a JScrollPane that displays the view component in a viewport whose view position can be controlled with a pair of scrollbars.

JScrollPane(int vsbPolicy, int hsbPolicy)
Creates an empty (no viewport view) JScrollPane with specified scrollbar policies.

Method Summary

JScrollBar	createHorizontalScrollBar() Returns a JScrollPane.ScrollBar by default.
JScrollBar	createVerticalScrollBar() Returns a JScrollPane.ScrollBar by default.
protected JViewport	createViewport() Returns a new JViewport by default.
AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this JScrollPane.
JViewport	getColumnHeader() Returns the column header.
Component	getCorner(String key) Returns the component at the specified corner.
JScrollBar	getHorizontalScrollBar() Returns the horizontal scroll bar that controls the viewport's horizontal view position.
int	getHorizontalScrollBarPolicy() Returns the horizontal scroll bar policy value.
JViewport	getRowHeader() Returns the row header.
ScrollPaneUI	getUI() Returns the look and feel (L&F) object that renders this component.
String	getUIClassID() Returns the suffix used to construct the name of the L&F class used to render this component.
JScrollBar	getVerticalScrollBar() Returns the vertical scroll bar that controls the viewports vertical view position.
int	getVerticalScrollBarPolicy() Returns the vertical scroll bar policy value.
JViewport	getViewport() Returns the current JViewport.
Border	getViewportBorder() Returns the Border object that surrounds the viewport.
Rectangle	getViewportBorderBounds() Returns the bounds of the viewport's border.
boolean	isValidateRoot() Calls revalidate on any descendant of this JScrollPane.
boolean	isWheelScrollingEnabled() Indicates whether or not scrolling will take place in response to the mouse wheel.
protected String	paramString() Returns a string representation of this JScrollPane.
void	setColumnHeader(JViewport columnHeader) Removes the old columnHeader, if it exists.
void	setColumnHeaderView(Component view) Creates a column-header viewport if necessary, sets its view, and then adds the column-header viewport to the scrollpane.
void	setComponentOrientation(ComponentOrientation co) Sets the orientation for the vertical and horizontal scrollbars as determined by the ComponentOrientation argument.
void	setCorner(String key, Component corner) Adds a child that will appear in one of the scroll panes corners, if there's room.
void	setHorizontalScrollBar(JScrollBar horizontalScrollBar) Adds the scrollbar that controls the viewport's horizontal view position to the scrollpane.
void	setHorizontalScrollBarPolicy(int policy) Determines when the horizontal scrollbar appears in the scrollpane.
void	setLayout(LayoutManager layout) Sets the layout manager for this JScrollPane.
void	setRowHeader(JViewport rowHeader) Removes the old rowHeader, if it exists.
void	setRowHeaderView(Component view) Creates a row-header viewport if necessary, sets its view and then adds the row-header viewport to the scrollpane.
void	setUI(ScrollPaneUI ui) Sets the ScrollPaneUI object that provides the look and feel (L&F) for this component.
void	setVerticalScrollBar(JScrollBar verticalScrollBar) Adds the scrollbar that controls the viewports vertical view position to the scrollpane.
void	setVerticalScrollBarPolicy(int policy) Determines when the vertical scrollbar appears in the scrollpane.
void	setViewport(JViewport viewport) Removes the old viewport (if there is one); forces the viewPosition of the new viewport to be in the +x,+y quadrant; syncs up the row and column headers (if there are any) with the new viewport; and finally syncs the scrollbars and headers with the new viewport.
void	setViewportBorder(Border viewportBorder) Adds a border around the viewport.
void	setViewportView(Component view) Creates a viewport if necessary and then sets its view.
void	setWheelScrollingEnabled(boolean handleWheel) Enables/disables scrolling in response to movement of the mouse wheel.
void	updateUI() Replaces the current ScrollPaneUI object with a version from the current default look and feel.

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getGraphics, getHeight, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, transferFocusBackward, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

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, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, 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, processMouseEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Field Detail

verticalScrollBarPolicy

protected int verticalScrollBarPolicy

The display policy for the vertical scrollbar. The default is JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED.

See Also:

setVerticalScrollBarPolicy(int)

horizontalScrollBarPolicy

protected int horizontalScrollBarPolicy

The display policy for the horizontal scrollbar. The default is JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED.

See Also:

setHorizontalScrollBarPolicy(int)

viewport

protected JViewport viewport

The scrollpane's viewport child. Default is an empty JViewport.

See Also:

setViewport(javax.swing.JViewport)

verticalScrollBar

protected JScrollBar verticalScrollBar

The scrollpane's vertical scrollbar child. Default is a JScrollBar.

See Also:

setVerticalScrollBar(javax.swing.JScrollBar)

horizontalScrollBar

protected JScrollBar horizontalScrollBar

The scrollpane's horizontal scrollbar child. Default is a JScrollBar.

See Also:

setHorizontalScrollBar(javax.swing.JScrollBar)

rowHeader

protected JViewport rowHeader

The row header child. Default is null.

See Also:

setRowHeader(javax.swing.JViewport)

columnHeader

protected JViewport columnHeader

The column header child. Default is null.

See Also:

setColumnHeader(javax.swing.JViewport)

lowerLeft

protected Component lowerLeft

The component to display in the lower left corner. Default is null.

See Also:

setCorner(java.lang.String, java.awt.Component)

lowerRight

protected Component lowerRight

The component to display in the lower right corner. Default is null.

See Also:

setCorner(java.lang.String, java.awt.Component)

upperLeft

protected Component upperLeft

The component to display in the upper left corner. Default is null.

See Also:

setCorner(java.lang.String, java.awt.Component)

upperRight

protected Component upperRight

The component to display in the upper right corner. Default is null.

See Also:

setCorner(java.lang.String, java.awt.Component)

Constructor Detail

JScrollPane

public JScrollPane(Component view,
                   int vsbPolicy,
                   int hsbPolicy)

Creates a JScrollPane that displays the view component in a viewport whose view position can be controlled with a pair of scrollbars. The scrollbar policies specify when the scrollbars are displayed, For example, if vsbPolicy is VERTICAL_SCROLLBAR_AS_NEEDED then the vertical scrollbar only appears if the view doesn't fit vertically. The available policy settings are listed at setVerticalScrollBarPolicy(int) and setHorizontalScrollBarPolicy(int).

Parameters:

view - the component to display in the scrollpanes viewport

vsbPolicy - an integer that specifies the vertical scrollbar policy

hsbPolicy - an integer that specifies the horizontal scrollbar policy

See Also:

setViewportView(java.awt.Component)

JScrollPane

public JScrollPane(Component view)

Creates a JScrollPane that displays the contents of the specified component, where both horizontal and vertical scrollbars appear whenever the component's contents are larger than the view.

Parameters:

view - the component to display in the scrollpane's viewport

See Also:

setViewportView(java.awt.Component)

JScrollPane

public JScrollPane(int vsbPolicy,
                   int hsbPolicy)

Creates an empty (no viewport view) JScrollPane with specified scrollbar policies. The available policy settings are listed at setVerticalScrollBarPolicy(int) and setHorizontalScrollBarPolicy(int).

Parameters:

vsbPolicy - an integer that specifies the vertical scrollbar policy

hsbPolicy - an integer that specifies the horizontal scrollbar policy

See Also:

setViewportView(java.awt.Component)

JScrollPane

public JScrollPane()

Creates an empty (no viewport view) JScrollPane where both horizontal and vertical scrollbars appear when needed.

Method Detail

getUI

public ScrollPaneUI getUI()

Returns the look and feel (L&F) object that renders this component.

Returns:

the ScrollPaneUI object that renders this component

See Also:

setUI(javax.swing.plaf.ScrollPaneUI)

setUI

public void setUI(ScrollPaneUI ui)

Sets the ScrollPaneUI object that provides the look and feel (L&F) for this component.

Parameters:

ui - the ScrollPaneUI L&F object

See Also:

getUI()

updateUI

public void updateUI()

Replaces the current ScrollPaneUI object with a version from the current default look and feel. To be called when the default look and feel changes.

Overrides:

updateUI in class JComponent

See Also:

JComponent.updateUI(), UIManager.getUI(javax.swing.JComponent)

getUIClassID

public String getUIClassID()

Returns the suffix used to construct the name of the L&F class used to render this component.

Overrides:

getUIClassID in class JComponent

Returns:

the string "ScrollPaneUI"

See Also:

JComponent.getUIClassID(), UIDefaults.getUI(javax.swing.JComponent)

setLayout

public void setLayout(LayoutManager layout)

Sets the layout manager for this JScrollPane. This method overrides setLayout in java.awt.Container to ensure that only LayoutManagers which are subclasses of ScrollPaneLayout can be used in a JScrollPane. If layout is non-null, this will invoke syncWithScrollPane on it.

Overrides:

setLayout in class Container

Parameters:

layout - the specified layout manager

Throws:

ClassCastException - if layout is not a ScrollPaneLayout

See Also:

Container.getLayout(), Container.setLayout(java.awt.LayoutManager)

isValidateRoot

public boolean isValidateRoot()

Calls revalidate on any descendant of this JScrollPane. For example, the viewport's view, will cause a request to be queued that will validate the JScrollPane and all its descendants.

Overrides:

isValidateRoot in class JComponent

Returns:

true

See Also:

JComponent.revalidate()

getVerticalScrollBarPolicy

public int getVerticalScrollBarPolicy()

Returns the vertical scroll bar policy value.

Returns:

the verticalScrollBarPolicy property

See Also:

setVerticalScrollBarPolicy(int)

setVerticalScrollBarPolicy

public void setVerticalScrollBarPolicy(int policy)

Determines when the vertical scrollbar appears in the scrollpane. Legal values are:

• JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED
• JScrollPane.VERTICAL_SCROLLBAR_NEVER
• JScrollPane.VERTICAL_SCROLLBAR_ALWAYS

Parameters:

policy - one of the three values listed above

Throws:

IllegalArgumentException - if policy is not one of the legal values shown above

See Also:

getVerticalScrollBarPolicy()

getHorizontalScrollBarPolicy

public int getHorizontalScrollBarPolicy()

Returns the horizontal scroll bar policy value.

Returns:

the horizontalScrollBarPolicy property

See Also:

setHorizontalScrollBarPolicy(int)

setHorizontalScrollBarPolicy

public void setHorizontalScrollBarPolicy(int policy)

Determines when the horizontal scrollbar appears in the scrollpane. The options are:

• JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED
• JScrollPane.HORIZONTAL_SCROLLBAR_NEVER
• JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS

Parameters:

policy - one of the three values listed above

Throws:

IllegalArgumentException - if policy is not one of the legal values shown above

See Also:

getHorizontalScrollBarPolicy()

getViewportBorder

public Border getViewportBorder()

Returns the Border object that surrounds the viewport.

Returns:

the viewportBorder property

See Also:

setViewportBorder(javax.swing.border.Border)

setViewportBorder

public void setViewportBorder(Border viewportBorder)

Adds a border around the viewport. Note that the border isn't set on the viewport directly, JViewport doesn't support the JComponent border property. Similarly setting the JScrollPanes viewport doesn't affect the viewportBorder property.

The default value of this property is computed by the look and feel implementation.

Parameters:

viewportBorder - the border to be added

See Also:

getViewportBorder(), setViewport(javax.swing.JViewport)

getViewportBorderBounds

public Rectangle getViewportBorderBounds()

Returns the bounds of the viewport's border.

Returns:

a Rectangle object specifying the viewport border

createHorizontalScrollBar

public JScrollBar createHorizontalScrollBar()

Returns a JScrollPane.ScrollBar by default. Subclasses may override this method to force ScrollPaneUI implementations to use a JScrollBar subclass. Used by ScrollPaneUI implementations to create the horizontal scrollbar.

Returns:

a JScrollBar with a horizontal orientation

See Also:

JScrollBar

getHorizontalScrollBar

public JScrollBar getHorizontalScrollBar()

Returns the horizontal scroll bar that controls the viewport's horizontal view position.

Returns:

the horizontalScrollBar property

See Also:

setHorizontalScrollBar(javax.swing.JScrollBar)

setHorizontalScrollBar

public void setHorizontalScrollBar(JScrollBar horizontalScrollBar)

Adds the scrollbar that controls the viewport's horizontal view position to the scrollpane. This is usually unnecessary, as JScrollPane creates horizontal and vertical scrollbars by default.

Parameters:

horizontalScrollBar - the horizontal scrollbar to be added

See Also:

createHorizontalScrollBar(), getHorizontalScrollBar()

createVerticalScrollBar

public JScrollBar createVerticalScrollBar()

Returns a JScrollPane.ScrollBar by default. Subclasses may override this method to force ScrollPaneUI implementations to use a JScrollBar subclass. Used by ScrollPaneUI implementations to create the vertical scrollbar.

Returns:

a JScrollBar with a vertical orientation

See Also:

JScrollBar

getVerticalScrollBar

public JScrollBar getVerticalScrollBar()

Returns the vertical scroll bar that controls the viewports vertical view position.

Returns:

the verticalScrollBar property

See Also:

setVerticalScrollBar(javax.swing.JScrollBar)

setVerticalScrollBar

public void setVerticalScrollBar(JScrollBar verticalScrollBar)

Adds the scrollbar that controls the viewports vertical view position to the scrollpane. This is usually unnecessary, as JScrollPane creates vertical and horizontal scrollbars by default.

Parameters:

verticalScrollBar - the new vertical scrollbar to be added

See Also:

createVerticalScrollBar(), getVerticalScrollBar()

createViewport

protected JViewport createViewport()

Returns a new JViewport by default. Used to create the viewport (as needed) in setViewportView, setRowHeaderView, and setColumnHeaderView. Subclasses may override this method to return a subclass of JViewport.

Returns:

a new JViewport

getViewport

public JViewport getViewport()

Returns the current JViewport.

Returns:

the viewport property

See Also:

setViewport(javax.swing.JViewport)

setViewport

public void setViewport(JViewport viewport)

Removes the old viewport (if there is one); forces the viewPosition of the new viewport to be in the +x,+y quadrant; syncs up the row and column headers (if there are any) with the new viewport; and finally syncs the scrollbars and headers with the new viewport.

Most applications will find it more convenient to use setViewportView to add a viewport and a view to the scrollpane.

Parameters:

viewport - the new viewport to be used; if viewport is null, the old viewport is still removed and the new viewport is set to null

See Also:

createViewport(), getViewport(), setViewportView(java.awt.Component)

setViewportView

public void setViewportView(Component view)

Creates a viewport if necessary and then sets its view. Applications that don't provide the view directly to the JScrollPane constructor should use this method to specify the scrollable child that's going to be displayed in the scrollpane. For example:

 JScrollPane scrollpane = new JScrollPane();
 scrollpane.setViewportView(myBigComponentToScroll);
 

Applications should not add children directly to the scrollpane.

Parameters:

view - the component to add to the viewport

See Also:

setViewport(javax.swing.JViewport), JViewport.setView(java.awt.Component)

getRowHeader

public JViewport getRowHeader()

Returns the row header.

Returns:

the rowHeader property

See Also:

setRowHeader(javax.swing.JViewport)

setRowHeader

public void setRowHeader(JViewport rowHeader)

Removes the old rowHeader, if it exists. If the new rowHeader isn't null, syncs the y coordinate of its viewPosition with the viewport (if there is one) and then adds it to the scrollpane.

Most applications will find it more convenient to use setRowHeaderView to add a row header component and its viewport to the scrollpane.

Parameters:

rowHeader - the new row header to be used; if null the old row header is still removed and the new rowHeader is set to null

See Also:

getRowHeader(), setRowHeaderView(java.awt.Component)

setRowHeaderView

public void setRowHeaderView(Component view)

Creates a row-header viewport if necessary, sets its view and then adds the row-header viewport to the scrollpane. For example:

 JScrollPane scrollpane = new JScrollPane();
 scrollpane.setViewportView(myBigComponentToScroll);
 scrollpane.setRowHeaderView(myBigComponentsRowHeader);
 

Parameters:

view - the component to display as the row header

See Also:

setRowHeader(javax.swing.JViewport), JViewport.setView(java.awt.Component)

getColumnHeader

public JViewport getColumnHeader()

Returns the column header.

Returns:

the columnHeader property

See Also:

setColumnHeader(javax.swing.JViewport)

setColumnHeader

public void setColumnHeader(JViewport columnHeader)

Removes the old columnHeader, if it exists. If the new columnHeader isn't null, sync the x coordinate of the its viewPosition with the viewport (if there is one) and then add it to the scrollpane.

Most applications will find it more convenient to use setRowHeaderView to add a row header component and its viewport to the scrollpane.

See Also:

getColumnHeader(), setColumnHeaderView(java.awt.Component)

setColumnHeaderView

public void setColumnHeaderView(Component view)

Creates a column-header viewport if necessary, sets its view, and then adds the column-header viewport to the scrollpane. For example:

 JScrollPane scrollpane = new JScrollPane();
 scrollpane.setViewportView(myBigComponentToScroll);
 scrollpane.setColumnHeaderView(myBigComponentsColumnHeader);
 

Parameters:

view - the component to display as the column header

See Also:

setColumnHeader(javax.swing.JViewport), JViewport.setView(java.awt.Component)

getCorner

public Component getCorner(String key)

Returns the component at the specified corner. The key value specifying the corner is one of:

• JScrollPane.LOWER_LEFT_CORNER
• JScrollPane.LOWER_RIGHT_CORNER
• JScrollPane.UPPER_LEFT_CORNER
• JScrollPane.UPPER_RIGHT_CORNER
• JScrollPane.LOWER_LEADING_CORNER
• JScrollPane.LOWER_TRAILING_CORNER
• JScrollPane.UPPER_LEADING_CORNER
• JScrollPane.UPPER_TRAILING_CORNER

Parameters:

key - one of the values as shown above

Returns:

one of the components listed below or null if key is invalid:

• lowerLeft
• lowerRight
• upperLeft
• upperRight

See Also:

setCorner(java.lang.String, java.awt.Component)

setCorner

public void setCorner(String key,
                      Component corner)

Adds a child that will appear in one of the scroll panes corners, if there's room. For example with both scrollbars showing (on the right and bottom edges of the scrollpane) the lower left corner component will be shown in the space between ends of the two scrollbars. Legal values for the key are:

• JScrollPane.LOWER_LEFT_CORNER
• JScrollPane.LOWER_RIGHT_CORNER
• JScrollPane.UPPER_LEFT_CORNER
• JScrollPane.UPPER_RIGHT_CORNER
• JScrollPane.LOWER_LEADING_CORNER
• JScrollPane.LOWER_TRAILING_CORNER
• JScrollPane.UPPER_LEADING_CORNER
• JScrollPane.UPPER_TRAILING_CORNER

Although "corner" doesn't match any beans property signature, PropertyChange events are generated with the property name set to the corner key.

Parameters:

key - identifies which corner the component will appear in

corner - one of the following components:

• lowerLeft
• lowerRight
• upperLeft
• upperRight

Throws:

IllegalArgumentException - if corner key is invalid

setComponentOrientation

public void setComponentOrientation(ComponentOrientation co)

Sets the orientation for the vertical and horizontal scrollbars as determined by the ComponentOrientation argument.

Overrides:

setComponentOrientation in class Component

Parameters:

co - one of the following values:

• java.awt.ComponentOrientation.LEFT_TO_RIGHT
• java.awt.ComponentOrientation.RIGHT_TO_LEFT
• java.awt.ComponentOrientation.UNKNOWN

See Also:

ComponentOrientation

isWheelScrollingEnabled

public boolean isWheelScrollingEnabled()

Indicates whether or not scrolling will take place in response to the mouse wheel. Wheel scrolling is enabled by default.

Since:

1.4

See Also:

setWheelScrollingEnabled(boolean)

setWheelScrollingEnabled

public void setWheelScrollingEnabled(boolean handleWheel)

Enables/disables scrolling in response to movement of the mouse wheel. Wheel scrolling is enabled by default.

Parameters:

handleWheel - true if scrolling should be done automatically for a MouseWheelEvent, false otherwise.

Since:

1.4

See Also:

isWheelScrollingEnabled(), MouseWheelEvent, MouseWheelListener

paramString

protected String paramString()

Returns a string representation of this JScrollPane. 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.

Overrides:

paramString in class JComponent

Returns:

a string representation of this JScrollPane.

getAccessibleContext

public AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this JScrollPane. For scroll panes, the AccessibleContext takes the form of an AccessibleJScrollPane. A new AccessibleJScrollPane instance is created if necessary.

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class JComponent

Returns:

an AccessibleJScrollPane that serves as the AccessibleContext of this JScrollPane