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## 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 `JScrollBar`s, 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 `getScrollableTracksViewportHeight`is 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 JavaBeansTM 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 `LayoutManager`s 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 `JScrollPane`s 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

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