ScrollPaneLayout

java.lang.Object
- javax.swing.ScrollPaneLayout

All Implemented Interfaces:

LayoutManager, Serializable, ScrollPaneConstants

Direct Known Subclasses:

ScrollPaneLayout.UIResource
```
public class ScrollPaneLayout
extends Object
implements LayoutManager, ScrollPaneConstants, Serializable
```
The layout manager used by JScrollPane. JScrollPaneLayout is responsible for nine components: a viewport, two scrollbars, a row header, a column header, and four "corner" components.
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.

See Also:

JScrollPane, JViewport

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
`static class`	`ScrollPaneLayout.UIResource` The UI resource version of `ScrollPaneLayout`.

Field Summary

Fields

Modifier and Type	Field and Description
`protected JViewport`	`colHead` The column header child.
`protected JScrollBar`	`hsb` The scrollpane's horizontal scrollbar child.
`protected int`	`hsbPolicy` 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`	`rowHead` 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 JViewport`	`viewport` The scrollpane's viewport child.
`protected JScrollBar`	`vsb` The scrollpane's vertical scrollbar child.
`protected int`	`vsbPolicy` The display policy for the vertical scrollbar.

Constructor Summary

Constructors

Constructor and Description
`ScrollPaneLayout()`

Method Summary

All Methods

Instance Methods

Concrete Methods

Deprecated Methods
Modifier and Type	Method and Description
`void`	`addLayoutComponent(String s, Component c)` Adds the specified component to the layout.
`protected Component`	`addSingletonComponent(Component oldC, Component newC)` Removes an existing component.
`JViewport`	`getColumnHeader()` Returns the `JViewport` object that is the column header.
`Component`	`getCorner(String key)` Returns the `Component` at the specified corner.
`JScrollBar`	`getHorizontalScrollBar()` Returns the `JScrollBar` object that handles horizontal scrolling.
`int`	`getHorizontalScrollBarPolicy()` Returns the horizontal scrollbar-display policy.
`JViewport`	`getRowHeader()` Returns the `JViewport` object that is the row header.
`JScrollBar`	`getVerticalScrollBar()` Returns the `JScrollBar` object that handles vertical scrolling.
`int`	`getVerticalScrollBarPolicy()` Returns the vertical scrollbar-display policy.
`JViewport`	`getViewport()` Returns the `JViewport` object that displays the scrollable contents.
`Rectangle`	`getViewportBorderBounds(JScrollPane scrollpane)` Deprecated. As of JDK version Swing1.1 replaced by `JScrollPane.getViewportBorderBounds()`.
`void`	`layoutContainer(Container parent)` Lays out the scrollpane.
`Dimension`	`minimumLayoutSize(Container parent)` The minimum size of a `ScrollPane` is the size of the insets plus minimum size of the viewport, plus the scrollpane's viewportBorder insets, plus the minimum size of the visible headers, plus the minimum size of the scrollbars whose displayPolicy isn't NEVER.
`Dimension`	`preferredLayoutSize(Container parent)` The preferred size of a `ScrollPane` is the size of the insets, plus the preferred size of the viewport, plus the preferred size of the visible headers, plus the preferred size of the scrollbars that will appear given the current view and the current scrollbar displayPolicies.
`void`	`removeLayoutComponent(Component c)` Removes the specified component from the layout.
`void`	`setHorizontalScrollBarPolicy(int x)` Sets the horizontal scrollbar-display policy.
`void`	`setVerticalScrollBarPolicy(int x)` Sets the vertical scrollbar-display policy.
`void`	`syncWithScrollPane(JScrollPane sp)` This method is invoked after the ScrollPaneLayout is set as the LayoutManager of a `JScrollPane`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - viewport
```
protected JViewport viewport
```
    The scrollpane's viewport child. Default is an empty JViewport.
    
    See Also:
    
    JScrollPane.setViewport(javax.swing.JViewport)
  - vsb
```
protected JScrollBar vsb
```
    The scrollpane's vertical scrollbar child. Default is a JScrollBar.
    
    See Also:
    
    JScrollPane.setVerticalScrollBar(javax.swing.JScrollBar)
  - hsb
```
protected JScrollBar hsb
```
    The scrollpane's horizontal scrollbar child. Default is a JScrollBar.
    
    See Also:
    
    JScrollPane.setHorizontalScrollBar(javax.swing.JScrollBar)
  - rowHead
```
protected JViewport rowHead
```
    The row header child. Default is null.
    
    See Also:
    
    JScrollPane.setRowHeader(javax.swing.JViewport)
  - colHead
```
protected JViewport colHead
```
    The column header child. Default is null.
    
    See Also:
    
    JScrollPane.setColumnHeader(javax.swing.JViewport)
  - lowerLeft
```
protected Component lowerLeft
```
    The component to display in the lower left corner. Default is null.
    
    See Also:
    
    JScrollPane.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:
    
    JScrollPane.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:
    
    JScrollPane.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:
    
    JScrollPane.setCorner(java.lang.String, java.awt.Component)
  - vsbPolicy
```
protected int vsbPolicy
```
    The display policy for the vertical scrollbar. The default is ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED.
    This field is obsolete, please use the JScrollPane field instead.
    
    See Also:
    
    JScrollPane.setVerticalScrollBarPolicy(int)
  - hsbPolicy
```
protected int hsbPolicy
```
    The display policy for the horizontal scrollbar. The default is ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED.
    This field is obsolete, please use the JScrollPane field instead.
    
    See Also:
    
    JScrollPane.setHorizontalScrollBarPolicy(int)
- Constructor Detail
  - ScrollPaneLayout
```
public ScrollPaneLayout()
```
- Method Detail
  - syncWithScrollPane
```
public void syncWithScrollPane(JScrollPane sp)
```
    This method is invoked after the ScrollPaneLayout is set as the LayoutManager of a JScrollPane. It initializes all of the internal fields that are ordinarily set by addLayoutComponent. For example:
```
 ScrollPaneLayout mySPLayout = new ScrollPanelLayout() {
     public void layoutContainer(Container p) {
         super.layoutContainer(p);
         // do some extra work here ...
     }
 };
 scrollpane.setLayout(mySPLayout):
 
```
  - addSingletonComponent
```
protected Component addSingletonComponent(Component oldC,
                                          Component newC)
```
    Removes an existing component. When a new component, such as the left corner, or vertical scrollbar, is added, the old one, if it exists, must be removed.
    This method returns newC. If oldC is not equal to newC and is non-null, it will be removed from its parent.
    
    Parameters:
    
    oldC - the Component to replace
    
    newC - the Component to add
    
    Returns:
    
    the newC
  - addLayoutComponent
```
public void addLayoutComponent(String s,
                               Component c)
```
    Adds the specified component to the layout. The layout is identified using one of:
    - ScrollPaneConstants.VIEWPORT
    - ScrollPaneConstants.VERTICAL_SCROLLBAR
    - ScrollPaneConstants.HORIZONTAL_SCROLLBAR
    - ScrollPaneConstants.ROW_HEADER
    - ScrollPaneConstants.COLUMN_HEADER
    - ScrollPaneConstants.LOWER_LEFT_CORNER
    - ScrollPaneConstants.LOWER_RIGHT_CORNER
    - ScrollPaneConstants.UPPER_LEFT_CORNER
    - ScrollPaneConstants.UPPER_RIGHT_CORNER
    Specified by:
    
    addLayoutComponent in interface LayoutManager
    
    Parameters:
    
    s - the component identifier
    
    c - the the component to be added
    
    Throws:
    
    IllegalArgumentException - if s is an invalid key
  - removeLayoutComponent
```
public void removeLayoutComponent(Component c)
```
    Removes the specified component from the layout.
    
    Specified by:
    
    removeLayoutComponent in interface LayoutManager
    
    Parameters:
    
    c - the component to remove
  - getVerticalScrollBarPolicy
```
public int getVerticalScrollBarPolicy()
```
    Returns the vertical scrollbar-display policy.
    
    Returns:
    
    an integer giving the display policy
    
    See Also:
    
    setVerticalScrollBarPolicy(int)
  - setVerticalScrollBarPolicy
```
public void setVerticalScrollBarPolicy(int x)
```
    Sets the vertical scrollbar-display policy. The options are:
    - ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED
    - ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER
    - ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS
    Note: Applications should use the JScrollPane version of this method. It only exists for backwards compatibility with the Swing 1.0.2 (and earlier) versions of this class.
    Parameters:
    
    x - an integer giving the display policy
    
    Throws:
    
    IllegalArgumentException - if x is an invalid vertical scroll bar policy, as listed above
  - getHorizontalScrollBarPolicy
```
public int getHorizontalScrollBarPolicy()
```
    Returns the horizontal scrollbar-display policy.
    
    Returns:
    
    an integer giving the display policy
    
    See Also:
    
    setHorizontalScrollBarPolicy(int)
  - setHorizontalScrollBarPolicy
```
public void setHorizontalScrollBarPolicy(int x)
```
    Sets the horizontal scrollbar-display policy. The options are:
    - ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED
    - ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER
    - ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS
    Note: Applications should use the JScrollPane version of this method. It only exists for backwards compatibility with the Swing 1.0.2 (and earlier) versions of this class.
    Parameters:
    
    x - an int giving the display policy
    
    Throws:
    
    IllegalArgumentException - if x is not a valid horizontal scrollbar policy, as listed above
  - getViewport
```
public JViewport getViewport()
```
    Returns the JViewport object that displays the scrollable contents.
    
    Returns:
    
    the JViewport object that displays the scrollable contents
    
    See Also:
    
    JScrollPane.getViewport()
  - getHorizontalScrollBar
```
public JScrollBar getHorizontalScrollBar()
```
    Returns the JScrollBar object that handles horizontal scrolling.
    
    Returns:
    
    the JScrollBar object that handles horizontal scrolling
    
    See Also:
    
    JScrollPane.getHorizontalScrollBar()
  - getVerticalScrollBar
```
public JScrollBar getVerticalScrollBar()
```
    Returns the JScrollBar object that handles vertical scrolling.
    
    Returns:
    
    the JScrollBar object that handles vertical scrolling
    
    See Also:
    
    JScrollPane.getVerticalScrollBar()
  - getRowHeader
```
public JViewport getRowHeader()
```
    Returns the JViewport object that is the row header.
    
    Returns:
    
    the JViewport object that is the row header
    
    See Also:
    
    JScrollPane.getRowHeader()
  - getColumnHeader
```
public JViewport getColumnHeader()
```
    Returns the JViewport object that is the column header.
    
    Returns:
    
    the JViewport object that is the column header
    
    See Also:
    
    JScrollPane.getColumnHeader()
  - getCorner
```
public Component getCorner(String key)
```
    Returns the Component at the specified corner.
    
    Parameters:
    
    key - the String specifying the corner
    
    Returns:
    
    the Component at the specified corner, as defined in ScrollPaneConstants; if key is not one of the four corners, null is returned
    
    See Also:
    
    JScrollPane.getCorner(java.lang.String)
  - preferredLayoutSize
```
public Dimension preferredLayoutSize(Container parent)
```
    The preferred size of a ScrollPane is the size of the insets, plus the preferred size of the viewport, plus the preferred size of the visible headers, plus the preferred size of the scrollbars that will appear given the current view and the current scrollbar displayPolicies.
    Note that the rowHeader is calculated as part of the preferred width and the colHeader is calculated as part of the preferred size.
    
    Specified by:
    
    preferredLayoutSize in interface LayoutManager
    
    Parameters:
    
    parent - the Container that will be laid out
    
    Returns:
    
    a Dimension object specifying the preferred size of the viewport and any scrollbars
    
    See Also:
    
    ViewportLayout, LayoutManager
  - minimumLayoutSize
```
public Dimension minimumLayoutSize(Container parent)
```
    The minimum size of a ScrollPane is the size of the insets plus minimum size of the viewport, plus the scrollpane's viewportBorder insets, plus the minimum size of the visible headers, plus the minimum size of the scrollbars whose displayPolicy isn't NEVER.
    
    Specified by:
    
    minimumLayoutSize in interface LayoutManager
    
    Parameters:
    
    parent - the Container that will be laid out
    
    Returns:
    
    a Dimension object specifying the minimum size
    
    See Also:
    
    LayoutManager.preferredLayoutSize(java.awt.Container)
  - layoutContainer
```
public void layoutContainer(Container parent)
```
    Lays out the scrollpane. The positioning of components depends on the following constraints:
    - The row header, if present and visible, gets its preferred width and the viewport's height.
    - The column header, if present and visible, gets its preferred height and the viewport's width.
    - If a vertical scrollbar is needed, i.e. if the viewport's extent height is smaller than its view height or if the displayPolicy is ALWAYS, it's treated like the row header with respect to its dimensions and is made visible.
    - If a horizontal scrollbar is needed, it is treated like the column header (see the paragraph above regarding the vertical scrollbar).
    - If the scrollpane has a non-null viewportBorder, then space is allocated for that.
    - The viewport gets the space available after accounting for the previous constraints.
    - The corner components, if provided, are aligned with the ends of the scrollbars and headers. If there is a vertical scrollbar, the right corners appear; if there is a horizontal scrollbar, the lower corners appear; a row header gets left corners, and a column header gets upper corners.
    Specified by:
    
    layoutContainer in interface LayoutManager
    
    Parameters:
    
    parent - the Container to lay out
  - getViewportBorderBounds
```
@Deprecated
public Rectangle getViewportBorderBounds(JScrollPane scrollpane)
```
    Deprecated. As of JDK version Swing1.1 replaced by JScrollPane.getViewportBorderBounds().
    
    Returns the bounds of the border around the specified scroll pane's viewport.
    
    Returns:
    
    the size and position of the viewport border

Class ScrollPaneLayout

Nested Class Summary

Nested Classes

Field Summary

Fields

Fields inherited from interface javax.swing.ScrollPaneConstants

Constructor Summary

Constructors

Method Summary

Methods inherited from class java.lang.Object

Field Detail

viewport

vsb

hsb

rowHead

colHead

lowerLeft

lowerRight

upperLeft

upperRight

vsbPolicy

hsbPolicy

Constructor Detail

ScrollPaneLayout

Method Detail

syncWithScrollPane

addSingletonComponent

addLayoutComponent

removeLayoutComponent

getVerticalScrollBarPolicy

setVerticalScrollBarPolicy

getHorizontalScrollBarPolicy

setHorizontalScrollBarPolicy

getViewport

getHorizontalScrollBar

getVerticalScrollBar

getRowHeader

getColumnHeader

getCorner

preferredLayoutSize

minimumLayoutSize

layoutContainer

getViewportBorderBounds