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ScrollPane (New)

Name

ScrollPane (New)

[Graphic: Figure from the text]

Description

The ScrollPane class provides automatic scrolling of a child component.

Class Definition

public class java.awt.ScrollPane
    extends java.awt.Container {
  // Constants
  public final static int SCROLLBARS_ALWAYS;
  public final static int SCROLLBARS_AS_NEEDED;
  public final static int SCROLLBARS_NEVER;
  // Constructors
  public ScrollPane();
  public ScrollPane (int scrollbarDisplayPolicy);
  // Public Instance Methods
  public void addNotify();
  public void doLayout();
  public Adjustable getHAdjustable();
  public int getHScrollbarHeight();
  public Point getScrollPosition();
  public int getScrollbarDisplayPolicy();
  public Adjustable getVAdjustable();
  public int getVScrollbarWidth();
  public Dimension getViewportSize();
  public void layout(); (Deprecated)
  public String paramString();
  public void printComponents (Graphics g);
  public final void setLayout (LayoutManager mgr);
  public void setScrollPosition (int x, int y);
  public void setScrollPosition (Point p);
  
  //Protected Instance Methods
  protected final void addImpl (Component comp, Object constraints,
    int index); 
}

Constants

SCROLLBARS_ALWAYS

public final static int SCROLLBARS_ALWAYS

Always show the scrollbars.

SCROLLBARS_AS_NEEDED

public final static int SCROLLBARS_AS_NEEDED

Only show the scrollbars if the contents of the ScrollPane are larger than what is visible.

SCROLLBARS_NEVER

public final static int SCROLLBARS_NEVER

Don't ever show the scrollbars. The ScrollPane can still be scrolled programmatically.

Constructors

ScrollPane

public ScrollPane()

Description

Constructs a ScrollPane object with SCROLLBARS_AS_NEEDED.

public ScrollPane (int scrollbarDisplayPolicy)

Parameters

scrollbarDisplayPolicy

One of the SCROLLBARS_ constants.

Description

Constructs a ScrollPane object with the specified scrollbar display policy.

Instance Methods

addImpl

protected final void addImpl (Component comp, Object constraints, int index)

Parameters

comp

The component to add to the Scrollpane.

constraints

Layout constraints; ignored.

index

The position at which to add the component; should always be less than or equal to 0.

Returns

The component that was added.

Overrides

Container.addImpl (Component, Object, int)

Throws

IllegalArgumentException

If pos is greater than 0.

Description

Adds a child component to the Scrollpane. If there already was a child component, it is replaced by the new component.

addNotify

public void addNotify()

Overrides

Container.addNotify()

Description

Creates ScrollPane's peer.

doLayout

public void doLayout()

Overrides

Container.doLayout()

Description

Lays out the ScrollPane. Resizes the child component to its preferred size.

getHAdjustable

public Adjustable getHAdjustable()

Returns

The object implementing the Adjustable interface that is used to adjust the ScrollPane horizontally. Usually this is a Scrollbar.

getHScrollbarHeight

public int getHScrollbarHeight()

Returns

The height a horizontal scrollbar would occupy, regardless of whether it's shown or not.

getScrollPosition

public Point getScrollPosition()

Returns

Returns the position within the child component that is displayed at 0, 0 in the ScrollPane.

getScrollbarDisplayPolicy

public int getScrollbarDisplayPolicy()

Returns

The display policy for the scrollbars (one of the SCROLLBARS_ constants).

getVAdjustable

public Adjustable getVAdjustable()

Returns

The object implementing the Adjustable interface that is used to adjust the ScrollPane vertically. Usually this is a Scrollbar.

getVScrollbarWidth

public int getVScrollbarWidth()

Returns

The width a vertical scrollbar would occupy, regardless of whether it's shown or not.

getViewportSize

public Dimension getViewportSize()

Returns

The size of the ScrollPane's port (the area of the child component that is shown).

layout

public void layout() (Deprecated)

Overrides

Container.layout()

Description

Lays out component. Replaced by doLayout().

paramString

public String paramString()

Returns

String with current settings of ScrollPane.

Overrides

Container.paramString()

Description

Helper method for toString() to generate string of current settings.

printComponents

public void printComponents (Graphics g)

Parameters

g

Graphics context.

Overrides

Container.printComponents(Graphics)

Description

Prints the ScrollPane's child component.

setLayout

public void setLayout (LayoutManager manager)

Parameters

manager

Ignored.

Overrides

Container.setLayout(LayoutManager)

Description

Does nothing. No layout manager is needed because there is only one child component.

setScrollPosition

public void setScrollPosition (int x, int y)

Parameters

x

New horizontal position.

y

New vertical position.

Throws

IllegalArgumentException

If the point given is not valid.

Description

Scroll to the given position in the child component.

public void setScrollPosition (Point p)

Parameters

p

New position.

Throws

IllegalArgumentException

If the point given is not valid.

Description

Scroll to the given position in the child component.

See Also

Adjustable, Container, Point, Scrollbar


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