java.awt
Class ScrollPaneAdjustable

java.lang.Object
  java.awt.ScrollPaneAdjustable

All Implemented Interfaces:

Adjustable, Serializable

public class ScrollPaneAdjustable

extends Object

implements Adjustable, Serializable

This class represents the state of a horizontal or vertical scrollbar of a ScrollPane. Objects of this class are returned by ScrollPane methods.

Since:

1.4

See Also:

Serialized Form

Field Summary

private AdjustmentListener	adjustmentListener
private int	blockIncrement The amount by which the scrollbar value will change when going up or down by a page.
private boolean	isAdjusting The adjusting status of the Scrollbar.
private int	maximum The maximum value of this scrollbar.
private int	minimum The minimum value of this scrollbar.
private int	orientation Orientation of this scrollbar.
private static String	SCROLLPANE_ONLY Error message for AWTError reported when one of the public but unsupported methods is called.
private static long	serialVersionUID JDK 1.1 serialVersionUID.
private ScrollPane	sp The ScrollPane this object is a scrollbar of.
private int	unitIncrement The amount by which the scrollbar value will change when going up or down by a line.
private int	value The value of this scrollbar.
private int	visibleAmount The size of the visible portion of this scrollbar.

Fields inherited from interface java.awt.Adjustable

HORIZONTAL, NO_ORIENTATION, VERTICAL

Constructor Summary

(package private)

ScrollPaneAdjustable(ScrollPane sp, AdjustmentListener l, int orientation) Constructs a new object to represent specified scrollabar of the specified ScrollPane.

Method Summary

void	addAdjustmentListener(AdjustmentListener l) Adds the specified adjustment listener to receive adjustment events from this ScrollPaneAdjustable.
AdjustmentListener[]	getAdjustmentListeners() Returns an array of all the adjustment listeners registered on this ScrollPaneAdjustable.
int	getBlockIncrement() Gets the block value increment for the adjustable object.
int	getMaximum() Gets the maximum value of the adjustable object.
int	getMinimum() Gets the minimum value of the adjustable object.
int	getOrientation() Returns the orientation of this scrollbar.
int	getUnitIncrement() Gets the unit value increment for the adjustable object.
int	getValue() Gets the current value of the adjustable object.
boolean	getValueIsAdjusting() Returns true if the value is in the process of changing as a result of actions being taken by the user.
int	getVisibleAmount() Gets the length of the proportional indicator.
private static void	initIDs() Initialize JNI field and method ids.
String	paramString() Returns a string representing the state of this scrollbar.
void	removeAdjustmentListener(AdjustmentListener l) Removes the specified adjustment listener so that it no longer receives adjustment events from this ScrollPaneAdjustable.
void	setBlockIncrement(int b) Sets the block value increment for the adjustable object.
void	setMaximum(int max) This method should NOT be called by user code.
void	setMinimum(int min) This method should NOT be called by user code.
(package private) void	setSpan(int min, int max, int visible) This is called by the scrollpane itself to update the minimum, maximum and visible values.
void	setUnitIncrement(int u) Sets the unit value increment for the adjustable object.
void	setValue(int v) Sets the value of this scrollbar to the specified value.
void	setValueIsAdjusting(boolean b) Sets the valueIsAdjusting property.
void	setVisibleAmount(int v) This method should NOT be called by user code.
String	toString() Returns a string representation of this scrollbar and its values.

Methods inherited from class java.lang.Object

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

Field Detail

sp

private ScrollPane sp

The ScrollPane this object is a scrollbar of.

orientation

private int orientation

Orientation of this scrollbar.

See Also:

getOrientation(), Adjustable.HORIZONTAL, Adjustable.VERTICAL

value

private int value

The value of this scrollbar. value should be greater than minimum and less than maximum

See Also:

getValue(), setValue(int)

minimum

private int minimum

The minimum value of this scrollbar. This value can only be set by the ScrollPane.

ATTN: In current implementation minimum is always 0. This field can only be altered via setSpan method and ScrollPane always calls that method with 0 for the minimum. getMinimum method always returns 0 without checking this field.

See Also:

getMinimum(), setSpan(int, int, int)

maximum

private int maximum

The maximum value of this scrollbar. This value can only be set by the ScrollPane.

See Also:

getMaximum(), setSpan(int, int, int)

visibleAmount

private int visibleAmount

The size of the visible portion of this scrollbar. This value can only be set by the ScrollPane.

See Also:

getVisibleAmount(), setSpan(int, int, int)

isAdjusting

private transient boolean isAdjusting

The adjusting status of the Scrollbar. True if the value is in the process of changing as a result of actions being taken by the user.

Since:

1.4

See Also:

getValueIsAdjusting(), setValueIsAdjusting(boolean)

unitIncrement

private int unitIncrement

The amount by which the scrollbar value will change when going up or down by a line. This value should be a non negative integer.

See Also:

getUnitIncrement(), setUnitIncrement(int)

blockIncrement

private int blockIncrement

The amount by which the scrollbar value will change when going up or down by a page. This value should be a non negative integer.

See Also:

getBlockIncrement(), setBlockIncrement(int)

adjustmentListener

private AdjustmentListener adjustmentListener

SCROLLPANE_ONLY

private static final String SCROLLPANE_ONLY

Error message for AWTError reported when one of the public but unsupported methods is called.

See Also:

Constant Field Values

serialVersionUID

private static final long serialVersionUID

JDK 1.1 serialVersionUID.

See Also:

Constant Field Values

Constructor Detail

ScrollPaneAdjustable

ScrollPaneAdjustable(ScrollPane sp,
                     AdjustmentListener l,
                     int orientation)

Constructs a new object to represent specified scrollabar of the specified ScrollPane. Only ScrollPane creates instances of this class.

Parameters:

sp - ScrollPane

l - AdjustmentListener to add upon creation.

orientation - specifies which scrollbar this object represents, can be either Adjustable.HORIZONTAL or Adjustable.VERTICAL.

Method Detail

initIDs

private static void initIDs()

Initialize JNI field and method ids.

setSpan

void setSpan(int min,
             int max,
             int visible)

This is called by the scrollpane itself to update the minimum, maximum and visible values. The scrollpane is the only one that should be changing these since it is the source of these values.

getOrientation

public int getOrientation()

Returns the orientation of this scrollbar.

Specified by:

getOrientation in interface Adjustable

Returns:

the orientation of this scrollbar, either Adjustable.HORIZONTAL or Adjustable.VERTICAL

setMinimum

public void setMinimum(int min)

This method should NOT be called by user code. This method is public for this class to properly implement Adjustable interface.

Specified by:

setMinimum in interface Adjustable

Parameters:

min - the minimum value

Throws:

AWTError - Always throws an error when called.

getMinimum

public int getMinimum()

Description copied from interface: Adjustable

Gets the minimum value of the adjustable object.

Specified by:

getMinimum in interface Adjustable

Returns:

the minimum value of the adjustable object

setMaximum

public void setMaximum(int max)

This method should NOT be called by user code. This method is public for this class to properly implement Adjustable interface.

Specified by:

setMaximum in interface Adjustable

Parameters:

max - the maximum value

Throws:

AWTError - Always throws an error when called.

getMaximum

public int getMaximum()

Description copied from interface: Adjustable

Gets the maximum value of the adjustable object.

Specified by:

getMaximum in interface Adjustable

Returns:

the maximum value of the adjustable object

setUnitIncrement

public void setUnitIncrement(int u)

Description copied from interface: Adjustable

Sets the unit value increment for the adjustable object.

Specified by:

setUnitIncrement in interface Adjustable

Parameters:

u - the unit increment

getUnitIncrement

public int getUnitIncrement()

Description copied from interface: Adjustable

Gets the unit value increment for the adjustable object.

Specified by:

getUnitIncrement in interface Adjustable

Returns:

the unit value increment for the adjustable object

setBlockIncrement

public void setBlockIncrement(int b)

Description copied from interface: Adjustable

Sets the block value increment for the adjustable object.

Specified by:

setBlockIncrement in interface Adjustable

Parameters:

b - the block increment

getBlockIncrement

public int getBlockIncrement()

Description copied from interface: Adjustable

Gets the block value increment for the adjustable object.

Specified by:

getBlockIncrement in interface Adjustable

Returns:

the block value increment for the adjustable object

setVisibleAmount

public void setVisibleAmount(int v)

This method should NOT be called by user code. This method is public for this class to properly implement Adjustable interface.

Specified by:

setVisibleAmount in interface Adjustable

Parameters:

v - the length of the indicator

Throws:

AWTError - Always throws an error when called.

getVisibleAmount

public int getVisibleAmount()

Description copied from interface: Adjustable

Gets the length of the proportional indicator.

Specified by:

getVisibleAmount in interface Adjustable

Returns:

the length of the proportional indicator

setValueIsAdjusting

public void setValueIsAdjusting(boolean b)

Sets the valueIsAdjusting property.

Parameters:

b - new adjustment-in-progress status

Since:

1.4

See Also:

getValueIsAdjusting()

getValueIsAdjusting

public boolean getValueIsAdjusting()

Returns true if the value is in the process of changing as a result of actions being taken by the user.

Returns:

the value of the valueIsAdjusting property

See Also:

setValueIsAdjusting(boolean)

setValue

public void setValue(int v)

Sets the value of this scrollbar to the specified value.

If the value supplied is less than the current minimum or greater than the current maximum, then one of those values is substituted, as appropriate.

Specified by:

setValue in interface Adjustable

Parameters:

v - the new value of the scrollbar

getValue

public int getValue()

Description copied from interface: Adjustable

Gets the current value of the adjustable object.

Specified by:

getValue in interface Adjustable

Returns:

the current value of the adjustable object

addAdjustmentListener

public void addAdjustmentListener(AdjustmentListener l)

Adds the specified adjustment listener to receive adjustment events from this ScrollPaneAdjustable. If l is null, no exception is thrown and no action is performed.

Specified by:

addAdjustmentListener in interface Adjustable

Parameters:

l - the adjustment listener.

See Also:

removeAdjustmentListener(java.awt.event.AdjustmentListener), getAdjustmentListeners(), AdjustmentListener, AdjustmentEvent

removeAdjustmentListener

public void removeAdjustmentListener(AdjustmentListener l)

Removes the specified adjustment listener so that it no longer receives adjustment events from this ScrollPaneAdjustable. If l is null, no exception is thrown and no action is performed.

Specified by:

removeAdjustmentListener in interface Adjustable

Parameters:

l - the adjustment listener.

Since:

JDK1.1

See Also:

addAdjustmentListener(java.awt.event.AdjustmentListener), getAdjustmentListeners(), AdjustmentListener, AdjustmentEvent

getAdjustmentListeners

public AdjustmentListener[] getAdjustmentListeners()

Returns an array of all the adjustment listeners registered on this ScrollPaneAdjustable.

Returns:

all of this ScrollPaneAdjustable's AdjustmentListeners or an empty array if no adjustment listeners are currently registered

Since:

1.4

See Also:

addAdjustmentListener(java.awt.event.AdjustmentListener), removeAdjustmentListener(java.awt.event.AdjustmentListener), AdjustmentListener, AdjustmentEvent

toString

public String toString()

Returns a string representation of this scrollbar and its values.

Overrides:

toString in class Object

Returns:

a string representation of this scrollbar.

paramString

public String paramString()

Returns a string representing the state of this scrollbar. 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.

Returns:

the parameter string of this scrollbar.