File	Doc	Category	Size	Date	Package
ScrollPaneAdjustable.java	API Doc	Java SE 6 API	13285	Tue Jun 10 00:25:18 BST 2008	java.awt

ScrollPaneAdjustable

• java.lang.Object

Fields Summary
private ScrollPane	sp The ScrollPane this object is a scrollbar of.
private int	orientation Orientation of this scrollbar.
private int	value The value of this scrollbar. value should be greater than minimum and less than maximum
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.
private int	maximum The maximum value of this scrollbar. This value can only be set by the ScrollPane.
private int	visibleAmount The size of the visible portion of this scrollbar. This value can only be set by the ScrollPane.
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.
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.
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.
private AdjustmentListener	adjustmentListener
private static final String	SCROLLPANE_ONLY Error message for AWTError reported when one of the public but unsupported methods is called.
private static final long	serialVersionUID JDK 1.1 serialVersionUID.

Constructors Summary

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. param sp ScrollPane param l AdjustmentListener to add upon creation. param orientation specifies which scrollbar this object represents, can be either Adjustable.HORIZONTAL or Adjustable.VERTICAL. this.sp = sp; this.orientation = orientation; addAdjustmentListener(l);

Methods Summary
public synchronized void	addAdjustmentListener(java.awt.event.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. Refer to AWT Threading Issues for details on AWT's threading model. param l the adjustment listener. see #removeAdjustmentListener see #getAdjustmentListeners see java.awt.event.AdjustmentListener see java.awt.event.AdjustmentEvent if (l == null) { return; } adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l);
public synchronized java.awt.event.AdjustmentListener[]	getAdjustmentListeners() Returns an array of all the adjustment listeners registered on this ScrollPaneAdjustable. return all of this ScrollPaneAdjustable's AdjustmentListeners or an empty array if no adjustment listeners are currently registered see #addAdjustmentListener see #removeAdjustmentListener see java.awt.event.AdjustmentListener see java.awt.event.AdjustmentEvent since 1.4 return (AdjustmentListener[])(AWTEventMulticaster.getListeners( adjustmentListener, AdjustmentListener.class));
public int	getBlockIncrement() return blockIncrement;
public int	getMaximum() return maximum;
public int	getMinimum() // XXX: This relies on setSpan always being called with 0 for // the minimum (which is currently true). return 0;
public int	getOrientation() Returns the orientation of this scrollbar. return the orientation of this scrollbar, either Adjustable.HORIZONTAL or Adjustable.VERTICAL return orientation;
public int	getUnitIncrement() return unitIncrement;
public int	getValue() return value;
public boolean	getValueIsAdjusting() Returns true if the value is in the process of changing as a result of actions being taken by the user. return the value of the valueIsAdjusting property see #setValueIsAdjusting return isAdjusting;
public int	getVisibleAmount() return visibleAmount;
private static native void	initIDs() Initialize JNI field and method ids.
public java.lang.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. return the parameter string of this scrollbar. return ((orientation == Adjustable.VERTICAL ? "vertical," :"horizontal,") + "[0.."+maximum+"]" + ",val=" + value + ",vis=" + visibleAmount + ",unit=" + unitIncrement + ",block=" + blockIncrement + ",isAdjusting=" + isAdjusting);
public synchronized void	removeAdjustmentListener(java.awt.event.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. Refer to AWT Threading Issues for details on AWT's threading model. param l the adjustment listener. see #addAdjustmentListener see #getAdjustmentListeners see java.awt.event.AdjustmentListener see java.awt.event.AdjustmentEvent since JDK1.1 if (l == null) { return; } adjustmentListener = AWTEventMulticaster.remove(adjustmentListener, l);
public synchronized void	setBlockIncrement(int b) blockIncrement = b;
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. throws AWTError Always throws an error when called. throw new AWTError(SCROLLPANE_ONLY);
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. throws AWTError Always throws an error when called. throw new AWTError(SCROLLPANE_ONLY);
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. // adjust the values to be reasonable minimum = min; maximum = Math.max(max, minimum + 1); visibleAmount = Math.min(visible, maximum - minimum); visibleAmount = Math.max(visibleAmount, 1); blockIncrement = Math.max((int)(visible * .90), 1); setValue(value);
private void	setTypedValue(int v, int type) 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. Also, creates and dispatches the AdjustementEvent with specified type and value. param v the new value of the scrollbar param type the type of the scrolling operation occured v = Math.max(v, minimum); v = Math.min(v, maximum - visibleAmount); if (v != value) { value = v; // Synchronously notify the listeners so that they are // guaranteed to be up-to-date with the Adjustable before // it is mutated again. AdjustmentEvent e = new AdjustmentEvent(this, AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, type, value, isAdjusting); adjustmentListener.adjustmentValueChanged(e); }
public synchronized void	setUnitIncrement(int u) if (u != unitIncrement) { unitIncrement = u; if (sp.peer != null) { ScrollPanePeer peer = (ScrollPanePeer) sp.peer; peer.setUnitIncrement(this, u); } }
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. param v the new value of the scrollbar setTypedValue(v, AdjustmentEvent.TRACK);
public void	setValueIsAdjusting(boolean b) Sets the valueIsAdjusting property. param b new adjustment-in-progress status see #getValueIsAdjusting since 1.4 if (isAdjusting != b) { isAdjusting = b; AdjustmentEvent e = new AdjustmentEvent(this, AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, AdjustmentEvent.TRACK, value, b); adjustmentListener.adjustmentValueChanged(e); }
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. throws AWTError Always throws an error when called. throw new AWTError(SCROLLPANE_ONLY);
public java.lang.String	toString() Returns a string representation of this scrollbar and its values. return a string representation of this scrollbar. return getClass().getName() + "[" + paramString() + "]";