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	/*
	* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package java.awt;

	import sun.awt.AWTAccessor;

	import java.awt.event.AdjustmentEvent;
	import java.awt.event.AdjustmentListener;
	import java.awt.peer.ScrollPanePeer;
	import java.io.Serializable;


	/**
	* This class represents the state of a horizontal or vertical
	* scrollbar of a <code>ScrollPane</code>. Objects of this class are
	* returned by <code>ScrollPane</code> methods.
	*
	* @since 1.4
	*/
	public class ScrollPaneAdjustable implements Adjustable, Serializable {

	/**
	* The <code>ScrollPane</code> this object is a scrollbar of.
	* @serial
	*/
	private ScrollPane sp;

	/**
	* Orientation of this scrollbar.
	*
	* @serial
	* @see #getOrientation
	* @see java.awt.Adjustable#HORIZONTAL
	* @see java.awt.Adjustable#VERTICAL
	*/
	private int orientation;

	/**
	* The value of this scrollbar.
	* <code>value</code> should be greater than <code>minimum</code>
	* and less than <code>maximum</code>
	*
	* @serial
	* @see #getValue
	* @see #setValue
	*/
	private int value;

	/**
	* The minimum value of this scrollbar.
	* This value can only be set by the <code>ScrollPane</code>.
	* <p>
	* <strong>ATTN:</strong> In current implementation
	* <code>minimum</code> is always <code>0</code>. This field can
	* only be altered via <code>setSpan</code> method and
	* <code>ScrollPane</code> always calls that method with
	* <code>0</code> for the minimum. <code>getMinimum</code> method
	* always returns <code>0</code> without checking this field.
	*
	* @serial
	* @see #getMinimum
	* @see #setSpan(int, int, int)
	*/
	private int minimum;

	/**
	* The maximum value of this scrollbar.
	* This value can only be set by the <code>ScrollPane</code>.
	*
	* @serial
	* @see #getMaximum
	* @see #setSpan(int, int, int)
	*/
	private int maximum;

	/**
	* The size of the visible portion of this scrollbar.
	* This value can only be set by the <code>ScrollPane</code>.
	*
	* @serial
	* @see #getVisibleAmount
	* @see #setSpan(int, int, int)
	*/
	private int visibleAmount;

	/**
	* The adjusting status of the <code>Scrollbar</code>.
	* True if the value is in the process of changing as a result of
	* actions being taken by the user.
	*
	* @see #getValueIsAdjusting
	* @see #setValueIsAdjusting
	* @since 1.4
	*/
	private transient boolean isAdjusting;

	/**
	* 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.
	*
	* @serial
	* @see #getUnitIncrement
	* @see #setUnitIncrement
	*/
	private int unitIncrement = 1;

	/**
	* 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.
	*
	* @serial
	* @see #getBlockIncrement
	* @see #setBlockIncrement
	*/
	private int blockIncrement = 1;

	private AdjustmentListener adjustmentListener;

	/**
	* Error message for <code>AWTError</code> reported when one of
	* the public but unsupported methods is called.
	*/
	private static final String SCROLLPANE_ONLY =
	"Can be set by scrollpane only";


	/**
	* Initialize JNI field and method ids.
	*/
	private static native void initIDs();

	static {
	Toolkit.loadLibraries();
	if (!GraphicsEnvironment.isHeadless()) {
	initIDs();
	}
	AWTAccessor.setScrollPaneAdjustableAccessor(new AWTAccessor.ScrollPaneAdjustableAccessor() {
	public void setTypedValue(final ScrollPaneAdjustable adj,
	final int v, final int type) {
	adj.setTypedValue(v, type);
	}
	});
	}

	/**
	* JDK 1.1 serialVersionUID.
	*/
	private static final long serialVersionUID = -3359745691033257079L;


	/**
	* Constructs a new object to represent specified scrollabar
	* of the specified <code>ScrollPane</code>.
	* Only ScrollPane creates instances of this class.
	* @param sp <code>ScrollPane</code>
	* @param l <code>AdjustmentListener</code> to add upon creation.
	* @param orientation specifies which scrollbar this object represents,
	* can be either <code>Adjustable.HORIZONTAL</code>
	* or <code>Adjustable.VERTICAL</code>.
	*/
	ScrollPaneAdjustable(ScrollPane sp, AdjustmentListener l, int orientation) {
	this.sp = sp;
	this.orientation = orientation;
	addAdjustmentListener(l);
	}

	/**
	* This is called by the scrollpane itself to update the
	* <code>minimum</code>, <code>maximum</code> and
	* <code>visible</code> values. The scrollpane is the only one
	* that should be changing these since it is the source of these
	* values.
	*/
	void setSpan(int min, int max, int visible) {
	// 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);
	}

	/**
	* Returns the orientation of this scrollbar.
	* @return the orientation of this scrollbar, either
	* <code>Adjustable.HORIZONTAL</code> or
	* <code>Adjustable.VERTICAL</code>
	*/
	public int getOrientation() {
	return orientation;
	}

	/**
	* This method should <strong>NOT</strong> be called by user code.
	* This method is public for this class to properly implement
	* <code>Adjustable</code> interface.
	*
	* @throws AWTError Always throws an error when called.
	*/
	public void setMinimum(int min) {
	throw new AWTError(SCROLLPANE_ONLY);
	}

	public int getMinimum() {
	// XXX: This relies on setSpan always being called with 0 for
	// the minimum (which is currently true).
	return 0;
	}

	/**
	* This method should <strong>NOT</strong> be called by user code.
	* This method is public for this class to properly implement
	* <code>Adjustable</code> interface.
	*
	* @throws AWTError Always throws an error when called.
	*/
	public void setMaximum(int max) {
	throw new AWTError(SCROLLPANE_ONLY);
	}

	public int getMaximum() {
	return maximum;
	}

	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 int getUnitIncrement() {
	return unitIncrement;
	}

	public synchronized void setBlockIncrement(int b) {
	blockIncrement = b;
	}

	public int getBlockIncrement() {
	return blockIncrement;
	}

	/**
	* This method should <strong>NOT</strong> be called by user code.
	* This method is public for this class to properly implement
	* <code>Adjustable</code> interface.
	*
	* @throws AWTError Always throws an error when called.
	*/
	public void setVisibleAmount(int v) {
	throw new AWTError(SCROLLPANE_ONLY);
	}

	public int getVisibleAmount() {
	return visibleAmount;
	}


	/**
	* Sets the <code>valueIsAdjusting</code> property.
	*
	* @param b new adjustment-in-progress status
	* @see #getValueIsAdjusting
	* @since 1.4
	*/
	public void setValueIsAdjusting(boolean b) {
	if (isAdjusting != b) {
	isAdjusting = b;
	AdjustmentEvent e =
	new AdjustmentEvent(this,
	AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED,
	AdjustmentEvent.TRACK, value, b);
	adjustmentListener.adjustmentValueChanged(e);
	}
	}

	/**
	* 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 <code>valueIsAdjusting</code> property
	* @see #setValueIsAdjusting
	*/
	public boolean getValueIsAdjusting() {
	return isAdjusting;
	}

	/**
	* Sets the value of this scrollbar to the specified value.
	* <p>
	* 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
	*/
	public void setValue(int v) {
	setTypedValue(v, AdjustmentEvent.TRACK);
	}

	/**
	* Sets the value of this scrollbar to the specified value.
	* <p>
	* 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 occurred
	*/
	private void setTypedValue(int v, int type) {
	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 int getValue() {
	return value;
	}

	/**
	* Adds the specified adjustment listener to receive adjustment
	* events from this <code>ScrollPaneAdjustable</code>.
	* If <code>l</code> is <code>null</code>, no exception is thrown
	* and no action is performed.
	* <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
	* >AWT Threading Issues</a> 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
	*/
	public synchronized void addAdjustmentListener(AdjustmentListener l) {
	if (l == null) {
	return;
	}
	adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l);
	}

	/**
	* Removes the specified adjustment listener so that it no longer
	* receives adjustment events from this <code>ScrollPaneAdjustable</code>.
	* If <code>l</code> is <code>null</code>, no exception is thrown
	* and no action is performed.
	* <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
	* >AWT Threading Issues</a> 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
	*/
	public synchronized void removeAdjustmentListener(AdjustmentListener l){
	if (l == null) {
	return;
	}
	adjustmentListener = AWTEventMulticaster.remove(adjustmentListener, l);
	}

	/**
	* Returns an array of all the adjustment listeners
	* registered on this <code>ScrollPaneAdjustable</code>.
	*
	* @return all of this <code>ScrollPaneAdjustable</code>'s
	* <code>AdjustmentListener</code>s
	* 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
	*/
	public synchronized AdjustmentListener[] getAdjustmentListeners() {
	return (AdjustmentListener[])(AWTEventMulticaster.getListeners(
	adjustmentListener,
	AdjustmentListener.class));
	}

	/**
	* Returns a string representation of this scrollbar and its values.
	* @return a string representation of this scrollbar.
	*/
	public String toString() {
	return getClass().getName() + "[" + 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 <code>null</code>.
	*
	* @return the parameter string of this scrollbar.
	*/
	public String paramString() {
	return ((orientation == Adjustable.VERTICAL ? "vertical,"
	:"horizontal,")
	+ "[0.."+maximum+"]"
	+ ",val=" + value
	+ ",vis=" + visibleAmount
	+ ",unit=" + unitIncrement
	+ ",block=" + blockIncrement
	+ ",isAdjusting=" + isAdjusting);
	}
	}

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