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	/*
	* Copyright (c) 1997, 1998, 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.
	*/

	/*
	* (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved
	* (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved
	*
	* The original version of this source code and documentation is
	* copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary
	* of IBM. These materials are provided under terms of a License
	* Agreement between Taligent and Sun. This technology is protected
	* by multiple US and International patents.
	*
	* This notice and attribution to Taligent may not be removed.
	* Taligent is a registered trademark of Taligent, Inc.
	*
	*/

	package java.awt.font;
	import java.lang.String;

	/**
	* The <code>TextHitInfo</code> class represents a character position in a
	* text model, and a <b>bias</b>, or "side," of the character. Biases are
	* either <EM>leading</EM> (the left edge, for a left-to-right character)
	* or <EM>trailing</EM> (the right edge, for a left-to-right character).
	* Instances of <code>TextHitInfo</code> are used to specify caret and
	* insertion positions within text.
	* <p>
	* For example, consider the text "abc". TextHitInfo.trailing(1)
	* corresponds to the right side of the 'b' in the text.
	* <p>
	* <code>TextHitInfo</code> is used primarily by {@link TextLayout} and
	* clients of <code>TextLayout</code>. Clients of <code>TextLayout</code>
	* query <code>TextHitInfo</code> instances for an insertion offset, where
	* new text is inserted into the text model. The insertion offset is equal
	* to the character position in the <code>TextHitInfo</code> if the bias
	* is leading, and one character after if the bias is trailing. The
	* insertion offset for TextHitInfo.trailing(1) is 2.
	* <p>
	* Sometimes it is convenient to construct a <code>TextHitInfo</code> with
	* the same insertion offset as an existing one, but on the opposite
	* character. The <code>getOtherHit</code> method constructs a new
	* <code>TextHitInfo</code> with the same insertion offset as an existing
	* one, with a hit on the character on the other side of the insertion offset.
	* Calling <code>getOtherHit</code> on trailing(1) would return leading(2).
	* In general, <code>getOtherHit</code> for trailing(n) returns
	* leading(n+1) and <code>getOtherHit</code> for leading(n)
	* returns trailing(n-1).
	* <p>
	* <strong>Example</strong>:<p>
	* Converting a graphical point to an insertion point within a text
	* model
	* <blockquote><pre>
	* TextLayout layout = ...;
	* Point2D.Float hitPoint = ...;
	* TextHitInfo hitInfo = layout.hitTestChar(hitPoint.x, hitPoint.y);
	* int insPoint = hitInfo.getInsertionIndex();
	* // insPoint is relative to layout; may need to adjust for use
	* // in a text model
	* </pre></blockquote>
	*
	* @see TextLayout
	*/

	public final class TextHitInfo {
	private int charIndex;
	private boolean isLeadingEdge;

	/**
	* Constructs a new <code>TextHitInfo</code>.
	* @param charIndex the index of the character hit
	* @param isLeadingEdge <code>true</code> if the leading edge of the
	* character was hit
	*/
	private TextHitInfo(int charIndex, boolean isLeadingEdge) {
	this.charIndex = charIndex;
	this.isLeadingEdge = isLeadingEdge;
	}

	/**
	* Returns the index of the character hit.
	* @return the index of the character hit.
	*/
	public int getCharIndex() {
	return charIndex;
	}

	/**
	* Returns <code>true</code> if the leading edge of the character was
	* hit.
	* @return <code>true</code> if the leading edge of the character was
	* hit; <code>false</code> otherwise.
	*/
	public boolean isLeadingEdge() {
	return isLeadingEdge;
	}

	/**
	* Returns the insertion index. This is the character index if
	* the leading edge of the character was hit, and one greater
	* than the character index if the trailing edge was hit.
	* @return the insertion index.
	*/
	public int getInsertionIndex() {
	return isLeadingEdge ? charIndex : charIndex + 1;
	}

	/**
	* Returns the hash code.
	* @return the hash code of this <code>TextHitInfo</code>, which is
	* also the <code>charIndex</code> of this <code>TextHitInfo</code>.
	*/
	public int hashCode() {
	return charIndex;
	}

	/**
	* Returns <code>true</code> if the specified <code>Object</code> is a
	* <code>TextHitInfo</code> and equals this <code>TextHitInfo</code>.
	* @param obj the <code>Object</code> to test for equality
	* @return <code>true</code> if the specified <code>Object</code>
	* equals this <code>TextHitInfo</code>; <code>false</code> otherwise.
	*/
	public boolean equals(Object obj) {
	return (obj instanceof TextHitInfo) && equals((TextHitInfo)obj);
	}

	/**
	* Returns <code>true</code> if the specified <code>TextHitInfo</code>
	* has the same <code>charIndex</code> and <code>isLeadingEdge</code>
	* as this <code>TextHitInfo</code>. This is not the same as having
	* the same insertion offset.
	* @param hitInfo a specified <code>TextHitInfo</code>
	* @return <code>true</code> if the specified <code>TextHitInfo</code>
	* has the same <code>charIndex</code> and <code>isLeadingEdge</code>
	* as this <code>TextHitInfo</code>.
	*/
	public boolean equals(TextHitInfo hitInfo) {
	return hitInfo != null && charIndex == hitInfo.charIndex &&
	isLeadingEdge == hitInfo.isLeadingEdge;
	}

	/**
	* Returns a <code>String</code> representing the hit for debugging
	* use only.
	* @return a <code>String</code> representing this
	* <code>TextHitInfo</code>.
	*/
	public String toString() {
	return "TextHitInfo[" + charIndex + (isLeadingEdge ? "L" : "T")+"]";
	}

	/**
	* Creates a <code>TextHitInfo</code> on the leading edge of the
	* character at the specified <code>charIndex</code>.
	* @param charIndex the index of the character hit
	* @return a <code>TextHitInfo</code> on the leading edge of the
	* character at the specified <code>charIndex</code>.
	*/
	public static TextHitInfo leading(int charIndex) {
	return new TextHitInfo(charIndex, true);
	}

	/**
	* Creates a hit on the trailing edge of the character at
	* the specified <code>charIndex</code>.
	* @param charIndex the index of the character hit
	* @return a <code>TextHitInfo</code> on the trailing edge of the
	* character at the specified <code>charIndex</code>.
	*/
	public static TextHitInfo trailing(int charIndex) {
	return new TextHitInfo(charIndex, false);
	}

	/**
	* Creates a <code>TextHitInfo</code> at the specified offset,
	* associated with the character before the offset.
	* @param offset an offset associated with the character before
	* the offset
	* @return a <code>TextHitInfo</code> at the specified offset.
	*/
	public static TextHitInfo beforeOffset(int offset) {
	return new TextHitInfo(offset-1, false);
	}

	/**
	* Creates a <code>TextHitInfo</code> at the specified offset,
	* associated with the character after the offset.
	* @param offset an offset associated with the character after
	* the offset
	* @return a <code>TextHitInfo</code> at the specified offset.
	*/
	public static TextHitInfo afterOffset(int offset) {
	return new TextHitInfo(offset, true);
	}

	/**
	* Creates a <code>TextHitInfo</code> on the other side of the
	* insertion point. This <code>TextHitInfo</code> remains unchanged.
	* @return a <code>TextHitInfo</code> on the other side of the
	* insertion point.
	*/
	public TextHitInfo getOtherHit() {
	if (isLeadingEdge) {
	return trailing(charIndex - 1);
	} else {
	return leading(charIndex + 1);
	}
	}

	/**
	* Creates a <code>TextHitInfo</code> whose character index is offset
	* by <code>delta</code> from the <code>charIndex</code> of this
	* <code>TextHitInfo</code>. This <code>TextHitInfo</code> remains
	* unchanged.
	* @param delta the value to offset this <code>charIndex</code>
	* @return a <code>TextHitInfo</code> whose <code>charIndex</code> is
	* offset by <code>delta</code> from the <code>charIndex</code> of
	* this <code>TextHitInfo</code>.
	*/
	public TextHitInfo getOffsetHit(int delta) {
	return new TextHitInfo(charIndex + delta, isLeadingEdge);
	}
	}

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