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/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.text;

import org.eclipse.core.runtime.Assert;


/**
 * Positions describe text ranges of a document. Positions are adapted to
 * changes applied to that document. The text range is specified by an offset
 * and a length. Positions can be marked as deleted. Deleted positions are
 * considered to no longer represent a valid text range in the managing
 * document.
 * 

* Positions attached to documents are usually updated by position updaters. * Because position updaters are freely definable and because of the frequency * in which they are used, the fields of a position are made publicly * accessible. Clients other than position updaters are not allowed to access * these public fields. *

*

* Positions cannot be used as keys in hash tables as they override * equals and hashCode as they would be value * objects. *

* * @see org.eclipse.jface.text.IDocument */ public class Position { /** The offset of the position */ public int offset; /** The length of the position */ public int length; /** Indicates whether the position has been deleted */ public boolean isDeleted; /** * Creates a new position with the given offset and length 0. * * @param offset the position offset, must be >= 0 */ public Position(int offset) { this(offset, 0); } /** * Creates a new position with the given offset and length. * * @param offset the position offset, must be >= 0 * @param length the position length, must be >= 0 */ public Position(int offset, int length) { Assert.isTrue(offset >= 0); Assert.isTrue(length >= 0); this.offset= offset; this.length= length; } /** * Creates a new, not initialized position. */ protected Position() { } @Override public int hashCode() { int deleted= isDeleted ? 0 : 1; return (offset << 24) | (length << 16) | deleted; } /** * Marks this position as deleted. */ public void delete() { isDeleted= true; } /** * Marks this position as not deleted. * * @since 2.0 */ public void undelete() { isDeleted= false; } @Override public boolean equals(Object other) { if (other instanceof Position) { Position rp= (Position) other; return (rp.offset == offset) && (rp.length == length); } return super.equals(other); } /** * Returns the length of this position. * * @return the length of this position */ public int getLength() { return length; } /** * Returns the offset of this position. * * @return the offset of this position */ public int getOffset() { return offset; } /** * Checks whether the given index is inside * of this position's text range. * * @param index the index to check * @return true if index is inside of this position */ public boolean includes(int index) { if (isDeleted) return false; return (this.offset <= index) && (index < this.offset + length); } /** * Checks whether the intersection of the given text range * and the text range represented by this position is empty * or not. * * @param rangeOffset the offset of the range to check * @param rangeLength the length of the range to check * @return true if intersection is not empty */ public boolean overlapsWith(int rangeOffset, int rangeLength) { if (isDeleted) return false; int end= rangeOffset + rangeLength; int thisEnd= this.offset + this.length; if (rangeLength > 0) { if (this.length > 0) return this.offset < end && rangeOffset < thisEnd; return rangeOffset <= this.offset && this.offset < end; } if (this.length > 0) return this.offset <= rangeOffset && rangeOffset < thisEnd; return this.offset == rangeOffset; } /** * Returns whether this position has been deleted or not. * * @return true if position has been deleted */ public boolean isDeleted() { return isDeleted; } /** * Changes the length of this position to the given length. * * @param length the new length of this position */ public void setLength(int length) { Assert.isTrue(length >= 0); this.length= length; } /** * Changes the offset of this position to the given offset. * * @param offset the new offset of this position */ public void setOffset(int offset) { Assert.isTrue(offset >= 0); this.offset= offset; } @Override public String toString() { String position= "offset: " + offset + ", length: " + length; //$NON-NLS-1$//$NON-NLS-2$ return isDeleted ? position + " (deleted)" : position; //$NON-NLS-1$ } }




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