Copyright (c) 2000, 2018 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
/*******************************************************************************
 * Copyright (c) 2000, 2018 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.jdt.internal.corext.dom;

import org.eclipse.core.runtime.Assert;

import org.eclipse.jface.text.IRegion;

import org.eclipse.jdt.core.dom.ASTNode;


public class Selection {

	
Flag indicating that the AST node somehow intersects with the selection. /** Flag indicating that the AST node somehow intersects with the selection. */
	public static final int INTERSECTS= 0;

	
Flag that indicates that an AST node appears before the selected nodes. /** Flag that indicates that an AST node appears before the selected nodes. */
	public static final int BEFORE= 1;

	
Flag indicating that an AST node is covered by the selection. /** Flag indicating that an AST node is covered by the selection. */
	public static final int SELECTED= 2;

	
Flag indicating that an AST nodes appears after the selected nodes. /** Flag indicating that an AST nodes appears after the selected nodes. */
	public static final int AFTER= 3;

	private int fStart;
	private int fLength;
	private int fExclusiveEnd;

	protected Selection() {
	}

	
Creates a new selection from the given start and length.
Params:
s – the start offset of the selection (inclusive)
l – the length of the selection
Returns:
the created selection object/**
	 * Creates a new selection from the given start and length.
	 *
	 * @param s the start offset of the selection (inclusive)
	 * @param l the length of the selection
	 * @return the created selection object
	 */
	public static Selection createFromStartLength(int s, int l) {
		Assert.isTrue(s >= 0 && l >= 0);
		Selection result= new Selection();
		result.fStart= s;
		result.fLength= l;
		result.fExclusiveEnd= s + l;
		return result;
	}

	
Creates a new selection from the given start and end.
Params:
s – the start offset of the selection (inclusive)
e – the end offset of the selection (inclusive)
Returns:
the created selection object/**
	 * Creates a new selection from the given start and end.
	 *
	 * @param s the start offset of the selection (inclusive)
	 * @param e the end offset of the selection (inclusive)
	 * @return the created selection object
	 */
	public static Selection createFromStartEnd(int s, int e) {
		Assert.isTrue(s >= 0 && e >= s);
		Selection result= new Selection();
		result.fStart= s;
		result.fLength= e - s + 1;
		result.fExclusiveEnd= result.fStart + result.fLength;
		return result;
	}

	public int getOffset() {
		return fStart;
	}

	public int getLength() {
		return fLength;
	}

	public int getInclusiveEnd() {
		return fExclusiveEnd - 1;
	}

	public int getExclusiveEnd() {
		return fExclusiveEnd;
	}

	
Returns the selection mode of the given AST node regarding this selection. Possible
values are INTERSECTS, BEFORE, SELECTED, and
AFTER.
Params:
node – the node to return the visit mode for
See Also:
INTERSECTS
BEFORE
SELECTED
AFTER
Returns:
the selection mode of the given AST node regarding this selection/**
	 * Returns the selection mode of the given AST node regarding this selection. Possible
	 * values are <code>INTERSECTS</code>, <code>BEFORE</code>, <code>SELECTED</code>, and
	 * <code>AFTER</code>.
	 *
	 * @param node the node to return the visit mode for
	 *
	 * @return the selection mode of the given AST node regarding this selection
	 * @see #INTERSECTS
	 * @see #BEFORE
	 * @see #SELECTED
	 * @see #AFTER
	 */
	public int getVisitSelectionMode(ASTNode node) {
		int nodeStart= node.getStartPosition();
		int nodeEnd= nodeStart + node.getLength();
		if (nodeEnd <= fStart)
			return BEFORE;
		else if (covers(node))
			return SELECTED;
		else if (fExclusiveEnd <= nodeStart)
			return AFTER;
		return INTERSECTS;
	}

	public int getEndVisitSelectionMode(ASTNode node) {
		int nodeStart= node.getStartPosition();
		int nodeEnd= nodeStart + node.getLength();
		if (nodeEnd <= fStart)
			return BEFORE;
		else if (covers(node))
			return SELECTED;
		else if (nodeEnd >= fExclusiveEnd)
			return AFTER;
		return INTERSECTS;
	}

	// cover* methods do a closed interval check.

	public boolean covers(int position) {
		return fStart <= position && position < fStart + fLength;
	}

	public boolean covers(ASTNode node) {
		int nodeStart= node.getStartPosition();
		return fStart <= nodeStart && nodeStart + node.getLength() <= fExclusiveEnd;
	}

	public boolean coveredBy(ASTNode node) {
		int nodeStart= node.getStartPosition();
		return nodeStart <= fStart && fExclusiveEnd <= nodeStart + node.getLength();
	}

	public boolean coveredBy(IRegion region) {
		int rangeStart= region.getOffset();
		return rangeStart <= fStart && fExclusiveEnd <= rangeStart + region.getLength();
	}

	public boolean endsIn(ASTNode node) {
		int nodeStart= node.getStartPosition();
		return nodeStart < fExclusiveEnd && fExclusiveEnd < nodeStart + node.getLength();
	}

	public boolean liesOutside(ASTNode node) {
		int nodeStart= node.getStartPosition();
		int nodeEnd= nodeStart + node.getLength();
		boolean nodeBeforeSelection= nodeEnd < fStart;
		boolean selectionBeforeNode= fExclusiveEnd < nodeStart;
		return nodeBeforeSelection || selectionBeforeNode;
	}

	@Override
	public String toString() {
		return "<start == " + fStart + ", length == " + fLength + "/>";  //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}
}