Copyright (c) 2000, 2015 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, 2015 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.text.edits;

import java.util.List;

import org.eclipse.core.runtime.Assert;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;

A copy target edit denotes the target of a copy operation. Copy
target edits are only valid inside an edit tree if they have a
corresponding source edit. Furthermore a target edit can't
can't be a direct or indirect child of the associated source edit.
Violating one of two requirements will result in a 
MalformedTreeException when executing the edit tree.

Copy target edits can't be used as a parent for other edits.
Trying to add an edit to a copy target edit results in a 
MalformedTreeException as well.
See Also:
CopySourceEdit
Since:
3.0/**
 * A copy target edit denotes the target of a copy operation. Copy
 * target edits are only valid inside an edit tree if they have a
 * corresponding source edit. Furthermore a target edit can't
 * can't be a direct or indirect child of the associated source edit.
 * Violating one of two requirements will result in a <code>
 * MalformedTreeException</code> when executing the edit tree.
 * <p>
 * Copy target edits can't be used as a parent for other edits.
 * Trying to add an edit to a copy target edit results in a <code>
 * MalformedTreeException</code> as well.
 *
 * @see org.eclipse.text.edits.CopySourceEdit
 *
 * @since 3.0
 */
public final class CopyTargetEdit extends TextEdit {

	private CopySourceEdit fSource;

	
Constructs a new copy target edit
Params:
offset – the edit's offset/**
	 * Constructs a new copy target edit
	 *
	 * @param offset the edit's offset
	 */
	public CopyTargetEdit(int offset) {
		super(offset, 0);
	}

	
Constructs an new copy target edit
Params:
offset – the edit's offset
source – the corresponding source edit/**
	 * Constructs an new copy target edit
	 *
	 * @param offset the edit's offset
	 * @param source the corresponding source edit
	 */
	public CopyTargetEdit(int offset, CopySourceEdit source) {
		this(offset);
		setSourceEdit(source);
	}

	/*
	 * Copy constructor
	 */
	private CopyTargetEdit(CopyTargetEdit other) {
		super(other);
	}

	
Returns the associated source edit or null
if no source edit is associated yet.
Returns:
the source edit or null/**
	 * Returns the associated source edit or <code>null</code>
	 * if no source edit is associated yet.
	 *
	 * @return the source edit or <code>null</code>
	 */
	public CopySourceEdit getSourceEdit() {
		return fSource;
	}

	
Sets the source edit.
Params:
edit – the source edit
Throws:
MalformedTreeException – is thrown if the target edit
 is a direct or indirect child of the source edit/**
	 * Sets the source edit.
	 *
	 * @param edit the source edit
	 *
	 * @exception MalformedTreeException is thrown if the target edit
	 *  is a direct or indirect child of the source edit
	 */
	public void setSourceEdit(CopySourceEdit edit) throws MalformedTreeException {
		Assert.isNotNull(edit);
		if (fSource != edit) {
			fSource= edit;
			fSource.setTargetEdit(this);
			TextEdit parent= getParent();
			while (parent != null) {
				if (parent == fSource)
					throw new MalformedTreeException(parent, this, TextEditMessages.getString("CopyTargetEdit.wrong_parent")); //$NON-NLS-1$
				parent= parent.getParent();
			}
		}
	}

	@Override
	protected TextEdit doCopy() {
		return new CopyTargetEdit(this);
	}

	@Override
	protected void postProcessCopy(TextEditCopier copier) {
		if (fSource != null) {
			CopyTargetEdit target= (CopyTargetEdit)copier.getCopy(this);
			CopySourceEdit source= (CopySourceEdit)copier.getCopy(fSource);
			if (target != null && source != null)
				target.setSourceEdit(source);
		}
	}

	@Override
	protected void accept0(TextEditVisitor visitor) {
		boolean visitChildren= visitor.visit(this);
		if (visitChildren) {
			acceptChildren(visitor);
		}
	}

	@Override
	int traverseConsistencyCheck(TextEditProcessor processor, IDocument document, List<List<TextEdit>> sourceEdits) {
		return super.traverseConsistencyCheck(processor, document, sourceEdits) + 1;
	}

	@Override
	void performConsistencyCheck(TextEditProcessor processor, IDocument document) throws MalformedTreeException {
		if (fSource == null)
			throw new MalformedTreeException(getParent(), this, TextEditMessages.getString("CopyTargetEdit.no_source")); //$NON-NLS-1$
		if (fSource.getTargetEdit() != this)
			throw new MalformedTreeException(getParent(), this, TextEditMessages.getString("CopyTargetEdit.different_target")); //$NON-NLS-1$
	}

	@Override
	int performDocumentUpdating(IDocument document) throws BadLocationException {
		String source= fSource.getContent();
		document.replace(getOffset(), getLength(), source);
		fDelta= source.length() - getLength();
		fSource.clearContent();
		return fDelta;
	}

	@Override
	boolean deleteChildren() {
		return false;
	}
}