CopyTargetEdit.java

/*******************************************************************************
 * Copyright (c) 2012-2015 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.ext.java.jdt.text.edits;

import org.eclipse.che.ide.api.editor.text.BadLocationException;
import org.eclipse.che.ide.ext.java.jdt.text.Document;

import java.util.List;

/**
 * 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.
 */
public final class CopyTargetEdit extends TextEdit {

    private CopySourceEdit fSource;

    /**
     * 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
     *
     * @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 <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.
     *
     * @param edit
     *         the source edit
     * @throws MalformedTreeException
     *         is thrown if the target edit is a direct or indirect child of the source edit
     */
    public void setSourceEdit(CopySourceEdit edit) throws MalformedTreeException {
        if (fSource != edit) {
            fSource = edit;
            fSource.setTargetEdit(this);
            TextEdit parent = getParent();
            while (parent != null) {
                if (parent == fSource)
                    throw new MalformedTreeException(parent, this, "Source edit must not be the parent of the target."); //$NON-NLS-1$
                parent = parent.getParent();
            }
        }
    }

    /* @see TextEdit#doCopy */
    protected TextEdit doCopy() {
        return new CopyTargetEdit(this);
    }

    /* @see TextEdit#postProcessCopy */
    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);
        }
    }

    /* @see TextEdit#accept0 */
    protected void accept0(TextEditVisitor visitor) {
        boolean visitChildren = visitor.visit(this);
        if (visitChildren) {
            acceptChildren(visitor);
        }
    }

    /* @see TextEdit#traverseConsistencyCheck */
    int traverseConsistencyCheck(TextEditProcessor processor, Document document, List<List<TextEdit>> sourceEdits) {
        return super.traverseConsistencyCheck(processor, document, sourceEdits) + 1;
    }

    /* @see TextEdit#performConsistencyCheck */
    void performConsistencyCheck(TextEditProcessor processor, Document document) throws MalformedTreeException {
        if (fSource == null)
            throw new MalformedTreeException(getParent(), this, "No source edit provided."); //$NON-NLS-1$
        if (fSource.getTargetEdit() != this)
            throw new MalformedTreeException(getParent(), this, "Source edit has different target edit."); //$NON-NLS-1$
    }

    /* @see TextEdit#performDocumentUpdating */
    int performDocumentUpdating(Document document) throws BadLocationException {
        String source = fSource.getContent();
        document.replace(getOffset(), getLength(), source);
        fDelta = source.length() - getLength();
        fSource.clearContent();
        return fDelta;
    }

    /* @see TextEdit#deleteChildren */
    boolean deleteChildren() {
        return false;
    }
}