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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.projection;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.BadPositionCategoryException;
import org.eclipse.jface.text.DefaultPositionUpdater;
import org.eclipse.jface.text.DocumentEvent;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.Position;
/**
* The position updater used to adapt the fragments of a master document. If an
* insertion happens at a fragment's offset, the fragment is extended rather
* than shifted. Also, the last fragment is extended if an insert operation
* happens at the end of the fragment.
*
* @since 3.0
*/
class FragmentUpdater extends DefaultPositionUpdater {
/** Indicates whether the position being updated represents the last fragment. */
private boolean fIsLast= false;
/**
* Creates the fragment updater for the given category.
*
* @param fragmentCategory the position category used for managing the fragments of a document
*/
protected FragmentUpdater(String fragmentCategory) {
super(fragmentCategory);
}
@Override
public void update(DocumentEvent event) {
try {
Position[] category= event.getDocument().getPositions(getCategory());
fOffset= event.getOffset();
fLength= event.getLength();
fReplaceLength= (event.getText() == null ? 0 : event.getText().length());
fDocument= event.getDocument();
for (int i= 0; i < category.length; i++) {
fPosition= category[i];
fIsLast= (i == category.length -1);
fOriginalPosition.offset= fPosition.offset;
fOriginalPosition.length= fPosition.length;
if (notDeleted())
adaptToReplace();
}
} catch (BadPositionCategoryException x) {
// do nothing
}
}
@Override
protected void adaptToInsert() {
int myStart= fPosition.offset;
int myEnd= Math.max(myStart, fPosition.offset + fPosition.length - (fIsLast || isAffectingReplace() ? 0 : 1));
if (myEnd < fOffset)
return;
if (fLength <= 0) {
if (myStart <= fOffset)
fPosition.length += fReplaceLength;
else
fPosition.offset += fReplaceLength;
} else {
if (myStart <= fOffset && fOriginalPosition.offset <= fOffset)
fPosition.length += fReplaceLength;
else
fPosition.offset += fReplaceLength;
}
}
/**
* Returns whether this updater considers any position affected by the given document event. A
* position is affected if event {@link Position#overlapsWith(int, int) overlaps}
* with it but not if the position is only shifted.
*
* @param event the event
* @return true if there is any affected position, false otherwise
*/
public boolean affectsPositions(DocumentEvent event) {
IDocument document= event.getDocument();
try {
int index= document.computeIndexInCategory(getCategory(), event.getOffset());
Position[] fragments= document.getPositions(getCategory());
if (0 < index) {
Position fragment= fragments[index - 1];
if (fragment.overlapsWith(event.getOffset(), event.getLength()))
return true;
if (index == fragments.length && fragment.offset + fragment.length == event.getOffset())
return true;
}
if (index < fragments.length) {
Position fragment= fragments[index];
return fragment.overlapsWith(event.getOffset(), event.getLength());
}
} catch (BadLocationException x) {
} catch (BadPositionCategoryException x) {
}
return false;
}
}