| /******************************************************************************* |
| * Copyright (c) 2005 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.internal.text; |
| |
| import org.eclipse.jface.text.BadPositionCategoryException; |
| import org.eclipse.jface.text.DocumentEvent; |
| import org.eclipse.jface.text.IPositionUpdater; |
| import org.eclipse.jface.text.Position; |
| |
| |
| /** |
| * A position updater that never deletes a position. If the region containing |
| * the position is deleted, the position is moved to the beginning/end (falling |
| * together) of the change. If the region containing the position is replaced, |
| * the position is placed at the same location inside the replacement text, but |
| * always inside the replacement text. |
| * |
| * @since 3.1 |
| */ |
| public final class NonDeletingPositionUpdater implements IPositionUpdater { |
| /** The position category. */ |
| private final String fCategory; |
| |
| /** |
| * Creates a new updater for the given <code>category</code>. |
| * |
| * @param category the new category. |
| */ |
| public NonDeletingPositionUpdater(String category) { |
| fCategory= category; |
| } |
| |
| @Override |
| public void update(DocumentEvent event) { |
| |
| int eventOffset= event.getOffset(); |
| int eventOldEndOffset= eventOffset + event.getLength(); |
| int eventNewLength= event.getText() == null ? 0 : event.getText().length(); |
| int eventNewEndOffset= eventOffset + eventNewLength; |
| int deltaLength= eventNewLength - event.getLength(); |
| |
| try { |
| Position[] positions= event.getDocument().getPositions(fCategory); |
| |
| for (int i= 0; i != positions.length; i++) { |
| |
| Position position= positions[i]; |
| |
| if (position.isDeleted()) |
| continue; |
| |
| int offset= position.getOffset(); |
| int length= position.getLength(); |
| int end= offset + length; |
| |
| if (offset > eventOldEndOffset) { |
| // position comes way after change - shift |
| position.setOffset(offset + deltaLength); |
| } else if (end < eventOffset) { |
| // position comes way before change - leave alone |
| } else if (offset <= eventOffset && end >= eventOldEndOffset) { |
| // event completely internal to the position - adjust length |
| position.setLength(length + deltaLength); |
| } else if (offset < eventOffset) { |
| // event extends over end of position - include the |
| // replacement text into the position |
| position.setLength(eventNewEndOffset - offset); |
| } else if (end > eventOldEndOffset) { |
| // event extends from before position into it - adjust |
| // offset and length, including the replacement text into |
| // the position |
| position.setOffset(eventOffset); |
| int deleted= eventOldEndOffset - offset; |
| position.setLength(length - deleted + eventNewLength); |
| } else { |
| // event comprises the position - keep it at the same |
| // position, but always inside the replacement text |
| int newOffset= Math.min(offset, eventNewEndOffset); |
| int newEndOffset= Math.min(end, eventNewEndOffset); |
| position.setOffset(newOffset); |
| position.setLength(newEndOffset - newOffset); |
| } |
| } |
| } catch (BadPositionCategoryException e) { |
| // ignore and return |
| } |
| } |
| |
| /** |
| * Returns the position category. |
| * |
| * @return the position category |
| */ |
| public String getCategory() { |
| return fCategory; |
| } |
| } |