| /******************************************************************************* |
| * Copyright (c) 2007, 2019 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; |
| |
| /** |
| * Auto edit strategy that converts tabs into spaces. |
| * <p> |
| * Clients usually instantiate and configure this class but |
| * can also extend it in their own subclass. |
| * </p> |
| * |
| * @since 3.3 |
| */ |
| public class TabsToSpacesConverter implements IAutoEditStrategy { |
| |
| private int fTabRatio; |
| |
| private boolean fDeleteSpacesAsTab; |
| |
| private ILineTracker fLineTracker; |
| |
| |
| public void setNumberOfSpacesPerTab(int ratio) { |
| fTabRatio= ratio; |
| } |
| |
| /** |
| * @param enabled if true, spaces deletion will be modified to match tabs behavior |
| * @since 3.16 |
| */ |
| public void setDeleteSpacesAsTab(boolean enabled) { |
| fDeleteSpacesAsTab= enabled; |
| } |
| |
| public void setLineTracker(ILineTracker lineTracker) { |
| fLineTracker= lineTracker; |
| } |
| |
| private int insertTabString(StringBuilder buffer, int offsetInLine) { |
| |
| if (fTabRatio == 0) |
| return 0; |
| |
| int remainder= offsetInLine % fTabRatio; |
| remainder= fTabRatio - remainder; |
| for (int i= 0; i < remainder; i++) |
| buffer.append(' '); |
| return remainder; |
| } |
| |
| @Override |
| public void customizeDocumentCommand(IDocument document, DocumentCommand command) { |
| String text= command.text; |
| if (text == null) |
| return; |
| |
| if (text.isEmpty()) { |
| |
| replaceDeleteSpaceByDeleteTab(document, command); |
| |
| } else if (text.indexOf('\t') > -1) { |
| |
| StringBuilder buffer= new StringBuilder(); |
| |
| fLineTracker.set(command.text); |
| int lines= fLineTracker.getNumberOfLines(); |
| |
| try { |
| |
| for (int i= 0; i < lines; i++) { |
| |
| int offset= fLineTracker.getLineOffset(i); |
| int endOffset= offset + fLineTracker.getLineLength(i); |
| String line= text.substring(offset, endOffset); |
| |
| int position= 0; |
| if (i == 0) { |
| IRegion firstLine= document.getLineInformationOfOffset(command.offset); |
| position= command.offset - firstLine.getOffset(); |
| } |
| |
| int length= line.length(); |
| for (int j= 0; j < length; j++) { |
| char c= line.charAt(j); |
| if (c == '\t') { |
| position += insertTabString(buffer, position); |
| } else { |
| buffer.append(c); |
| ++ position; |
| } |
| } |
| |
| } |
| |
| command.text= buffer.toString(); |
| |
| } catch (BadLocationException x) { |
| throw new IllegalArgumentException("should never happen", x); //$NON-NLS-1$ |
| } |
| } |
| } |
| |
| private void replaceDeleteSpaceByDeleteTab(IDocument document, DocumentCommand command) { |
| if (!fDeleteSpacesAsTab || fTabRatio == 0 || command.length != 1) |
| return; |
| ITextSelection selection= command.fSelection; |
| if (selection == null || selection.getLength() != 0) |
| return; |
| try { |
| if (document.getChar(command.offset) != ' ') |
| return; |
| |
| IRegion line= document.getLineInformationOfOffset(command.offset); |
| int offsetInLine= command.offset - line.getOffset(); |
| boolean isDeleteKey= selection.getOffset() == command.offset; |
| if (isDeleteKey) { |
| int spacesToRemove= fTabRatio - (offsetInLine % fTabRatio) - 1; |
| while (spacesToRemove-- > 0 && document.getChar(command.offset + command.length) == ' ') { |
| command.length++; |
| } |
| } else { //backspace |
| int spacesToRemove= offsetInLine % fTabRatio; |
| while (spacesToRemove-- > 0 && document.getChar(command.offset - 1) == ' ') { |
| command.offset--; |
| command.length++; |
| } |
| } |
| } catch (BadLocationException e) { |
| throw new IllegalArgumentException("should never happen", e); //$NON-NLS-1$ |
| } |
| } |
| } |