Java Code Examples for org.eclipse.jface.text.source.ISourceViewer#setSelectedRange()

/**
 * @since 2.3
 */
protected void selectAndRevealQuickfix(IQuickAssistInvocationContext invocationContext, Set<Annotation> applicableAnnotations, List<ICompletionProposal> completionProposals) {
       if (completionProposals.isEmpty()) {
       	return;
       }
	if (!(invocationContext instanceof QuickAssistInvocationContext && ((QuickAssistInvocationContext) invocationContext).isSuppressSelection())) {
		ISourceViewer sourceViewer = invocationContext.getSourceViewer();
		IAnnotationModel annotationModel = sourceViewer.getAnnotationModel();
		Iterator<Annotation> iterator = applicableAnnotations.iterator();
		while (iterator.hasNext()) {
			Position pos = annotationModel.getPosition(iterator.next());
			if (pos != null) {
				sourceViewer.setSelectedRange(pos.getOffset(), pos.getLength());
				sourceViewer.revealRange(pos.getOffset(), pos.getLength());
				break;
			}
		}
	}
}
 

public void open(IOutlineNode node, ISourceViewer textViewer) {
	if (node != null) {
		ITextRegion textRegion = node.getSignificantTextRegion();
		if (textRegion != null && textRegion != ITextRegion.EMPTY_REGION) {
			int offset = textRegion.getOffset();
			int length = textRegion.getLength();
			textViewer.setRangeIndication(offset, length, true);
			textViewer.revealRange(offset, length);
			textViewer.setSelectedRange(offset, length);
		} else {
			node.tryReadOnly(new IUnitOfWork.Void<EObject>() {
				@Override
				public void process(EObject state) throws Exception {
					openEObject(state);
				}
			});
		}
		
	}
}
 

public boolean start(IRenameElementContext renameElementContext, Provider<LinkedPositionGroup> provider, IProgressMonitor monitor) {
	if (renameElementContext == null)
		throw new IllegalArgumentException("RenameElementContext is null");
	this.linkedPositionGroup = provider.get();
	if (linkedPositionGroup == null || linkedPositionGroup.isEmpty())
		return false;
	this.editor = (XtextEditor) renameElementContext.getTriggeringEditor();
	this.focusEditingSupport = new FocusEditingSupport();
	ISourceViewer viewer = editor.getInternalSourceViewer();
	IDocument document = viewer.getDocument();
	originalSelection = viewer.getSelectedRange();
	currentPosition = linkedPositionGroup.getPositions()[0];
	originalName = getCurrentName();
	try {
		linkedModeModel = new LinkedModeModel();
		linkedModeModel.addGroup(linkedPositionGroup);
		linkedModeModel.forceInstall();
		linkedModeModel.addLinkingListener(new EditorSynchronizer());
		LinkedModeUI ui = new EditorLinkedModeUI(linkedModeModel, viewer);
		ui.setExitPolicy(new ExitPolicy(document));
		if (currentPosition.includes(originalSelection.x))
			ui.setExitPosition(viewer, originalSelection.x, 0, Integer.MAX_VALUE);
		ui.enter();
		if (currentPosition.includes(originalSelection.x)
				&& currentPosition.includes(originalSelection.x + originalSelection.y))
			viewer.setSelectedRange(originalSelection.x, originalSelection.y);
		if (viewer instanceof IEditingSupportRegistry) {
			IEditingSupportRegistry registry = (IEditingSupportRegistry) viewer;
			registry.register(focusEditingSupport);
		}
		openPopup();
		return true;
	} catch (BadLocationException e) {
		throw new WrappedException(e);
	}
}
 

protected XtextEditor doubleClick(XtextEditor xtextEditor, int cursorPosition) {
	ISourceViewer viewer = xtextEditor.getInternalSourceViewer();

	// Set the cursor position
	viewer.setSelectedRange(cursorPosition, 0);

	// Fire a mouse down event with the left mouse button
	Event event = new Event();
	event.button = 1;
	viewer.getTextWidget().notifyListeners(SWT.MouseDown, event);

	return xtextEditor;
}
 

void doFormat(ISourceViewer sourceViewer, final String xtendCode, Point selection) {
	int offset = selection.x;
	int length = xtendCode.length();
	if (offset - 1 >= 0) {
		offset--;
		length++;
	}
	sourceViewer.setSelectedRange(offset, length);
	sourceViewer.getTextOperationTarget().doOperation(ISourceViewer.FORMAT);
	int restoreCaretAtOffset = sourceViewer.getSelectedRange().x + sourceViewer.getSelectedRange().y;
	sourceViewer.setSelectedRange(restoreCaretAtOffset, 0);
}
 

/**
 * Selects the given range on the editor.
 * 
 * @param newOffset
 *            the selection offset
 * @param newLength
 *            the selection range
 */
private void selectAndReveal(int newOffset, int newLength) {
	Assert.isTrue(newOffset >= 0);
	Assert.isTrue(newLength >= 0);
	ITextEditor editor = getTextEditor();
	if (editor instanceof TypeScriptEditor) {
		ISourceViewer viewer = ((TypeScriptEditor) editor).getViewer();
		if (viewer != null)
			viewer.setSelectedRange(newOffset, newLength);
	} else
		// this is too intrusive, but will never get called anyway
		getTextEditor().selectAndReveal(newOffset, newLength);

}
 

protected void leave(int offset, int len, boolean isWidget) {
	addToHistory();
	ISourceViewer viewer = getViewer();
	if (viewer != null) {
		int off = (isWidget ? MarkUtils.widget2ModelOffset(getViewer(), offset) : offset);
		viewer.setSelectedRange(off, len);
		viewer.revealRange(off,0);
	}
	super.leave(true);
}
 

/**
 * Selects the given range on the editor.
 *
 * @param newOffset the selection offset
 * @param newLength the selection range
 */
private void selectAndReveal(int newOffset, int newLength) {
	Assert.isTrue(newOffset >= 0);
	Assert.isTrue(newLength >= 0);
	ITextEditor editor= getTextEditor();
	if (editor instanceof JavaEditor) {
		ISourceViewer viewer= ((JavaEditor)editor).getViewer();
		if (viewer != null)
			viewer.setSelectedRange(newOffset, newLength);
	} else
		// this is too intrusive, but will never get called anyway
		getTextEditor().selectAndReveal(newOffset, newLength);

}
 

/**
 * Mostly based on code from {@link org.eclipse.jdt.internal.ui.text.correction.proposals.LinkedNamesAssistProposal}
 */
private void startEditing(ISourceViewer viewer) throws ExecutionException {
	Point selOffsetAndLen = viewer.getSelectedRange();
	int selStart = CoordinatesUtil.fromOffsetAndLengthToStartAndEnd(selOffsetAndLen).x;

	IDocument document = viewer.getDocument();
	try {
		String selectedText;
		if (selOffsetAndLen.y == 0) { // no characters selected
			String documentText = document.get();
			Point wordOffsetAndLen = TextUtil.findWordSurrounding(documentText, selStart);
			if (wordOffsetAndLen != null) {
				selectedText = document.get(wordOffsetAndLen.x, wordOffsetAndLen.y);
			} else {
				IRegion selectedLine = document.getLineInformationOfOffset(selStart);
				selectedText = document.get(selectedLine.getOffset(), selectedLine.getLength());
			}
		} else {
			selectedText = document.get(selOffsetAndLen.x, selOffsetAndLen.y);
		}

		LinkedPositionGroup linkedPositionGroup = new LinkedPositionGroup();

		FindReplaceDocumentAdapter findReplaceAdaptor = new FindReplaceDocumentAdapter(document);
		IRegion matchingRegion = findReplaceAdaptor.find(0, selectedText, true, true, false, false);
		while (matchingRegion != null) {
			linkedPositionGroup.addPosition(new LinkedPosition(document, matchingRegion.getOffset(), matchingRegion
					.getLength()));

			matchingRegion = findReplaceAdaptor.find(matchingRegion.getOffset() + matchingRegion.getLength(),
					selectedText, true, true, false, false);
		}

		LinkedModeModel model = new LinkedModeModel();
		model.addGroup(linkedPositionGroup);
		model.forceInstall();

		LinkedModeUI ui = new EditorLinkedModeUI(model, viewer);
		ui.setExitPolicy(new DeleteBlockingExitPolicy(document));
		ui.enter();

		// by default the text being edited is selected so restore original selection
		viewer.setSelectedRange(selOffsetAndLen.x, selOffsetAndLen.y);
	} catch (BadLocationException e) {
		throw new ExecutionException("Editing failed", e);
	}
}
 

/**
 * implementation copied from org.eclipse.ui.externaltools.internal.ant.editor.PlantyEditor#setSelection
 */
public void setSelection(int offset, int length) {
    ISourceViewer sourceViewer = getSourceViewer();
    sourceViewer.setSelectedRange(offset, length);
    sourceViewer.revealRange(offset, length);
}
 

private void setSelection(int off) {
	ISourceViewer viewer = getViewer();
	viewer.setSelectedRange(MarkUtils.widget2ModelOffset(viewer, off), 0);
}
 

/**
 * Jumps to the matching bracket.
 */
public void gotoMatchingBracket() {

	ISourceViewer sourceViewer= getSourceViewer();
	IDocument document= sourceViewer.getDocument();
	if (document == null)
		return;

	IRegion selection= getSignedSelection(sourceViewer);
	if (fPreviousSelections == null)
		initializePreviousSelectionList();

	IRegion region= fBracketMatcher.match(document, selection.getOffset(), selection.getLength());
	if (region == null) {
		region= fBracketMatcher.findEnclosingPeerCharacters(document, selection.getOffset(), selection.getLength());
		initializePreviousSelectionList();
		fPreviousSelections.add(selection);
	} else {
		if (fPreviousSelections.size() == 2) {
			if (!selection.equals(fPreviousSelections.get(1))) {
				initializePreviousSelectionList();
			}
		} else if (fPreviousSelections.size() == 3) {
			if (selection.equals(fPreviousSelections.get(2)) && !selection.equals(fPreviousSelections.get(0))) {
				IRegion originalSelection= fPreviousSelections.get(0);
				sourceViewer.setSelectedRange(originalSelection.getOffset(), originalSelection.getLength());
				sourceViewer.revealRange(originalSelection.getOffset(), originalSelection.getLength());
				initializePreviousSelectionList();
				return;
			}
			initializePreviousSelectionList();
		}
	}

	if (region == null) {
		setStatusLineErrorMessage(JavaEditorMessages.GotoMatchingBracket_error_noMatchingBracket);
		sourceViewer.getTextWidget().getDisplay().beep();
		return;
	}

	int offset= region.getOffset();
	int length= region.getLength();

	if (length < 1)
		return;

	int anchor= fBracketMatcher.getAnchor();
	// http://dev.eclipse.org/bugs/show_bug.cgi?id=34195
	int targetOffset= (ICharacterPairMatcher.RIGHT == anchor) ? offset + 1 : offset + length - 1;

	boolean visible= false;
	if (sourceViewer instanceof ITextViewerExtension5) {
		ITextViewerExtension5 extension= (ITextViewerExtension5) sourceViewer;
		visible= (extension.modelOffset2WidgetOffset(targetOffset) > -1);
	} else {
		IRegion visibleRegion= sourceViewer.getVisibleRegion();
		// http://dev.eclipse.org/bugs/show_bug.cgi?id=34195
		visible= (targetOffset >= visibleRegion.getOffset() && targetOffset <= visibleRegion.getOffset() + visibleRegion.getLength());
	}

	if (!visible) {
		setStatusLineErrorMessage(JavaEditorMessages.GotoMatchingBracket_error_bracketOutsideSelectedElement);
		sourceViewer.getTextWidget().getDisplay().beep();
		return;
	}

	int adjustment= getOffsetAdjustment(document, selection.getOffset() + selection.getLength(), selection.getLength());
	targetOffset+= adjustment;
	int direction= (selection.getLength() == 0) ? 0 : ((selection.getLength() > 0) ? 1 : -1);
	if (fPreviousSelections.size() == 1 && direction < 0) {
		targetOffset++;
	}

	if (fPreviousSelections.size() > 0) {
		fPreviousSelections.add(new Region(targetOffset, direction));
	}
	sourceViewer.setSelectedRange(targetOffset, direction);
	sourceViewer.revealRange(targetOffset, direction);
}
 

public void start() {
		if (getActiveLinkedMode() != null) {
			// for safety; should already be handled in RenameJavaElementAction
			fgActiveLinkedMode.startFullDialog();
			return;
		}

		ISourceViewer viewer= fEditor.getViewer();
		IDocument document= viewer.getDocument();
		fOriginalSelection= viewer.getSelectedRange();
		int offset= fOriginalSelection.x;

		try {
			CompilationUnit root= SharedASTProvider.getAST(getCompilationUnit(), SharedASTProvider.WAIT_YES, null);

			fLinkedPositionGroup= new LinkedPositionGroup();
			ASTNode selectedNode= NodeFinder.perform(root, fOriginalSelection.x, fOriginalSelection.y);
			if (! (selectedNode instanceof SimpleName)) {
				return; // TODO: show dialog
			}
			SimpleName nameNode= (SimpleName) selectedNode;

			if (viewer instanceof ITextViewerExtension6) {
				IUndoManager undoManager= ((ITextViewerExtension6)viewer).getUndoManager();
				if (undoManager instanceof IUndoManagerExtension) {
					IUndoManagerExtension undoManagerExtension= (IUndoManagerExtension)undoManager;
					IUndoContext undoContext= undoManagerExtension.getUndoContext();
					IOperationHistory operationHistory= OperationHistoryFactory.getOperationHistory();
					fStartingUndoOperation= operationHistory.getUndoOperation(undoContext);
				}
			}
			
			fOriginalName= nameNode.getIdentifier();
			final int pos= nameNode.getStartPosition();
			ASTNode[] sameNodes= LinkedNodeFinder.findByNode(root, nameNode);

			//TODO: copied from LinkedNamesAssistProposal#apply(..):
			// sort for iteration order, starting with the node @ offset
			Arrays.sort(sameNodes, new Comparator<ASTNode>() {
				public int compare(ASTNode o1, ASTNode o2) {
					return rank(o1) - rank(o2);
				}
				/**
				 * Returns the absolute rank of an <code>ASTNode</code>. Nodes
				 * preceding <code>pos</code> are ranked last.
				 *
				 * @param node the node to compute the rank for
				 * @return the rank of the node with respect to the invocation offset
				 */
				private int rank(ASTNode node) {
					int relativeRank= node.getStartPosition() + node.getLength() - pos;
					if (relativeRank < 0)
						return Integer.MAX_VALUE + relativeRank;
					else
						return relativeRank;
				}
			});
			for (int i= 0; i < sameNodes.length; i++) {
				ASTNode elem= sameNodes[i];
				LinkedPosition linkedPosition= new LinkedPosition(document, elem.getStartPosition(), elem.getLength(), i);
				if (i == 0)
					fNamePosition= linkedPosition;
				fLinkedPositionGroup.addPosition(linkedPosition);
			}

			fLinkedModeModel= new LinkedModeModel();
			fLinkedModeModel.addGroup(fLinkedPositionGroup);
			fLinkedModeModel.forceInstall();
			fLinkedModeModel.addLinkingListener(new EditorHighlightingSynchronizer(fEditor));
			fLinkedModeModel.addLinkingListener(new EditorSynchronizer());

			LinkedModeUI ui= new EditorLinkedModeUI(fLinkedModeModel, viewer);
			ui.setExitPosition(viewer, offset, 0, Integer.MAX_VALUE);
			ui.setExitPolicy(new ExitPolicy(document));
			ui.enter();

			viewer.setSelectedRange(fOriginalSelection.x, fOriginalSelection.y); // by default, full word is selected; restore original selection

			if (viewer instanceof IEditingSupportRegistry) {
				IEditingSupportRegistry registry= (IEditingSupportRegistry) viewer;
				registry.register(fFocusEditingSupport);
			}

			openSecondaryPopup();
//			startAnimation();
			fgActiveLinkedMode= this;

		} catch (BadLocationException e) {
			JavaPlugin.log(e);
		}
	}
 

public void start() {
	if (getActiveLinkedMode() != null) {
		// for safety; should already be handled in RenameJavaElementAction
		fgActiveLinkedMode.startFullDialog();
		return;
	}

	ISourceViewer viewer = fEditor.getViewer();
	IDocument document = viewer.getDocument();

	ITypeScriptFile tsFile = fEditor.getTypeScriptFile();
	tsFile.setDisableChanged(true);
	fOriginalSelection = viewer.getSelectedRange();
	int offset = fOriginalSelection.x;

	try {
		fLinkedPositionGroup = new LinkedPositionGroup();
		if (viewer instanceof ITextViewerExtension6) {
			IUndoManager undoManager = ((ITextViewerExtension6) viewer).getUndoManager();
			if (undoManager instanceof IUndoManagerExtension) {
				IUndoManagerExtension undoManagerExtension = (IUndoManagerExtension) undoManager;
				IUndoContext undoContext = undoManagerExtension.getUndoContext();
				IOperationHistory operationHistory = OperationHistoryFactory.getOperationHistory();
				fStartingUndoOperation = operationHistory.getUndoOperation(undoContext);
			}
		}

		// Find occurrences
		List<OccurrencesResponseItem> occurrences = tsFile.occurrences(offset).get(1000, TimeUnit.MILLISECONDS);

		// Create Eclipse linked position from the occurrences list.
		int start, length;
		for (int i = 0; i < occurrences.size(); i++) {
			OccurrencesResponseItem item = occurrences.get(i);
			start = tsFile.getPosition(item.getStart());
			length = tsFile.getPosition(item.getEnd()) - start;
			LinkedPosition linkedPosition = new LinkedPosition(document, start, length, i);
			if (i == 0) {
				fOriginalName = document.get(start, length);
				fNamePosition = linkedPosition;
			}
			fLinkedPositionGroup.addPosition(linkedPosition);
		}

		fLinkedModeModel = new LinkedModeModel();
		fLinkedModeModel.addGroup(fLinkedPositionGroup);
		fLinkedModeModel.forceInstall();
		fLinkedModeModel.addLinkingListener(new EditorHighlightingSynchronizer(fEditor));
		fLinkedModeModel.addLinkingListener(new EditorSynchronizer());

		LinkedModeUI ui = new EditorLinkedModeUI(fLinkedModeModel, viewer);
		ui.setExitPosition(viewer, offset, 0, Integer.MAX_VALUE);
		ui.setExitPolicy(new ExitPolicy(document));
		ui.enter();

		viewer.setSelectedRange(fOriginalSelection.x, fOriginalSelection.y); // by
																				// default,
																				// full
																				// word
																				// is
																				// selected;
																				// restore
																				// original
																				// selection

		if (viewer instanceof IEditingSupportRegistry) {
			IEditingSupportRegistry registry = (IEditingSupportRegistry) viewer;
			registry.register(fFocusEditingSupport);
		}

		openSecondaryPopup();
		// startAnimation();
		fgActiveLinkedMode = this;

	} catch (Exception e) {
		JSDTTypeScriptUIPlugin.log(e);
	}
}
 

/**
 * Jumps to the matching bracket.
 */
public void gotoMatchingBracket() {

	ISourceViewer sourceViewer = getSourceViewer();
	IDocument document = sourceViewer.getDocument();
	if (document == null)
		return;

	IRegion selection = getSignedSelection(sourceViewer);

	int selectionLength = Math.abs(selection.getLength());
	if (selectionLength > 1) {
		setStatusLineErrorMessage(JSDTTypeScriptUIMessages.GotoMatchingBracket_error_invalidSelection);
		sourceViewer.getTextWidget().getDisplay().beep();
		return;
	}

	// #26314
	int sourceCaretOffset = selection.getOffset() + selection.getLength();
	if (isSurroundedByBrackets(document, sourceCaretOffset))
		sourceCaretOffset -= selection.getLength();

	IRegion region = fBracketMatcher.match(document, sourceCaretOffset);
	if (region == null) {
		setStatusLineErrorMessage(JSDTTypeScriptUIMessages.GotoMatchingBracket_error_noMatchingBracket);
		sourceViewer.getTextWidget().getDisplay().beep();
		return;
	}

	int offset = region.getOffset();
	int length = region.getLength();

	if (length < 1)
		return;

	int anchor = fBracketMatcher.getAnchor();
	// http://dev.eclipse.org/bugs/show_bug.cgi?id=34195
	int targetOffset = (ICharacterPairMatcher.RIGHT == anchor) ? offset + 1 : offset + length;

	boolean visible = false;
	if (sourceViewer instanceof ITextViewerExtension5) {
		ITextViewerExtension5 extension = (ITextViewerExtension5) sourceViewer;
		visible = (extension.modelOffset2WidgetOffset(targetOffset) > -1);
	} else {
		IRegion visibleRegion = sourceViewer.getVisibleRegion();
		// http://dev.eclipse.org/bugs/show_bug.cgi?id=34195
		visible = (targetOffset >= visibleRegion.getOffset()
				&& targetOffset <= visibleRegion.getOffset() + visibleRegion.getLength());
	}

	if (!visible) {
		setStatusLineErrorMessage(JSDTTypeScriptUIMessages.GotoMatchingBracket_error_bracketOutsideSelectedElement);
		sourceViewer.getTextWidget().getDisplay().beep();
		return;
	}

	if (selection.getLength() < 0)
		targetOffset -= selection.getLength();

	sourceViewer.setSelectedRange(targetOffset, selection.getLength());
	sourceViewer.revealRange(targetOffset, selection.getLength());
}
 

/**
 * Highlights and moves to a corresponding element in editor
 * 
 * @param reference
 *            corresponding entity in editor
 * @param moveCursor
 *            if true, moves cursor to the reference
 */
private void setSelection(NavigationBarItem reference, boolean moveCursor) {
	if (reference == null) {
		return;
	}

	if (moveCursor) {
		markInNavigationHistory();
	}

	ISourceViewer sourceViewer = getSourceViewer();
	if (sourceViewer == null) {
		return;
	}
	StyledText textWidget = sourceViewer.getTextWidget();
	if (textWidget == null) {
		return;
	}
	try {
		Location start = reference.getSpans().get(0).getStart();
		Location end = reference.getSpans().get(0).getEnd();

		if (start == null || end == null)
			return;

		ITypeScriptFile tsFile = getTypeScriptFile();

		int offset = tsFile.getPosition(start);
		int length = tsFile.getPosition(end) - offset;

		if (offset < 0 || length < 0 || length > sourceViewer.getDocument().getLength()) {
			return;
		}
		textWidget.setRedraw(false);

		// Uncomment that if we wish to select only variable and not the
		// whole block.
		// but there is a bug with this code with
		// private a: string. it's the first 'a' (of private) which is
		// selected and not the second.
		// String documentPart = sourceViewer.getDocument().get(offset,
		// length);
		//
		// // Try to find name because position returns for whole block
		// String name = reference.getText();
		// if (name != null) {
		// int nameoffset = documentPart.indexOf(name);
		// if (nameoffset != -1) {
		// offset += nameoffset;
		// length = name.length();
		// }
		// }
		if (length > 0) {
			setHighlightRange(offset, length, moveCursor);
		}

		if (!moveCursor) {
			return;
		}

		if (offset > -1 && length > 0) {
			sourceViewer.revealRange(offset, length);
			// Selected region begins one index after offset
			sourceViewer.setSelectedRange(offset, length);
			markInNavigationHistory();
		}
	} catch (Exception e) {

	} finally {
		textWidget.setRedraw(true);
	}
}
 

public void run(IAction action) {
    if (targetEditor == null) return;
    ISourceViewer sourceViewer= targetEditor.getViewer();
    IDocument document= sourceViewer.getDocument();
    if (document == null)
        return;
    ITextSelection selection = (ITextSelection) targetEditor.getSelectionProvider().getSelection();
    SubStatusLineManager slm = 
        (SubStatusLineManager) targetEditor.getEditorSite().getActionBars().getStatusLineManager();
    
    int selectionLength= Math.abs(selection.getLength());
    if (selectionLength > 1) {
        slm.setErrorMessage(TexlipsePlugin.getResourceString("gotoMatchingBracketNotSelected"));
        slm.setVisible(true);
        sourceViewer.getTextWidget().getDisplay().beep();
        return;
    }
    
    int sourceCaretOffset= selection.getOffset() + selection.getLength();

    TexPairMatcher fBracketMatcher = new TexPairMatcher("{}[]()");
    
    IRegion region= fBracketMatcher.match(document, sourceCaretOffset);
    if (region == null) {
        slm.setErrorMessage(TexlipsePlugin.getResourceString("gotoMatchingBracketNotFound"));
        slm.setVisible(true);            
        sourceViewer.getTextWidget().getDisplay().beep();
        return;
    }

    int offset= region.getOffset();
    int length= region.getLength();

    if (length < 1) return;

    int anchor = fBracketMatcher.getAnchor();
    int targetOffset= (ICharacterPairMatcher.RIGHT == anchor) ? offset + 1: offset + length;

    if (selection.getLength() < 0)
        targetOffset -= selection.getLength();

    sourceViewer.setSelectedRange(targetOffset, selection.getLength());
    sourceViewer.revealRange(targetOffset, selection.getLength());
}