org.eclipse.jface.text.IDocument#addPosition ( )源码实例Demo

/**
 * Insert tab/spaces at selection offset and each subsequent line origin
 * 
 * @see com.mulgasoft.emacsplus.commands.EmacsPlusCmdHandler#transform(ITextEditor, IDocument, ITextSelection, ExecutionEvent)
 */
@Override
protected int transform(ITextEditor editor, IDocument document, ITextSelection currentSelection, ExecutionEvent event)
throws BadLocationException {
	// if we're here, either ^U or no relevant ^I
	ColumnSupport cs = new ColumnSupport(document,editor); 
	String tab = cs.getSpaces(0,cs.getTabWidth());
	int off = currentSelection.getOffset();
	Position coff = new Position(getCursorOffset(editor,currentSelection),0);
	try {
		document.addPosition(coff);
		int begin = document.getLineOfOffset(off);
		int end = document.getLineOfOffset(off+ currentSelection.getLength());
		if (begin != end) {
			while (++begin <= end) {
				document.replace(document.getLineOffset(begin), 0, tab);
			}
		}
		document.replace(off, 0, tab);
	} finally {
		document.removePosition(coff);
	} 
	return coff.offset;
}
 

/**
 * Positions created for template contexts have to be added to the document so they are updated when the document
 * is modified.
 * 
 * @since 2.8
 */
protected Position createPosition(ContentAssistContext context) {
	Position position = new Position(context.getReplaceRegion().getOffset(), context.getReplaceRegion().getLength());
	IDocument document = context.getDocument();
	if (document.containsPositionCategory(XTEXT_TEMPLATE_POS_CATEGORY)) {
		try {
			document.addPosition(XTEXT_TEMPLATE_POS_CATEGORY, position);
		} catch (Exception e) {
			log.error(e.getMessage(), e);
		}
	}
	return position;
}
 

/**
 * Called before document changes occur. It must be followed by a call to postReplace().
 *
 * @param document the document on which to track the reference position.
 * @param offset the offset
 * @throws BadLocationException if the offset describes an invalid range in this document
 *
 */
public void preReplace(IDocument document, int offset) throws BadLocationException {
	fPosition.setOffset(offset);
	try {
		document.addPositionCategory(CATEGORY);
		document.addPositionUpdater(fPositionUpdater);
		document.addPosition(CATEGORY, fPosition);

	} catch (BadPositionCategoryException e) {
		// should not happen
		JavaPlugin.log(e);
	}
}
 

/**
 * @see com.mulgasoft.emacsplus.commands.EmacsPlusCmdHandler#transform(ITextEditor, IDocument, ITextSelection, ExecutionEvent)
 */
@Override
protected int transform(ITextEditor editor, IDocument document, ITextSelection currentSelection, ExecutionEvent event)
throws BadLocationException {
	int result = NO_OFFSET; 
	Control c = MarkUtils.getTextWidget(editor);
	if (c instanceof StyledText) {
		StyledText st = (StyledText)c;
		String ld = st.getLineDelimiter();
		int insertionOffset = getCursorOffset(editor,currentSelection);
		int widgetInsertionOffset = st.getCaretOffset();
		
		// the offset position will be updated by the internals on insertion/indent
		Position caret= new Position(insertionOffset, 0);
		document.addPosition(caret);
		
		st.setSelectionRange(widgetInsertionOffset, 0);
		// operate directly on the widget
		st.replaceTextRange(widgetInsertionOffset, 0, ld);
		document.removePosition(caret);
		
		if (st.getSelection().x == widgetInsertionOffset) {
			// move cursor by the amount detected
			result = getCursorOffset(editor) + caret.offset - insertionOffset;
		} 
	}
	return result;
}
 

/**
 * Really do apply the proposal. Assumed to be run within the prevent flickering mode.
 */
private int doApply(QualifiedName qualifiedName, String alias, IDocument document,
		ConfigurableCompletionProposal proposal) throws BadLocationException {
	String shortSemanticReplacementString = alias != null ? alias : lastSegmentOrDefaultHost(qualifiedName);
	String shortSyntacticReplacementString = valueConverter.toString(shortSemanticReplacementString);
	String longReplacementString = shortSyntacticReplacementString
			+ ConfigurableCompletionProposalExtensions.getReplacementSuffix(proposal);

	ImportRewriter importRewriter = importRewriterFactory.create(document, context);

	ReplaceEdit replaceEdit = new ReplaceEdit(
			proposal.getReplacementOffset(),
			proposal.getReplacementLength(),
			longReplacementString);
	MultiTextEdit compound = new MultiTextEdit();
	AliasLocation aliasLocation = null;
	if (alias != null) {
		aliasLocation = importRewriter.addSingleImport(qualifiedName, alias, compound);
	} else {
		importRewriter.addSingleImport(qualifiedName, compound);
	}
	compound.addChild(replaceEdit);

	Position caret = new Position(proposal.getReplacementOffset(), 0);
	document.addPosition(caret);
	compound.apply(document);
	document.removePosition(caret);

	int cursorPosition = caret.getOffset();
	proposal.setReplacementOffset(cursorPosition - longReplacementString.length());
	proposal.setReplacementLength(shortSyntacticReplacementString.length()); // do not include suffix!
	proposal.setCursorPosition(
			cursorPosition - proposal.getReplacementOffset()); // cursorPosition is relative to replacementOffset!

	if (aliasLocation != null) {
		final int aliasOffset = aliasLocation.getBaseOffset() + aliasLocation.getRelativeOffset();
		final int aliasLength = shortSyntacticReplacementString.length();
		N4JSCompletionProposal castedProposal = (N4JSCompletionProposal) proposal;
		castedProposal.setLinkedModeBuilder((appliedProposal, currentDocument) -> {
			if (viewer.getTextWidget() == null || viewer.getTextWidget().isDisposed()) {
				return; // do not attempt to set up linked mode in a disposed UI
			}
			try {
				LinkedPositionGroup group = new LinkedPositionGroup();
				group.addPosition(new LinkedPosition(
						currentDocument,
						aliasOffset,
						aliasLength,
						LinkedPositionGroup.NO_STOP));
				group.addPosition(new LinkedPosition(
						currentDocument,
						proposal.getReplacementOffset(),
						proposal.getReplacementLength(),
						LinkedPositionGroup.NO_STOP));
				proposal.setSelectionStart(proposal.getReplacementOffset());
				proposal.setSelectionLength(proposal.getReplacementLength());
				LinkedModeModel model = new LinkedModeModel();
				model.addGroup(group);
				model.forceInstall();

				LinkedModeUI ui = new LinkedModeUI(model, viewer);
				ui.setExitPolicy(new IdentifierExitPolicy('\n'));
				ui.setExitPosition(
						viewer,
						proposal.getReplacementOffset()
								+ proposal.getCursorPosition()
								+ ConfigurableCompletionProposalExtensions.getCursorOffset(proposal),
						0,
						Integer.MAX_VALUE);
				ui.setCyclingMode(LinkedModeUI.CYCLE_NEVER);
				ui.enter();
			} catch (BadLocationException e) {
				logger.error(e.getMessage(), e);
			}
		});
	} else {
		adjustCursorPositionIfRequested(proposal);
	}
	return cursorPosition;
}
 

/**
 * Constructor for the position.
 * 
 * For the offset and length for the proof and statement, first obtain the {@link Location} from the syntax tree. For the proof, use
 * the location returned by {@link ProofNode#getLocation()}, where the {@link ProofNode} is obtained by {@link TheoremNode#getProof()}.
 * 
 * For initTheoremOffset, use the beginning of the location returned by {@link TheoremNode#getLocation()}.
 * 
 * For the end of the statement, use the end of the location returned by {@link LevelNode#getLocation()} 
 * for the {@link LevelNode} returned by {@link TheoremNode#getTheorem()}.
 *
 * To convert from the 4-int {@link Location} to the offset and length, use {@link AdapterFactory#locationToRegion(IDocument, Location)} and
 * then use the offset and length for the returned region.
 * 
 * @param initProofOffset initial offset of the proof
 * @param initProofLength initial length of the proof
 * @param initTheoremOffset initial offset of the theorem or step
 * for which this is a proof
 * @param initLengthToEndOfStatement initial length from initTheoremOffset to the end of
 * the statement of the theorem
 * @param annotation {@link ProjectionAnnotation} that should be at this position
 * @param document
 */
public TLAProofPosition(int initProofOffset, int initProofLength, int initTheoremOffset,
        int initLengthToEndOfStatement, ProjectionAnnotation annotation, IDocument document)
{
    /*
     * This seems to be a bit of a hack, but I see
     * no other way to do it correctly because of
     * how eclipse expands folds. In particular, when eclipse
     * is asked to expand a fold, it expands all lines between
     * the start line and end line, including the start line but
     * excluding the end line. It computes start
     * and end lines for a fold with offset and length in the following way:
     * 
     * start line: the greatest numbered line with
     *      first character offset <= offset of fold
     * 
     * end line: the greatest numbered line with
     *      first character offset <= offset + length of fold
     *      
     * In other words, it takes the offset of the fold and moves it back until it finds the start
     * of a line and takes the offset+length of a fold and moves it back until it finds the
     * start of a line. It then expands all lines in between and including the start line but excluding
     * the end line. See ProjectionViewer.addMasterDocumentRange() to see the exact implementation.
     * 
     * I think this is a silly way of doing things. The interface IProjectionPosition
     * allows the position to compute what lines are collapsed using the method
     * computeProjectionRegions but does not provide a way for the position to compute
     * what lines are expanded. This asymmetry can result in lines being collapsed
     * when a fold is collapsed but not re-expanded when the fold is expanded so that
     * lines just disappear. This requires being careful about the offset and length
     * of the position as well as what regions are collapsed.
     * 
     * The method alignRegion is stolen from the code for Java editor folding. Read the method
     * comments to see what it does. It should ensure that the entire proof is revealed
     * when expanded.
     */
    IRegion region = alignRegion(new Region(initTheoremOffset, initProofOffset + initProofLength
            - initTheoremOffset), document);

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

    positionOfStatement = new Position(initTheoremOffset, initLengthToEndOfStatement);
    positionOfProof = new Position(initProofOffset, initProofLength);
    this.annotation = annotation;

    // add positions to document so that they are updated on document changes.
    try
    {
        document.addPosition(positionOfProof);
        document.addPosition(positionOfStatement);
    } catch (BadLocationException e)
    {
        Activator.getDefault().logError("Error installing positions for proof fold at " + this, e);
    }

}
 

private List<TypedPosition> createRangeMarkers(TemplateVariable[] variables, IDocument document) throws MalformedTreeException, BadLocationException {
	Map<ReplaceEdit, String> markerToOriginal= new HashMap<ReplaceEdit, String>();

	MultiTextEdit root= new MultiTextEdit(0, document.getLength());
	List<TextEdit> edits= new ArrayList<TextEdit>();
	boolean hasModifications= false;
	for (int i= 0; i != variables.length; i++) {
		final TemplateVariable variable= variables[i];
		int[] offsets= variable.getOffsets();

		String value= variable.getDefaultValue();
		if (isWhitespaceVariable(value)) {
			// replace whitespace positions with unformattable comments
			String placeholder= COMMENT_START + value + COMMENT_END;
			for (int j= 0; j != offsets.length; j++) {
				ReplaceEdit replace= new ReplaceEdit(offsets[j], value.length(), placeholder);
				root.addChild(replace);
				hasModifications= true;
				markerToOriginal.put(replace, value);
				edits.add(replace);
			}
		} else {
			for (int j= 0; j != offsets.length; j++) {
				RangeMarker marker= new RangeMarker(offsets[j], value.length());
				root.addChild(marker);
				edits.add(marker);
			}
		}
	}

	if (hasModifications) {
		// update the document and convert the replaces to markers
		root.apply(document, TextEdit.UPDATE_REGIONS);
	}

	List<TypedPosition> positions= new ArrayList<TypedPosition>();
	for (Iterator<TextEdit> it= edits.iterator(); it.hasNext();) {
		TextEdit edit= it.next();
		try {
			// abuse TypedPosition to piggy back the original contents of the position
			final TypedPosition pos= new TypedPosition(edit.getOffset(), edit.getLength(), markerToOriginal.get(edit));
			document.addPosition(CATEGORY, pos);
			positions.add(pos);
		} catch (BadPositionCategoryException x) {
			Assert.isTrue(false);
		}
	}

	return positions;
}
 

/**
 * Determine the correct set of lines and delete the whitespace at the end of each of them.
 * 
 * @see com.mulgasoft.emacsplus.commands.EmacsPlusCmdHandler#transform(ITextEditor, IDocument, ITextSelection, ExecutionEvent)
 */
@Override
protected int transform(ITextEditor editor, IDocument document, ITextSelection currentSelection,
		ExecutionEvent event) throws BadLocationException {
	int result = NO_OFFSET;
	int lastLine = 0;
	int firstLine = 0;
	int maxOffset = Integer.MAX_VALUE;		
	if (editor.showsHighlightRangeOnly()) {
		// if the buffer is narrowed, then operate on precise region
		IRegion narrow = editor.getHighlightRange();
		int lastOffset = narrow.getOffset() + narrow.getLength();
		firstLine = document.getLineOfOffset(narrow.getOffset()); 
		lastLine = document.getLineOfOffset(lastOffset);
		IRegion endInfo = document.getLineInformationOfOffset(lastOffset);
		if (endInfo.getOffset() != lastOffset) {
			// point maxOffset at the last character in the narrowed region
			maxOffset = lastOffset -1;
		} else {
			// back up if we're at the first offset of the last line
			lastLine--;
		}
	} else {
		lastLine = document.getNumberOfLines() -1;
	}
	if (firstLine <= lastLine) {
		Position coff = new Position(getCursorOffset(editor,currentSelection),0);
		try {
			// record the position so we can restore it after any whitespace deletions
			document.addPosition(coff);
			deleteWhitepace(lastLine,firstLine,maxOffset,document);
		} catch (BadLocationException e) {
			// shouldn't happen, but alert user if it does
			asyncShowMessage(editor,BAD_LOCATION_ERROR,true);
		} finally {
			result = coff.getOffset();
			document.removePosition(coff);
		}
	}
	return result;
}
 

private List<TypedPosition> createRangeMarkers(TemplateVariable[] variables, IDocument document) throws MalformedTreeException, BadLocationException {
	Map<ReplaceEdit, String> markerToOriginal= new HashMap<ReplaceEdit, String>();

	MultiTextEdit root= new MultiTextEdit(0, document.getLength());
	List<TextEdit> edits= new ArrayList<TextEdit>();
	boolean hasModifications= false;
	for (int i= 0; i != variables.length; i++) {
		final TemplateVariable variable= variables[i];
		int[] offsets= variable.getOffsets();

		String value= variable.getDefaultValue();
		if (isWhitespaceVariable(value)) {
			// replace whitespace positions with unformattable comments
			String placeholder= COMMENT_START + value + COMMENT_END;
			for (int j= 0; j != offsets.length; j++) {
				ReplaceEdit replace= new ReplaceEdit(offsets[j], value.length(), placeholder);
				root.addChild(replace);
				hasModifications= true;
				markerToOriginal.put(replace, value);
				edits.add(replace);
			}
		} else {
			for (int j= 0; j != offsets.length; j++) {
				RangeMarker marker= new RangeMarker(offsets[j], value.length());
				root.addChild(marker);
				edits.add(marker);
			}
		}
	}

	if (hasModifications) {
		// update the document and convert the replaces to markers
		root.apply(document, TextEdit.UPDATE_REGIONS);
	}

	List<TypedPosition> positions= new ArrayList<TypedPosition>();
	for (Iterator<TextEdit> it= edits.iterator(); it.hasNext();) {
		TextEdit edit= it.next();
		try {
			// abuse TypedPosition to piggy back the original contents of the position
			final TypedPosition pos= new TypedPosition(edit.getOffset(), edit.getLength(), markerToOriginal.get(edit));
			document.addPosition(CATEGORY, pos);
			positions.add(pos);
		} catch (BadPositionCategoryException x) {
			Assert.isTrue(false);
		}
	}

	return positions;
}