Java Code Examples for org.eclipse.jface.text.IDocument#getChar()

/**
 * Count the whitespace to the left and right of offset, potentially counting over EOLs.
 * @param document
 * @param offset
 * @param dir
 * @param ignoreCR - count over EOLs if true
 * @return the whitespace count
 * @throws BadLocationException
 */
protected int countWS(IDocument document, int offset, int dir, boolean ignoreCR) throws BadLocationException {
	String eol = getLineDelimiter();
	int lineOff = offset;
	int off = offset;
	int lastOff = document.getLength(); // -1;	// n
	char c;
	while ((-1 < off && off < lastOff) && (c = document.getChar(off)) <= ' ') { 
		if (eol.indexOf(c) != -1) {
			if (!ignoreCR) {
				break;
			}
			// preserve the position past the last EOL
			lineOff = off + dir;
		}
		off = off + dir;
	}
	// if ignoreCR == true, then we're interested in complete blank lines only
	return Math.abs(offset - (ignoreCR ? lineOff : off));
}
 

protected IRegion performMatch(IDocument doc, int caretOffset) throws BadLocationException {
	final int charOffset= caretOffset - 1;
	final char prevChar= doc.getChar(Math.max(charOffset, 0));
	if (!fPairs.contains(prevChar)) return null;
	final boolean isForward= fPairs.isStartCharacter(prevChar);
	fAnchor= isForward ? ICharacterPairMatcher.LEFT : ICharacterPairMatcher.RIGHT;
	final int searchStartPosition= isForward ? caretOffset : caretOffset - 2;
	final int adjustedOffset= isForward ? charOffset : caretOffset;
	final String partition= TextUtilities.getContentType(doc, fPartitioning, charOffset, false);
	final DocumentPartitionAccessor partDoc= new DocumentPartitionAccessor(doc, fPartitioning, partition);
	int endOffset= findMatchingPeer(partDoc, prevChar, fPairs.getMatching(prevChar),
			isForward,  isForward ? doc.getLength() : -1,
			searchStartPosition);
	if (endOffset == -1) return null;
	final int adjustedEndOffset= isForward ? endOffset + 1: endOffset;
	if (adjustedEndOffset == adjustedOffset) return null;
	return new Region(Math.min(adjustedOffset, adjustedEndOffset),
			Math.abs(adjustedEndOffset - adjustedOffset));
}
 

public ExitFlags doExit(LinkedModeModel model, VerifyEvent event, int offset, int length) {

			if (fSize == fStack.size() && !isMasked(offset)) {
				if (event.character == fExitCharacter) {
					BracketLevel level = (BracketLevel) fStack.peek();
					if (level.fFirstPosition.offset > offset || level.fSecondPosition.offset < offset)
						return null;
					if (level.fSecondPosition.offset == offset && length == 0)
						// don't enter the character if if its the closing peer
						return new ExitFlags(ILinkedModeListener.UPDATE_CARET, false);
				}
				// when entering an anonymous class between the parenthesis', we
				// don't want
				// to jump after the closing parenthesis when return is pressed
				if (event.character == SWT.CR && offset > 0) {
					IDocument document = getSourceViewer().getDocument();
					try {
						if (document.getChar(offset - 1) == '{')
							return new ExitFlags(ILinkedModeListener.EXIT_ALL, true);
					} catch (BadLocationException e) {
					}
				}
			}
			return null;
		}
 

/**
 * If a _ is not a word break character, see if the BreakIterator stopped on one
 * 
 * @param doc
 * @param pos
 * @return new offset if word moves past any _'s, else pos
 */
int checkUnder(IDocument doc, int pos) {
	int result = pos;
	try {
		if (!isUnder()) {
			char c = doc.getChar(pos);
			if (!isDot() || c != '.') {
				IRegion lineInfo = doc.getLineInformationOfOffset(pos);
				int p = pos;
				// if we're at or just moved over an _
				if (c == '_' || (--p >= lineInfo.getOffset() && doc.getChar(p) == '_')) {
					int end = (lineInfo.getOffset() + lineInfo.getLength()); 
					if (end > p) {
						Matcher matcher = getUnderMatcher();
						matcher.reset(doc.get(p, end - p));
						if (matcher.matches()) {
							result = p + matcher.end(1);
						}
					}
				}
			}
		}
	} catch (BadLocationException e) {
	}
	return result;
}
 

protected int getCommentEnd(IDocument d, int pos, int end) throws BadLocationException {
	while (pos < end) {
		char curr= d.getChar(pos);
		pos++;
		if (curr == '*') {
			if (pos < end && d.getChar(pos) == '/') {
				return pos + 1;
			}
		}
	}
	return end;
}
 

private boolean hasEndJavadoc(IDocument document, int offset) throws BadLocationException {
	int pos = -1;
	while (offset < document.getLength()) {
		char c = document.getChar(offset);
		if (!Character.isWhitespace(c) && !(c == '*')) {
			pos = offset;
			break;
		}
		offset++;
	}
	if (document.getLength() >= pos + 2 && document.get(pos - 1, 2).equals("*/")) {
		return true;
	}
	return false;
}
 

/**
 * At a given position in text retrieves the region marking the word, starting at and ending after the current position 
 * @param document document
 * @param documentOffset offset (position of the cursor)
 * @param detector for identification of words 
 * @return a region expanded forward
 */
public static IRegion getRegionExpandedForwards(IDocument document, int documentOffset, IWordDetector detector)
{

    // Use string buffer to collect characters
    int charCounter = 0;
    while (true)
    {
        try
        {
            // Read character forward
            char c = document.getChar(++documentOffset);

            // This was the start of a word
            if (!detector.isWordPart(c))
                break;

            // Count character
            charCounter++;

        } catch (BadLocationException e)
        {

            // Document end reached, no word
            break;
        }
    }

    return new Region(documentOffset - charCounter, charCounter + 1);
}
 

/**
 * From <code>position</code> to the left, eats any whitespace and then a pair of brackets
 * as used to declare an array return type like <pre>String [ ]</pre>.
 * The return value is either the position of the opening bracket or <code>position</code> if no
 * pair of brackets can be parsed.
 *
 * @param document the document being modified
 * @param position the first character position in <code>document</code> to be considered
 * @param partitioning the document partitioning
 * @return the smallest character position of bracket pair or <code>position</code>
 */
private static int eatBrackets(IDocument document, int position, String partitioning) {
	// accept array return type
	int pos= firstNonWhitespaceBackward(document, position, partitioning, -1);
	try {
		if (pos > 1 && document.getChar(pos) == ']') {
			pos= firstNonWhitespaceBackward(document, pos - 1, partitioning, -1);
			if (pos > 0 && document.getChar(pos) == '[')
				return pos;
		}
	} catch (BadLocationException e) {
		// won't happen
	}
	return position;
}
 

private int getCommentEnd(IDocument d, int offset, int endOffset) throws BadLocationException {
	while (offset < endOffset) {
		char curr= d.getChar(offset);
		offset++;
		if (curr == '*') {
			if (offset < endOffset && d.getChar(offset) == '/') {
				return offset + 1;
			}
		}
	}
	return endOffset;
}
 

public int getIndentationLevelAtOffset(int offset, IDocument document, XtextResource resource) {
	try {
		if (offset <= 0)
			return 0;
		int currentOffset = offset - 1;
		char currentChr = document.getChar(currentOffset);
		int indentationOffset = 0;
		if(currentChr == '\n' || currentChr == '\r') {
			-- currentOffset;
			if(currentOffset < 0)
				return 0;
			currentChr = document.getChar(currentOffset);
		}
		while (currentChr != '\n' && currentChr != '\r' && currentOffset > 0) {
			if (Character.isWhitespace(currentChr))
				++indentationOffset;
			else
				indentationOffset = 0;
			--currentOffset;
			currentChr = document.getChar(currentOffset);
		}
		return indentationOffset / getIndentString(resource).length();
	} catch (BadLocationException e) {
		LOG.error("Error calculating indentation at offset", e);
	}
	return 0;
}
 

/**
 * Computes an insert position for an opening brace if <code>offset</code> maps to a position in
 * <code>document</code> that looks like being the RHS of an assignment or like an array definition.
 *
 * @param document the document being modified
 * @param line the current line under investigation
 * @param offset the offset of the caret position, relative to the line start.
 * @param partitioning the document partitioning
 * @return an insert position  relative to the line start if <code>line</code> looks like being an array initialization at <code>offset</code>, -1 otherwise
 */
private static int computeArrayInitializationPos(IDocument document, ITextSelection line, int offset, String partitioning) {
	// search backward while WS, find = (not != <= >= ==) in default partition
	int pos= offset + line.getOffset();

	if (pos == 0)
		return -1;

	int p= firstNonWhitespaceBackward(document, pos - 1, partitioning, -1);

	if (p == -1)
		return -1;

	try {

		char ch= document.getChar(p);
		if (ch != '=' && ch != ']')
			return -1;

		if (p == 0)
			return offset;

		p= firstNonWhitespaceBackward(document, p - 1, partitioning, -1);
		if (p == -1)
			return -1;

		ch= document.getChar(p);
		if (Character.isJavaIdentifierPart(ch) || ch == ']' || ch == '[')
			return offset;

	} catch (BadLocationException e) {
	}
	return -1;
}
 

/**
 * 
 * This leaves a bit of a mess e.g. "import " or "from " for some later process to clean up.
 * 
 */
private void deleteImport(PySelection ps, MarkerAnnotationAndPosition markerInfo)
        throws BadLocationException, CoreException {
    IMarker marker = markerInfo.markerAnnotation.getMarker();

    Integer start = (Integer) marker.getAttribute(IMarker.CHAR_START);
    Integer end = (Integer) marker.getAttribute(IMarker.CHAR_END);
    IDocument doc = ps.getDoc();
    while (start > 0) {
        char c;
        try {
            c = doc.getChar(start - 1);
        } catch (Exception e) {
            break;
        }
        if (c == '\r' || c == '\n') {
            break;
        }
        if (Character.isWhitespace(c) || c == ',') {
            start--;
            continue;
        }
        break;
    }
    ps.setSelection(start, end);
    ps.deleteSelection();
}
 

/**
 * @see com.mulgasoft.emacsplus.commands.EmacsPlusNoEditHandler#transform(org.eclipse.ui.texteditor.ITextEditor, org.eclipse.jface.text.IDocument, org.eclipse.jface.text.ITextSelection, org.eclipse.core.commands.ExecutionEvent)
 */
@Override
protected int transform(ITextEditor editor, IDocument document, ITextSelection currentSelection,
		ExecutionEvent event) throws BadLocationException {
	
	String msg = null;
	
	int offset = getCursorOffset(editor,currentSelection);
	int docLen = document.getLength();
	IRegion line = document.getLineInformationOfOffset(offset); 

	if (offset >= docLen) {
		msg = String.format(EOB_POSITION, offset,docLen);
	} else {
		char curChar = document.getChar(offset);
		String sChar = "";	//$NON-NLS-1$
		int percent = new Float(((offset * 100) / docLen) + .5).intValue();

		if (offset == line.getOffset() + line.getLength()){
			String ld = document.getLineDelimiter(document.getLineOfOffset(offset));
			char[] points = ld.toCharArray();
			for (int i=0; i<points.length; i++) {
				sChar += normalizeChar(points[i]);
			}
			msg = String.format(EOL_POSITION, sChar,offset,docLen,percent);
		} else {

			int curCode = (int) curChar;
			sChar = (curChar <= ' ' ? normalizeChar(curChar) : String.valueOf(curChar));
			msg = String.format(CURSOR_POSITION, sChar, curCode, curCode, curCode, offset, docLen, percent);
		}
	}
	EmacsPlusUtils.showMessage(editor, msg, false);
	setCmdResult(new Integer(offset));
	return super.transform(editor, document, currentSelection, event);

}
 

public String updateReplacementString(IDocument document, int offset, ImportRewrite impRewrite) throws CoreException, BadLocationException {
	// Construct empty body for performance concern
	// See https://github.com/microsoft/language-server-protocol/issues/1032#issuecomment-648748013
	String newBody = fSnippetSupport ? "{\n\t${0}\n}" : "{\n\n}";

	StringBuilder buf = new StringBuilder("new A()"); //$NON-NLS-1$
	buf.append(newBody);
	// use the code formatter
	String lineDelim = TextUtilities.getDefaultLineDelimiter(document);
	final IJavaProject project = fCompilationUnit.getJavaProject();
	IRegion lineInfo = document.getLineInformationOfOffset(fReplacementOffset);
	Map<String, String> options = project != null ? project.getOptions(true) : JavaCore.getOptions();
	String replacementString = CodeFormatterUtil.format(CodeFormatter.K_EXPRESSION, buf.toString(), 0, lineDelim, options);
	int lineEndOffset = lineInfo.getOffset() + lineInfo.getLength();
	int p = offset;
	if (p < document.getLength()) {
		char ch = document.getChar(p);
		while (p < lineEndOffset) {
			if (ch == '(' || ch == ')' || ch == ';' || ch == ',') {
				break;
			}
			ch = document.getChar(++p);
		}
		if (ch != ';' && ch != ',' && ch != ')') {
			replacementString = replacementString + ';';
		}
	}
	int beginIndex = replacementString.indexOf('(');
	replacementString = replacementString.substring(beginIndex);
	return replacementString;
}
 

/**
 * Checks whether a character to be inserted is already present at the insert location (perhaps
 * separated by some whitespace from <code>position</code>.
 *
 * @param document the document we are working on
 * @param position the insert position of <code>ch</code>
 * @param ch the character to be inserted
 * @return <code>true</code> if <code>ch</code> is already present at <code>location</code>, <code>false</code> otherwise
 */
private boolean alreadyPresent(IDocument document, char ch, int position) {
	int pos= firstNonWhitespaceForward(document, position, fPartitioning, document.getLength());
	try {
		if (pos != -1 && document.getChar(pos) == ch)
			return true;
	} catch (BadLocationException e) {
	}

	return false;
}
 

/**
 *
 * @param ps
 * @throws BadLocationException
 */
private void eraseSingleChar(PySelection ps) throws BadLocationException {
    ICoreTextSelection textSelection = ps.getTextSelection();

    int replaceLength = 1;
    int replaceOffset = textSelection.getOffset() - replaceLength;
    IDocument doc = ps.getDoc();

    if (replaceOffset >= 0 && replaceOffset + replaceLength < doc.getLength()) {
        char c = doc.getChar(replaceOffset);
        if (c == '(' || c == '[' || c == '{') {
            //When removing a (, check if we have to delete the corresponding ) too.
            char peer = StringUtils.getPeer(c);
            if (replaceOffset + replaceLength < doc.getLength()) {
                char c2 = doc.getChar(replaceOffset + 1);
                if (c2 == peer) {
                    //Ok, there's a closing one right next to it, now, what we have to do is
                    //check if the user was actually removing that one because there's an opening
                    //one without a match.
                    //To do that, we go backwards in the document searching for an opening match and then
                    //search its match. If it's found, it means we can delete both, otherwise, this
                    //delete will make things correct.

                    //Create a matcher only matching this char
                    PythonPairMatcher pythonPairMatcher = new PythonPairMatcher(new char[] { c, peer });
                    int openingPeerOffset = pythonPairMatcher.searchForAnyOpeningPeer(replaceOffset, doc);
                    if (openingPeerOffset == -1) {
                        replaceLength += 1;
                    } else {
                        int closingPeerOffset = pythonPairMatcher.searchForClosingPeer(openingPeerOffset, c, peer,
                                doc);
                        if (closingPeerOffset != -1) {
                            //we have a match, so, things are balanced and we can delete the next
                            replaceLength += 1;
                        }
                    }
                }
            }

        } else if (c == '\'' || c == '"') {
            //when removing a ' or ", check if we have to delete another ' or " too.
            Tuple<String, String> beforeAndAfterMatchingChars = ps.getBeforeAndAfterMatchingChars(c);
            int matchesBefore = beforeAndAfterMatchingChars.o1.length();
            int matchesAfter = beforeAndAfterMatchingChars.o2.length();
            if (matchesBefore == 1 && matchesBefore == matchesAfter) {
                replaceLength += 1;
            }
        }
    }

    makeDelete(doc, replaceOffset, replaceLength);
}
 

private ICompletionProposal[] standardMethod(ITextViewer viewer, int offset, List<String> keywords, List<ICompletionProposal> autoCompProposals) {
	
	int index = offset - 1;
	StringBuffer prefix = new StringBuffer();
	IDocument document = viewer.getDocument();
			
	while (index > 0) {
		try {
			char prev = document.getChar(index);
			if (Character.isWhitespace(prev)) {
				break;
			}
			prefix.insert(0, prev);
			index--;
		}
		catch (BadLocationException ble) {
			Activator.getDefault().log("could not get char", ble);
		}
	}

	if (prefix.length() > 0) {
		String word = prefix.toString();
		// limit to attributes
		if (containsOpenBracket(word)) {
			autoCompProposals.addAll(addHeaderAttributes(word, offset));
		}
		for (String keyword : keywords) {
			if (keyword.toUpperCase(Locale.ENGLISH).startsWith(word.toUpperCase(Locale.ENGLISH)) && word.length() < keyword.length()) {
				autoCompProposals.add(new CompletionProposal(keyword + " ", index + 1, offset - (index + 1), keyword.length() + 1));
			}
		}
	}
	else {
		// propose header keywords
		proposeHeaderOperands(offset, document, autoCompProposals);
	}
	
	if (!autoCompProposals.isEmpty()) {
		return (ICompletionProposal[]) autoCompProposals.toArray(new ICompletionProposal[autoCompProposals.size()]);
	}
	return null;

}
 

/**
 * Computes quick assists for the console.
 */
@Override
public ICompletionProposal[] computeQuickAssistProposals(IQuickAssistInvocationContext invocationContext) {
    ISourceViewer sourceViewer = invocationContext.getSourceViewer();
    List<ICompletionProposalHandle> props = new ArrayList<ICompletionProposalHandle>();
    if (sourceViewer instanceof ScriptConsoleViewer) {
        ScriptConsoleViewer viewer = (ScriptConsoleViewer) sourceViewer;

        //currently, only the assign quick assist is used
        AssistAssign assistAssign = new AssistAssign();

        ISelection selection = sourceViewer.getSelectionProvider().getSelection();
        if (selection instanceof ITextSelection) {
            PySelection ps = PySelectionFromEditor.createPySelectionFromEditor(sourceViewer,
                    (ITextSelection) selection);
            int offset = viewer.getCaretOffset();
            String commandLine = viewer.getCommandLine();

            //let's calculate the 1st line that is not a whitespace.
            if (assistAssign.isValid(ps.getSelLength(), commandLine, offset)) {
                int commandLineOffset = viewer.getCommandLineOffset();
                try {
                    IDocument doc = sourceViewer.getDocument();
                    while (true) {
                        if (commandLineOffset == doc.getLength() - 1) {
                            break;
                        }
                        char c = doc.getChar(commandLineOffset);
                        if (Character.isWhitespace(c)) {
                            commandLineOffset++;
                        } else {
                            break;
                        }
                    }
                    props.addAll(assistAssign.getProps(ps, SharedUiPlugin.getImageCache(), sourceViewer, offset,
                            commandLine, commandLineOffset));

                } catch (BadLocationException e) {
                    Log.log(e);
                }
            }
        }
    }
    return ConvertCompletionProposals
            .convertHandlesToProposals(props.toArray(new ICompletionProposalHandle[props.size()]));
}
 

/**
 * Computes and returns the indentation for a javadoc line. The line
 * must be inside a javadoc comment.
 *
 * @param document the document
 * @param line the line in document
 * @param scanner the scanner
 * @param partition the comment partition
 * @return the indent, or <code>null</code> if not computable
 * @throws BadLocationException
 */
private static String computeJavadocIndent(IDocument document, int line, JavaHeuristicScanner scanner, ITypedRegion partition) throws BadLocationException {
	if (line == 0) // impossible - the first line is never inside a javadoc comment
		return null;

	// don't make any assumptions if the line does not start with \s*\* - it might be
	// commented out code, for which we don't want to change the indent
	final IRegion lineInfo= document.getLineInformation(line);
	final int lineStart= lineInfo.getOffset();
	final int lineLength= lineInfo.getLength();
	final int lineEnd= lineStart + lineLength;
	int nonWS= scanner.findNonWhitespaceForwardInAnyPartition(lineStart, lineEnd);
	if (nonWS == JavaHeuristicScanner.NOT_FOUND || document.getChar(nonWS) != '*') {
		if (nonWS == JavaHeuristicScanner.NOT_FOUND)
			return document.get(lineStart, lineLength);
		return document.get(lineStart, nonWS - lineStart);
	}

	// take the indent from the previous line and reuse
	IRegion previousLine= document.getLineInformation(line - 1);
	int previousLineStart= previousLine.getOffset();
	int previousLineLength= previousLine.getLength();
	int previousLineEnd= previousLineStart + previousLineLength;

	StringBuffer buf= new StringBuffer();
	int previousLineNonWS= scanner.findNonWhitespaceForwardInAnyPartition(previousLineStart, previousLineEnd);
	if (previousLineNonWS == JavaHeuristicScanner.NOT_FOUND || document.getChar(previousLineNonWS) != '*') {
		// align with the comment start if the previous line is not an asterix line
		previousLine= document.getLineInformationOfOffset(partition.getOffset());
		previousLineStart= previousLine.getOffset();
		previousLineLength= previousLine.getLength();
		previousLineEnd= previousLineStart + previousLineLength;
		previousLineNonWS= scanner.findNonWhitespaceForwardInAnyPartition(previousLineStart, previousLineEnd);
		if (previousLineNonWS == JavaHeuristicScanner.NOT_FOUND)
			previousLineNonWS= previousLineEnd;

		// add the initial space
		// TODO this may be controlled by a formatter preference in the future
		buf.append(' ');
	}

	String indentation= document.get(previousLineStart, previousLineNonWS - previousLineStart);
	buf.insert(0, indentation);
	return buf.toString();
}
 

/**
 * Returns the first offset greater than <code>offset</code> and smaller than
 * <code>end</code> whose character is not a space or tab character. If no such
 * offset is found, <code>end</code> is returned.
 *
 * @param document the document to search in
 * @param offset the offset at which searching start
 * @param end the offset at which searching stops
 * @return the offset in the specified range whose character is not a space or tab
 * @exception BadLocationException if position is an invalid range in the given document
 */
private int findEndOfWhiteSpace(IDocument document, int offset, int end) throws BadLocationException {
    while (offset < end) {
        char c = document.getChar(offset);
        if (c != ' ' && c != '\t') {
            return offset;
        }
        offset++;
    }
    return end;
}