Example usage for org.eclipse.jdt.internal.compiler.parser Scanner getNextCharAsJavaIdentifierPart

Introduction

In this page you can find the example usage for org.eclipse.jdt.internal.compiler.parser Scanner getNextCharAsJavaIdentifierPart.

Prototype

public boolean getNextCharAsJavaIdentifierPart() 

Source Link

Usage

From source file:com.codenvy.ide.ext.java.server.internal.codeassist.SelectionEngine.java

License:Open Source License

private boolean checkSelection(char[] source, int selectionStart, int selectionEnd) {

    Scanner scanner = new Scanner(false /*comment*/, false /*whitespace*/, false /*nls*/,
            this.compilerOptions.sourceLevel, this.compilerOptions.complianceLevel, null/*taskTag*/,
            null/*taskPriorities*/, true /*taskCaseSensitive*/);
    scanner.setSource(source);/*  w w w .  j  a va 2s  . c  o  m*/

    int lastIdentifierStart = -1;
    int lastIdentifierEnd = -1;
    char[] lastIdentifier = null;
    int token;

    if (selectionStart > selectionEnd) {
        int end = source.length - 1;

        // compute start position of current line
        int currentPosition = selectionStart - 1;
        int nextCharacterPosition = selectionStart;
        char currentCharacter = ' ';
        try {
            lineLoop: while (currentPosition > 0) {

                if (source[currentPosition] == '\\' && source[currentPosition + 1] == 'u') {
                    int pos = currentPosition + 2;
                    int c1 = 0, c2 = 0, c3 = 0, c4 = 0;
                    while (source[pos] == 'u') {
                        pos++;
                    }

                    int endOfUnicode = pos + 3;
                    if (end < endOfUnicode) {
                        if (endOfUnicode < source.length) {
                            end = endOfUnicode;
                        } else {
                            return false; // not enough characters to decode an unicode
                        }
                    }

                    if ((c1 = ScannerHelper.getHexadecimalValue(source[pos++])) > 15 || c1 < 0
                            || (c2 = ScannerHelper.getHexadecimalValue(source[pos++])) > 15 || c2 < 0
                            || (c3 = ScannerHelper.getHexadecimalValue(source[pos++])) > 15 || c3 < 0
                            || (c4 = ScannerHelper.getHexadecimalValue(source[pos++])) > 15 || c4 < 0) {
                        return false;
                    } else {
                        currentCharacter = (char) (((c1 * 16 + c2) * 16 + c3) * 16 + c4);
                        nextCharacterPosition = pos;
                    }
                } else {
                    currentCharacter = source[currentPosition];
                    nextCharacterPosition = currentPosition + 1;
                }

                switch (currentCharacter) {
                case '\r':
                case '\n':
                case '/':
                case '"':
                case '\'':
                    break lineLoop;
                }
                currentPosition--;
            }
        } catch (ArrayIndexOutOfBoundsException e) {
            return false;
        }

        // compute start and end of the last token
        scanner.resetTo(nextCharacterPosition, end);
        isolateLastName: do {
            try {
                token = scanner.getNextToken();
            } catch (InvalidInputException e) {
                return false;
            }
            switch (token) {
            case TerminalTokens.TokenNamethis:
            case TerminalTokens.TokenNamesuper:
            case TerminalTokens.TokenNamenew:
            case TerminalTokens.TokenNameIdentifier:
                if (scanner.startPosition <= selectionStart && selectionStart <= scanner.currentPosition) {
                    if (scanner.currentPosition == scanner.eofPosition) {
                        int temp = scanner.eofPosition;
                        scanner.eofPosition = scanner.source.length;
                        while (scanner.getNextCharAsJavaIdentifierPart()) {
                            /*empty*/}
                        scanner.eofPosition = temp;
                    }
                    lastIdentifierStart = scanner.startPosition;
                    lastIdentifierEnd = scanner.currentPosition - 1;
                    lastIdentifier = scanner.getCurrentTokenSource();
                    break isolateLastName;
                }
                break;
            }
        } while (token != TerminalTokens.TokenNameEOF);
    } else {
        if (selectionStart == selectionEnd) { // Widen the selection to scan -> || :: if needed. No unicode handling for now.
            if (selectionStart > 0 && selectionEnd < source.length - 1) {
                if ((source[selectionStart] == '>' && source[selectionStart - 1] == '-')
                        || source[selectionStart] == ':' && source[selectionStart - 1] == ':') {
                    selectionStart--;
                } else {
                    if ((source[selectionStart] == '-' && source[selectionEnd + 1] == '>')
                            || source[selectionStart] == ':' && source[selectionEnd + 1] == ':') {
                        selectionEnd++;
                    }
                }
            }
        } // there could be some innocuous widening, shouldn't matter.
        scanner.resetTo(selectionStart, selectionEnd);

        boolean expectingIdentifier = true;
        do {
            try {
                token = scanner.getNextToken();
            } catch (InvalidInputException e) {
                return false;
            }
            switch (token) {
            case TerminalTokens.TokenNamethis:
            case TerminalTokens.TokenNamesuper:
            case TerminalTokens.TokenNamenew:
            case TerminalTokens.TokenNameIdentifier:
                if (!expectingIdentifier)
                    return false;
                lastIdentifier = scanner.getCurrentTokenSource();
                lastIdentifierStart = scanner.startPosition;
                lastIdentifierEnd = scanner.currentPosition - 1;
                if (lastIdentifierEnd > selectionEnd) {
                    lastIdentifierEnd = selectionEnd;
                    lastIdentifier = CharOperation.subarray(lastIdentifier, 0,
                            lastIdentifierEnd - lastIdentifierStart + 1);
                }
                expectingIdentifier = false;
                break;
            case TerminalTokens.TokenNameCOLON_COLON:
                if (selectionStart >= scanner.startPosition && selectionEnd < scanner.currentPosition) {
                    this.actualSelectionStart = selectionStart;
                    this.actualSelectionEnd = selectionEnd;
                    this.selectedIdentifier = CharOperation.NO_CHAR;
                    return true;
                }
                //$FALL-THROUGH$
            case TerminalTokens.TokenNameDOT:
                if (expectingIdentifier)
                    return false;
                expectingIdentifier = true;
                break;
            case TerminalTokens.TokenNameEOF:
                if (expectingIdentifier)
                    return false;
                break;
            case TerminalTokens.TokenNameLESS:
                if (!checkTypeArgument(scanner))
                    return false;
                break;
            case TerminalTokens.TokenNameAT:
                if (scanner.startPosition != scanner.initialPosition)
                    return false;
                break;
            case TerminalTokens.TokenNameARROW:
                if (selectionStart >= scanner.startPosition && selectionEnd < scanner.currentPosition) {
                    this.actualSelectionStart = selectionStart;
                    this.actualSelectionEnd = selectionEnd;
                    this.selectedIdentifier = CharOperation.NO_CHAR;
                    return true;
                }
                return false;
            default:
                return false;
            }
        } while (token != TerminalTokens.TokenNameEOF);
    }
    if (lastIdentifierStart > 0) {
        this.actualSelectionStart = lastIdentifierStart;
        this.actualSelectionEnd = lastIdentifierEnd;
        this.selectedIdentifier = lastIdentifier;
        return true;
    }
    return false;
}

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