ChaiScriptSyntaxHighlighter.cpp

/*
 * ChaiScriptSyntaxHighlighter.cpp
 *
 *  Created on: 21.10.2016
 *      Author: klemens.morgenstern
 */

#include <widgets/ChaiScriptSyntaxHighlighter.hpp>

namespace widgets
{

ChaiScriptSyntaxHighlighter::ChaiScriptSyntaxHighlighter(QTextDocument *parent)
 : QSyntaxHighlighter(parent)
{
    keywords = QStringList() << "attr" << "auto" << "break" << // "class" << "def" <<
    		"else" << "for" << "fun" << "if" << "try" << "catch" << "while" << "var"
			<< "true" << "false"
		   ;

    operators = QStringList() << "=" <<
           // Comparison
           "==" << "!=" << "<" << "<=" << ">" << ">=" <<
           // Arithmetic
           "\\+" << "-" << "\\*" << "/" << "//" << "%" << "\\*\\*" <<
           // In-place
           "\\+=" << "-=" << "\\*=" << "/=" << "%=" <<
           // Bitwise
           "\\^" << "\\|" << "&" << "~" << ">>" << "<<";

    braces = QStringList() << "{" << "}" << "\\(" << "\\)" << "\\[" << "]";

    basicStyles.insert("keyword", getTextCharFormat("blue"));
    basicStyles.insert("operator", getTextCharFormat("red"));
    basicStyles.insert("brace", getTextCharFormat("darkGray"));
    basicStyles.insert("defclass", getTextCharFormat("black", "bold"));
    basicStyles.insert("brace", getTextCharFormat("darkGray"));
    basicStyles.insert("string", getTextCharFormat("magenta"));
    basicStyles.insert("comment", getTextCharFormat("darkGreen", "italic"));
    basicStyles.insert("numbers", getTextCharFormat("brown"));

    initializeRules();
}

void ChaiScriptSyntaxHighlighter::initializeRules()
{
    for (auto & currKeyword : keywords)
    {
        rules.append(ChaiScriptRule(QString("\\b%1\\b").arg(currKeyword), 0, basicStyles.value("keyword")));
    }
    for (auto & currOperator : operators)
    {
        rules.append(ChaiScriptRule(QString("%1").arg(currOperator), 0, basicStyles.value("operator")));
    }
    for (auto & currBrace : braces)
    {
        rules.append(ChaiScriptRule(QString("%1").arg(currBrace), 0, basicStyles.value("brace")));
    }
    // Double-quoted string, possibly containing escape sequences
    // FF: originally in python : r'"[^"\\]*(\\.[^"\\]*)*"'
    rules.append(ChaiScriptRule("\"[^\"\\\\]*(\\\\.[^\"\\\\]*)*\"", 0, basicStyles.value("string")));
    // Single-quoted string, possibly containing escape sequences
    // FF: originally in python : r"'[^'\\]*(\\.[^'\\]*)*'"
    rules.append(ChaiScriptRule("'[^'\\\\]*(\\\\.[^'\\\\]*)*'", 0, basicStyles.value("string")));

    // 'def' followed by an identifier
    // FF: originally: r'\bdef\b\s*(\w+)'
    rules.append(ChaiScriptRule("\\bdef\\b\\s*(\\w+)", 1, basicStyles.value("defclass")));
    //  'class' followed by an identifier
    // FF: originally: r'\bclass\b\s*(\w+)'
    rules.append(ChaiScriptRule("\\bclass\\b\\s*(\\w+)", 1, basicStyles.value("defclass")));

    // From '#' until a newline
    // FF: originally: r'#[^\\n]*'
    rules.append(ChaiScriptRule("//[^\\n]*", 0, basicStyles.value("comment")));

    // Numeric literals
    rules.append(ChaiScriptRule("\\b[+-]?[0-9]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+[lL]?\b'
    rules.append(ChaiScriptRule("\\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\b'
    rules.append(ChaiScriptRule("\\b[+-]?[0-9]+(?:\\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\b'
}

void ChaiScriptSyntaxHighlighter::highlightBlock(const QString &text)
{
    for (ChaiScriptRule & currRule : rules)
    {
        int idx = currRule.pattern.indexIn(text, 0);
        while (idx >= 0)
        {
            // Get index of Nth match
            idx = currRule.pattern.pos(currRule.nth);
            int length = currRule.pattern.cap(currRule.nth).length();
            setFormat(idx, length, currRule.format);
            idx = currRule.pattern.indexIn(text, idx + length);
        }
    }

    setCurrentBlockState(0);
}

bool ChaiScriptSyntaxHighlighter::matchMultiline(const QString &text, const QRegExp &delimiter, const int inState, const QTextCharFormat &style)
{
    int start = -1;
    int add = -1;
    int end = -1;
    int length = 0;

    // If inside triple-single quotes, start at 0
    if (previousBlockState() == inState)
    {
        start = 0;
        add = 0;
    }
    // Otherwise, look for the delimiter on this line
    else {
        start = delimiter.indexIn(text);
        // Move past this match
        add = delimiter.matchedLength();
    }

    // As long as there's a delimiter match on this line...
    while (start >= 0)
    {
        // Look for the ending delimiter
        end = delimiter.indexIn(text, start + add);
        // Ending delimiter on this line?
        if (end >= add) {
            length = end - start + add + delimiter.matchedLength();
            setCurrentBlockState(0);
    }
        // No; multi-line string
        else {
            setCurrentBlockState(inState);
            length = text.length() - start + add;
    }
        // Apply formatting and look for next
        setFormat(start, length, style);
        start = delimiter.indexIn(text, start + length);
    }
    // Return True if still inside a multi-line string, False otherwise
    if (currentBlockState() == inState)
        return true;
    else
        return false;
}

const QTextCharFormat ChaiScriptSyntaxHighlighter::getTextCharFormat(const QString &colorName, const QString &style)
{
    QTextCharFormat charFormat;
    QColor color(colorName);
    charFormat.setForeground(color);
    if (style.contains("bold", Qt::CaseInsensitive))
        charFormat.setFontWeight(QFont::Bold);
    if (style.contains("italic", Qt::CaseInsensitive))
        charFormat.setFontItalic(true);
    return charFormat;
}


} /* namespace widgets */