We were in need for some basic Python syntax highlighting in a QTextEdit box, and didn't immediately want to go fully pro with a Scintilla wrapper. (Update: We did that, too, in the end, according to this scintilla/qt post).
So we looked for a QSyntaxHighlighter subclass for Python formatting, but only found a PyQt example which seems to be from Torsten Marek ( shlomme.diotavelli.net ) originally.
I asked Frankie to create a C++ Qt4 QSyntaxHighlighter class based on this, so here it is:
So we looked for a QSyntaxHighlighter subclass for Python formatting, but only found a PyQt example which seems to be from Torsten Marek ( shlomme.diotavelli.net ) originally.
I asked Frankie to create a C++ Qt4 QSyntaxHighlighter class based on this, so here it is:
/* $Id: PythonSyntaxHighlighter.cpp 167 2013-11-03 17:01:22Z oliver $ This is a C++ port of the following PyQt example http://diotavelli.net/PyQtWiki/Python%20syntax%20highlighting C++ port by Frankie Simon (www.kickdrive.de, www.fuh-edv.de) The following free software license applies for this file ("X11 license"): Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include "PythonSyntaxHighlighter.h" PythonSyntaxHighlighter::PythonSyntaxHighlighter(QTextDocument *parent) : QSyntaxHighlighter(parent) { keywords = QStringList() << "and" << "assert" << "break" << "class" << "continue" << "def" << "del" << "elif" << "else" << "except" << "exec" << "finally" << "for" << "from" << "global" << "if" << "import" << "in" << "is" << "lambda" << "not" << "or" << "pass" << "print" << "raise" << "return" << "try" << "while" << "yield" << "None" << "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("string2", getTextCharFormat("darkMagenta")); basicStyles.insert("comment", getTextCharFormat("darkGreen", "italic")); basicStyles.insert("self", getTextCharFormat("black", "italic")); basicStyles.insert("numbers", getTextCharFormat("brown")); triSingleQuote.setPattern("'''"); triDoubleQuote.setPattern("\"\"\""); initializeRules(); } void PythonSyntaxHighlighter::initializeRules() { foreach (QString currKeyword, keywords) { rules.append(HighlightingRule(QString("\\b%1\\b").arg(currKeyword), 0, basicStyles.value("keyword"))); } foreach (QString currOperator, operators) { rules.append(HighlightingRule(QString("%1").arg(currOperator), 0, basicStyles.value("operator"))); } foreach (QString currBrace, braces) { rules.append(HighlightingRule(QString("%1").arg(currBrace), 0, basicStyles.value("brace"))); } // 'self' rules.append(HighlightingRule("\\bself\\b", 0, basicStyles.value("self"))); // Double-quoted string, possibly containing escape sequences // FF: originally in python : r'"[^"\\]*(\\.[^"\\]*)*"' rules.append(HighlightingRule("\"[^\"\\\\]*(\\\\.[^\"\\\\]*)*\"", 0, basicStyles.value("string"))); // Single-quoted string, possibly containing escape sequences // FF: originally in python : r"'[^'\\]*(\\.[^'\\]*)*'" rules.append(HighlightingRule("'[^'\\\\]*(\\\\.[^'\\\\]*)*'", 0, basicStyles.value("string"))); // 'def' followed by an identifier // FF: originally: r'\bdef\b\s*(\w+)' rules.append(HighlightingRule("\\bdef\\b\\s*(\\w+)", 1, basicStyles.value("defclass"))); // 'class' followed by an identifier // FF: originally: r'\bclass\b\s*(\w+)' rules.append(HighlightingRule("\\bclass\\b\\s*(\\w+)", 1, basicStyles.value("defclass"))); // From '#' until a newline // FF: originally: r'#[^\\n]*' rules.append(HighlightingRule("#[^\\n]*", 0, basicStyles.value("comment"))); // Numeric literals rules.append(HighlightingRule("\\b[+-]?[0-9]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+[lL]?\b' rules.append(HighlightingRule("\\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(HighlightingRule("\\b[+-]?[0-9]+(?:\\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\b' } void PythonSyntaxHighlighter::highlightBlock(const QString &text) { foreach (HighlightingRule 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); // Do multi-line strings bool isInMultilne = matchMultiline(text, triSingleQuote, 1, basicStyles.value("string2")); if (!isInMultilne) isInMultilne = matchMultiline(text, triDoubleQuote, 2, basicStyles.value("string2")); } bool PythonSyntaxHighlighter::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 PythonSyntaxHighlighter::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; }
$Id: KickPythonSyntaxHighlighter.h 167 2013-11-03 17:01:22Z oliver $ This is a C++ port of the following PyQt example http://diotavelli.net/PyQtWiki/Python%20syntax%20highlighting C++ port by Frankie Simon (docklight.de, www.fuh-edv.de) The following free software license applies for this file ("X11 license"): Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #ifndef KICKPYTHONSYNTAXHIGHLIGHTER_H #define KICKPYTHONSYNTAXHIGHLIGHTER_H #include <QSyntaxHighlighter> //! Container to describe a highlighting rule. Based on a regular expression, a relevant match # and the format. class HighlightingRule { public: HighlightingRule(const QString &patternStr, int n, const QTextCharFormat &matchingFormat) { originalRuleStr = patternStr; pattern = QRegExp(patternStr); nth = n; format = matchingFormat; } QString originalRuleStr; QRegExp pattern; int nth; QTextCharFormat format; }; //! Implementation of highlighting for Python code. class KickPythonSyntaxHighlighter : public QSyntaxHighlighter { Q_OBJECT public: KickPythonSyntaxHighlighter(QTextDocument *parent = 0); protected: void highlightBlock(const QString &text); private: QStringList keywords; QStringList operators; QStringList braces; QHash<QString, QTextCharFormat> basicStyles; void initializeRules(); //! Highlighst multi-line strings, returns true if after processing we are still within the multi-line section. bool matchMultiline(const QString &text, const QRegExp &delimiter, const int inState, const QTextCharFormat &style); const QTextCharFormat getTextCharFormat(const QString &colorName, const QString &style = QString()); QList<HighlightingRule> rules; QRegExp triSingleQuote; QRegExp triDoubleQuote; }; #endif
Using a QSyntaxHighlighter for QTextEdit is a one-liner, e.g.PythonSyntaxHighlighter *pythonHighlighter = new PythonSyntaxHighlighter(ui.plainTextEditScript->document());
Is the header for this published anywhere? I'd like to try it out, but it's a little annoying trying to infer some of the types.
ReplyDeletein fact, forgot to add the header. Corrected. Sorry for the guesswork. I somehow forgot about this, because as mentioned in the end we went for a Scintilla based solution.
DeleteMuch obliged. I know there are more generic syntax highlighting options out there, but for a current project, this was basically the perfect little thing to drop in without any fuss. (Okay, I fussed over the colors for a minute to match my app's theme. But that was the only fuss.)
Delete