syntax.py

Go to the documentation of this file.

# syntax.py

import sys

from python_qt_binding.QtCore import QRegExp, Qt
from python_qt_binding.QtGui import QColor, QTextCharFormat, QFont, QSyntaxHighlighter

def format(color, style=''):
        """Return a QTextCharFormat with the given attributes.
        """
        _color = QColor()
        if type(color) == QColor:
                _color = color
        else:
                _color.setNamedColor(color)

        _format = QTextCharFormat()
        _format.setForeground(_color)
        if 'bold' in style:
                _format.setFontWeight(QFont.Bold)
        if 'italic' in style:
                _format.setFontItalic(True)

        return _format

reformat = format


# Syntax styles that can be shared by all languages
BRIGHT_STYLES = {
        'defaults': format('black'),
        'keyword': format('blue'),
        'operator': format('red'),
        'brace': format('black'),
        'defclass': format('black', 'bold'),
        'string': format('darkmagenta'),
        'string2': format('green'),
        'comment': format('darkGray', 'italic'),
        'self': format('black', 'italic'),
        'numbers': format('brown'),
}

DARK_STYLES = {
        'defaults': format('white'),
        'keyword': format('lightBlue', 'bold'),
        'operator': format('orange'),
        'brace': format('white'),
        'defclass': format('lightGreen', 'bold'),
        'string': format('darkmagenta'),
        'string2': format('green'),
        'comment': format('darkGray', 'italic'),
        'self': format('white', 'italic'),
        'numbers': format('brown'),
}


class PythonHighlighter (QSyntaxHighlighter):
        """Syntax highlighter for the Python language.
        """

        # defaults
        defaults = [
                ':', '\.'
        ]

        # Python keywords
        keywords = [
                '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', 'str', 'as'
        ]

        # Python operators
        operators = [
                '=',
                # Comparison
                '==', '!=', '<', '<=', '>', '>=',
                # Arithmetic
                '\+', '-', '\*', '/', '//', '\%', '\*\*',
                # In-place
                '\+=', '-=', '\*=', '/=', '\%=',
                # Bitwise
                '\^', '\|', '\&', '\~', '>>', '<<',
        ]

        # Python braces
        braces = [
                '\{', '\}', '\(', '\)', '\[', '\]',
        ]
        def __init__(self, document, is_dark = False, default = None):
                QSyntaxHighlighter.__init__(self, document)

                def contents_changed():
                        self.highlightBlock("document.toPlainText()")

                document.contentsChanged.connect(contents_changed)

                self.is_dark = is_dark
                self.default = default

                global reformat

                if is_dark:
                        STYLES = DARK_STYLES
                else:
                        STYLES = BRIGHT_STYLES

                if default != None:
                        STYLES['defaults'] = reformat(*default)

                # Multi-line strings (expression, flag, style)
                # FIXME: The triple-quotes in these two lines will mess up the
                # syntax highlighting from this point onward
                self.tri_single = (QRegExp("'''"), 1, STYLES['string2'])
                self.tri_double = (QRegExp('"""'), 2, STYLES['string2'])

                rules = []

                rules += [(r'%s' % w, 0, STYLES['defaults'])
                        for w in PythonHighlighter.defaults]                                            
                # Keyword, operator, and brace rules
                rules += [(r'\b%s\b' % w, 0, STYLES['keyword'])
                        for w in PythonHighlighter.keywords]
                rules += [(r'%s' % o, 0, STYLES['operator'])
                        for o in PythonHighlighter.operators]
                rules += [(r'%s' % b, 0, STYLES['brace'])
                        for b in PythonHighlighter.braces]

                # All other rules
                rules += [
                        # 'self'
                        (r'\bself\b', 0, STYLES['self']),

                        # Double-quoted string, possibly containing escape sequences
                        (r'"[^"\\]*(\\.[^"\\]*)*"', 0, STYLES['string']),
                        # Single-quoted string, possibly containing escape sequences
                        (r"'[^'\\]*(\\.[^'\\]*)*'", 0, STYLES['string']),

                        # 'def' followed by an identifier
                        (r'\bdef\b\s*(\w+)', 1, STYLES['defclass']),
                        # 'class' followed by an identifier
                        (r'\bclass\b\s*(\w+)', 1, STYLES['defclass']),

                        # From '#' until a newline
                        (r'#[^\n]*', 0, STYLES['comment']),

                        # Numeric literals
                        (r'\b[+-]?[0-9]+[lL]?\b', 0, STYLES['numbers']),
                        (r'\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\b', 0, STYLES['numbers']),
                        (r'\b[+-]?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\b', 0, STYLES['numbers']),
                ]

                # Build a QRegExp for each pattern
                self.rules = [(QRegExp(pat), index, fmt)
                        for (pat, index, fmt) in rules]



        def highlightBlock(self, text):
                """Apply syntax highlighting to the given block of text.
                """
                # print "&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&7"

                global reformat
                
                if self.is_dark:
                        STYLES = DARK_STYLES
                else:
                        STYLES = BRIGHT_STYLES

                if self.default != None:
                        STYLES['defaults'] = reformat(*self.default)

                # Do other syntax formatting
                self.setFormat( 0, len(text), STYLES['defaults'])


                for expression, nth, format in self.rules:
                        index = expression.indexIn(text, 0)

                        while index >= 0:
                                # We actually want the index of the nth match
                                index = expression.pos(nth)
                                # length = expression.cap(nth).length()
                                length = len(expression.cap(nth))
                                self.setFormat(index, length, format)
                                index = expression.indexIn(text, index + length)

                self.setCurrentBlockState(0)

                # Do multi-line strings
                in_multiline = self.match_multiline(text, *self.tri_single)
                if not in_multiline:
                        in_multiline = self.match_multiline(text, *self.tri_double)


        def match_multiline(self, text, delimiter, in_state, style):
                """Do highlighting of multi-line strings. ``delimiter`` should be a
                ``QRegExp`` for triple-single-quotes or triple-double-quotes, and
                ``in_state`` should be a unique integer to represent the corresponding
                state changes when inside those strings. Returns True if we're still
                inside a multi-line string when this function is finished.
                """
                # If inside triple-single quotes, start at 0
                if self.previousBlockState() == in_state:
                        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()
                                self.setCurrentBlockState(0)
                        # No; multi-line string
                        else:
                                self.setCurrentBlockState(in_state)
                                length = len(text) - start + add
                        # Apply formatting
                        self.setFormat(start, length, style)
                        # Look for the next match
                        start = delimiter.indexIn(text, start + length)

                # Return True if still inside a multi-line string, False otherwise
                if self.currentBlockState() == in_state:
                        return True
                else:
                        return False