python - 如何在用户更改文本时更新 QSyntaxHighlighter 颜色编码

Question

我已经编写了一个小的 Python PyQt4 程序来语法高亮 QPlainTextEdit 字段中的 MySQL 源代码。以下代码用于正确地对 MySQL 文本进行颜色编码。

如果有人编辑明文字段，我如何自动更新文本颜色？感谢您提供任何帮助或建议。

import sys, time
from PyQt4 import QtCore, QtGui
import syntax

class MyApp(QtGui.QWidget):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)

        self.setGeometry(300, 300, 410, 220)
        self.setWindowTitle('MySQL Source Color Coding')

        self.layout = QtGui.QVBoxLayout(self)

        self.plaintext = QtGui.QPlainTextEdit()
        self.plaintext.setFont(QtGui.QFont ("Consolas", 9))
        self.plaintext.setLineWrapMode(QtGui.QPlainTextEdit.NoWrap)

        x = syntax.PythonHighlighter(self.plaintext.document())

        self.layout.addWidget(self.plaintext)

        mysqlcode = """\
   select dt as 'Date', 
          dayName as "Day",
          count(create_date) as 'Transaction Count'
     from calendar
left join transaction 
       on dt = date(create_date) 
    where dt <= NOW() 
      and dt >= '2015-07-21'
 group by dt
 order by dt desc;  
        """

        self.plaintext.setPlainText(mysqlcode)

if __name__ == "__main__":

    app = QtGui.QApplication(sys.argv)
    window = MyApp()
    window.show()
    app.exec_()

语法.py

import sys

from PyQt4.QtCore import QRegExp
from PyQt4.QtGui import QColor, QTextCharFormat, QFont, QSyntaxHighlighter

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


# Syntax styles that can be shared by all languages
STYLES = {
    'keyword': format('blue'),
    'operator': format('darkred'),
    'brace': format('black','bold'),
    'defclass': format('black', 'bold'),
    'string': format('darkGreen'),
    'string2': format('darkMagenta'),
    'comment': format('Grey', 'italic'),
    'self': format('black', 'italic'),
    'numbers': format('darkMagenta'),
}


class PythonHighlighter (QSyntaxHighlighter):
    """Syntax highlighter for the mysql language.
    """
    # mysql keywords
    keywords = [
        "use", "select", "as", "then", "case", "end",
        "from", "where", "group by", "order by", "desc", "asc",
        "distinct", "on", "left join", "right join", "count",
        "sum", "max", "min","distinct", "and", "in", "or",
        "date","NOW", "like",
    ]

    # Python operators
    operators = [
        "&&", "between", "binary", "&",
        "\\^", "=", ">=", ">",
        "is null", "null", "<=", "<",
        " like ", "regexp", "not", ";",",",
    ]

    # Python braces
    braces = [
        '\{', '\}', '\(', '\)', '\[', '\]',
    ]
    def __init__(self, document):
        QSyntaxHighlighter.__init__(self, document)
        print "QSyntaxHighlighter"

        # 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 = []

        # 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):
        print "highlightBlock"
        """Apply syntax highlighting to the given block of text.
        """
        # Do other syntax formatting
        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()
                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 = text.length() - 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

Answer 1

我在以下位置找到了一个很好的如何使用 QSyntaxHighlighter 的示例:

http://carsonfarmer.com/2009/07/syntax-highlighting-with-pyqt/

Carson Farmer 的 QSyntaxHighlighter 实现效果很好，并在用户修改文本字段时自动更新语法颜色编码。

'''
Python Syntax Highlighting Example
Copyright (C) 2009 Carson J. Q. Farmer
'''

import sys
from PyQt4.QtGui import *
from PyQt4.QtCore import *

class MyHighlighter( QSyntaxHighlighter ):

    def __init__( self, parent, theme ):
      QSyntaxHighlighter.__init__( self, parent )
      self.parent = parent
      keyword = QTextCharFormat()
      reservedClasses = QTextCharFormat()
      assignmentOperator = QTextCharFormat()
      delimiter = QTextCharFormat()
      specialConstant = QTextCharFormat()
      boolean = QTextCharFormat()
      number = QTextCharFormat()
      comment = QTextCharFormat()
      string = QTextCharFormat()
      singleQuotedString = QTextCharFormat()

      self.highlightingRules = []

      # keyword
      brush = QBrush( Qt.darkBlue, Qt.SolidPattern )
      keyword.setForeground( brush )
      keyword.setFontWeight( QFont.Bold )
      keywords = QStringList( [ "break", "else", "for", "if", "in",
                                "next", "repeat", "return", "switch",
                                "try", "while" ] )
      for word in keywords:
        pattern = QRegExp("\\b" + word + "\\b")
        rule = HighlightingRule( pattern, keyword )
        self.highlightingRules.append( rule )

      # reservedClasses
      reservedClasses.setForeground( brush )
      reservedClasses.setFontWeight( QFont.Bold )
      keywords = QStringList( [ "array", "character", "complex",
                                "data.frame", "double", "factor",
                                "function", "integer", "list",
                                "logical", "matrix", "numeric",
                                "vector" ] )
      for word in keywords:
        pattern = QRegExp("\\b" + word + "\\b")
        rule = HighlightingRule( pattern, reservedClasses )
        self.highlightingRules.append( rule )


      # assignmentOperator
      brush = QBrush( Qt.yellow, Qt.SolidPattern )
      pattern = QRegExp( "(<){1,2}-" )
      assignmentOperator.setForeground( brush )
      assignmentOperator.setFontWeight( QFont.Bold )
      rule = HighlightingRule( pattern, assignmentOperator )
      self.highlightingRules.append( rule )

      # delimiter
      pattern = QRegExp( "[\)\(]+|[\{\}]+|[][]+" )
      delimiter.setForeground( brush )
      delimiter.setFontWeight( QFont.Bold )
      rule = HighlightingRule( pattern, delimiter )
      self.highlightingRules.append( rule )

      # specialConstant
      brush = QBrush( Qt.green, Qt.SolidPattern )
      specialConstant.setForeground( brush )
      keywords = QStringList( [ "Inf", "NA", "NaN", "NULL" ] )
      for word in keywords:
        pattern = QRegExp("\\b" + word + "\\b")
        rule = HighlightingRule( pattern, specialConstant )
        self.highlightingRules.append( rule )

      # boolean
      boolean.setForeground( brush )
      keywords = QStringList( [ "TRUE", "FALSE" ] )
      for word in keywords:
        pattern = QRegExp("\\b" + word + "\\b")
        rule = HighlightingRule( pattern, boolean )
        self.highlightingRules.append( rule )

      # number
      pattern = QRegExp( "[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?" )
      pattern.setMinimal( True )
      number.setForeground( brush )
      rule = HighlightingRule( pattern, number )
      self.highlightingRules.append( rule )

      # comment
      brush = QBrush( Qt.blue, Qt.SolidPattern )
      pattern = QRegExp( "#[^\n]*" )
      comment.setForeground( brush )
      rule = HighlightingRule( pattern, comment )
      self.highlightingRules.append( rule )

      # string
      brush = QBrush( Qt.red, Qt.SolidPattern )
      pattern = QRegExp( "\".*\"" )
      pattern.setMinimal( True )
      string.setForeground( brush )
      rule = HighlightingRule( pattern, string )
      self.highlightingRules.append( rule )

      # singleQuotedString
      pattern = QRegExp( "\'.*\'" )
      pattern.setMinimal( True )
      singleQuotedString.setForeground( brush )
      rule = HighlightingRule( pattern, singleQuotedString )
      self.highlightingRules.append( rule )

    def highlightBlock( self, text ):
      for rule in self.highlightingRules:
        expression = QRegExp( rule.pattern )
        index = expression.indexIn( text )
        while index >= 0:
          length = expression.matchedLength()
          self.setFormat( index, length, rule.format )
          index = text.indexOf( expression, index + length )
      self.setCurrentBlockState( 0 )

class HighlightingRule():
  def __init__( self, pattern, format ):
    self.pattern = pattern
    self.format = format

class TestApp( QMainWindow ):
  def __init__(self):
    QMainWindow.__init__(self)
    font = QFont()
    font.setFamily( "Courier" )
    font.setFixedPitch( True )
    font.setPointSize( 10 )
    editor = QTextEdit()
    editor.setFont( font )
    highlighter = MyHighlighter( editor, "Classic" )
    self.setCentralWidget( editor )
    self.setWindowTitle( "Syntax Highlighter" )


if __name__ == "__main__":
  app = QApplication( sys.argv )
  window = TestApp()
  window.show()
  sys.exit( app.exec_() )