cola/widgets/highlighter.py

   1 from qtpy import QtCore
   2 from qtpy import QtGui
   3 from qtpy import QtWidgets
   4
   5 have_pygments = True
   6 try:
   7     from pygments.styles import get_style_by_name
   8     from pygments import lex
   9     from pygments.util import ClassNotFound
  10     from pygments.lexers import get_lexer_for_filename
  11 except ImportError:
  12     have_pygments = False
  13
  14
  15 def highlight_document(edit, filename):
  16     if not have_pygments:
  17         return
  18     doc = edit.document()
  19     try:
  20         lexer = get_lexer_for_filename(filename, stripnl=False)
  21     except ClassNotFound:
  22         return
  23
  24     style = get_style_by_name('default')
  25
  26     font = doc.defaultFont()
  27     base_format = QtGui.QTextCharFormat()
  28     base_format.setFont(font)
  29     token_formats = {}
  30
  31     window = edit.window()
  32     if hasattr(window, 'processEvents'):
  33         processEvents = window.processEvents
  34     else:
  35         processEvents = QtCore.QCoreApplication.processEvents
  36
  37     def get_token_format(token):
  38         if token in token_formats:
  39             return token_formats[token]
  40
  41         if token.parent:
  42             parent_format = get_token_format(token.parent)
  43         else:
  44             parent_format = base_format
  45
  46         fmt = QtGui.QTextCharFormat(parent_format)
  47         font = fmt.font()
  48         if style.styles_token(token):
  49             tstyle = style.style_for_token(token)
  50             if tstyle['color']:
  51                 fmt.setForeground(QtGui.QColor('#' + tstyle['color']))
  52             if tstyle['bold']:
  53                 font.setWeight(QtGui.QFont.Bold)
  54             if tstyle['italic']:
  55                 font.setItalic(True)
  56             if tstyle['underline']:
  57                 fmt.setFontUnderline(True)
  58             if tstyle['bgcolor']:
  59                 fmt.setBackground(QtGui.QColor('#' + tstyle['bgcolor']))
  60         token_formats[token] = fmt
  61         return fmt
  62
  63     text = doc.toPlainText()
  64
  65     block_count = 0
  66     block = doc.firstBlock()
  67     assert isinstance(block, QtGui.QTextBlock)
  68     block_pos = 0
  69     block_len = block.length()
  70     block_formats = []
  71
  72     for token, ttext in lex(text, lexer):
  73         format_len = len(ttext)
  74         fmt = get_token_format(token)
  75         while format_len > 0:
  76             format_range = QtGui.QTextLayout.FormatRange()
  77             format_range.start = block_pos
  78             format_range.length = min(format_len, block_len)
  79             format_range.format = fmt
  80             block_formats.append(format_range)
  81             block_len -= format_range.length
  82             format_len -= format_range.length
  83             block_pos += format_range.length
  84             if block_len == 0:
  85                 block.layout().setAdditionalFormats(block_formats)
  86                 doc.markContentsDirty(block.position(), block.length())
  87                 block = block.next()
  88                 block_pos = 0
  89                 block_len = block.length()
  90                 block_formats = []
  91
  92                 block_count += 1
  93                 if block_count % 100 == 0:
  94                     processEvents()
  95
  96
  97 if __name__ == '__main__':
  98     app = QtWidgets.QApplication([])
  99
 100     python = QtWidgets.QPlainTextEdit()
 101     with open(__file__, encoding='utf-8') as f:
 102         python.setPlainText(f.read())
 103
 104     python.setWindowTitle('python')
 105     python.show()
 106     highlight_document(python, __file__)
 107
 108     app.exec_()