cola/widgets/highlighter.py

   1 from __future__ import division, absolute_import, unicode_literals
   2
   3 from PyQt4 import QtCore, QtGui
   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 def highlight_document(edit, filename):
  15     doc = edit.document()
  16
  17     if not have_pygments:
  18         return
  19
  20     try:
  21         lexer = get_lexer_for_filename(filename, stripnl=False)
  22     except ClassNotFound:
  23         return
  24
  25     style = get_style_by_name("default")
  26
  27     font = doc.defaultFont()
  28     base_format = QtGui.QTextCharFormat()
  29     base_format.setFont(font)
  30     token_formats = {}
  31
  32     window = edit.window()
  33     if hasattr(window, "processEvents"):
  34         processEvents = window.processEvents
  35     else:
  36         processEvents = QtCore.QCoreApplication.processEvents
  37
  38     def get_token_format(token):
  39         if token in token_formats:
  40             return token_formats[token]
  41
  42         if token.parent:
  43             parent_format = get_token_format(token.parent)
  44         else:
  45             parent_format = base_format
  46
  47         format = QtGui.QTextCharFormat(parent_format)
  48         font = format.font()
  49         if style.styles_token(token):
  50             tstyle = style.style_for_token(token)
  51             if tstyle['color']:
  52                 format.setForeground (QtGui.QColor("#"+tstyle['color']))
  53             if tstyle['bold']: font.setWeight(QtGui.QFont.Bold)
  54             if tstyle['italic']: font.setItalic (True)
  55             if tstyle['underline']: format.setFontUnderline(True)
  56             if tstyle['bgcolor']: format.setBackground (QtGui.QColor("#"+tstyle['bgcolor']))
  57             # No way to set this for a QTextCharFormat
  58             #if tstyle['border']: format.
  59         token_formats[token] = format
  60         return format
  61
  62     text = doc.toPlainText()
  63
  64     block_count = 0
  65     block = doc.firstBlock()
  66     assert(isinstance(block, QtGui.QTextBlock))
  67     block_pos = 0
  68     block_len = block.length()
  69     block_formats = []
  70
  71     for token, ttext in lex(text, lexer):
  72         format_len = len(ttext)
  73         format = get_token_format(token)
  74         while format_len > 0:
  75             format_range = QtGui.QTextLayout.FormatRange()
  76             format_range.start = block_pos
  77             format_range.length = min(format_len, block_len)
  78             format_range.format = format
  79             block_formats.append(format_range)
  80             block_len -= format_range.length
  81             format_len -= format_range.length
  82             block_pos += format_range.length
  83             if block_len == 0:
  84                 block.layout().setAdditionalFormats(block_formats)
  85                 doc.markContentsDirty(block.position(), block.length())
  86                 block = block.next()  # pylint: disable=next-method-called
  87                 block_pos = 0
  88                 block_len = block.length()
  89                 block_formats = []
  90
  91                 block_count += 1
  92                 if block_count % 100 == 0:
  93                     processEvents()
  94
  95
  96 if __name__ == "__main__":
  97     import sys
  98     app = QtGui.QApplication(sys.argv)
  99
 100     python = QtGui.QPlainTextEdit()
 101     f = open(__file__, 'r')
 102     python.setPlainText(f.read())
 103     f.close()
 104
 105     python.setWindowTitle('python')
 106     python.show()
 107     highlight_document(python, __file__)
 108
 109     sys.exit(app.exec_())