buffer.py

   1 import rox
   2 from rox import g
   3
   4 # GtkSourceBuffer is a subclass of GtkTextBuffer which provides extra
   5 # features. We'll use it if it's available, or GtkTextBuffer if not.
   6 try:
   7         import gtksourceview
   8         _parentClass = gtksourceview.SourceBuffer
   9         have_sourceview = True
  10 except:
  11         _parentClass = g.TextBuffer
  12         have_sourceview = False
  13
  14
  15 DELETE = 1
  16 INSERT = 2
  17
  18 # As operations are performed, they are added to 'in_progress'.
  19 # When complete, the whole group is added to undo_buffer.
  20
  21 class Buffer(_parentClass):
  22         "A buffer that deals with undo/redo."
  23
  24         action_nest_level = 0
  25
  26         def __init__(self):
  27                 if have_sourceview:
  28                         _parentClass.__init__(self)
  29                         self.set_max_undo_levels(1000)
  30                 else:
  31                         _parentClass.__init__(self, None)
  32
  33                 self.in_progress = None
  34                 self.undo_buffer = []
  35                 self.redo_buffer = []   # Will be None during undo or redo
  36
  37                 if have_sourceview:
  38                         self.lm = gtksourceview.SourceLanguagesManager()
  39                         self.set_data('languages-manager', self.lm)
  40
  41         def set_type(self, mime_type):
  42                 """Set up syntax highlighting, if available"""
  43                 self.language = None
  44                 if not have_sourceview: return
  45                 if not mime_type: return
  46
  47                 language = self.lm.get_language_from_mime_type(mime_type.media + '/' + mime_type.subtype)
  48                 if language:
  49                         self.set_highlight(True)
  50                         self.set_language(language)
  51                         self.language = language.get_name()
  52                 else:
  53                         #print 'No language found for mime type "%s"' % mime_type
  54                         self.set_highlight(False)
  55
  56         def start_undo_history(self):
  57                 if have_sourceview: return
  58                 def begin(buffer):
  59                         self.action_nest_level += 1
  60                         if self.action_nest_level == 1:
  61                                 assert self.in_progress is None
  62                                 self.in_progress = []
  63
  64                 self.connect('begin-user-action', begin)
  65                 def end_action(buffer):
  66                         self.action_nest_level -= 1
  67                         assert self.action_nest_level >= 0
  68                         if self.action_nest_level == 0:
  69                                 assert self.in_progress is not None
  70                                 if self.in_progress:
  71                                         self.undo_buffer.append(self.in_progress)
  72                                 self.in_progress = None
  73                 self.connect('end-user-action', end_action)
  74                 self.connect('delete-range', self.delete_range)
  75                 self.connect('insert-text', self.insert_text)
  76
  77         def delete_range(self, buffer, start, end):
  78                 self.in_progress.append((INSERT,
  79                                  start.get_offset(),
  80                                  buffer.get_slice(start, end, True)))
  81                 if self.redo_buffer:
  82                         self.redo_buffer = []
  83
  84         def insert_text(self, buffer, where, text, len):
  85                 text = text[:len]       # PyGtk bug?
  86                 start = where.get_offset()
  87                 self.in_progress.append((DELETE,
  88                                         start, start + len, text))
  89                 if self.redo_buffer:
  90                         self.redo_buffer = []
  91
  92         try:
  93                 g.TextBuffer(None).insert_at_cursor('hello')
  94         except:
  95                 # Old version of pygtk
  96                 def insert(self, iter, text):
  97                         g.TextBuffer.insert(self, iter, text, -1)
  98                 def insert_at_cursor(self, text):
  99                         g.TextBuffer.insert_at_cursor(self, text, -1)
 100
 101         def do_action(self, op):
 102                 if op[0] == DELETE:
 103                         start = self.get_iter_at_offset(op[1])
 104                         end = self.get_iter_at_offset(op[2])
 105                         self.delete(start, end)
 106                 elif op[0] == INSERT:
 107                         start = self.get_iter_at_offset(op[1])
 108                         self.insert(start, op[2])
 109                 else:
 110                         rox.alert('Unknown entry in undo buffer!\n' + `op`)
 111
 112         def undo(self, hist = None):
 113                 if have_sourceview:
 114                         if self.can_undo():
 115                                 _parentClass.undo(self)
 116                         return
 117
 118                 if hist is None: hist = self.undo_buffer
 119
 120                 if not hist:
 121                         g.gdk.beep()
 122                         return  # Nothing to undo/redo
 123
 124                 assert not self.in_progress
 125
 126                 # List of actions to perform
 127                 group = hist.pop()
 128
 129                 old_redo, self.redo_buffer = self.redo_buffer, None
 130
 131                 try:
 132                         self.begin_user_action()
 133                         group.reverse()
 134                         for action in group:
 135                                 self.do_action(action)
 136                 finally:
 137                         self.redo_buffer = old_redo
 138                         if hist is self.undo_buffer:
 139                                 self.redo_buffer.append(self.in_progress)
 140                         else:
 141                                 self.undo_buffer.append(self.in_progress)
 142                         self.in_progress = []
 143
 144                         self.end_user_action()
 145
 146         def redo(self):
 147                 if have_sourceview:
 148                         _parentClass.redo(self)
 149                 else:
 150                         self.undo(hist = self.redo_buffer)
 151
 152
 153         def begin_not_undoable_action(self):
 154                 if have_sourceview:
 155                         _parentClass.begin_not_undoable_action(self)
 156
 157         def end_not_undoable_action(self):
 158                 if have_sourceview:
 159                         _parentClass.end_not_undoable_action(self)
 160
 161