Initial commit

src/lineWalker.py

@@ -0,0 +1,101 @@
+import urwid
+
+class LineWalker:
+	"""ListWalker-compatible class for lazily reading file contents."""
+
+	def __init__(self, name):
+		self.file = open(name)
+		self.lines = []
+		self.focus = 0
+
+	def get_focus(self):
+		return self._get_at_pos( self.focus )
+
+	def set_focus(self, focus):
+		self.focus = focus
+
+	def get_next(self, start_from):
+		return self._get_at_pos( start_from + 1 )
+
+	def get_prev(self, start_from):
+		return self._get_at_pos( start_from - 1 )
+
+	def read_next_line(self):
+		"""Read another line from the file."""
+
+		next_line = self.file.readline()
+
+		if not next_line or next_line[-1:] != '\n':
+			# no newline on last line of file
+			self.file = None
+		else:
+			# trim newline characters
+			next_line = next_line[:-1]
+
+		expanded = next_line.expandtabs()
+
+		edit = urwid.Edit( "", expanded, allow_tab=True )
+		edit.set_edit_pos(0)
+		edit.original_text = next_line
+		self.lines.append( edit )
+
+		return next_line
+
+
+	def _get_at_pos(self, pos):
+		"""Return a widget for the line number passed."""
+
+		if pos < 0:
+			# line 0 is the start of the file, no more above
+			return None, None
+
+		if len(self.lines) > pos:
+			# we have that line so return it
+			return self.lines[pos], pos
+
+		if self.file is None:
+			# file is closed, so there are no more lines
+			return None, None
+
+		assert pos == len(self.lines), "out of order request?"
+
+		self.read_next_line()
+
+		return self.lines[-1], pos
+
+	def split_focus(self):
+		"""Divide the focus edit widget at the cursor location."""
+
+		focus = self.lines[self.focus]
+		pos = focus.edit_pos
+		edit = urwid.Edit("",focus.edit_text[pos:], allow_tab=True )
+		edit.original_text = ""
+		focus.set_edit_text( focus.edit_text[:pos] )
+		edit.set_edit_pos(0)
+		self.lines.insert( self.focus+1, edit )
+
+	def combine_focus_with_prev(self):
+		"""Combine the focus edit widget with the one above."""
+
+		above, ignore = self.get_prev(self.focus)
+		if above is None:
+			# already at the top
+			return
+
+		focus = self.lines[self.focus]
+		above.set_edit_pos(len(above.edit_text))
+		above.set_edit_text( above.edit_text + focus.edit_text )
+		del self.lines[self.focus]
+		self.focus -= 1
+
+	def combine_focus_with_next(self):
+		"""Combine the focus edit widget with the one below."""
+
+		below, ignore = self.get_next(self.focus)
+		if below is None:
+			# already at bottom
+			return
+
+		focus = self.lines[self.focus]
+		focus.set_edit_text( focus.edit_text + below.edit_text )
+		del self.lines[self.focus+1]