#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2009 Florian Heinle
# Copyright (C) 2010 Doug Blank <doug.blank@gmail.com>
# Copyright (C) 2010 Benny Malengier
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
"""
gtk textbuffer with undo functionality
"""
from __future__ import print_function
__all__ = ["UndoableBuffer"]
# Originally LGLP from:
# http://bitbucket.org/tiax/gtk-textbuffer-with-undo/
# Please send bugfixes and comments upstream to Florian
from gi.repository import GObject
from gi.repository import Gtk
from gramps.gen.constfunc import cuni
[docs]class Stack(list):
"""
Very simple stack implementation that cannot grow beyond an at init
determined size.
Inherits from list.
Only append checks if this is really the case!
"""
def __init__(self, stack_size=None):
super(Stack, self).__init__()
self.stack_size = stack_size
[docs] def append(self, item):
if self.stack_size and len(self) == self.stack_size:
self.pop(0)
return super(Stack, self).append(item)
[docs]class UndoableInsert(object):
"""something that has been inserted into our textbuffer"""
def __init__(self, text_iter, text, length, text_buffer):
self.offset = text_iter.get_offset()
self.text = str(text)
#unicode char can have length > 1 as it points in the buffer
charlength = len(cuni(text))
self.length = charlength
if charlength > 1 or self.text in ("\r", "\n", " "):
self.mergeable = False
else:
self.mergeable = True
self.tags = None
[docs]class UndoableDelete(object):
"""something that has been deleted from our textbuffer"""
def __init__(self, text_buffer, start_iter, end_iter):
self.text = str(text_buffer.get_text(start_iter, end_iter, True))
self.start = start_iter.get_offset()
self.end = end_iter.get_offset()
# need to find out if backspace or delete key has been used
# so we don't mess up during redo
insert_iter = text_buffer.get_iter_at_mark(text_buffer.get_insert())
if insert_iter.get_offset() <= self.start:
self.delete_key_used = True
else:
self.delete_key_used = False
if self.end - self.start > 1 or self.text in ("\r", "\n", " "):
self.mergeable = False
else:
self.mergeable = True
self.tags = None
[docs]class UndoableBuffer(Gtk.TextBuffer):
"""text buffer with added undo capabilities
designed as a drop-in replacement for gtksourceview,
at least as far as undo is concerned"""
insertclass = UndoableInsert
deleteclass = UndoableDelete
#how many undo's are remembered
undo_stack_size = 700
def __init__(self):
"""
we'll need empty stacks for undo/redo and some state keeping
"""
GObject.GObject.__init__(self)
self.undo_stack = Stack(self.undo_stack_size)
self.redo_stack = []
self.not_undoable_action = False
self.undo_in_progress = False
self.connect('insert-text', self.on_insert_text_undoable)
self.connect('delete-range', self.on_delete_range_undoable)
@property
[docs] def can_undo(self):
return bool(self.undo_stack)
@property
[docs] def can_redo(self):
return bool(self.redo_stack)
def _empty_redo_stack(self):
self.redo_stack = []
[docs] def on_insert_text_undoable(self, textbuffer, text_iter, text, length):
def can_be_merged(prev, cur):
"""
see if we can merge multiple inserts here
will try to merge words or whitespace
can't merge if prev and cur are not mergeable in the first place
can't merge when user set the input bar somewhere else
can't merge across word boundaries
"""
WHITESPACE = (' ', '\t')
if not cur.mergeable or not prev.mergeable:
return False
elif cur.offset != (prev.offset + prev.length):
return False
elif cur.text in WHITESPACE and not prev.text in WHITESPACE:
return False
elif prev.text in WHITESPACE and not cur.text in WHITESPACE:
return False
return True
if not self.undo_in_progress:
self._empty_redo_stack()
if self.not_undoable_action:
return
undo_action = self.insertclass(text_iter, text, length, textbuffer)
try:
prev_insert = self.undo_stack.pop()
except IndexError:
self.undo_stack.append(undo_action)
return
if not isinstance(prev_insert, self.insertclass):
self.undo_stack.append(prev_insert)
self.undo_stack.append(undo_action)
return
if can_be_merged(prev_insert, undo_action):
prev_insert.length += undo_action.length
prev_insert.text += undo_action.text
self.undo_stack.append(prev_insert)
else:
self.undo_stack.append(prev_insert)
self.undo_stack.append(undo_action)
[docs] def on_delete_range_undoable(self, text_buffer, start_iter, end_iter):
def can_be_merged(prev, cur):
"""
see if we can merge multiple deletions here
will try to merge words or whitespace
can't merge if prev and cur are not mergeable in the first place
can't merge if delete and backspace key were both used
can't merge across word boundaries
"""
WHITESPACE = (' ', '\t')
if not cur.mergeable or not prev.mergeable:
return False
elif prev.delete_key_used != cur.delete_key_used:
return False
elif prev.start != cur.start and prev.start != cur.end:
return False
elif cur.text not in WHITESPACE and \
prev.text in WHITESPACE:
return False
elif cur.text in WHITESPACE and \
prev.text not in WHITESPACE:
return False
return True
if not self.undo_in_progress:
self._empty_redo_stack()
if self.not_undoable_action:
return
undo_action = self.deleteclass(text_buffer, start_iter, end_iter)
try:
prev_delete = self.undo_stack.pop()
except IndexError:
self.undo_stack.append(undo_action)
return
if not isinstance(prev_delete, self.deleteclass):
self.undo_stack.append(prev_delete)
self.undo_stack.append(undo_action)
return
if can_be_merged(prev_delete, undo_action):
if prev_delete.start == undo_action.start: # delete key used
prev_delete.text += undo_action.text
prev_delete.end += (undo_action.end - undo_action.start)
else: # Backspace used
prev_delete.text = "%s%s" % (undo_action.text,
prev_delete.text)
prev_delete.start = undo_action.start
self.undo_stack.append(prev_delete)
else:
self.undo_stack.append(prev_delete)
self.undo_stack.append(undo_action)
[docs] def begin_not_undoable_action(self):
"""don't record the next actions
toggles self.not_undoable_action"""
self.not_undoable_action = True
[docs] def end_not_undoable_action(self):
"""record next actions
toggles self.not_undoable_action"""
self.not_undoable_action = False
[docs] def reset(self):
"""
Resets buffer to initial state.
"""
self.undo_stack = Stack(self.undo_stack_size)
self.redo_stack[:] = []
self.not_undoable_action = False
self.undo_in_progress = False
[docs] def undo(self):
"""undo inserts or deletions
undone actions are being moved to redo stack"""
if not self.undo_stack:
return
self.begin_not_undoable_action()
self.undo_in_progress = True
undo_action = self.undo_stack.pop()
self.redo_stack.append(undo_action)
if isinstance(undo_action, self.insertclass):
self._undo_insert(undo_action)
elif isinstance(undo_action, self.deleteclass):
self._undo_delete(undo_action)
else:
self._handle_undo(undo_action)
self.end_not_undoable_action()
self.undo_in_progress = False
def _undo_insert(self, undo_action):
start = self.get_iter_at_offset(undo_action.offset)
stop = self.get_iter_at_offset(
undo_action.offset + undo_action.length
)
self.delete(start, stop)
self.place_cursor(self.get_iter_at_offset(undo_action.offset))
def _undo_delete(self, undo_action):
start = self.get_iter_at_offset(undo_action.start)
self.insert(start, undo_action.text)
if undo_action.delete_key_used:
self.place_cursor(self.get_iter_at_offset(undo_action.start))
else:
self.place_cursor(self.get_iter_at_offset(undo_action.end))
def _handle_undo(self, undo_action):
raise NotImplementedError
[docs] def redo(self):
"""redo inserts or deletions
redone actions are moved to undo stack"""
if not self.redo_stack:
return
self.begin_not_undoable_action()
self.undo_in_progress = True
redo_action = self.redo_stack.pop()
self.undo_stack.append(redo_action)
if isinstance(redo_action, self.insertclass):
self._redo_insert(redo_action)
elif isinstance(redo_action, self.deleteclass):
self._redo_delete(redo_action)
else:
self._handle_redo(redo_action)
self.end_not_undoable_action()
self.undo_in_progress = False
def _redo_insert(self, redo_action):
start = self.get_iter_at_offset(redo_action.offset)
self.insert(start, redo_action.text)
new_cursor_pos = self.get_iter_at_offset(
redo_action.offset + redo_action.length
)
self.place_cursor(new_cursor_pos)
def _redo_delete(self, redo_action):
start = self.get_iter_at_offset(redo_action.start)
stop = self.get_iter_at_offset(redo_action.end)
self.delete(start, stop)
self.place_cursor(self.get_iter_at_offset(redo_action.start))
def _handle_redo(self, redo_action):
raise NotImplementedError
## for test, run script as
## PYTHONPATH=$PYTHONPATH:~/gramps/trunk/src/ python gui/widgets/undoablebuffer.py
if __name__ == '__main__':
test = Stack(5)
if test:
print('WRONG: test is empty')
else:
print('CORRECT: test is empty')
test.append(0);test.append(1);test.append(2);test.append(3);test.append(4);
print('5 inserts', test)
test.append(5);test.append(6);test.append(7);test.append(8);test.append(9);
print('5 more inserts', test)
print('last element', test[-1])