sort of for real

--HG--
branch : pmacs2

application.py

@@ -87,7 +87,7 @@ class Application(object):
 #            'nasm':        mode_nasm.Nasm,
             'perl':        mode_perl.Perl,
             'python':      mode_python.Python,
-#            'replace':     mode_replace.Replace,
+            'replace':     mode_replace.Replace,
             'search':      mode_search.Search,
 #            'sh':          mode_sh.Sh,
 #            'text':        mode_text.Text,
@@ -211,7 +211,7 @@ class Application(object):
         assert n >= 0 and n < len(self.bufferlist.slots), \
             "invalid slot: %r (%r)" % (n, len(self.bufferlist.slots))
         self.bufferlist.remove_slot(n)
-        if self.active_slot > slotname:
+        if self.active_slot > n:
             self.active_slot = max(0, self.active_slot - 1) #XYZ
     def single_slot(self):
         while len(self.bufferlist.slots) > 1:

bufferlist.py

@@ -67,16 +67,13 @@ class BufferList:
 
     # manipulate slots
     def add_slot(self):
-        assert len(self.slots) == 0, "fuck"
         self.slots.append(Slot(self.height, self.width, 0))
         self.fit_slots()
         return len(self.slots) - 1
     def empty_slot(self, i):
-        assert len(self.slots) == 0, "fuck"
         assert i > -1 and i < len(self.slots), "slot %d does not exist" % i
         return self.slots[i].is_empty()
     def unset_slot(self, i):
-        assert len(self.slots) == 1, "fuck"
         assert i > -1 and i < len(self.slots), "slot %d does not exist" % i
         old_w = self.slots[i].unset()
         if old_w is not None:
@@ -87,7 +84,6 @@ class BufferList:
                 old_b.remove_window(old_w)
 
     def set_slot(self, i, b):
-        assert len(self.slots) == 1, "fuck"
         assert i > -1 and i < len(self.slots), "slot %d does not exist" % i
         assert b in self.buffers, "buffer %s does not exist" % (b.name())
         slot = self.slots[i]
@@ -103,7 +99,6 @@ class BufferList:
         slot.set(w)
 
     def remove_slot(self, i):
-        assert False, "fuck"
         assert i > -1 and i < len(self.slots), "slot %d does not exist" % i
         self.unset_slot(i)
         del self.slots[i]

highlight2.py

@@ -160,7 +160,6 @@ class Highlighter:
     def update_del(self, lines, y1, x1, y2, x2):
         assert y1 >= 0
         assert y1 <= y2
-        assert y2 < len(lines)
 
         # first let's delete any token who falls in the range of the change (or,
         # in the case of child tokens, whose parent is being deleted).

method.py

@@ -2,6 +2,8 @@ import os, commands, popen2, re
 import buffer2, default, regex, util, window2
 from point2 import Point
 
+WHITESPACE = [' ', '\n']
+
 DATATYPES = {
     "path":         None,
     "buffer":       None,
@@ -220,7 +222,7 @@ class OpenAesFile(Method):
         if not w.application.has_buffer_name(path):
             b = buffer2.AesBuffer(path, password)
             b.open()
-            window.Window(b, a, height=0, width=0)
+            window2.Window(b, a, height=0, width=0)
             w.application.add_buffer(b)
         SwitchBuffer().execute(w, buffername=path)
 class SwitchBuffer(Method):
@@ -261,6 +263,10 @@ class KillBuffer(Method):
         b.close()
 class ForceKillBuffer(KillBuffer):
     force=True
+    def _args(self):
+        return [Argument('buffername', datatype="buffer",
+                         prompt="Force Kill Buffer: ",
+                         default=default.current_buffer)]
 class ListBuffers(Method):
     '''List all open buffers in a new buffer'''
     def _execute(self, w, **vargs):
@@ -284,8 +290,11 @@ class SaveBufferAs(Method):
             w.application.set_error("buffer for %r is already open" % path)
             return
         w.application.file_buffer(path, data, switch_to=True)
+        if curr_buffer_name != '*Scratch*':
             w.application.methods['kill-buffer'].execute(w, buffername=curr_buffer_name)
-        #w.application.set_error('Wrote %r' % path)
+        else:
+            curr_buffer.set_data('')
+        w.application.set_error('Wrote %r' % path)
 class SaveBuffer(Method):
     '''Save the contents of a buffer'''    
     def _execute(self, w, **vargs):
@@ -421,30 +430,28 @@ class DeleteRightWord(Method):
 class DeleteLeftWhitespace(Method):
     '''Delete all contiguous of whitespace left of the cursor'''
     def _execute(self, w, **vargs):
-        cursor = w.logical_cursor()
+        c = w.logical_cursor()
-        cursor_offset = w.get_cursor_offset()
+        p = c
-        left_offset = cursor_offset - 1
+        l = w.point_left(p)
-        s = w.buffer.make_string()
+        if l is None:
-        while left_offset >= 0 and (s[left_offset] == ' ' or
+            return
-                                    s[left_offset] == '\n'):
+        while l is not None and w.point_char(l) in WHITESPACE:
-            left_offset -= 1
+            p = l
-        left_offset += 1
+            l = w.point_left(p)
-        if left_offset < cursor_offset - 1:
+        if p < c:
-            left_point = w.buffer.get_offset_point(left_offset)
+            w.kill(p, c)
-            w.kill(left_point, cursor)
 class DeleteRightWhitespace(Method):
     '''Delete all contiguous of whitespace under and right of the cursor'''
     def _execute(self, w, **vargs):
-        cursor = w.logical_cursor()
+        c = w.logical_cursor()
-        cursor_offset = w.get_cursor_offset()
+        p = c
-        right_offset = cursor_offset
+        while w.point_char(p) in WHITESPACE:
-        s = w.buffer.make_string()
+            r = w.point_right(p)
-        while right_offset < len(s) and (s[right_offset] == ' ' or
+            if r is None:
-                                         s[right_offset] == '\n'):
+                break
-            right_offset += 1
+            p = r
-        if right_offset > cursor_offset:
+        if p > c:
-            right_point = w.buffer.get_offset_point(right_offset)
+            w.kill(c, p)
-            w.kill(cursor, right_point)
 
 # random stuff
 class DumpTokens(Method):
@@ -487,77 +494,78 @@ class ToggleMargins(Method):
         a.margins_visible = not a.margins_visible
 class CenterView(Method):
     '''Move view to center on cursor'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.center_view()
+        w.center_view()
 class SetMark(Method):
     '''Set the mark to the current cursor location'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.set_mark()
+        w.set_mark()
 class SwitchMark(Method):
     '''Switch the mark and the cursor locations'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.switch_mark()
+        w.switch_mark()
 
 # insertion methods
 class InsertNewline(Method):
     '''Insert newline into buffer at the cursor'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.insert_string_at_cursor('\n')
+        w.insert_string_at_cursor('\n')
 class InsertSpace(Method):
     '''Insert space into buffer at the cursor'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.insert_string_at_cursor(' ')
+        w.insert_string_at_cursor(' ')
 class InsertTab(Method):
     '''Insert tab into buffer, or tabbify line, depending on mode'''
-    def _execute(self, window, **vargs):
+    #XYZ
-        cursor = window.logical_cursor()
+    def _execute(self, w, **vargs):
-        #i = window.mode.get_indentation_level(cursor.y)
+        cursor = w.logical_cursor()
+        #i = w.mode.get_indentation_level(cursor.y)
         i = None
         if i is None:
-            window.insert_string_at_cursor('    ')
+            w.insert_string_at_cursor('    ')
         else:
-            j = window.buffer.count_leading_whitespace(cursor.y)
+            j = w.buffer.count_leading_whitespace(cursor.y)
             if i != j:
-                KillWhitespace().execute(window)
+                KillWhitespace().execute(w)
-                window.insert(Point(0, cursor.y), ' ' * i)
+                w.insert(Point(0, cursor.y), ' ' * i)
             else:
-                window.goto(Point(j, cursor.y))
+                w.goto(Point(j, cursor.y))
 class KillWhitespace(Method):
     '''Delete leading whitespace on current line'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        cursor = window.logical_cursor()
+        cursor = w.logical_cursor()
-        i = window.buffer.count_leading_whitespace(cursor.y)
+        i = w.buffer.count_leading_whitespace(cursor.y)
         if i > 0:
-            window.kill(Point(0, cursor.y),
+            w.kill(Point(0, cursor.y),
                         Point(i, cursor.y))
 
 # tabification
 class TabBuffer(Method):
     '''Tabbify every line in the current buffer'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        y = window.logical_cursor().y
+        y = w.logical_cursor().y
         it = InsertTab()
-        for i in range(0, len(window.buffer.lines)):
+        for i in range(0, len(w.buffer.lines)):
-            window.goto_line(i)
+            w.goto_line(i)
-            it.execute(window)
+            it.execute(w)
-        window.goto_line(y)
+        w.goto_line(y)
 
 # commenting
 class CommentRegion(Method):
     '''Prepend a comment to every line in the current buffer'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        cursor = window.logical_cursor()
+        cursor = w.logical_cursor()
-        if cursor < window.mark:
+        if cursor < w.mark:
             p1 = cursor
-            p2 = window.mark
+            p2 = w.mark
-        elif window.mark < cursor:
+        elif w.mark < cursor:
-            p1 = window.mark
+            p1 = w.mark
             p2 = cursor
         else:
-            window.input_line = "Empty kill region"
+            w.input_line = "Empty kill region"
             return
         for y in range(p1.y, p2.y):
-            window.buffer.insert_string_at_cursor(Point(0, y), "#")
+            w.buffer.insert_string_at_cursor(Point(0, y), "#")
 class UncommentRegion(Method):
     '''Remove a comment from every line in the current buffer'''
     def _execute(self, w, **vargs):
@@ -579,33 +587,33 @@ class UncommentRegion(Method):
 class WrapLine(Method):
     '''Wrap the current line at 80 characters by word'''
     limit = 80
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        cursor = window.logical_cursor()
+        cursor = w.logical_cursor()
         old_cursor = cursor.copy()
         i = cursor.y
         move_old_cursor = old_cursor.x > self.limit
 
-        while len(window.buffer.lines[i]) > self.limit:
+        while len(w.buffer.lines[i]) > self.limit:
-            if ' ' in window.buffer.lines[i][:self.limit]:
+            if ' ' in w.buffer.lines[i][:self.limit]:
-                j = window.buffer.lines[i][:self.limit].rindex(' ')
+                j = w.buffer.lines[i][:self.limit].rindex(' ')
-            elif ' ' in window.buffer.lines[i][self.limit:]:
+            elif ' ' in w.buffer.lines[i][self.limit:]:
-                j = window.buffer.lines[i][self.limit:].index(' ')
+                j = w.buffer.lines[i][self.limit:].index(' ')
             else:
                 break
             if move_old_cursor:
                 move_old_cursor = False
                 old_cursor.x -= j + 1
                 old_cursor.y += 1
-            window.goto(Point(j, i))
+            w.goto(Point(j, i))
-            window.right_delete()
+            w.right_delete()
-            window.insert_string_at_cursor('\n')
+            w.insert_string_at_cursor('\n')
             i += 1
 
-        l = len(window.buffer.lines[old_cursor.y])
+        l = len(w.buffer.lines[old_cursor.y])
         if l > old_cursor.x:
-            window.goto(old_cursor)
+            w.goto(old_cursor)
         else:
-            window.goto(Point(l, old_cursor.y))
+            w.goto(Point(l, old_cursor.y))
 class WrapParagraph(Method):
     limit = 80
     wrapper = WrapLine
@@ -624,11 +632,11 @@ class WrapParagraph(Method):
 
 class JustifyRight(Method):
     '''Justify text with the previous line right from the cursor by whitespace'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        DeleteLeftWhitespace().execute(window)
+        DeleteLeftWhitespace().execute(w)
-        cursor = window.logical_cursor()
+        cursor = w.logical_cursor()
-        prev_line = window.buffer.lines[cursor.y-1]
+        prev_line = w.buffer.lines[cursor.y-1]
-        this_line = window.buffer.lines[cursor.y]
+        this_line = w.buffer.lines[cursor.y]
         if cursor.y <= 0:
             return
         if cursor.x >= len(prev_line):
@@ -643,14 +651,14 @@ class JustifyRight(Method):
             if i >= len(prev_line):
                 return
         s = ' ' * (i - cursor.x)
-        window.insert_string_at_cursor(s)
+        w.insert_string_at_cursor(s)
 class JustifyLeft(Method):
     '''Justify text with the previous line left from the cursor by whitespace'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        DeleteRightWhitespace().execute(window)
+        DeleteRightWhitespace().execute(w)
-        cursor = window.logical_cursor()
+        cursor = w.logical_cursor()
-        prev_line = window.buffer.lines[cursor.y-1]
+        prev_line = w.buffer.lines[cursor.y-1]
-        this_line = window.buffer.lines[cursor.y]
+        this_line = w.buffer.lines[cursor.y]
         if cursor.y <= 0:
             return
         if cursor.x <= 0:
@@ -674,73 +682,73 @@ class JustifyLeft(Method):
                 return
             if this_line[i] != ' ':
                 return
-        window.buffer.delete_string(Point(i, cursor.y), cursor)
+        w.buffer.delete_string(Point(i, cursor.y), cursor)
 
 # undo/redo
 class Undo(Method):
     '''Undo last action'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
         try:
-            window.buffer.undo()
+            w.buffer.undo()
         except Exception, e:
-            window.application.set_error("%s" % (e))
+            w.application.set_error("%s" % (e))
 class Redo(Method):
     '''Redo last undone action'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
         try:
-            window.buffer.redo()
+            w.buffer.redo()
         except Exception, e:
-            window.application.set_error("%s" % (e))
+            w.application.set_error("%s" % (e))
 
-# window navigation methods
+# w navigation methods
 class StartOfLine(Method):
     '''Move the cursor to the start of the current line'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.start_of_line()
+        w.start_of_line()
 class EndOfLine(Method):
     '''Move the cursor to the end of the current line'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.end_of_line()
+        w.end_of_line()
 class Forward(Method):
     '''Move the cursor right one character'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.forward()
+        w.forward()
 class Backward(Method):
     '''Move the cursor left one character'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.backward()
+        w.backward()
 class NextLine(Method):
     '''Move the cursor down one line'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.next_line()
+        w.next_line()
 class PreviousLine(Method):
     '''Move the cursor up one line'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.previous_line()
+        w.previous_line()
 class PageUp(Method):
     '''Move the cursor up one page'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.page_up()
+        w.page_up()
 class PageDown(Method):
     '''Move the cursor down one page'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.page_down()
+        w.page_down()
 class GotoBeginning(Method):
     '''Move the cursor to the beginning of the buffer'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.goto_beginning()
+        w.goto_beginning()
 class GotoEnd(Method):
     '''Move the cursor to the end of the buffer'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.goto_end()
+        w.goto_end()
 class RightWord(Method):
     '''Move the cursor to the start of the word to the right'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.right_word()
+        w.right_word()
 class LeftWord(Method):
     '''Move the cursor to the start of the word to the left'''
-    def _execute(self, window, **vargs):
+    def _execute(self, w, **vargs):
-        window.left_word()
+        w.left_word()
 class NextSection(Method):
     '''Move the cursor to the next section'''
     def _execute(self, w, **vargs):
@@ -862,7 +870,7 @@ class OpenConsole(Method):
         if not a.has_buffer_name('*Console*'):
             a.add_buffer(buffer2.ConsoleBuffer())
         b = a.bufferlist.get_buffer_by_name('*Console*')
-        if a.window().buffer is not b:
+        if a.w().buffer is not b:
             a.switch_buffer(b)
         f = lambda x: None
         w.application.open_mini_buffer('>>> ', f, self, None, 'console')

mode_replace.py

@@ -11,12 +11,13 @@ class Replace(mode2.Fundamental):
         self.actions = {}
         self.bindings = {}
 
-        default_actions = ((ReplaceAll(), ('a', '!',)),
+        default_actions = (
+            (ReplaceAll(), ('a', '!',)),
             (ReplaceOne(), ('y', 'SPACE',)),
             (SkipReplace(), ('n', 'DELETE',)),
-                           (CancelReplace(), ('q', 'RETURN', 'C-]', 'C-n',
+            (CancelReplace(), ('q', 'RETURN', 'C-]', 'C-n', 'C-p', 'C-a', 'C-e',
-                                              'C-p', 'C-a', 'C-e', 'C-f',
+                               'C-f', 'C-b')),
-                                              'C-b')))
+        )
         
         # add the replace actions
         for pair in default_actions:
@@ -31,51 +32,55 @@ class Replace(mode2.Fundamental):
         return "Replace"
 
 class ReplaceOne(method.Method):
-    def execute(self, window, **vargs):
+    def execute(self, w, **vargs):
-        m = window.buffer.method
+        m = w.buffer.method
         old_window = m.old_window
         _replace(m, old_window)
-        _find_next(window, True)
+        _find_next(w, True)
-        _finish(m, window, old_window)
+        _finish(m, w, old_window)
 
 class SkipReplace(method.Method):
-    def execute(self, window, **vargs):
+    def execute(self, w, **vargs):
-        m = window.buffer.method
+        m = w.buffer.method
         old_window = m.old_window
-        _find_next(window, True)
+        _find_next(w, True)
-        _finish(m, window, old_window)
+        _finish(m, w, old_window)
 
 class ReplaceAll(method.Method):
-    def execute(self, window, **vargs):
+    def execute(self, w, **vargs):
-        m = window.buffer.method
+        m = w.buffer.method
         old_window = m.old_window
         while m.p1 is not None:
             _replace(m, old_window)
-            _find_next(window, True)
+            _find_next(w, True)
-        _end(window)
+        _end(w)
-        window.application.set_error("Replace ended")
+        w.application.set_error("Replace ended")
 
 class CancelReplace(method.Method):
-    def execute(self, window, **vargs):
+    def execute(self, w, **vargs):
-        _end(window)
+        _end(w)
-        window.application.set_error("Replace cancelled")
+        w.application.set_error("Replace cancelled")
 
-def _set_prompt(m, window):
+def _set_prompt(m, w):
-    i = m.old_window.buffer.get_point_offset(m.p1)
+    (x, y) = m.p1.xy()
-    s = m.old_window.buffer.make_string()
+    count = 0
-    count = s[i:].count(m.before)
+    while y < len(w.buffer.lines):
+        count += w.buffer.lines[y][x:].count(m.before)
+        y += 1
+        x = 0
     if count > 1:
-        window.application.mini_prompt = 'Replace %r with %r [ynaq] (%d occurances)?' % (m.before, m.after, count)
+        p = 'Replace %r with %r [ynaq] (%d occurances)?' % (m.before, m.after, count)
     else:
-        window.application.mini_prompt = 'Replace %r with %r [ynaq] (1 occurance)?' % (m.before, m.after)
+        p = 'Replace %r with %r [ynaq] (1 occurance)?' % (m.before, m.after)
+    w.application.mini_prompt = p
 
 def _replace(m, old_window):
-    old_window.buffer.delete_string(m.p1, m.p2)
+    old_window.buffer.delete(m.p1, m.p2)
     if m.after:
         old_window.buffer.insert_string(m.p1, m.after)
 
-def _find_next(window, move=False):
+def _find_next(w, move=False):
-    m = window.buffer.method
+    m = w.buffer.method
     old_window = m.old_window
     b = old_window.buffer
     s = m.before
@@ -111,16 +116,15 @@ def _find_next(window, move=False):
     m.p1 = None
     m.p2 = None
 
-def _finish(m, window, old_window):
+def _finish(m, w, old_window):
     if m.p1 is None:
-        _end(window)
+        _end(w)
-        window.application.set_error("Replace ended")
+        w.application.set_error("Replace ended")
     else:
         _set_prompt(m, old_window)
 
-def _end(window):
+def _end(w):
-    window.application.close_mini_buffer()
+    w.application.close_mini_buffer()
-    #window.application.highlighted_range = []
+    w.application.clear_highlighted_ranges()
-    window.application.clear_highlighted_ranges()
+    w.buffer.method.old_cursor = None
-    window.buffer.method.old_cursor = None
+    w.buffer.method.old_window = None
-    window.buffer.method.old_window = None

window2.py

@@ -4,12 +4,11 @@ from point2 import Point
 
 WORD_LETTERS = list(string.letters + string.digits)
 
-# note about the cursor: the cursor position will insert in front of
+# note about the cursor: the cursor position will insert in front of the
-# the character it highlights. to this end, it needs to be able to
+# character it highlights. to this end, it needs to be able to highlight behind
-# highlight behind the last character on a line. thus, the x
+# the last character on a line. thus, the x coordinate of the (logical) cursor
-# coordinate of the (logical) cursor can equal the length of lines[y],
+# can equal the length of lines[y], even though lines[y][x] throws an index
-# even though lines[y][x] throws an index error. both buffer and
+# error. both buffer and window need to be aware of this possibility for points.
-# window need to be aware of this possibility for points.
 
 class Window(object):
     def __init__(self, b, a, height=24, width=80, mode_name=None):
@@ -85,9 +84,31 @@ class Window(object):
         if not self.point_is_visible(p):
             self.application.set_error(msg % {'x': p.x, 'y': p.y})
 
+    # point left
+    def point_left(self, p):
+        if p.y == 0 and p.x == 0:
+            return None
+        elif p.x == 0:
+            return Point(len(self.buffer.lines[p.y - 1]), p.y - 1)
+        else:
+            return Point(p.x - 1, p.y)
+
+    # point right
+    def point_right(self, p):
+        if p.y == len(self.buffer.lines)-1 and p.x == len(self.buffer.lines[-1]):
+            return None
+        elif p.x == len(self.buffer.lines[p.y]):
+            return Point(0, p.y + 1)
+        else:
+            return Point(p.x + 1, p.y)
+
     # cursors
     def logical_cursor(self):
-        x = min(self.cursor.x, len(self.buffer.lines[self.cursor.y]))
+        if len(self.buffer.lines) > self.cursor.y:
+            l = len(self.buffer.lines[self.cursor.y])
+        else:
+            l = 0
+        x = min(self.cursor.x, l)
         return Point(x, self.cursor.y)
 
     # last visible point
@@ -454,17 +475,20 @@ class Window(object):
         return self.application.pop_kill()
 
     # querying
-    def highlighted_char(self):
+    def cursor_char(self):
         self.point_char(self.logical_cursor())
     def point_char(self, p):
         return self.xy_char(p.x, p.y)
     def xy_char(self, x, y):
+        #assert 0 <= y and y < len(self.buffer.lines)
+        #assert 0 <= x and x <= len(self.buffer.lines[y])
         if x == len(self.buffer.lines[y]):
             return "\n"
         else:
             return self.buffer.lines[y][x]
 
     # undo/redo
+    # XYZ
     def undo(self):
         # TODO: put something here to move the cursor to the area of the undo
         self.buffer.undo()