[meld] Move buffer undo helpers to meldbuffer

[Kai Willadsen <kaiw src gnome org>]

commit 58815911389517740786c95d8ab986f826fa60b0
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Wed Sep 28 13:04:49 2011 +1000

    Move buffer undo helpers to meldbuffer

 meld/filediff.py   |   33 ++-------------------------------
 meld/meldbuffer.py |   27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 31 deletions(-)
---
diff --git a/meld/filediff.py b/meld/filediff.py
index a6c910d..b68f301 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -757,7 +757,7 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
     def on_text_insert_text(self, buf, it, text, textlen):
         text = unicode(text, 'utf8')
         self.undosequence.add_action(
-            BufferInsertionAction(buf, it.get_offset(), text))
+            meldbuffer.BufferInsertionAction(buf, it.get_offset(), text))
         buf.create_mark("insertion-start", it, True)
 
     def on_text_delete_range(self, buf, it0, it1):
@@ -765,7 +765,7 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
         assert self.deleted_lines_pending == -1
         self.deleted_lines_pending = it1.get_line() - it0.get_line()
         self.undosequence.add_action(
-            BufferDeletionAction(buf, it0.get_offset(), text))
+            meldbuffer.BufferDeletionAction(buf, it0.get_offset(), text))
 
     def on_undo_checkpointed(self, undosequence, buf, checkpointed):
         self.set_buffer_modified(buf, not checkpointed)
@@ -1620,32 +1620,3 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
         anim = TextviewLineAnimation(mark0, mark1, rgba0, rgba1, 0.5)
         self.animating_chunks[src].append(anim)
 
-
-
-
-class BufferAction(object):
-    """A helper to undo/redo text insertion/deletion into/from a text buffer"""
-
-    def __init__(self, buf, offset, text):
-        self.buffer = buf
-        self.offset = offset
-        self.text = text
-
-    def delete(self):
-        start = self.buffer.get_iter_at_offset(self.offset)
-        end = self.buffer.get_iter_at_offset(self.offset + len(self.text))
-        self.buffer.delete(start, end)
-
-    def insert(self):
-        start = self.buffer.get_iter_at_offset(self.offset)
-        self.buffer.insert(start, self.text)
-
-
-class BufferInsertionAction(BufferAction):
-    undo = BufferAction.delete
-    redo = BufferAction.insert
-
-
-class BufferDeletionAction(BufferAction):
-    undo = BufferAction.insert
-    redo = BufferAction.delete
diff --git a/meld/meldbuffer.py b/meld/meldbuffer.py
index fb1a35d..3e19bfa 100644
--- a/meld/meldbuffer.py
+++ b/meld/meldbuffer.py
@@ -138,3 +138,30 @@ class BufferLines(object):
     def __len__(self):
         return self.buf.get_line_count()
 
+
+class BufferAction(object):
+    """A helper to undo/redo text insertion/deletion into/from a text buffer"""
+
+    def __init__(self, buf, offset, text):
+        self.buffer = buf
+        self.offset = offset
+        self.text = text
+
+    def delete(self):
+        start = self.buffer.get_iter_at_offset(self.offset)
+        end = self.buffer.get_iter_at_offset(self.offset + len(self.text))
+        self.buffer.delete(start, end)
+
+    def insert(self):
+        start = self.buffer.get_iter_at_offset(self.offset)
+        self.buffer.insert(start, self.text)
+
+
+class BufferInsertionAction(BufferAction):
+    undo = BufferAction.delete
+    redo = BufferAction.insert
+
+
+class BufferDeletionAction(BufferAction):
+    undo = BufferAction.insert
+    redo = BufferAction.delete