less cursor jumping on auto-ident; close #28

--HG--
branch : pmacs2

method/__init__.py

@@ -478,20 +478,28 @@ class InsertTab(Method):
     '''Insert tab into buffer, or tabbify line, depending on mode'''
     def _execute(self, w, **vargs):
         cursor = w.logical_cursor()
-        if w.mode.tabber:
-            i = w.mode.tabber.get_level(cursor.y)
-        else:
-            i = None
+        x  = cursor.x
+        y  = cursor.y
 
-        if i is None:
-            w.insert_string_at_cursor(' ' * w.mode.tabwidth)
+        # get the correct indentation lvl, if applicable
+        if w.mode.tabber:
+            lvl = w.mode.tabber.get_level(y)
         else:
-            j = w.buffer.count_leading_whitespace(cursor.y)
-            if i != j:
-                KillWhitespace().execute(w)
-                w.insert_string(Point(0, cursor.y), ' ' * i)
-            else:
-                w.goto(Point(j, cursor.y))
+            lvl = None
+
+        # if no lvl, insert a literal tab
+        if lvl is None:
+            w.insert_string_at_cursor(' ' * w.mode.tabwidth)
+            return
+
+        # insert the correct amount of whitespace
+        ws  = w.buffer.count_leading_whitespace(y)
+        if lvl != ws:
+            w.delete(Point(0, y), Point(ws, y))
+            w.insert_string(Point(0, y), ' ' * lvl)
+        x2 = max(x, lvl)
+        if w.logical_cursor().x < x2:
+            w.goto(Point(x2, y))
 
 class KillWhitespace(Method):
     '''Delete leading whitespace on current line'''