Do not sort all todos when the items will be grouped

When grouping takes place, don't sort the full list of todo items first
and then group. Because the todos in the group won't necessarily match
the given sort expression, for those items which match multiple groups.

These are the steps instead:

1. Get all todo items
2. Filter them
3. Pre-order them according to the group expression
4. Split in groups using groupby()
5. Then sort the individual groups according to the sort expression

topydo/lib/Sorter.py

@@ -98,7 +98,7 @@ class Sorter(object):
 
     def __init__(self, p_sortstring="desc:priority", p_groupstring=""):
         self.groupfunctions = self._parse(p_groupstring) if p_groupstring else []
-        self.sortfunctions = self._parse(p_groupstring + ',' + p_sortstring)
+        self.sortfunctions = self._parse(p_sortstring)
 
     def sort(self, p_todos):
         """
@@ -121,6 +121,11 @@ class Sorter(object):
         Groups the todos according to the given group string. Assumes that the
         given todos have already been sorted with self.sort().
         """
+        # preorder todos for the group sort
+        for function, _ in self.groupfunctions:
+            p_todos = sorted(p_todos, key=function)
+
+        # initialize result with a single group
         result = OrderedDict([((), p_todos)])
 
         for function, _ in self.groupfunctions:
@@ -141,6 +146,10 @@ class Sorter(object):
                         else:
                             result[newkey] = newgroup
 
+        # sort all groups
+        for key, group in result.items():
+            result[key] = self.sort(group)
+
         return result
 
     def _parse(self, p_string):

topydo/lib/View.py

@@ -29,17 +29,22 @@ class View(object):
         self._sorter = p_sorter
         self._filters = p_filters
 
-    @property
-    def todos(self):
-        """ Returns a sorted and filtered list of todos in this view. """
-        result = self._sorter.sort(self.todolist.todos())
+    def _apply_filters(self, p_todos):
+        """ Applies the filters to the list of todo items. """
+        result = p_todos
 
         for _filter in self._filters:
             result = _filter.filter(result)
 
         return result
 
+    @property
+    def todos(self):
+        """ Returns a sorted and filtered list of todos in this view. """
+        result = self._sorter.sort(self.todolist.todos())
+        return self._apply_filters(result)
+
     @property
     def groups(self):
-        todos = self.todos
-        return self._sorter.group(self.todos)
+        result = self._apply_filters(self.todolist.todos())
+        return self._sorter.group(result)