In case a todo has parents, use the max progress of all its parents

The parent color is only used when the todo item has not enough information to
determine its own progress.

test/test_progress_color.py

@@ -21,6 +21,7 @@ from test.topydo_testcase import TopydoTest
 from topydo.lib.Config import config
 from topydo.lib.ProgressColor import progress_color
 from topydo.lib.Todo import Todo
+from topydo.lib.TodoList import TodoList
 
 def set_256_colors():
     config(p_overrides={('topydo', 'colors'): '256'})
@@ -186,5 +187,43 @@ class ProgressColorTest(TopydoTest):
         # a length of 14 days is assumed
         self.assertEqual(color.color, 208)
 
+    def test_progress28(self):
+        """ Progress color determined by parent """
+        todolist = TodoList([
+            "Overdue id:1 due:2015-12-31",
+            "Bar p:1",
+        ])
+
+        color = progress_color(todolist.todo(2))
+
+        # color the subitem red because it has no color of its own and its
+        # parent is overdue
+        self.assertEqual(color.color, 1)
+
+    def test_progress29(self):
+        """ Progress color determined by parent """
+        todolist = TodoList([
+            "Overdue id:1 due:2015-12-31",
+            "Bar p:1 t:2016-01-01 due:2016-01-01",
+        ])
+
+        color = progress_color(todolist.todo(2))
+
+        # the parent has no influence here
+        self.assertEqual(color.color, 3)
+
+    def test_progress30(self):
+        """ Progress color determined by parent """
+        todolist = TodoList([
+            "Foo id:1",
+            "Bar p:1",
+        ])
+
+        color = progress_color(todolist.todo(2))
+
+        # the parent has no influence here
+        self.assertEqual(color.color, 2)
+
+
 if __name__ == '__main__':
     unittest.main()

topydo/lib/ProgressColor.py

@@ -77,11 +77,21 @@ def progress_color(p_todo):
         # a todo item is at least one day long
         return max(1, result)
 
-    def get_progress():
+    def get_progress(p_todo, p_consider_parents=True):
         """
         Returns a value from 0 to 1 where we are today in a date range. Returns
         a value >1 when a todo item is overdue.
         """
+        def progress_of_parents():
+            try:
+                parents = p_todo.parents()
+            except AttributeError:
+                parents = []
+
+            if parents:
+                return max(get_progress(parent, False) for parent in parents)
+            else:
+                return 0
 
         if p_todo.is_overdue():
             return 1.1
@@ -89,11 +99,13 @@ def progress_color(p_todo):
             days_till_due = p_todo.days_till_due()
             length = get_length()
             return max((length - days_till_due), 0) / length
+        elif p_consider_parents:
+            return progress_of_parents()
         else:
             return 0
 
     color_range = color256_range if config().colors() == 256 else color16_range
-    progress = get_progress()
+    progress = get_progress(p_todo)
 
     # TODO: remove linear scale to exponential scale
     if progress > 1: