From 1af564f2a013ddeb47a3ba64cd28a5133afe23c3 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Fri, 25 Oct 2013 02:52:10 -0700
Subject: [PATCH] models.main: manage 'head' from within set_mode() only

Remove the set_head() method and simplify callers by making set_mode()
manage the 'head' variable.  This is simpler since its value is always
tied to the mode (amend = 'HEAD^', all others = 'HEAD').

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 cola/cmds.py        |  7 -------
 cola/models/main.py | 12 ++++++------
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/cola/cmds.py b/cola/cmds.py
index f51694ad..8790f449 100644
--- a/cola/cmds.py
+++ b/cola/cmds.py
@@ -67,17 +67,14 @@ class Command(BaseCommand):
         self.old_diff_text = self.model.diff_text
         self.old_filename = self.model.filename
         self.old_mode = self.model.mode
-        self.old_head = self.model.head
 
         self.new_diff_text = self.old_diff_text
         self.new_filename = self.old_filename
-        self.new_head = self.old_head
         self.new_mode = self.old_mode
 
     def do(self):
         """Perform the operation."""
         self.model.set_filename(self.new_filename)
-        self.model.set_head(self.new_head)
         self.model.set_mode(self.new_mode)
         self.model.set_diff_text(self.new_diff_text)
 
@@ -85,7 +82,6 @@ class Command(BaseCommand):
         """Undo the operation."""
         self.model.set_diff_text(self.old_diff_text)
         self.model.set_filename(self.old_filename)
-        self.model.set_head(self.old_head)
         self.model.set_mode(self.old_mode)
 
 
@@ -110,13 +106,11 @@ class AmendMode(Command):
 
         if self.amending:
             self.new_mode = self.model.mode_amend
-            self.new_head = 'HEAD^'
             self.new_commitmsg = self.model.prev_commitmsg()
             AmendMode.LAST_MESSAGE = self.model.commitmsg
             return
         # else, amend unchecked, regular commit
         self.new_mode = self.model.mode_none
-        self.new_head = 'HEAD'
         self.new_diff_text = ''
         self.new_commitmsg = self.model.commitmsg
         # If we're going back into new-commit-mode then search the
@@ -287,7 +281,6 @@ class ResetMode(Command):
     def __init__(self):
         Command.__init__(self)
         self.new_mode = self.model.mode_none
-        self.new_head = 'HEAD'
         self.new_diff_text = ''
 
     def do(self):
diff --git a/cola/models/main.py b/cola/models/main.py
index 693dee79..28064888 100644
--- a/cola/models/main.py
+++ b/cola/models/main.py
@@ -36,7 +36,6 @@ class MainModel(Observable):
     message_diff_text_changed = 'diff_text_changed'
     message_directory_changed = 'directory_changed'
     message_filename_changed = 'filename_changed'
-    message_head_changed = 'head_changed'
     message_mode_about_to_change = 'mode_about_to_change'
     message_mode_changed = 'mode_changed'
     message_updated = 'updated'
@@ -138,17 +137,18 @@ class MainModel(Observable):
         self.filename = filename
         self.notify_observers(self.message_filename_changed, filename)
 
-    def set_head(self, head):
-        self.head = head
-        self.notify_observers(self.message_head_changed, head)
-
     def set_mode(self, mode):
-        self.notify_observers(self.message_mode_about_to_change, mode)
         if self.amending():
             if mode != self.mode_none:
                 return
         if self.is_merging and mode == self.mode_amend:
             mode = self.mode
+        if mode == self.mode_amend:
+            head = 'HEAD^'
+        else:
+            head = 'HEAD'
+        self.notify_observers(self.message_mode_about_to_change, mode)
+        self.head = head
         self.mode = mode
         self.notify_observers(self.message_mode_changed, mode)
 
-- 
2.11.4.GIT