[PATCH] histedit: editcomment method to histedit actions

[Mateusz Kwapich]

# HG changeset patch
# User Mateusz Kwapich <mitrandir at fb.com>
# Date 1449603153 28800
#      Tue Dec 08 11:32:33 2015 -0800
# Node ID b7f518564771929ff03a57523fdaba2b8121ac0d
# Parent  93f42371f4b0ebbe28fc93233283f08da788ee26
histedit: editcomment method to histedit actions

Let each action show its own help in histedit editor. The comments
have priorities for sorting purposes.

diff --git a/hgext/histedit.py b/hgext/histedit.py
--- a/hgext/histedit.py
+++ b/hgext/histedit.py
@@ -207,21 +207,6 @@
 # leave the attribute unspecified.
 testedwith = 'internal'
 
-# i18n: command names and abbreviations must remain untranslated
-editcomment = _("""# Edit history between %s and %s
-#
-# Commits are listed from least to most recent
-#
-# Commands:
-#  p, pick = use commit
-#  e, edit = use commit, but stop for amending
-#  f, fold = use commit, but combine it with the one above
-#  r, roll = like fold, but discard this commit's description
-#  d, drop = remove commit from history
-#  m, mess = edit commit message without changing commit content
-#
-""")
-
 class histeditstate(object):
     def __init__(self, repo, parentctxnode=None, actions=None, keep=None,
             topmost=None, replacements=None, lock=None, wlock=None):
@@ -445,6 +430,15 @@
             return ctx, []
         return ctx, [(self.node, (ctx.node(),))]
 
+    @classmethod
+    def editcomment(self):
+        """Return a help line which will be visible as a coments below initial
+        rules. Your line should <= 78 charactes ("# " will be prepended).
+
+        For example for pick command you can return "p, pick = use commit"
+        """
+        return None
+
 def commitfuncfor(repo, src):
     """Build a commit function for the replacement of <src>
 
@@ -589,6 +583,10 @@
 
 @addhisteditaction(['pick', 'p'])
 class pick(histeditaction):
+    @classmethod
+    def editcomment(self):
+        return 10, _("p, pick = use commit")
+
     def run(self):
         rulectx = self.repo[self.node]
         if rulectx.parents()[0].node() == self.state.parentctxnode:
@@ -599,6 +597,10 @@
 
 @addhisteditaction(['edit', 'e'])
 class edit(histeditaction):
+    @classmethod
+    def editcomment(self):
+        return 20, _("e, edit = use commit, but stop for amending")
+
     def run(self):
         repo = self.repo
         rulectx = repo[self.node]
@@ -614,6 +616,10 @@
 
 @addhisteditaction(['fold', 'f'])
 class fold(histeditaction):
+    @classmethod
+    def editcomment(self):
+        return 30, _("f, fold = use commit, but combine it with the one above")
+
     def continuedirty(self):
         repo = self.repo
         rulectx = repo[self.node]
@@ -733,11 +739,19 @@
     when the last fold operation runs we can show the user all the
     commit messages in their editor.
     """
+    @classmethod
+    def editcomment(self):
+        return None
+
     def skipprompt(self):
         return True
 
 @addhisteditaction(["roll", "r"])
 class rollup(fold):
+    @classmethod
+    def editcomment(self):
+        return 40, _("r, roll = like fold, but discard this commit's description")
+
     def mergedescs(self):
         return False
 
@@ -746,12 +760,20 @@
 
 @addhisteditaction(["drop", "d"])
 class drop(histeditaction):
+    @classmethod
+    def editcomment(self):
+        return 50, _("d, drop = remove commit from history")
+
     def run(self):
         parentctx = self.repo[self.state.parentctxnode]
         return parentctx, [(self.node, tuple())]
 
 @addhisteditaction(["mess", "m"])
 class message(histeditaction):
+    @classmethod
+    def editcomment(self):
+        return 60, _("m, mess = edit commit message without changing commit content")
+
     def commiteditor(self):
         return cmdutil.getcommiteditor(edit=True, editform='histedit.mess')
 
@@ -951,7 +973,7 @@
     elif goal == 'edit-plan':
         state.read()
         if not rules:
-            comment = editcomment % (node.short(state.parentctxnode),
+            comment = editcomment(node.short(state.parentctxnode),
                                      node.short(state.topmost))
             rules = ruleeditor(repo, ui, state.actions, comment)
         else:
@@ -1036,7 +1058,7 @@
 
         ctxs = [repo[r] for r in revs]
         if not rules:
-            comment = editcomment % (node.short(root), node.short(topmost))
+            comment = editcomment(node.short(root), node.short(topmost))
             actions = [pick(state, r) for r in revs]
             rules = ruleeditor(repo, ui, actions, comment)
         else:
@@ -1157,6 +1179,19 @@
                              hint=_('see "hg help phases" for details'))
     return [c.node() for c in ctxs]
 
+def editcomment(old, new):
+    pricomments = filter(None, [act.editcomment() for act in actionlist])
+    comments = [comment for (pri, comment) in sorted(pricomments)]
+    return _("""# Edit history between %s and %s
+#
+# Commits are listed from least to most recent
+#
+# Commands:
+%s
+#
+"""
+             ) % (old, new, '\n'.join(["#  %s" % c for c in comments]))
+
 def ruleeditor(repo, ui, actions, editcomment=""):
     """open an editor to edit rules