From 39dffab5d36a997cc76ad9069fe00de51d3147a0 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@drexel.edu>
Date: Fri, 27 Aug 2010 18:44:01 -0400
Subject: [PATCH] Don't load curves becore clearing their command stack.

Loading a curve (which would happen if it had been unloaded before
being summoned by current_curve_callback) executes its command stack.
Since 'clear curve command stack' is only trying to remove the stack,
that stack execution is a waste of time.  With the unloaded callback,
we can remove the command stack without ever loading the curve.
---
 hooke/playlist.py     |  5 +++--
 hooke/plugin/curve.py | 14 ++++++++++++--
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/hooke/playlist.py b/hooke/playlist.py
index 80d60fb..79f785c 100644
--- a/hooke/playlist.py
+++ b/hooke/playlist.py
@@ -91,11 +91,12 @@ class NoteIndexList (list):
             return self._index
         return super(NoteIndexList, self).index(value, *args, **kwargs)
 
-    def current(self):
+    def current(self, load=True):
         if len(self) == 0:
             return None
         item = self[self._index]
-        self._setup_item(item)
+        if load == True:
+            self._setup_item(item)
         return item
 
     def jump(self, index):
diff --git a/hooke/plugin/curve.py b/hooke/plugin/curve.py
index 931dca3..d51ddfd 100644
--- a/hooke/plugin/curve.py
+++ b/hooke/plugin/curve.py
@@ -41,15 +41,20 @@ from .playlist import current_playlist_callback
 
 # Define common or complicated arguments
 
-def current_curve_callback(hooke, command, argument, value):
+def current_curve_callback(hooke, command, argument, value, load=True):
     if value != None:
         return value
     playlist = current_playlist_callback(hooke, command, argument, value)
-    curve = playlist.current()
+    curve = playlist.current(load=load)
     if curve == None:
         raise Failure('No curves in %s' % playlist)
     return curve
 
+def unloaded_current_curve_callback(hooke, command, argument, value):
+    return current_curve_callback(
+        hooke=hooke, command=command, argument=argument, value=value,
+        load=False)
+
 CurveArgument = Argument(
     name='curve', type='curve', callback=current_curve_callback,
     help="""
@@ -634,6 +639,11 @@ class ClearStackCommand (CurveCommand):
         super(ClearStackCommand, self).__init__(
             name='clear curve command stack',
             help=self.__doc__, plugin=plugin)
+        i,arg = [(i,arg) for i,arg in enumerate(self.arguments)
+                 if arg.name == 'curve'][0]
+        arg = copy.copy(arg)
+        arg.callback = unloaded_current_curve_callback
+        self.arguments[i] = arg
 
     def _run(self, hooke, inqueue, outqueue, params):
         curve = self._curve(hooke, params)
-- 
2.26.2