SF.net SVN: matplotlib:[8665] trunk/matplotlib/lib/matplotlib/animation.py

[<ry...@us...>]

Revision: 8665
          http://matplotlib.svn.sourceforge.net/matplotlib/?rev=8665&view=rev
Author:   ryanmay
Date:     2010-08-27 18:13:22 +0000 (Fri, 27 Aug 2010)

Log Message:
-----------
Fix some issues with saving movies from FuncAnimation. The initialization draw was putting data in the saved sequence, which needed to be removed. Also, handle the case where there is no saved sequence. Make sure to disconnect signals for first draw, otherwise saving the movie will start the animation.

Modified Paths:
--------------
    trunk/matplotlib/lib/matplotlib/animation.py

Modified: trunk/matplotlib/lib/matplotlib/animation.py
===================================================================
--- trunk/matplotlib/lib/matplotlib/animation.py	2010-08-27 07:13:14 UTC (rev 8664)
+++ trunk/matplotlib/lib/matplotlib/animation.py	2010-08-27 18:13:22 UTC (rev 8665)
@@ -26,6 +26,7 @@
         return ret
     return wrapper
 
+import itertools
 from matplotlib.cbook import iterable
 
 class Animation(object):
@@ -78,6 +79,7 @@
         self.event_source.add_callback(self._step)
         self.event_source.start()
         self._fig.canvas.mpl_disconnect(self._first_draw_id)
+        self._first_draw_id = None # So we can check on save
 
     def _stop(self, *args):
         # On stop we disconnect all of our events.
@@ -103,6 +105,14 @@
         image files.  This prefix will have a frame number (i.e. 0001) appended
         when saving individual frames.
         '''
+        # Need to disconnect the first draw callback, since we'll be doing
+        # draws. Otherwise, we'll end up starting the animation.
+        if self._first_draw_id is not None:
+            self._fig.canvas.mpl_disconnect(self._first_draw_id)
+            reconnect_first_draw = True
+        else:
+            reconnect_first_draw = False
+
         fnames = []
         # Create a new sequence of frames for saved data. This is different
         # from new_frame_seq() to give the ability to save 'live' generated
@@ -121,6 +131,11 @@
             for fname in fnames:
                 os.remove(fname)
 
+        # Reconnect signal for first draw if necessary
+        if reconnect_first_draw:
+            self._first_draw_id = self._fig.canvas.mpl_connect('draw_event',
+                self._start)
+
     def ffmpeg_cmd(self, fname, fps, codec, frame_prefix):
         # Returns the command line parameters for subprocess to use
         # ffmpeg to create a movie
@@ -401,7 +416,6 @@
         # be a generator. An iterable will be used as is, and anything else
         # will be treated as a number of frames.
         if frames is None:
-            import itertools
             self._iter_gen = itertools.count
         elif callable(frames):
             self._iter_gen = frames
@@ -417,17 +431,28 @@
             self.save_count = 100
 
         self._init_func = init_func
-        self._save_seq = []
 
+        # Needs to be initialized so the draw functions work without checking
+        self._save_seq = [] 
+
         TimedAnimation.__init__(self, fig, **kwargs)
 
+        # Need to reset the saved seq, since right now it will contain data
+        # for a single frame from init, which is not what we want.
+        self._save_seq = []
+
     def new_frame_seq(self):
         # Use the generating function to generate a new frame sequence
         return self._iter_gen()
 
     def new_saved_frame_seq(self):
-        # Generate an iterator for the sequence of saved data.
-        return iter(self._save_seq)
+        # Generate an iterator for the sequence of saved data. If there are
+        # no saved frames, generate a new frame sequence and take the first
+        # save_count entries in it.
+        if self._save_seq:
+            return iter(self._save_seq)
+        else:
+            return itertools.islice(self.new_frame_seq(), self.save_count)
 
     def _init_draw(self):
         # Initialize the drawing either using the given init_func or by


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