From 7a9c7d4e4ebae4d095c446fd9f79e0be62b1bdc6 Mon Sep 17 00:00:00 2001
From: Michael Droettboom <mdboom@gmail.com>
Date: Mon, 20 Aug 2012 10:59:48 -0400
Subject: [PATCH 1/2] Add a "show" method to figures that don't have a GUI
 backend.  Fixed #835.

---
 lib/matplotlib/backend_bases.py | 12 +++++++++---
 lib/matplotlib/figure.py        | 14 ++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
index c0eeb0543db6..c860f3686057 100644
--- a/lib/matplotlib/backend_bases.py
+++ b/lib/matplotlib/backend_bases.py
@@ -2423,14 +2423,20 @@ def __init__(self, canvas, num):
                                                             self.key_press)
         """
         The returned id from connecting the default key handler via :meth:`FigureCanvasBase.mpl_connnect`.
-        
+
         To disable default key press handling::
-        
+
             manager, canvas = figure.canvas.manager, figure.canvas
             canvas.mpl_disconnect(manager.key_press_handler_id)
-            
+
         """
 
+    def show(self):
+        """
+        For GUI backends, show the figure window and redraw.
+        """
+        pass
+
     def destroy(self):
         pass
 
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
index 2dafa2c5827b..d14a7b442361 100644
--- a/lib/matplotlib/figure.py
+++ b/lib/matplotlib/figure.py
@@ -328,6 +328,20 @@ def __init__(self,
         self.clf()
         self._cachedRenderer = None
 
+    def show(self):
+        """
+        If using a GUI backend, display the figure window.
+
+        For non-GUI backends, this does nothing.
+        """
+        manager = getattr(self.canvas, 'manager')
+        if manager is not None:
+            manager.show()
+        import warnings
+        warnings.warn(
+            "matplotlib is currently using a non-GUI backend, "
+            "so can not show the figure")
+
     def _get_axes(self):
         return self._axstack.as_list()
 

From 58425248e38956a9aa276e1913d23476d469c5ec Mon Sep 17 00:00:00 2001
From: Michael Droettboom <mdboom@gmail.com>
Date: Tue, 28 Aug 2012 11:18:24 -0400
Subject: [PATCH 2/2] Warn when calling "show" in a non-GUI backend, and
 provide a convenient way to suppress the warning.

---
 lib/matplotlib/__init__.py      | 18 ++++++++++++++++++
 lib/matplotlib/backend_bases.py |  3 ++-
 lib/matplotlib/figure.py        | 14 +++++++-------
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
index d8e014c845e0..03c21da82de7 100644
--- a/lib/matplotlib/__init__.py
+++ b/lib/matplotlib/__init__.py
@@ -1034,6 +1034,24 @@ def get_backend():
     "Returns the current backend."
     return rcParams['backend']
 
+
+class NonGUIBackendWarning(Warning):
+    pass
+
+
+def _warn_non_gui_show():
+    warnings.warn(
+        "matplotlib is currently using a non-GUI backend, "
+        "so the figure can not be shown.  Call "
+        "matplotlib.hide_show_warnings() to suppress "
+        "these warnings.",
+        NonGUIBackendWarning)
+
+
+def hide_show_warnings():
+    warnings.simplefilter('ignore', NonGUIBackendWarning)
+
+
 def interactive(b):
     """
     Set interactive mode to boolean b.
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
index c860f3686057..ee3603a55aab 100644
--- a/lib/matplotlib/backend_bases.py
+++ b/lib/matplotlib/backend_bases.py
@@ -39,6 +39,7 @@
 from matplotlib import rcParams
 from matplotlib import is_interactive
 from matplotlib._pylab_helpers import Gcf
+from matplotlib import _warn_non_gui_show
 
 from matplotlib.transforms import Bbox, TransformedBbox, Affine2D
 import cStringIO
@@ -2435,7 +2436,7 @@ def show(self):
         """
         For GUI backends, show the figure window and redraw.
         """
-        pass
+        _warn_non_gui_show()
 
     def destroy(self):
         pass
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
index d14a7b442361..78299c3c8a61 100644
--- a/lib/matplotlib/figure.py
+++ b/lib/matplotlib/figure.py
@@ -39,6 +39,7 @@
 from matplotlib.text import Text, _process_text_args
 from matplotlib.transforms import (Affine2D, Bbox, BboxTransformTo,
                                     TransformedBbox)
+from matplotlib import _warn_non_gui_show
 
 
 docstring.interpd.update(projection_names = get_projection_names())
@@ -334,13 +335,12 @@ def show(self):
 
         For non-GUI backends, this does nothing.
         """
-        manager = getattr(self.canvas, 'manager')
-        if manager is not None:
-            manager.show()
-        import warnings
-        warnings.warn(
-            "matplotlib is currently using a non-GUI backend, "
-            "so can not show the figure")
+        if hasattr(self, 'canvas'):
+            manager = getattr(self.canvas, 'manager', None)
+            if manager is not None:
+                manager.show()
+                return
+        _warn_non_gui_show()
 
     def _get_axes(self):
         return self._axstack.as_list()