Deprecate GTKAgg and GTKCairo backends.

QuLogic · QuLogic · commit e014266ff7ef · 2018-02-10T17:02:24.000-05:00
They require pygtk, which does not build on Python 3. Thus, they could
never be supported in mpl 3 anyway. The last major release of GTK2 was 7
years ago (though bugfixes have been released in the meantime), so it's
rather outdated.
diff --git a/lib/matplotlib/backends/backend_gtkagg.py b/lib/matplotlib/backends/backend_gtkagg.py
@@ -7,6 +7,7 @@
 import six
 
 import matplotlib
+from matplotlib.cbook import warn_deprecated
 from matplotlib.backends.backend_agg import FigureCanvasAgg
 from matplotlib.backends.backend_gtk import (
     gtk, _BackendGTK, FigureCanvasGTK, FigureManagerGTK, NavigationToolbar2GTK,
@@ -34,6 +35,16 @@ class FigureCanvasGTKAgg(FigureCanvasGTK, FigureCanvasAgg):
     filetypes = FigureCanvasGTK.filetypes.copy()
     filetypes.update(FigureCanvasAgg.filetypes)
 
+    def __init__(self, *args, **kwargs):
+        warn_deprecated('2.2',
+                        message=('The GTKAgg backend is deprecated. It is '
+                                 'untested and will be removed in Matplotlib '
+                                 '3.0. Use the GTK3Agg backend instead. See '
+                                 'Matplotlib usage FAQ for more info on '
+                                 'backends.'),
+                        alternative='GTK3Agg')
+        super(FigureCanvasGTKAgg, self).__init__(*args, **kwargs)
+
     def configure_event(self, widget, event=None):
 
         if widget.window is None:
diff --git a/lib/matplotlib/backends/backend_gtkcairo.py b/lib/matplotlib/backends/backend_gtkcairo.py
@@ -33,6 +33,16 @@ class FigureCanvasGTKCairo(backend_cairo.FigureCanvasCairo, FigureCanvasGTK):
     filetypes = FigureCanvasGTK.filetypes.copy()
     filetypes.update(backend_cairo.FigureCanvasCairo.filetypes)
 
+    def __init__(self, *args, **kwargs):
+        warn_deprecated('2.2',
+                        message=('The GTKCairo backend is deprecated. It is '
+                                 'untested and will be removed in Matplotlib '
+                                 '3.0. Use the GTK3Cairo backend instead. See '
+                                 'Matplotlib usage FAQ for more info on '
+                                 'backends.'),
+                        alternative='GTK3Cairo')
+        super(FigureCanvasGTKCairo, self).__init__(*args, **kwargs)
+
     def _renderer_init(self):
         """Override to use cairo (rather than GDK) renderer"""
         self._renderer = RendererGTKCairo(self.figure.dpi)
