Apply gtk3 background.

anntzer · anntzer · commit 91850cc6f638 · 2018-06-30T15:12:46.000+02:00
Currently, gtk3 widget backgrounds are not being applied (which only matters if the figure patch is partially transparent). The lines added by this PR are equivalent to the call to `painter.eraseRect(self.rect())` in the qt5agg backend (compare http://doc.qt.io/qt-5/qpainter.html#eraseRect and https://developer.gnome.org/gtk3/stable/GtkStyleContext.html#gtk-render-background). As an example, run import os; os.environ["MPLBACKEND"] = "gtk3cairo" from pylab import * from gi.repository import Gtk rcParams["figure.facecolor"] = (0, 0, 0, 0) css = Gtk.CssProvider() css.load_from_data(b"* {background-color: red;}") gcf().canvas.get_style_context().add_provider( css, Gtk.STYLE_PROVIDER_PRIORITY_USER) gca() show() Without this patch, the red background is not drawn.
diff --git a/lib/matplotlib/backends/backend_gtk3agg.py b/lib/matplotlib/backends/backend_gtk3agg.py
@@ -4,7 +4,7 @@
 from . import backend_agg, backend_cairo, backend_gtk3
 from ._gtk3_compat import gi
 from .backend_cairo import cairo
-from .backend_gtk3 import _BackendGTK3
+from .backend_gtk3 import Gtk, _BackendGTK3
 from matplotlib import transforms
 
 # The following combinations are allowed:
@@ -38,6 +38,10 @@ def on_draw_event(self, widget, ctx):
 
         if not len(self._bbox_queue):
             self._render_figure(w, h)
+            Gtk.render_background(
+                self.get_style_context(), ctx,
+                allocation.x, allocation.y,
+                allocation.width, allocation.height)
             bbox_queue = [transforms.Bbox([[0, 0], [w, h]])]
         else:
             bbox_queue = self._bbox_queue
diff --git a/lib/matplotlib/backends/backend_gtk3cairo.py b/lib/matplotlib/backends/backend_gtk3cairo.py
@@ -1,7 +1,7 @@
 from . import backend_cairo, backend_gtk3
 from ._gtk3_compat import gi
 from .backend_cairo import cairo
-from .backend_gtk3 import _BackendGTK3
+from .backend_gtk3 import Gtk, _BackendGTK3
 from matplotlib.backend_bases import cursors
 
 
@@ -39,6 +39,9 @@ def on_draw_event(self, widget, ctx):
         #     toolbar.set_cursor(cursors.WAIT)
         self._renderer.set_context(ctx)
         allocation = self.get_allocation()
+        Gtk.render_background(
+            self.get_style_context(), ctx,
+            allocation.x, allocation.y, allocation.width, allocation.height)
         self._render_figure(allocation.width, allocation.height)
         # if toolbar:
         #     toolbar.set_cursor(toolbar._lastCursor)
