Set widget background to white.

anntzer · anntzer · commit 4be01d0383fc · 2017-11-05T22:50:05.000-08:00
The background color of the widget can be seen by setting a transparent
figure facecolor, e.g.

    from pylab import *
    rcParams["figure.facecolor"] = (0, 0, 0, 0); gca(); show()

The goal is to ultimately replace setting `savefig.transparent` by
`figure.facecolor = (0, 0, 0, 0)`.

As far as I can tell, gtk3 already defaults to a white background.  Not
sure what the situation is on OSX.
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
@@ -252,6 +252,9 @@ def __init__(self, figure):
         # Key auto-repeat enabled by default
         self._keyautorepeat = True
 
+        palette = QtGui.QPalette(QtCore.Qt.white)
+        self.setPalette(palette)
+
     @property
     def _dpi_ratio(self):
         # Not available on Qt4 or some older Qt5.
diff --git a/lib/matplotlib/backends/backend_tkagg.py b/lib/matplotlib/backends/backend_tkagg.py
@@ -176,8 +176,8 @@ def __init__(self, figure, master=None, resize_callback=None):
         t1,t2,w,h = self.figure.bbox.bounds
         w, h = int(w), int(h)
         self._tkcanvas = Tk.Canvas(
-            master=master, width=w, height=h, borderwidth=0,
-            highlightthickness=0)
+            master=master, background="white",
+            width=w, height=h, borderwidth=0, highlightthickness=0)
         self._tkphoto = Tk.PhotoImage(
             master=self._tkcanvas, width=w, height=h)
         self._tkcanvas.create_image(w//2, h//2, image=self._tkphoto)
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -691,6 +691,7 @@ def do_nothing(*args, **kwargs):
         else:
             # this does the same in 2.9+
             self.SetBackgroundStyle(wx.BG_STYLE_PAINT)
+        self.SetBackgroundColour(wx.WHITE)
 
         self.macros = {}  # dict from wx id to seq of macros
 
