From dd562095cb5b881c1d96dc4a63d4275bf3f642c9 Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Sun, 5 Nov 2017 22:14:24 -0800
Subject: [PATCH 1/2] Small cleanups.

---
 lib/matplotlib/backends/backend_qt5.py   | 16 ++++++----------
 lib/matplotlib/backends/backend_tkagg.py |  1 -
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
index 6d4546644aa3..07439093db48 100644
--- a/lib/matplotlib/backends/backend_qt5.py
+++ b/lib/matplotlib/backends/backend_qt5.py
@@ -233,20 +233,12 @@ def _update_figure_dpi(self):
     @_allow_super_init
     def __init__(self, figure):
         _create_qApp()
-        figure._original_dpi = figure.dpi
-
         super(FigureCanvasQT, self).__init__(figure=figure)
 
+        figure._original_dpi = figure.dpi
         self.figure = figure
         self._update_figure_dpi()
-
-        w, h = self.get_width_height()
-        self.resize(w, h)
-
-        self.setMouseTracking(True)
-        # Key auto-repeat enabled by default
-        self._keyautorepeat = True
-
+        self.resize(*self.get_width_height())
         # In cases with mixed resolution displays, we need to be careful if the
         # dpi_ratio changes - in this case we need to resize the canvas
         # accordingly. We could watch for screenChanged events from Qt, but
@@ -256,6 +248,10 @@ def __init__(self, figure):
         # needed.
         self._dpi_ratio_prev = None
 
+        self.setMouseTracking(True)
+        # Key auto-repeat enabled by default
+        self._keyautorepeat = True
+
     @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
index 70b06274c00d..da8773fac277 100644
--- a/lib/matplotlib/backends/backend_tkagg.py
+++ b/lib/matplotlib/backends/backend_tkagg.py
@@ -661,7 +661,6 @@ class NavigationToolbar2TkAgg(NavigationToolbar2, Tk.Frame):
     def __init__(self, canvas, window):
         self.canvas = canvas
         self.window = window
-        self._idle = True
         NavigationToolbar2.__init__(self, canvas)
 
     def destroy(self, *args):

From d5d553a050890ea9c754438aaa1baa8d426ac62a Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Sun, 5 Nov 2017 22:21:43 -0800
Subject: [PATCH 2/2] Set widget background to white.

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.
---
 examples/user_interfaces/embedding_in_wx3_sgskip.py |  4 ----
 lib/matplotlib/backends/backend_qt5.py              |  3 +++
 lib/matplotlib/backends/backend_tkagg.py            |  4 ++--
 lib/matplotlib/backends/backend_wx.py               | 11 ++---------
 4 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/examples/user_interfaces/embedding_in_wx3_sgskip.py b/examples/user_interfaces/embedding_in_wx3_sgskip.py
index 9368b2917438..c1aca8b6d144 100644
--- a/examples/user_interfaces/embedding_in_wx3_sgskip.py
+++ b/examples/user_interfaces/embedding_in_wx3_sgskip.py
@@ -99,10 +99,6 @@ def OnWhiz(self, evt):
 
         self.canvas.draw()
 
-    def onEraseBackground(self, evt):
-        # this is supposed to prevent redraw flicker on some X servers...
-        pass
-
 
 class MyApp(wx.App):
     def OnInit(self):
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
index 07439093db48..e3ac5467508e 100644
--- 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
index da8773fac277..58d171f0d737 100644
--- 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
index 49ba3e87f9f2..7be2117f483e 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -684,8 +684,8 @@ def do_nothing(*args, **kwargs):
         self.Bind(wx.EVT_MOUSE_CAPTURE_CHANGED, self._onCaptureLost)
         self.Bind(wx.EVT_MOUSE_CAPTURE_LOST, self._onCaptureLost)
 
-        # Reduce flicker.
-        self.SetBackgroundStyle(wx.BG_STYLE_PAINT)
+        self.SetBackgroundStyle(wx.BG_STYLE_PAINT)  # Reduce flicker.
+        self.SetBackgroundColour(wx.WHITE)
 
         self.macros = {}  # dict from wx id to seq of macros
 
@@ -941,13 +941,6 @@ def _onPaint(self, evt):
             self.gui_repaint(drawDC=drawDC)
         evt.Skip()
 
-    def _onEraseBackground(self, evt):
-        """
-        Called when window is redrawn; since we are blitting the entire
-        image, we can leave this blank to suppress flicker.
-        """
-        pass
-
     def _onSize(self, evt):
         """
         Called when wxEventSize is generated.