From 39c17b05f25e0fbf5245d3e36e96f57a8cf06360 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Sun, 26 Aug 2018 21:12:15 +0200
Subject: [PATCH 01/14] Don't use ClientDC any more but do all drawing in the
 EVT_PAINT handler.

For rubberband selection etc., use Refresh to trigger a screen update.
---
 lib/matplotlib/backends/backend_wx.py      | 271 ++++++---------------
 lib/matplotlib/backends/backend_wxagg.py   |   9 +-
 lib/matplotlib/backends/backend_wxcairo.py |   2 +-
 3 files changed, 85 insertions(+), 197 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 7edf773c12a6..7bfe3f48a8de 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -531,6 +531,8 @@ def __init__(self, parent, id, figure):
         _log.debug("%s - __init__() - bitmap w:%d h:%d", type(self), w, h)
         # TODO: Add support for 'point' inspection and plot navigation.
         self._isDrawn = False
+        self._rubberband = None  # a selection rectangle to be drawn
+        self._overlay = None
 
         self.Bind(wx.EVT_SIZE, self._onSize)
         self.Bind(wx.EVT_PAINT, self._onPaint)
@@ -619,29 +621,6 @@ def _get_imagesave_wildcards(self):
         wildcards = '|'.join(wildcards)
         return wildcards, extensions, filter_index
 
-    def gui_repaint(self, drawDC=None, origin='WX'):
-        """
-        Performs update of the displayed image on the GUI canvas, using the
-        supplied wx.PaintDC device context.
-
-        The 'WXAgg' backend sets origin accordingly.
-        """
-        _log.debug("%s - gui_repaint()", type(self))
-        if self.IsShownOnScreen():
-            if not drawDC:
-                # not called from OnPaint use a ClientDC
-                drawDC = wx.ClientDC(self)
-
-            # following is for 'WX' backend on Windows
-            # the bitmap can not be in use by another DC,
-            # see GraphicsContextWx._cache
-            if wx.Platform == '__WXMSW__' and origin == 'WX':
-                img = self.bitmap.ConvertToImage()
-                bmp = img.ConvertToBitmap()
-                drawDC.DrawBitmap(bmp, 0, 0)
-            else:
-                drawDC.DrawBitmap(self.bitmap, 0, 0)
-
     filetypes = {
         **FigureCanvasBase.filetypes,
         'bmp': 'Windows bitmap',
@@ -666,12 +645,41 @@ def print_figure(self, filename, *args, **kwargs):
     def _onPaint(self, event):
         """Called when wxPaintEvt is generated."""
         _log.debug("%s - _onPaint()", type(self))
-        drawDC = wx.PaintDC(self)
         if not self._isDrawn:
-            self.draw(drawDC=drawDC)
+            self.draw()
+
+        # the bitmap can not be in use by another DC
+        img = self.bitmap.ConvertToImage()
+        bmp = img.ConvertToBitmap()
+        dc = wx.BufferedPaintDC(self, bmp)
+
+        if not self._rubberband:
+            return
+
+        # draw rubberband / selection using an overlay
+        if self._overlay is None:
+            self._overlay = wx.Overlay()
+        odc = wx.DCOverlay(self._overlay, dc)
+
+        if not 'wxMac' in wx.PlatformInfo:
+            # draw a box with border and 50% transparency
+            dc = wx.GCDC(dc)
+            # Set the pen, for the box's border
+            bc = wx.BLUE
+            dc.SetPen(wx.Pen(colour=bc, width=1, style=wx.PENSTYLE_SOLID))
+            # Create a brush (for the box's interior) with the same colour,
+            # but 50% transparency.
+            bc = wx.Colour(bc.red, bc.green, bc.blue, 0x80)
+            dc.SetBrush(wx.Brush(bc))
         else:
-            self.gui_repaint(drawDC=drawDC)
-        drawDC.Destroy()
+            # draw without transparency which is buggy on Retina displays
+            dc.SetPen(wx.Pen(wx.BLUE, 1, wx.SOLID))
+            dc.SetBrush(wx.TRANSPARENT_BRUSH)
+
+        # Draw the rectangle
+        topLeft, bottomRight = self._rubberband
+        rect = wx.Rect(topLeft=topLeft, bottomRight=bottomRight)
+        dc.DrawRectangle(rect)
 
     def _onSize(self, event):
         """
@@ -824,11 +832,44 @@ def _onEnter(self, event):
         event.Skip()
         FigureCanvasBase.enter_notify_event(self, guiEvent=event, xy=(x, y))
 
+    def _draw_rubberband(self, x0, y0, x1, y1):
+        # trigger a refresh to draw a rubberband-like selection box
+        previous_rubberband = self._rubberband
+        height = self.figure.bbox.height
+        y1 = height - y1
+        y0 = height - y0
+        self._rubberband = [(x0, y0), (x1, y1)]
+        self._refresh_rubberband(previous_rubberband)
+
+    def _remove_rubberband(self):
+        # end drawing of a rubberband-like selection box
+        if not self._rubberband:
+            return
+        self._overlay.Reset()
+        self._overlay = None
+        self._refresh_rubberband()  # trigger a later redraw over the last rubberband area
+        self._rubberband = None
+
+    def _refresh_rubberband(self, previous_rubberband=None):
+        # initiate a refresh on the area that contains the previous and
+        # current selection / rubberband
+        points = list(self._rubberband)
+        if previous_rubberband:
+            points += previous_rubberband
+        # find the rectangle that covers the previous and current selection
+        top    = min(point[1] for point in points)
+        left   = min(point[0] for point in points)
+        bottom = max(point[1] for point in points)
+        right  = max(point[0] for point in points)
+
+        rect = wx.Rect(topLeft=wx.Point(left,top), bottomRight=wx.Point(right, bottom))
+        self.Refresh(False, rect)
+
 
 class FigureCanvasWx(_FigureCanvasWxBase):
     # Rendering to a Wx canvas using the deprecated Wx renderer.
 
-    def draw(self, drawDC=None):
+    def draw(self):
         """
         Render the figure using RendererWx instance renderer, or using a
         previously defined renderer if none is specified.
@@ -837,7 +878,6 @@ def draw(self, drawDC=None):
         self.renderer = RendererWx(self.bitmap, self.figure.dpi)
         self.figure.draw(self.renderer)
         self._isDrawn = True
-        self.gui_repaint(drawDC=drawDC)
 
     def print_bmp(self, filename, *args, **kwargs):
         return self._print_image(filename, wx.BITMAP_TYPE_BMP, *args, **kwargs)
@@ -1120,11 +1160,6 @@ def __init__(self, canvas):
         self.canvas = canvas
         self._idle = True
         self.prevZoomRect = None
-        # for now, use alternate zoom-rectangle drawing on all
-        # Macs. N.B. In future versions of wx it may be possible to
-        # detect Retina displays with window.GetContentScaleFactor()
-        # and/or dc.GetContentScaleFactor()
-        self.retinaFix = 'wxMac' in wx.PlatformInfo
 
     def get_canvas(self, frame, fig):
         return type(self.canvas)(frame, -1, fig)
@@ -1216,85 +1251,14 @@ def set_cursor(self, cursor):
         self.canvas.Update()
 
     def press(self, event):
-        if self._active == 'ZOOM':
-            if not self.retinaFix:
-                self.wxoverlay = wx.Overlay()
-            else:
-                if event.inaxes is not None:
-                    self.savedRetinaImage = self.canvas.copy_from_bbox(
-                        event.inaxes.bbox)
-                    self.zoomStartX = event.xdata
-                    self.zoomStartY = event.ydata
-                    self.zoomAxes = event.inaxes
+        pass
 
     def release(self, event):
         if self._active == 'ZOOM':
-            # When the mouse is released we reset the overlay and it
-            # restores the former content to the window.
-            if not self.retinaFix:
-                self.wxoverlay.Reset()
-                del self.wxoverlay
-            else:
-                del self.savedRetinaImage
-                if self.prevZoomRect:
-                    self.prevZoomRect.pop(0).remove()
-                    self.prevZoomRect = None
-                if self.zoomAxes:
-                    self.zoomAxes = None
+            self.canvas._remove_rubberband()
 
     def draw_rubberband(self, event, x0, y0, x1, y1):
-        if self.retinaFix:  # On Macs, use the following code
-            # wx.DCOverlay does not work properly on Retina displays.
-            rubberBandColor = '#C0C0FF'
-            if self.prevZoomRect:
-                self.prevZoomRect.pop(0).remove()
-            self.canvas.restore_region(self.savedRetinaImage)
-            X0, X1 = self.zoomStartX, event.xdata
-            Y0, Y1 = self.zoomStartY, event.ydata
-            lineX = (X0, X0, X1, X1, X0)
-            lineY = (Y0, Y1, Y1, Y0, Y0)
-            self.prevZoomRect = self.zoomAxes.plot(
-                lineX, lineY, '-', color=rubberBandColor)
-            self.zoomAxes.draw_artist(self.prevZoomRect[0])
-            self.canvas.blit(self.zoomAxes.bbox)
-            return
-
-        # Use an Overlay to draw a rubberband-like bounding box.
-
-        dc = wx.ClientDC(self.canvas)
-        odc = wx.DCOverlay(self.wxoverlay, dc)
-        odc.Clear()
-
-        # Mac's DC is already the same as a GCDC, and it causes
-        # problems with the overlay if we try to use an actual
-        # wx.GCDC so don't try it.
-        if 'wxMac' not in wx.PlatformInfo:
-            dc = wx.GCDC(dc)
-
-        height = self.canvas.figure.bbox.height
-        y1 = height - y1
-        y0 = height - y0
-
-        if y1 < y0:
-            y0, y1 = y1, y0
-        if x1 < x0:
-            x0, x1 = x1, x0
-
-        w = x1 - x0
-        h = y1 - y0
-        rect = wx.Rect(x0, y0, w, h)
-
-        rubberBandColor = '#C0C0FF'  # or load from config?
-
-        # Set a pen for the border
-        color = wx.Colour(rubberBandColor)
-        dc.SetPen(wx.Pen(color, 1))
-
-        # use the same color, plus alpha for the brush
-        r, g, b, a = color.Get(True)
-        color.Set(r, g, b, 0x60)
-        dc.SetBrush(wx.Brush(color))
-        dc.DrawRectangle(rect)
+        self.canvas._draw_rubberband(x0, y0, x1, y1)
 
     @cbook.deprecated("3.2")
     def set_status_bar(self, statbar):
@@ -1451,91 +1415,16 @@ def set_cursor(self, cursor):
             self._make_classic_style_pseudo_toolbar(), cursor)
 
 
-if 'wxMac' not in wx.PlatformInfo:
-    # on most platforms, use overlay
-    class RubberbandWx(backend_tools.RubberbandBase):
-        def __init__(self, *args, **kwargs):
-            backend_tools.RubberbandBase.__init__(self, *args, **kwargs)
-            self.wxoverlay = None
-
-        def draw_rubberband(self, x0, y0, x1, y1):
-            # Use an Overlay to draw a rubberband-like bounding box.
-            if self.wxoverlay is None:
-                self.wxoverlay = wx.Overlay()
-            dc = wx.ClientDC(self.canvas)
-            odc = wx.DCOverlay(self.wxoverlay, dc)
-            odc.Clear()
-
-            dc = wx.GCDC(dc)
-
-            height = self.canvas.figure.bbox.height
-            y1 = height - y1
-            y0 = height - y0
-
-            if y1 < y0:
-                y0, y1 = y1, y0
-            if x1 < x0:
-                x0, x1 = x1, x0
-
-            w = x1 - x0
-            h = y1 - y0
-            rect = wx.Rect(x0, y0, w, h)
-
-            rubberBandColor = '#C0C0FF'  # or load from config?
-
-            # Set a pen for the border
-            color = wx.Colour(rubberBandColor)
-            dc.SetPen(wx.Pen(color, 1))
-
-            # use the same color, plus alpha for the brush
-            r, g, b, a = color.Get(True)
-            color.Set(r, g, b, 0x60)
-            dc.SetBrush(wx.Brush(color))
-            dc.DrawRectangle(rect)
+class RubberbandWx(backend_tools.RubberbandBase):
+    def __init__(self, *args, **kwargs):
+        backend_tools.RubberbandBase.__init__(self, *args, **kwargs)
 
-        def remove_rubberband(self):
-            if self.wxoverlay is None:
-                return
-            self.wxoverlay.Reset()
-            self.wxoverlay = None
-
-else:
-    # on Mac OS retina displays DCOverlay does not work
-    # and dc.SetLogicalFunction does not have an effect on any display
-    # the workaround is to blit the full image for remove_rubberband
-    class RubberbandWx(backend_tools.RubberbandBase):
-        def __init__(self, *args, **kwargs):
-            backend_tools.RubberbandBase.__init__(self, *args, **kwargs)
-            self._rect = None
-
-        def draw_rubberband(self, x0, y0, x1, y1):
-            dc = wx.ClientDC(self.canvas)
-            # this would be required if the Canvas is a ScrolledWindow,
-            # which is not the case for now
-            # self.PrepareDC(dc)
-
-            # delete old rubberband
-            if self._rect:
-                self.remove_rubberband(dc)
-
-            # draw new rubberband
-            dc.SetPen(wx.Pen(wx.BLACK, 1, wx.SOLID))
-            dc.SetBrush(wx.TRANSPARENT_BRUSH)
-            self._rect = (x0, self.canvas._height-y0, x1-x0, -y1+y0)
-            dc.DrawRectangle(self._rect)
+    def draw_rubberband(self, x0, y0, x1, y1):
+        # Use an Overlay to draw a rubberband-like bounding box.
+        self.canvas._draw_rubberband(x0, y0, x1, y1)
 
-        def remove_rubberband(self, dc=None):
-            if not self._rect:
-                return
-            if self.canvas.bitmap:
-                if dc is None:
-                    dc = wx.ClientDC(self.canvas)
-                dc.DrawBitmap(self.canvas.bitmap, 0, 0)
-                #  for testing the method on Windows, use this code instead:
-                # img = self.canvas.bitmap.ConvertToImage()
-                # bmp = img.ConvertToBitmap()
-                # dc.DrawBitmap(bmp, 0, 0)
-            self._rect = None
+    def remove_rubberband(self):
+        self.canvas._remove_rubberband()
 
 
 class _HelpDialog(wx.Dialog):
diff --git a/lib/matplotlib/backends/backend_wxagg.py b/lib/matplotlib/backends/backend_wxagg.py
index 3bbb4ab25f4a..a91da955b267 100644
--- a/lib/matplotlib/backends/backend_wxagg.py
+++ b/lib/matplotlib/backends/backend_wxagg.py
@@ -22,7 +22,7 @@ class FigureCanvasWxAgg(FigureCanvasAgg, _FigureCanvasWxBase):
     size.
     """
 
-    def draw(self, drawDC=None):
+    def draw(self):
         """
         Render the figure using agg.
         """
@@ -30,13 +30,11 @@ def draw(self, drawDC=None):
 
         self.bitmap = _convert_agg_to_wx_bitmap(self.get_renderer(), None)
         self._isDrawn = True
-        self.gui_repaint(drawDC=drawDC, origin='WXAgg')
 
     def blit(self, bbox=None):
-        # docstring inherited
         if bbox is None:
             self.bitmap = _convert_agg_to_wx_bitmap(self.get_renderer(), None)
-            self.gui_repaint()
+            self.Refresh()
             return
 
         l, b, w, h = bbox.bounds
@@ -56,7 +54,8 @@ def blit(self, bbox=None):
 
         destDC.SelectObject(wx.NullBitmap)
         srcDC.SelectObject(wx.NullBitmap)
-        self.gui_repaint()
+
+        self.Refresh(rect=wx.Rect(x,y, int(w), int(h)))
 
 
 def _convert_agg_to_wx_bitmap(agg, bbox):
diff --git a/lib/matplotlib/backends/backend_wxcairo.py b/lib/matplotlib/backends/backend_wxcairo.py
index 5fcd263685a2..c7b0b48a45d0 100644
--- a/lib/matplotlib/backends/backend_wxcairo.py
+++ b/lib/matplotlib/backends/backend_wxcairo.py
@@ -38,7 +38,7 @@ def draw(self, drawDC=None):
         self.figure.draw(self._renderer)
         self.bitmap = wxcairo.BitmapFromImageSurface(surface)
         self._isDrawn = True
-        self.gui_repaint(drawDC=drawDC, origin='WXCairo')
+        self.Refresh()
 
 
 @_BackendWx.export

From cff5f637af9d5c7e19be725cc731a7d442c141d3 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Sun, 26 Aug 2018 23:01:33 +0200
Subject: [PATCH 02/14] rubberband: extend by one pixel to avoid residuals on
 Mac OS

---
 lib/matplotlib/backends/backend_wx.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 7bfe3f48a8de..4c6dec0c1fca 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -861,6 +861,16 @@ def _refresh_rubberband(self, previous_rubberband=None):
         left   = min(point[0] for point in points)
         bottom = max(point[1] for point in points)
         right  = max(point[0] for point in points)
+        if previous_rubberband:
+            # extend by one pixel to avoid residuals on Mac OS
+            if left > 0:
+                left -= 1
+            if top > 0:
+                top -= 1
+            if bottom < self.figure.bbox.height - 1:
+                bottom += 1
+            if top < self.figure.bbox.width - 1:
+                top += 1
 
         rect = wx.Rect(topLeft=wx.Point(left,top), bottomRight=wx.Point(right, bottom))
         self.Refresh(False, rect)

From b31c7366f41888525b4b22f1baf19c82269f4913 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Sun, 26 Aug 2018 23:11:51 +0200
Subject: [PATCH 03/14] fix bug in previous commit

---
 lib/matplotlib/backends/backend_wx.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 4c6dec0c1fca..b1befe1d0cc1 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -861,6 +861,7 @@ def _refresh_rubberband(self, previous_rubberband=None):
         left   = min(point[0] for point in points)
         bottom = max(point[1] for point in points)
         right  = max(point[0] for point in points)
+
         if previous_rubberband:
             # extend by one pixel to avoid residuals on Mac OS
             if left > 0:
@@ -869,8 +870,8 @@ def _refresh_rubberband(self, previous_rubberband=None):
                 top -= 1
             if bottom < self.figure.bbox.height - 1:
                 bottom += 1
-            if top < self.figure.bbox.width - 1:
-                top += 1
+            if right < self.figure.bbox.width - 1:
+                right += 1
 
         rect = wx.Rect(topLeft=wx.Point(left,top), bottomRight=wx.Point(right, bottom))
         self.Refresh(False, rect)

From 452ab5c7a293da17bbf773927ab5e69afd2b7035 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Sun, 26 Aug 2018 23:15:06 +0200
Subject: [PATCH 04/14] shorten lines for PEP 8

---
 lib/matplotlib/backends/backend_wx.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index b1befe1d0cc1..5e732bc73609 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -847,7 +847,7 @@ def _remove_rubberband(self):
             return
         self._overlay.Reset()
         self._overlay = None
-        self._refresh_rubberband()  # trigger a later redraw over the last rubberband area
+        self._refresh_rubberband()  # trigger a later redraw
         self._rubberband = None
 
     def _refresh_rubberband(self, previous_rubberband=None):
@@ -873,7 +873,8 @@ def _refresh_rubberband(self, previous_rubberband=None):
             if right < self.figure.bbox.width - 1:
                 right += 1
 
-        rect = wx.Rect(topLeft=wx.Point(left,top), bottomRight=wx.Point(right, bottom))
+        rect = wx.Rect(topLeft=wx.Point(left,top),
+                       bottomRight=wx.Point(right, bottom))
         self.Refresh(False, rect)
 
 

From 779efc017a03951091daf18ad55d139e29a3a0d6 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Sun, 26 Aug 2018 23:42:39 +0200
Subject: [PATCH 05/14] trigger Refresh after draw

---
 lib/matplotlib/backends/backend_wx.py    | 1 +
 lib/matplotlib/backends/backend_wxagg.py | 1 +
 2 files changed, 2 insertions(+)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 5e732bc73609..5db610ba7f79 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -890,6 +890,7 @@ def draw(self):
         self.renderer = RendererWx(self.bitmap, self.figure.dpi)
         self.figure.draw(self.renderer)
         self._isDrawn = True
+        self.Refresh()
 
     def print_bmp(self, filename, *args, **kwargs):
         return self._print_image(filename, wx.BITMAP_TYPE_BMP, *args, **kwargs)
diff --git a/lib/matplotlib/backends/backend_wxagg.py b/lib/matplotlib/backends/backend_wxagg.py
index a91da955b267..203901819ba0 100644
--- a/lib/matplotlib/backends/backend_wxagg.py
+++ b/lib/matplotlib/backends/backend_wxagg.py
@@ -30,6 +30,7 @@ def draw(self):
 
         self.bitmap = _convert_agg_to_wx_bitmap(self.get_renderer(), None)
         self._isDrawn = True
+        self.Refresh()
 
     def blit(self, bbox=None):
         if bbox is None:

From 4ff217daba48f5f7ce920afc9ee206196ddf0463 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 27 Aug 2018 00:07:38 +0200
Subject: [PATCH 06/14] PEP 8 compliance

---
 lib/matplotlib/backends/backend_wx.py    | 10 +++++-----
 lib/matplotlib/backends/backend_wxagg.py |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 5db610ba7f79..adbfc575e261 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -661,7 +661,7 @@ def _onPaint(self, event):
             self._overlay = wx.Overlay()
         odc = wx.DCOverlay(self._overlay, dc)
 
-        if not 'wxMac' in wx.PlatformInfo:
+        if 'wxMac' not in wx.PlatformInfo:
             # draw a box with border and 50% transparency
             dc = wx.GCDC(dc)
             # Set the pen, for the box's border
@@ -857,10 +857,10 @@ def _refresh_rubberband(self, previous_rubberband=None):
         if previous_rubberband:
             points += previous_rubberband
         # find the rectangle that covers the previous and current selection
-        top    = min(point[1] for point in points)
-        left   = min(point[0] for point in points)
+        top = min(point[1] for point in points)
+        left = min(point[0] for point in points)
         bottom = max(point[1] for point in points)
-        right  = max(point[0] for point in points)
+        right = max(point[0] for point in points)
 
         if previous_rubberband:
             # extend by one pixel to avoid residuals on Mac OS
@@ -873,7 +873,7 @@ def _refresh_rubberband(self, previous_rubberband=None):
             if right < self.figure.bbox.width - 1:
                 right += 1
 
-        rect = wx.Rect(topLeft=wx.Point(left,top),
+        rect = wx.Rect(topLeft=wx.Point(left, top),
                        bottomRight=wx.Point(right, bottom))
         self.Refresh(False, rect)
 
diff --git a/lib/matplotlib/backends/backend_wxagg.py b/lib/matplotlib/backends/backend_wxagg.py
index 203901819ba0..60dc66e08a21 100644
--- a/lib/matplotlib/backends/backend_wxagg.py
+++ b/lib/matplotlib/backends/backend_wxagg.py
@@ -56,7 +56,7 @@ def blit(self, bbox=None):
         destDC.SelectObject(wx.NullBitmap)
         srcDC.SelectObject(wx.NullBitmap)
 
-        self.Refresh(rect=wx.Rect(x,y, int(w), int(h)))
+        self.Refresh(rect=wx.Rect(x, y, int(w), int(h)))
 
 
 def _convert_agg_to_wx_bitmap(agg, bbox):

From 97fccf1ee1ccad22ffb296adc216569781ca4612 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 27 Aug 2018 23:12:24 +0200
Subject: [PATCH 07/14] Use dashed black line for rubberband on Mac OS

---
 lib/matplotlib/backends/backend_wx.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index adbfc575e261..6700733c159d 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -673,7 +673,7 @@ def _onPaint(self, event):
             dc.SetBrush(wx.Brush(bc))
         else:
             # draw without transparency which is buggy on Retina displays
-            dc.SetPen(wx.Pen(wx.BLUE, 1, wx.SOLID))
+            dc.SetPen(wx.Pen(wx.BLACK, 1, wx.PENSTYLE_SHORT_DASH))
             dc.SetBrush(wx.TRANSPARENT_BRUSH)
 
         # Draw the rectangle

From 5f408d710dd1dafa8991bc5d4d86247dc176625b Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 27 Aug 2018 23:12:49 +0200
Subject: [PATCH 08/14] clearer calculation of extended rubberband box

---
 lib/matplotlib/backends/backend_wx.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 6700733c159d..255fcf79d858 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -864,14 +864,10 @@ def _refresh_rubberband(self, previous_rubberband=None):
 
         if previous_rubberband:
             # extend by one pixel to avoid residuals on Mac OS
-            if left > 0:
-                left -= 1
-            if top > 0:
-                top -= 1
-            if bottom < self.figure.bbox.height - 1:
-                bottom += 1
-            if right < self.figure.bbox.width - 1:
-                right += 1
+            left = max(left - 1, 0)
+            top = max(top - 1, 0)
+            bottom = min(bottom + 1, self.figure.bbox.height - 1)
+            right = min(right + 1, self.figure.bbox.width - 1)
 
         rect = wx.Rect(topLeft=wx.Point(left, top),
                        bottomRight=wx.Point(right, bottom))

From 98146f3030e7e60ec97821c636365e0e7019142a Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 27 Aug 2018 23:56:26 +0200
Subject: [PATCH 09/14] separate rendering and Refresh into _draw() and draw()

---
 lib/matplotlib/backends/backend_wx.py      | 104 +++++++++++++++++++--
 lib/matplotlib/backends/backend_wxagg.py   |   8 +-
 lib/matplotlib/backends/backend_wxcairo.py |   8 +-
 3 files changed, 112 insertions(+), 8 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 255fcf79d858..bd85cb58c550 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -646,7 +646,7 @@ def _onPaint(self, event):
         """Called when wxPaintEvt is generated."""
         _log.debug("%s - _onPaint()", type(self))
         if not self._isDrawn:
-            self.draw()
+            self._draw()
 
         # the bitmap can not be in use by another DC
         img = self.bitmap.ConvertToImage()
@@ -877,15 +877,18 @@ def _refresh_rubberband(self, previous_rubberband=None):
 class FigureCanvasWx(_FigureCanvasWxBase):
     # Rendering to a Wx canvas using the deprecated Wx renderer.
 
+    def _draw(self):
+        _log.debug("%s - _draw()", type(self))
+        self.renderer = RendererWx(self.bitmap, self.figure.dpi)
+        self.figure.draw(self.renderer)
+        self._isDrawn = True
+
     def draw(self):
         """
         Render the figure using RendererWx instance renderer, or using a
         previously defined renderer if none is specified.
         """
-        _log.debug("%s - draw()", type(self))
-        self.renderer = RendererWx(self.bitmap, self.figure.dpi)
-        self.figure.draw(self.renderer)
-        self._isDrawn = True
+        self._draw()
         self.Refresh()
 
     def print_bmp(self, filename, *args, **kwargs):
@@ -957,7 +960,7 @@ def _print_image(self, filename, filetype, *args, **kwargs):
         # been cleaned up.  The artist contains() methods will fail
         # otherwise.
         if self._isDrawn:
-            self.draw()
+            self._draw()
         self.Refresh()
 
 
@@ -1507,6 +1510,95 @@ def trigger(self, *args, **kwargs):
 backend_tools.ToolCopyToClipboard = ToolCopyToClipboardWx
 
 
+<<<<<<< HEAD
+=======
+# < Additions for printing support: Matt Newville
+
+class PrintoutWx(wx.Printout):
+    """
+    Simple wrapper around wx Printout class -- all the real work
+    here is scaling the matplotlib canvas bitmap to the current
+    printer's definition.
+    """
+
+    def __init__(self, canvas, width=5.5, margin=0.5, title='matplotlib'):
+        wx.Printout.__init__(self, title=title)
+        self.canvas = canvas
+        # width, in inches of output figure (approximate)
+        self.width = width
+        self.margin = margin
+
+    def HasPage(self, page):
+        # current only supports 1 page print
+        return page == 1
+
+    def GetPageInfo(self):
+        return (1, 1, 1, 1)
+
+    def OnPrintPage(self, page):
+        self.canvas._draw()
+
+        dc = self.GetDC()
+        ppw, pph = self.GetPPIPrinter()      # printer's pixels per in
+        pgw, pgh = self.GetPageSizePixels()  # page size in pixels
+        dcw, dch = dc.GetSize()
+        grw, grh = self.canvas.GetSize()
+
+        # save current figure dpi resolution and bg color,
+        # so that we can temporarily set them to the dpi of
+        # the printer, and the bg color to white
+        bgcolor = self.canvas.figure.get_facecolor()
+        fig_dpi = self.canvas.figure.dpi
+
+        # draw the bitmap, scaled appropriately
+        vscale = float(ppw) / fig_dpi
+
+        # set figure resolution,bg color for printer
+        self.canvas.figure.dpi = ppw
+        self.canvas.figure.set_facecolor('#FFFFFF')
+
+        renderer = RendererWx(self.canvas.bitmap, self.canvas.figure.dpi)
+        self.canvas.figure.draw(renderer)
+        self.canvas.bitmap.SetWidth(
+            int(self.canvas.bitmap.GetWidth() * vscale))
+        self.canvas.bitmap.SetHeight(
+            int(self.canvas.bitmap.GetHeight() * vscale))
+        self.canvas._draw()
+
+        # page may need additional scaling on preview
+        page_scale = 1.0
+        if self.IsPreview():
+            page_scale = float(dcw) / pgw
+
+        # get margin in pixels = (margin in in) * (pixels/in)
+        top_margin = int(self.margin * pph * page_scale)
+        left_margin = int(self.margin * ppw * page_scale)
+
+        # set scale so that width of output is self.width inches
+        # (assuming grw is size of graph in inches....)
+        user_scale = (self.width * fig_dpi * page_scale) / float(grw)
+
+        dc.SetDeviceOrigin(left_margin, top_margin)
+        dc.SetUserScale(user_scale, user_scale)
+
+        # this cute little number avoid API inconsistencies in wx
+        try:
+            dc.DrawBitmap(self.canvas.bitmap, 0, 0)
+        except Exception:
+            try:
+                dc.DrawBitmap(self.canvas.bitmap, (0, 0))
+            except Exception:
+                pass
+
+        # restore original figure  resolution
+        self.canvas.figure.set_facecolor(bgcolor)
+        self.canvas.figure.dpi = fig_dpi
+        self.canvas.draw()
+        return True
+# >
+
+
+>>>>>>> d2cb5900b... separate rendering and Refresh into _draw() and draw()
 @_Backend.export
 class _BackendWx(_Backend):
     FigureCanvas = FigureCanvasWx
diff --git a/lib/matplotlib/backends/backend_wxagg.py b/lib/matplotlib/backends/backend_wxagg.py
index 60dc66e08a21..bdf6e017e9ed 100644
--- a/lib/matplotlib/backends/backend_wxagg.py
+++ b/lib/matplotlib/backends/backend_wxagg.py
@@ -22,7 +22,7 @@ class FigureCanvasWxAgg(FigureCanvasAgg, _FigureCanvasWxBase):
     size.
     """
 
-    def draw(self):
+    def _draw(self):
         """
         Render the figure using agg.
         """
@@ -30,6 +30,12 @@ def draw(self):
 
         self.bitmap = _convert_agg_to_wx_bitmap(self.get_renderer(), None)
         self._isDrawn = True
+
+    def draw(self):
+        """
+        Render the figure using agg and trigger a screen refresh.
+        """
+        self._draw()
         self.Refresh()
 
     def blit(self, bbox=None):
diff --git a/lib/matplotlib/backends/backend_wxcairo.py b/lib/matplotlib/backends/backend_wxcairo.py
index c7b0b48a45d0..77a37b97df84 100644
--- a/lib/matplotlib/backends/backend_wxcairo.py
+++ b/lib/matplotlib/backends/backend_wxcairo.py
@@ -29,7 +29,7 @@ def __init__(self, parent, id, figure):
         FigureCanvasCairo.__init__(self, figure)
         self._renderer = RendererCairo(self.figure.dpi)
 
-    def draw(self, drawDC=None):
+    def _draw(self):
         width = int(self.figure.bbox.width)
         height = int(self.figure.bbox.height)
         surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
@@ -38,6 +38,12 @@ def draw(self, drawDC=None):
         self.figure.draw(self._renderer)
         self.bitmap = wxcairo.BitmapFromImageSurface(surface)
         self._isDrawn = True
+
+    def draw(self):
+        """
+        Render the figure and trigger a screen refresh.
+        """
+        self._draw()
         self.Refresh()
 
 

From b86d842b1a01c9ad1e747386e14ce97436d837a0 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 3 Sep 2018 22:07:33 +0200
Subject: [PATCH 10/14] re-introduce attribute _retinaFix, but on canvas level

---
 lib/matplotlib/backends/backend_wx.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index bd85cb58c550..16afc9ae11e9 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -507,6 +507,7 @@ class _FigureCanvasWxBase(FigureCanvasBase, wx.Panel):
         wx.WXK_NUMPAD_INSERT: 'insert',
         wx.WXK_NUMPAD_DELETE: 'delete',
     }
+    _retinaFix = 'wxMac' in wx.PlatformInfo
 
     def __init__(self, parent, id, figure):
         """
@@ -661,7 +662,7 @@ def _onPaint(self, event):
             self._overlay = wx.Overlay()
         odc = wx.DCOverlay(self._overlay, dc)
 
-        if 'wxMac' not in wx.PlatformInfo:
+        if not self._retinaFix:
             # draw a box with border and 50% transparency
             dc = wx.GCDC(dc)
             # Set the pen, for the box's border

From ac89e8b0cb58a3a83da4eb8272a43441edb213c7 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 3 Sep 2018 22:09:02 +0200
Subject: [PATCH 11/14] add API change notes

---
 .../2018-09-01-DS-backends_wx.rst                 | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 doc/api/next_api_changes/2018-09-01-DS-backends_wx.rst

diff --git a/doc/api/next_api_changes/2018-09-01-DS-backends_wx.rst b/doc/api/next_api_changes/2018-09-01-DS-backends_wx.rst
new file mode 100644
index 000000000000..645a052cd8ec
--- /dev/null
+++ b/doc/api/next_api_changes/2018-09-01-DS-backends_wx.rst
@@ -0,0 +1,15 @@
+wx Backends
+-----------
+
+The internal implementation of the wx backends was changed to do all
+the screen painting inside the ``_OnPaint`` method which handles wx
+``EVT_PAINT`` events.
+So for a screen update due to a call to ``draw`` or for drawing a
+selection rubberband, the ``Refresh`` method is called to trigger
+a later paint event instead of drawing directly to a ``ClientDC``.
+
+The atribute ``_retinaFix`` has moved from ``NavigationToolbar2Wx``
+to ``_FigureCanvasWxBase``.
+
+The method ``gui_repaint`` of all wx canvases has been removed.
+The ``draw`` method no longer accepts an argument ``drawDC``.

From 2f00cdcf32d19c6e069f1eb94b216c78f434a2a6 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Fri, 26 Oct 2018 22:00:16 +0200
Subject: [PATCH 12/14] remove unused overlay; unify code for all platforms

---
 lib/matplotlib/backends/backend_wx.py | 27 ++++++++-------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 16afc9ae11e9..df62e9dadabf 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -657,25 +657,16 @@ def _onPaint(self, event):
         if not self._rubberband:
             return
 
-        # draw rubberband / selection using an overlay
-        if self._overlay is None:
-            self._overlay = wx.Overlay()
-        odc = wx.DCOverlay(self._overlay, dc)
-
+        # draw rubberband / selection: a box with border and 50% transparency
         if not self._retinaFix:
-            # draw a box with border and 50% transparency
             dc = wx.GCDC(dc)
-            # Set the pen, for the box's border
-            bc = wx.BLUE
-            dc.SetPen(wx.Pen(colour=bc, width=1, style=wx.PENSTYLE_SOLID))
-            # Create a brush (for the box's interior) with the same colour,
-            # but 50% transparency.
-            bc = wx.Colour(bc.red, bc.green, bc.blue, 0x80)
-            dc.SetBrush(wx.Brush(bc))
-        else:
-            # draw without transparency which is buggy on Retina displays
-            dc.SetPen(wx.Pen(wx.BLACK, 1, wx.PENSTYLE_SHORT_DASH))
-            dc.SetBrush(wx.TRANSPARENT_BRUSH)
+        # Set the pen, for the box's border
+        bc = wx.BLUE
+        dc.SetPen(wx.Pen(colour=bc, width=1, style=wx.PENSTYLE_SOLID))
+        # Create a brush (for the box's interior) with the same colour,
+        # but 50% transparency.
+        bc = wx.Colour(bc.red, bc.green, bc.blue, 0x80)
+        dc.SetBrush(wx.Brush(bc))
 
         # Draw the rectangle
         topLeft, bottomRight = self._rubberband
@@ -846,8 +837,6 @@ def _remove_rubberband(self):
         # end drawing of a rubberband-like selection box
         if not self._rubberband:
             return
-        self._overlay.Reset()
-        self._overlay = None
         self._refresh_rubberband()  # trigger a later redraw
         self._rubberband = None
 

From 885c7d5278d61125245935537fd8816ba31b5ddb Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Mon, 29 Oct 2018 23:19:34 +0100
Subject: [PATCH 13/14] use x,y,width,height for rubberband rectangle

---
 lib/matplotlib/backends/backend_wx.py | 43 ++++++++++++---------------
 1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index df62e9dadabf..88550a714f04 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -669,9 +669,7 @@ def _onPaint(self, event):
         dc.SetBrush(wx.Brush(bc))
 
         # Draw the rectangle
-        topLeft, bottomRight = self._rubberband
-        rect = wx.Rect(topLeft=topLeft, bottomRight=bottomRight)
-        dc.DrawRectangle(rect)
+        dc.DrawRectangle(*self._rubberband)
 
     def _onSize(self, event):
         """
@@ -826,41 +824,38 @@ def _onEnter(self, event):
 
     def _draw_rubberband(self, x0, y0, x1, y1):
         # trigger a refresh to draw a rubberband-like selection box
+        width = abs(x1 - x0)
+        x0 = min(x0, x1)
+        height = abs(y1 - y0)
+        y0 = self.figure.bbox.height - max(y0, y1)
         previous_rubberband = self._rubberband
-        height = self.figure.bbox.height
-        y1 = height - y1
-        y0 = height - y0
-        self._rubberband = [(x0, y0), (x1, y1)]
+        self._rubberband = (x0, y0, width, height)
         self._refresh_rubberband(previous_rubberband)
 
     def _remove_rubberband(self):
         # end drawing of a rubberband-like selection box
         if not self._rubberband:
             return
-        self._refresh_rubberband()  # trigger a later redraw
+        previous_rubberband = self._rubberband
         self._rubberband = None
+        self._refresh_rubberband(previous_rubberband)  # trigger a later redraw
 
     def _refresh_rubberband(self, previous_rubberband=None):
         # initiate a refresh on the area that contains the previous and
         # current selection / rubberband
-        points = list(self._rubberband)
-        if previous_rubberband:
-            points += previous_rubberband
-        # find the rectangle that covers the previous and current selection
-        top = min(point[1] for point in points)
-        left = min(point[0] for point in points)
-        bottom = max(point[1] for point in points)
-        right = max(point[0] for point in points)
-
+        if self._rubberband:
+            rect = wx.Rect(self._rubberband)
+        else:
+            rect = None
         if previous_rubberband:
+            previous_rubberband = wx.Rect(*previous_rubberband)
             # extend by one pixel to avoid residuals on Mac OS
-            left = max(left - 1, 0)
-            top = max(top - 1, 0)
-            bottom = min(bottom + 1, self.figure.bbox.height - 1)
-            right = min(right + 1, self.figure.bbox.width - 1)
-
-        rect = wx.Rect(topLeft=wx.Point(left, top),
-                       bottomRight=wx.Point(right, bottom))
+            previous_rubberband.Inflate(1, 1)
+            if rect:
+                rect.Union(previous_rubberband)
+            else:
+                rect = previous_rubberband
+        rect.Intersect(self.Rect)
         self.Refresh(False, rect)
 
 

From 24bfbed1aa698325019960fe10afcee51be80914 Mon Sep 17 00:00:00 2001
From: DietmarSchwertberger <github@schwertberger.de>
Date: Sat, 28 Mar 2020 19:34:44 +0100
Subject: [PATCH 14/14] forgotten conflict from rebasing

---
 lib/matplotlib/backends/backend_wx.py | 89 ---------------------------
 1 file changed, 89 deletions(-)

diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
index 88550a714f04..c2cdad39086a 100644
--- a/lib/matplotlib/backends/backend_wx.py
+++ b/lib/matplotlib/backends/backend_wx.py
@@ -1495,95 +1495,6 @@ def trigger(self, *args, **kwargs):
 backend_tools.ToolCopyToClipboard = ToolCopyToClipboardWx
 
 
-<<<<<<< HEAD
-=======
-# < Additions for printing support: Matt Newville
-
-class PrintoutWx(wx.Printout):
-    """
-    Simple wrapper around wx Printout class -- all the real work
-    here is scaling the matplotlib canvas bitmap to the current
-    printer's definition.
-    """
-
-    def __init__(self, canvas, width=5.5, margin=0.5, title='matplotlib'):
-        wx.Printout.__init__(self, title=title)
-        self.canvas = canvas
-        # width, in inches of output figure (approximate)
-        self.width = width
-        self.margin = margin
-
-    def HasPage(self, page):
-        # current only supports 1 page print
-        return page == 1
-
-    def GetPageInfo(self):
-        return (1, 1, 1, 1)
-
-    def OnPrintPage(self, page):
-        self.canvas._draw()
-
-        dc = self.GetDC()
-        ppw, pph = self.GetPPIPrinter()      # printer's pixels per in
-        pgw, pgh = self.GetPageSizePixels()  # page size in pixels
-        dcw, dch = dc.GetSize()
-        grw, grh = self.canvas.GetSize()
-
-        # save current figure dpi resolution and bg color,
-        # so that we can temporarily set them to the dpi of
-        # the printer, and the bg color to white
-        bgcolor = self.canvas.figure.get_facecolor()
-        fig_dpi = self.canvas.figure.dpi
-
-        # draw the bitmap, scaled appropriately
-        vscale = float(ppw) / fig_dpi
-
-        # set figure resolution,bg color for printer
-        self.canvas.figure.dpi = ppw
-        self.canvas.figure.set_facecolor('#FFFFFF')
-
-        renderer = RendererWx(self.canvas.bitmap, self.canvas.figure.dpi)
-        self.canvas.figure.draw(renderer)
-        self.canvas.bitmap.SetWidth(
-            int(self.canvas.bitmap.GetWidth() * vscale))
-        self.canvas.bitmap.SetHeight(
-            int(self.canvas.bitmap.GetHeight() * vscale))
-        self.canvas._draw()
-
-        # page may need additional scaling on preview
-        page_scale = 1.0
-        if self.IsPreview():
-            page_scale = float(dcw) / pgw
-
-        # get margin in pixels = (margin in in) * (pixels/in)
-        top_margin = int(self.margin * pph * page_scale)
-        left_margin = int(self.margin * ppw * page_scale)
-
-        # set scale so that width of output is self.width inches
-        # (assuming grw is size of graph in inches....)
-        user_scale = (self.width * fig_dpi * page_scale) / float(grw)
-
-        dc.SetDeviceOrigin(left_margin, top_margin)
-        dc.SetUserScale(user_scale, user_scale)
-
-        # this cute little number avoid API inconsistencies in wx
-        try:
-            dc.DrawBitmap(self.canvas.bitmap, 0, 0)
-        except Exception:
-            try:
-                dc.DrawBitmap(self.canvas.bitmap, (0, 0))
-            except Exception:
-                pass
-
-        # restore original figure  resolution
-        self.canvas.figure.set_facecolor(bgcolor)
-        self.canvas.figure.dpi = fig_dpi
-        self.canvas.draw()
-        return True
-# >
-
-
->>>>>>> d2cb5900b... separate rendering and Refresh into _draw() and draw()
 @_Backend.export
 class _BackendWx(_Backend):
     FigureCanvas = FigureCanvasWx