From 87a97054f2ca89e2932df9d91da1bd526faa85cf Mon Sep 17 00:00:00 2001
From: Maarten Bent <MaartenBent@users.noreply.github.com>
Date: Sun, 13 Jan 2019 15:45:06 +0100
Subject: [PATCH] Allow to retrieve the wxWindow associated with a
 wxBufferedPaintDC

When a wxBufferedPaintDC is created, the base classes does not initialize the
m_window variable with the used wxWindow. Only the associated m_paintdc
initializes this variable. Add a protected function that allows to set the
wxWindow of a wxDC so GetWindow() will return the window.

This fixes the font size of custom attributes in wxDataViewCtrl when the DPI
changes.
---
 include/wx/dc.h       | 5 +++++
 include/wx/dcbuffer.h | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/include/wx/dc.h b/include/wx/dc.h
index 847b7f64e5..cc0a48238e 100644
--- a/include/wx/dc.h
+++ b/include/wx/dc.h
@@ -269,6 +269,8 @@ public:
 
     wxWindow* GetWindow() const { return m_window; }
 
+    void SetWindow(wxWindow* w) { m_window = w; }
+
     virtual bool IsOk() const { return m_ok; }
 
     // query capabilities
@@ -1364,6 +1366,9 @@ protected:
 
     wxDCImpl * const m_pimpl;
 
+    void SetWindow(wxWindow* w)
+        { return m_pimpl->SetWindow(w); }
+
 private:
     wxDECLARE_ABSTRACT_CLASS(wxDC);
     wxDECLARE_NO_COPY_CLASS(wxDC);
diff --git a/include/wx/dcbuffer.h b/include/wx/dcbuffer.h
index 4a29fda820..8fc23d66cd 100644
--- a/include/wx/dcbuffer.h
+++ b/include/wx/dcbuffer.h
@@ -153,6 +153,8 @@ public:
     wxBufferedPaintDC(wxWindow *window, wxBitmap& buffer, int style = wxBUFFER_CLIENT_AREA)
         : m_paintdc(window)
     {
+        SetWindow(window);
+
         // If we're buffering the virtual window, scale the paint DC as well
         if (style & wxBUFFER_VIRTUAL_AREA)
             window->PrepareDC( m_paintdc );
@@ -167,6 +169,8 @@ public:
     wxBufferedPaintDC(wxWindow *window, int style = wxBUFFER_CLIENT_AREA)
         : m_paintdc(window)
     {
+        SetWindow(window);
+
         // If we're using the virtual window, scale the paint DC as well
         if (style & wxBUFFER_VIRTUAL_AREA)
             window->PrepareDC( m_paintdc );