Fix build w/wxUSE_GLCANVAS_EGL=0, on Fedora

Disable the EGL subsurface move backport for Wayland GLCanvas if the wx
config sets wxUSE_GLCANVAS_EGL=0 (off.)

This fixes the build failure on Fedora. To fix the functionality,
however, they need to enable the EGL GLCanvas in their wx builds.

Also use a different hack to access the private wxGLCanvasEGL member
using template instantiation instead of redefining a keyword as a macro.

Refer #1028

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

src/wx/CMakeLists.txt

@@ -318,7 +318,6 @@ else()
         set(WX_TEST_CONSOLE_APP "
 #include <cstdlib>
 #include <iostream>
-#include <wx/wxprec.h>
 #include <wx/wx.h>
 
 #ifdef _WIN32
@@ -459,7 +458,7 @@ int main(int argc, char** argv)
 
     if(NOT DEFINED WX_HAS_OPENGL)
         check_cxx_source_compiles("
-#include <wx/wxprec.h>
+#include <wx/wx.h>
 #include <wx/config.h>
 #include <wx/glcanvas.h>
 

src/wx/wayland.cpp

@@ -11,16 +11,26 @@ bool IsWayland() { return GDK_IS_WAYLAND_DISPLAY(gdk_display_get_default()); }
 // Temporary hack to backport 800d6ed69b from wxWidgets until 3.2.2 is released.
 #ifdef WAYLAND_MOVE_SUBSURFACE_BACKPORT
 #include <wayland-egl.h>
-#define private public
 #include <wx/glcanvas.h>
-#undef private
 
-void MoveWaylandSubsurface(wxGLCanvas* win)
+wl_subsurface* wxGLCanvasEGL::* private_ptr;
+
+template <auto Ptr>
+struct accessor {
+    static int force_init;
+};
+
+template <auto Ptr>
+int accessor<Ptr>::force_init = ((private_ptr = Ptr), 0);
+
+template struct accessor<&wxGLCanvasEGL::m_wlSubsurface>;
+
+void MoveWaylandSubsurface(wxGLCanvasEGL* win)
 {
     if (!IsWayland()) return;
 
     int x, y;
     gdk_window_get_origin(win->GTKGetDrawingWindow(), &x, &y);
-    wl_subsurface_set_position(win->m_wlSubsurface, x, y);
+    wl_subsurface_set_position(win->*private_ptr, x, y);
 }
 #endif

src/wx/wayland.h

@@ -4,6 +4,7 @@
 #include <wx/config.h>
 
 class wxGLCanvas;	// Forward declare.
+class wxGLCanvasEGL;
 
 #if defined(__WXGTK__)
 #include <gdk/gdk.h>
@@ -21,11 +22,11 @@ constexpr bool IsWayland() { return false; }
 #endif // wayland
 
 // Temporary hack to backport 800d6ed69b from wxWidgets until 3.2.2 is released.
-#if defined(__WXGTK__) && defined(HAVE_EGL) && wxCHECK_VERSION(3, 2, 0) && !wxCHECK_VERSION(3, 2, 2)
+#if defined(__WXGTK__) && defined(HAVE_EGL) && wxCHECK_VERSION(3, 2, 0) && !wxCHECK_VERSION(3, 2, 2) && wxUSE_GLCANVAS_EGL
 
 #define WAYLAND_MOVE_SUBSURFACE_BACKPORT
 
-void MoveWaylandSubsurface(wxGLCanvas* win);
+void MoveWaylandSubsurface(wxGLCanvasEGL* win);
 
 #else
 

src/wx/widgets/checkedlistctrl.cpp

@@ -9,8 +9,7 @@
 // Licence:     wxWidgets licence
 /////////////////////////////////////////////////////////////////////////////
 
-// For compilers that support precompilation, includes "wx.h".
+#include <wx/wx.h>
-#include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 #pragma hdrstop

src/wx/wxhead.h

@@ -1,18 +1,11 @@
 #ifndef WX_WXHEAD_H
 #define WX_WXHEAD_H
 
-// For compilers that support precompilation, includes <wx/wx.h>.
-#include <wx/wxprec.h>
-
 #ifdef __BORLANDC__
 #pragma hdrstop
 #endif
 
-// for all others, include the necessary headers (this file is usually all you
-// need because it includes almost all "standard" wxWidgets headers)
-#ifndef WX_PRECOMP
 #include <wx/wx.h>
-#endif
 
 // The following are not pulled in by wx.h