From a2a3897124dab93e11fb834205ee150121df3faf Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Tue, 21 Apr 2020 16:29:03 +0200
Subject: [PATCH] Simplify wxWindowID definition

Define it in wx/defs.h directly instead of conditionally including
wx/windowid.h from there just in order to get this type definition.

This has several advantages:

- wxWindowIDRef is not defined in (maybe) non-GUI code including
  wx/defs.h, as it should be the case for this class defined in
  core library only.
- wx/windowid.h becomes a normal header, including wx/defs.h as
  (almost) all the other ones instead of being exceptional.
- wx/windowid.h doesn't need to be included by wx/utils.h at all
  just to get wxWindowID definition.

Closes https://github.com/wxWidgets/wxWidgets/pull/1850
---
 include/wx/defs.h       | 14 +++-----------
 include/wx/menuitem.h   |  2 ++
 include/wx/utils.h      |  1 -
 include/wx/window.h     |  1 +
 include/wx/windowid.h   |  4 +---
 src/common/windowid.cpp |  4 +---
 6 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/include/wx/defs.h b/include/wx/defs.h
index 3322d7c5cf..f49ab60f29 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -1937,17 +1937,9 @@ enum wxStandardID
 /*  wxWindowID type                                                              */
 /*  ---------------------------------------------------------------------------- */
 
-/*
- * wxWindowID used to be just a typedef defined here, now it's a class, but we
- * still continue to define it here for compatibility, so that the code using
- * it continues to compile even if it includes just wx/defs.h.
- *
- * Notice that wx/windowid.h can only be included after wxID_XYZ definitions
- * (as it uses them).
- */
-#if defined(__cplusplus) && wxUSE_GUI
-    #include "wx/windowid.h"
-#endif
+/* Note that this is defined even in non-GUI code as the same type is also used
+   for e.g. timer IDs. */
+typedef int wxWindowID;
 
 /*  ---------------------------------------------------------------------------- */
 /*  other constants */
diff --git a/include/wx/menuitem.h b/include/wx/menuitem.h
index 29f63eec7d..8c1d2c68e2 100644
--- a/include/wx/menuitem.h
+++ b/include/wx/menuitem.h
@@ -21,6 +21,8 @@
 
 #include "wx/object.h"  // base class
 
+#include "wx/windowid.h"
+
 // ----------------------------------------------------------------------------
 // forward declarations
 // ----------------------------------------------------------------------------
diff --git a/include/wx/utils.h b/include/wx/utils.h
index dbb87cd0aa..4588479e98 100644
--- a/include/wx/utils.h
+++ b/include/wx/utils.h
@@ -20,7 +20,6 @@
 #include "wx/filefn.h"
 #include "wx/hashmap.h"
 #include "wx/versioninfo.h"
-#include "wx/windowid.h"
 #include "wx/meta/implicitconversion.h"
 
 #if wxUSE_GUI
diff --git a/include/wx/window.h b/include/wx/window.h
index 814e9487ad..e574fe9df2 100644
--- a/include/wx/window.h
+++ b/include/wx/window.h
@@ -27,6 +27,7 @@
 #include "wx/intl.h"
 
 #include "wx/validate.h"        // for wxDefaultValidator (always include it)
+#include "wx/windowid.h"
 
 #if wxUSE_PALETTE
     #include "wx/palette.h"
diff --git a/include/wx/windowid.h b/include/wx/windowid.h
index 0c174b5f0c..a6618b6188 100644
--- a/include/wx/windowid.h
+++ b/include/wx/windowid.h
@@ -10,9 +10,7 @@
 #ifndef _WX_WINDOWID_H_
 #define _WX_WINDOWID_H_
 
-// NB: do not include defs.h as we are included from it
-
-typedef int wxWindowID;
+#include "wx/defs.h"
 
 // ----------------------------------------------------------------------------
 // wxWindowIDRef: reference counted id value
diff --git a/src/common/windowid.cpp b/src/common/windowid.cpp
index 20a0efbe20..547ff7fc46 100644
--- a/src/common/windowid.cpp
+++ b/src/common/windowid.cpp
@@ -22,9 +22,7 @@
 #endif //WX_PRECOMP
 
 #include "wx/hashmap.h"
-
-// Not needed, included in defs.h
-// #include "wx/windowid.h"
+#include "wx/windowid.h"
 
 namespace
 {