From e961307043f0ff1a877a68c6dbd155f8d7e565bf Mon Sep 17 00:00:00 2001
From: Ian McInerney <Ian.S.McInerney@ieee.org>
Date: Sun, 25 Aug 2019 15:24:44 +0200
Subject: [PATCH] Add compatibility warning for invalid GTK accelerator keys

---
 include/wx/accel.h      |  8 +++-
 src/common/accelcmn.cpp | 90 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+), 1 deletion(-)

diff --git a/include/wx/accel.h b/include/wx/accel.h
index c1f78d58ed..c0f23ca534 100644
--- a/include/wx/accel.h
+++ b/include/wx/accel.h
@@ -53,7 +53,9 @@ public:
         , m_keyCode(keyCode)
         , m_command(cmd)
         , m_item(item)
-        { }
+    {
+        ValidateKey(flags, keyCode);
+    }
 
     // create accelerator corresponding to the specified string, return NULL if
     // string couldn't be parsed or a pointer to be deleted by the caller
@@ -61,6 +63,8 @@ public:
 
     void Set(int flags, int keyCode, int cmd, wxMenuItem *item = NULL)
     {
+        ValidateKey(flags, keyCode);
+
         m_flags = flags;
         m_keyCode = keyCode;
         m_command = cmd;
@@ -118,6 +122,8 @@ public:
 private:
     wxString AsPossiblyLocalizedString(bool localized) const;
 
+    static bool ValidateKey(int flags, int keycode);
+
     // common part of Create() and FromString()
     static bool ParseAccel(const wxString& str, int *flags, int *keycode);
 
diff --git a/src/common/accelcmn.cpp b/src/common/accelcmn.cpp
index 820985df26..bc8937a2b8 100644
--- a/src/common/accelcmn.cpp
+++ b/src/common/accelcmn.cpp
@@ -156,6 +156,96 @@ static int IsNumberedAccelKey(const wxString& str,
     return prefixCode + num - first;
 }
 
+// static
+bool wxAcceleratorEntry::ValidateKey(int flags, int keycode)
+{
+    wxString keyname;
+    if ( keycode )
+    {
+        for ( size_t n = 0; n < WXSIZEOF(wxKeyNames); n++ )
+        {
+            const wxKeyName& kn = wxKeyNames[n];
+            if ( kn.code == keycode )
+            {
+                keyname = kn.name;
+                break;
+            }
+        }
+
+        if ( keyname.IsEmpty() && keycode >= WXK_SPECIAL1 && keycode <= WXK_SPECIAL20 )
+            keyname << wxS("SPECIAL")  << keycode - WXK_SPECIAL1 + 1;
+    }
+
+    bool valid = true;
+    switch ( keycode )
+    {
+        /*
+         The following keycodes must have modifier keys to be valid on GTK
+         */
+        case WXK_UP:
+        case WXK_DOWN:
+        case WXK_LEFT:
+        case WXK_RIGHT:
+        case WXK_NUMPAD_UP:
+        case WXK_NUMPAD_DOWN:
+        case WXK_NUMPAD_LEFT:
+        case WXK_NUMPAD_RIGHT:
+            if ( !flags )
+            {
+                valid = false;
+                wxLogDebug( wxString::Format( wxT("Compatibility issue: %s key must have modifiers to be an accelerator key on GTK"),
+                                              keyname ) );
+            }
+            break;
+
+        /*
+         The following keycodes have been shown not to work as accelerator
+         keys on GTK (see https://trac.wxwidgets.org/ticket/10049)
+         and are not valid
+         (see gtkaccelgroup.c inside gtk_accelerator_valid())
+         */
+        case WXK_COMMAND:   // Same as WXK_CONTROL
+        case WXK_SHIFT:
+        case WXK_ALT:
+        case WXK_SCROLL:    // Scroll lock
+        case WXK_CAPITAL:   // Caps lock
+        case WXK_NUMLOCK:
+        case WXK_NUMPAD_TAB:
+        case WXK_TAB:
+        case WXK_WINDOWS_LEFT:
+        case WXK_WINDOWS_RIGHT:
+
+        /*
+         The following keycodes do not map clearly into a GTK keycode,
+         so they are not included in the accelerator mapping:
+         */
+        case WXK_ADD:
+        case WXK_SEPARATOR:
+        case WXK_SUBTRACT:
+        case WXK_DECIMAL:
+        case WXK_DIVIDE:
+        case WXK_SNAPSHOT:
+
+        /*
+         The following special codes do not map into GTK keycodes,
+         see gdk/keynames.txt
+         */
+        case WXK_SPECIAL1:  case WXK_SPECIAL2:  case WXK_SPECIAL3:
+        case WXK_SPECIAL4:  case WXK_SPECIAL5:  case WXK_SPECIAL6:
+        case WXK_SPECIAL7:  case WXK_SPECIAL8:  case WXK_SPECIAL9:
+        case WXK_SPECIAL10: case WXK_SPECIAL11: case WXK_SPECIAL12:
+        case WXK_SPECIAL13: case WXK_SPECIAL14: case WXK_SPECIAL15:
+        case WXK_SPECIAL16: case WXK_SPECIAL17: case WXK_SPECIAL18:
+        case WXK_SPECIAL19: case WXK_SPECIAL20:
+            valid = false;
+            wxLogDebug( wxString::Format( wxT("Compatibility issue: %s is not supported as a keyboard accelerator key on GTK"),
+                                          keyname ) );
+            break;
+    }
+
+    return valid;
+}
+
 /* static */
 bool
 wxAcceleratorEntry::ParseAccel(const wxString& text, int *flagsOut, int *keyOut)