Return false from wxKeyEvent::IsKeyInCategory(WXK_TAB) for Ctrl+I

Although TAB and Ctrl+I generate the same key code in the events passed
to wxEVT_CHAR handlers, it seems more reasonable to only consider the
former to be in "TAB category", but not the latter.

See #10268.

Closes #24254.

interface/wx/event.h

@@ -1300,10 +1300,20 @@ enum wxKeyCategoryFlags
     /// home and end keys, on and off numeric keypads
     WXK_CATEGORY_JUMP,
 
-    /// tab key, on and off numeric keypads
+    /**
+        Tab key, on and off numeric keypads.
+
+        Note that while `Ctrl+I` and `TAB` keys generate the same key code,
+        only the latter is considered to be in this category.
+     */
     WXK_CATEGORY_TAB,
 
-    /// backspace and delete keys, on and off numeric keypads
+    /**
+        Backspace and delete keys, on and off numeric keypads.
+
+        Note that while `Ctrl+H` and `BACKSPACE` keys generate the same key
+        code, only the latter is considered to be in this category.
+     */
     WXK_CATEGORY_CUT,
 
     /// union of WXK_CATEGORY_ARROW, WXK_CATEGORY_PAGING, and WXK_CATEGORY_JUMP categories

src/common/event.cpp

@@ -849,10 +849,58 @@ bool wxKeyEvent::IsKeyInCategory(int category) const
             return (category & WXK_CATEGORY_JUMP) != 0;
 
         case WXK_TAB:
+            // We have to make an extra check for this one, as it's a synonym
+            // for Ctrl-I, but we don't want to recognize Ctrl-I as a TAB key.
+            // As raw key codes are platform-dependent we have to do it in
+            // platform-specific way.
+#ifdef __WXMSW__
+            // Under Windows the native WM_CHAR already does the translation
+            // and so we need to look at the scan code, which is part of the
+            // flags, rather than the key code itself.
+            if ( ((GetRawKeyFlags() >> 16) & 0xff) == 0x17 )
+            {
+                return false;
+            }
+#else // !__WXMSW__
+            // For the other platforms we can use the raw key code, but it's
+            // still different, with Mac doing its own thing. We assume all the
+            // other platforms do as GTK does and use either "I" or "i" for
+            // this letter events.
+            switch ( GetRawKeyCode() )
+            {
+#ifdef __WXOSX__
+                case 0x22: // kVK_ANSI_I
+#else
+                case 'I':
+                case 'i':
+#endif
+                    return false;
+            }
+#endif // __WXMSW__/!__WXMSW__
+            wxFALLTHROUGH;
         case WXK_NUMPAD_TAB:
             return (category & WXK_CATEGORY_TAB) != 0;
 
         case WXK_BACK:
+            // See the comment above for TAB.
+#ifdef __WXMSW__
+            if ( ((GetRawKeyFlags() >> 16) & 0xff) == 0x23 )
+            {
+                return false;
+            }
+#else // !__WXMSW__
+            switch ( GetRawKeyCode() )
+            {
+#ifdef __WXOSX__
+                case 0x04: // kVK_ANSI_H
+#else
+                case 'H':
+                case 'h':
+#endif
+                    return false;
+            }
+#endif // __WXMSW__/!__WXMSW__
+            wxFALLTHROUGH;
         case WXK_DELETE:
         case WXK_NUMPAD_DELETE:
             return (category & WXK_CATEGORY_CUT) != 0;