1 files changed, 25 insertions, 0 deletions
diff --git a/src/nvim/vterm/vterm_internal_defs.h b/src/nvim/vterm/vterm_internal_defs.h
index d4d59867bf..19e809490f 100644
--- a/src/nvim/vterm/vterm_internal_defs.h
+++ b/src/nvim/vterm/vterm_internal_defs.h
@@ -21,7 +21,14 @@
 #define BUFIDX_PRIMARY   0
 #define BUFIDX_ALTSCREEN 1
 
+#define KEY_ENCODING_DISAMBIGUATE 0x1
+#define KEY_ENCODING_REPORT_EVENTS 0x2
+#define KEY_ENCODING_REPORT_ALTERNATE 0x4
+#define KEY_ENCODING_REPORT_ALL_KEYS 0x8
+#define KEY_ENCODING_REPORT_ASSOCIATED 0x10
+
 typedef struct VTermEncoding VTermEncoding;
+typedef struct VTermKeyEncodingFlags VTermKeyEncodingFlags;
 
 typedef struct {
   VTermEncoding *enc;
@@ -46,6 +53,21 @@ struct VTermPen {
   unsigned baseline:2;
 };
 
+// https://sw.kovidgoyal.net/kitty/keyboard-protocol/#progressive-enhancement
+struct VTermKeyEncodingFlags {
+  bool disambiguate:1;
+  bool report_events:1;
+  bool report_alternate:1;
+  bool report_all_keys:1;
+  bool report_associated:1;
+};
+
+struct VTermKeyEncodingStack {
+  VTermKeyEncodingFlags items[16];
+  uint8_t size;  ///< Number of items in the stack. This is at least 1 and at
+                 ///< most the length of the "items" array.
+};
+
 struct VTermState {
   VTerm *vt;
 
@@ -171,6 +193,9 @@ struct VTermState {
     char *buffer;
     size_t buflen;
   } selection;
+
+  // Maintain two stacks, one for primary screen and one for altscreen
+  struct VTermKeyEncodingStack key_encoding_stacks[2];
 };
 
 struct VTerm {