feat(tui): support DCS responses in TermResponse event (#26061)

runtime/doc/api.txt

@@ -3598,13 +3598,13 @@ nvim_ui_set_option({name}, {value})                     *nvim_ui_set_option()*
         |RPC| only
 
 nvim_ui_term_event({event}, {value})                    *nvim_ui_term_event()*
-    Tells Nvim when a terminal event has occurred: sets |v:termresponse| and
+    Tells Nvim when a terminal event has occurred
-    fires |TermResponse|.
 
     The following terminal events are supported:
 
-    • "osc_response": The terminal sent a OSC response sequence to Nvim. The
+    • "termresponse": The terminal sent an OSC or DCS response sequence to
-      payload is the received OSC sequence.
+      Nvim. The payload is the received response. Sets |v:termresponse| and
+      fires |TermResponse|.
 
     Attributes: ~
         |RPC| only

runtime/doc/autocmd.txt

@@ -987,8 +987,8 @@ TermClose			When a |terminal| job ends.
 				Sets these |v:event| keys:
 				    status
 							*TermResponse*
-TermResponse			When Nvim receives a OSC response from the
+TermResponse			When Nvim receives an OSC or DCS response from
-				terminal.  Sets |v:termresponse|. When used
+				the terminal.  Sets |v:termresponse|. When used
 				from Lua, the response string is included in
 				the "data" field of the autocommand callback.
 				May be triggered halfway through another event

runtime/doc/eval.txt

@@ -2318,10 +2318,10 @@ v:t_string	Value of |String| type.  Read-only.  See: |type()|
 v:t_blob	Value of |Blob| type.  Read-only.  See: |type()|
 
 				*v:termresponse* *termresponse-variable*
-v:termresponse	The value of the most recent OSC escape sequence received by
+v:termresponse	The value of the most recent OSC or DCS escape sequence
-		Nvim from the terminal. This can be read in a |TermResponse|
+		received by Nvim from the terminal. This can be read in a
-		event handler after querying the terminal using another escape
+		|TermResponse| event handler after querying the terminal using
-		sequence.
+		another escape sequence.
 
 					*v:testing* *testing-variable*
 v:testing	Must be set before using `test_garbagecollect_now()`.

runtime/lua/vim/_meta/api.lua

@@ -2065,11 +2065,12 @@ function vim.api.nvim_ui_set_focus(gained) end
 --- @param value any
 function vim.api.nvim_ui_set_option(name, value) end
 
---- Tells Nvim when a terminal event has occurred.
+--- Tells Nvim when a terminal event has occurred
 --- The following terminal events are supported:
 ---
---- • "osc_response": The terminal sent a OSC response sequence to Nvim. The
+--- • "termresponse": The terminal sent an OSC or DCS response sequence to
----   payload is the received OSC sequence.
+---   Nvim. The payload is the received response. Sets `v:termresponse` and
+---   fires `TermResponse`.
 ---
 ---
 --- @param event string Event name

src/nvim/api/ui.c

@@ -513,12 +513,13 @@ void nvim_ui_pum_set_bounds(uint64_t channel_id, Float width, Float height, Floa
   ui->pum_pos = true;
 }
 
-/// Tells Nvim when a terminal event has occurred: sets |v:termresponse| and fires |TermResponse|.
+/// Tells Nvim when a terminal event has occurred
 ///
 /// The following terminal events are supported:
 ///
-///   - "osc_response": The terminal sent a OSC response sequence to Nvim. The
+///   - "termresponse": The terminal sent an OSC or DCS response sequence to
-///                     payload is the received OSC sequence.
+///                     Nvim. The payload is the received response. Sets
+///                     |v:termresponse| and fires |TermResponse|.
 ///
 /// @param channel_id
 /// @param event Event name
@@ -527,14 +528,14 @@ void nvim_ui_pum_set_bounds(uint64_t channel_id, Float width, Float height, Floa
 void nvim_ui_term_event(uint64_t channel_id, String event, Object value, Error *err)
   FUNC_API_SINCE(12) FUNC_API_REMOTE_ONLY
 {
-  if (strequal("osc_response", event.data)) {
+  if (strequal("termresponse", event.data)) {
     if (value.type != kObjectTypeString) {
-      api_set_error(err, kErrorTypeValidation, "osc_response must be a string");
+      api_set_error(err, kErrorTypeValidation, "termresponse must be a string");
       return;
     }
 
-    const String osc_response = value.data.string;
+    const String termresponse = value.data.string;
-    set_vim_var_string(VV_TERMRESPONSE, osc_response.data, (ptrdiff_t)osc_response.size);
+    set_vim_var_string(VV_TERMRESPONSE, termresponse.data, (ptrdiff_t)termresponse.size);
     apply_autocmds_group(EVENT_TERMRESPONSE, NULL, NULL, false, AUGROUP_ALL, NULL, NULL, &value);
   }
 }

src/nvim/tui/input.c

@@ -476,8 +476,8 @@ static void tk_getkeys(TermInput *input, bool force)
           }
         }
       }
-    } else if (key.type == TERMKEY_TYPE_OSC) {
+    } else if (key.type == TERMKEY_TYPE_OSC || key.type == TERMKEY_TYPE_DCS) {
-      handle_osc_event(input, &key);
+      handle_term_response(input, &key);
     } else if (key.type == TERMKEY_TYPE_MODEREPORT) {
       handle_modereport(input, &key);
     }
@@ -578,22 +578,34 @@ static HandleState handle_bracketed_paste(TermInput *input)
   return kNotApplicable;
 }
 
-static void handle_osc_event(TermInput *input, const TermKeyKey *key)
+static void handle_term_response(TermInput *input, const TermKeyKey *key)
   FUNC_ATTR_NONNULL_ALL
 {
   const char *str = NULL;
   if (termkey_interpret_string(input->tk, key, &str) == TERMKEY_RES_KEY) {
     assert(str != NULL);
 
-    // Send an event to nvim core. This will update the v:termresponse variable and fire the
+    // Send an event to nvim core. This will update the v:termresponse variable
-    // TermResponse event
+    // and fire the TermResponse event
     MAXSIZE_TEMP_ARRAY(args, 2);
-    ADD_C(args, STATIC_CSTR_AS_OBJ("osc_response"));
+    ADD_C(args, STATIC_CSTR_AS_OBJ("termresponse"));
 
-    // libtermkey strips the OSC bytes from the response. We add it back in so that downstream
+    // libtermkey strips the OSC/DCS bytes from the response. We add it back in
-    // consumers of v:termresponse can differentiate between OSC and CSI events.
+    // so that downstream consumers of v:termresponse can differentiate between
+    // the two.
     StringBuilder response = KV_INITIAL_VALUE;
-    kv_printf(response, "\x1b]%s", str);
+    switch (key->type) {
+    case TERMKEY_TYPE_OSC:
+      kv_printf(response, "\x1b]%s", str);
+      break;
+    case TERMKEY_TYPE_DCS:
+      kv_printf(response, "\x1bP%s", str);
+      break;
+    default:
+      // Key type already checked for OSC/DCS in termkey_interpret_string
+      UNREACHABLE;
+    }
+
     ADD_C(args, STRING_OBJ(cbuf_as_string(response.items, response.size)));
     rpc_send_event(ui_client_channel_id, "nvim_ui_term_event", args);
     kv_destroy(response);