Merge #5026 from joshtriplett/term-title-statusline

Please support setting terminal title in :terminal

runtime/doc/nvim_terminal_emulator.txt

@@ -10,6 +10,7 @@ Embedded terminal emulator				   *terminal-emulator*
 2. Spawning			|terminal-emulator-spawning|
 3. Input			|terminal-emulator-input|
 4. Configuration		|terminal-emulator-configuration|
+5. Status Variables		|terminal-emulator-status|
 
 ==============================================================================
 1. Introduction					     *terminal-emulator-intro*
@@ -112,5 +113,26 @@ There is also a corresponding |TermClose| event.
 The terminal cursor can be highlighted via |hl-TermCursor| and
 |hl-TermCursorNC|.
 
+==============================================================================
+5. Status Variables				    *terminal-emulator-status*
+
+Terminal buffers maintain some information about the terminal in buffer-local
+variables:
+
+- *b:term_title* The settable title of the terminal, typically displayed in
+  the window title or tab title of a graphical terminal emulator. Programs
+  running in the terminal can set this title via an escape sequence.
+- *b:terminal_job_id* The nvim job ID of the job running in the terminal. See
+  |job-control| for more information.
+- *b:terminal_job_pid* The PID of the top-level process running in the
+  terminal.
+
+These variables will have a value by the time the TermOpen autocmd runs, and
+will continue to have a value for the lifetime of the terminal buffer, making
+them suitable for use in 'statusline'. For example, to show the terminal title
+as the status line:
+>
+    :autocmd TermOpen * setlocal statusline=%{b:term_title}
+<
 ==============================================================================
  vim:tw=78:ts=8:noet:ft=help:norl:

src/nvim/terminal.c

@@ -241,6 +241,7 @@ Terminal *terminal_open(TerminalOptions opts)
   set_option_value((uint8_t *)"wrap", false, NULL, OPT_LOCAL);
   set_option_value((uint8_t *)"number", false, NULL, OPT_LOCAL);
   set_option_value((uint8_t *)"relativenumber", false, NULL, OPT_LOCAL);
+  buf_set_term_title(curbuf, (char *)curbuf->b_ffname);
   RESET_BINDING(curwin);
   // Apply TermOpen autocmds so the user can configure the terminal
   apply_autocmds(EVENT_TERMOPEN, NULL, NULL, false, curbuf);
@@ -618,6 +619,17 @@ static int term_movecursor(VTermPos new, VTermPos old, int visible,
   return 1;
 }
 
+static void buf_set_term_title(buf_T *buf, char *title)
+    FUNC_ATTR_NONNULL_ALL
+{
+  Error err;
+  api_free_object(dict_set_value(buf->b_vars,
+                                 cstr_as_string("term_title"),
+                                 STRING_OBJ(cstr_as_string(title)),
+                                 false,
+                                 &err));
+}
+
 static int term_settermprop(VTermProp prop, VTermValue *val, void *data)
 {
   Terminal *term = data;
@@ -633,12 +645,7 @@ static int term_settermprop(VTermProp prop, VTermValue *val, void *data)
 
     case VTERM_PROP_TITLE: {
       buf_T *buf = handle_get_buffer(term->buf_handle);
-      Error err;
+      buf_set_term_title(buf, val->string);
-      api_free_object(dict_set_value(buf->b_vars,
-                                     cstr_as_string("term_title"),
-                                     STRING_OBJ(cstr_as_string(val->string)),
-                                     false,
-                                     &err));
       break;
     }