win,tty: add uv_tty_{get,set}_vterm_state

PR-URL: https://github.com/libuv/libuv/pull/2501
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Saúl Ibarra Corretgé <s@saghul.net>
Reviewed-By: Jameson Nash <vtjnash+github@gmail.com>

docs/src/tty.rst

@@ -33,6 +33,23 @@ Data types
           UV_TTY_MODE_IO
       } uv_tty_mode_t;
 
+.. c:type:: uv_tty_vtermstate_t
+    Console virtual terminal mode type:
+
+    ::
+
+      typedef enum {
+          /*
+           * The console supports handling of virtual terminal sequences
+           * (Windows10 new console, ConEmu)
+           */
+          UV_TTY_SUPPORTED,
+          /* The console cannot process virtual terminal sequences.  (Legacy
+           * console)
+           */
+          UV_TTY_UNSUPPORTED
+      } uv_tty_vtermstate_t
+
 
 
 Public members
@@ -98,3 +115,25 @@ API
     Gets the current Window size. On success it returns 0.
 
 .. seealso:: The :c:type:`uv_stream_t` API functions also apply.
+
+.. c:function:: void uv_tty_set_vterm_state(uv_tty_vtermstate_t state)
+
+    Controls whether console virtual terminal sequences are processed by libuv
+    or console.
+    Useful in particular for enabling ConEmu support of ANSI X3.64 and Xterm
+    256 colors. Otherwise Windows10 consoles are usually detected automatically.
+
+    This function is only meaningful on Windows systems. On Unix it is silently
+    ignored.
+
+    .. versionadded:: 1.33.0
+
+.. c:function:: int uv_tty_get_vterm_state(uv_tty_vtermstate_t* state)
+
+    Get the current state of whether console virtual terminal sequences are
+    handled by libuv or the console.
+
+    This function is not implemented on Unix, where it returns ``UV_ENOTSUP``.
+
+    .. versionadded:: 1.33.0
+

include/uv.h

@@ -706,10 +706,25 @@ typedef enum {
   UV_TTY_MODE_IO
 } uv_tty_mode_t;
 
+typedef enum {
+  /*
+   * The console supports handling of virtual terminal sequences
+   * (Windows10 new console, ConEmu)
+   */
+  UV_TTY_SUPPORTED,
+  /* The console cannot process the virtual terminal sequence.  (Legacy
+   * console)
+   */
+  UV_TTY_UNSUPPORTED
+} uv_tty_vtermstate_t;
+
+
 UV_EXTERN int uv_tty_init(uv_loop_t*, uv_tty_t*, uv_file fd, int readable);
 UV_EXTERN int uv_tty_set_mode(uv_tty_t*, uv_tty_mode_t mode);
 UV_EXTERN int uv_tty_reset_mode(void);
 UV_EXTERN int uv_tty_get_winsize(uv_tty_t*, int* width, int* height);
+UV_EXTERN void uv_tty_set_vterm_state(uv_tty_vtermstate_t state);
+UV_EXTERN int uv_tty_get_vterm_state(uv_tty_vtermstate_t* state);
 
 #ifdef __cplusplus
 extern "C++" {

src/unix/tty.c

@@ -365,3 +365,10 @@ int uv_tty_reset_mode(void) {
 
   return err;
 }
+
+void uv_tty_set_vterm_state(uv_tty_vtermstate_t state) {
+}
+
+int uv_tty_get_vterm_state(uv_tty_vtermstate_t* state) {
+  return UV_ENOTSUP;
+}

src/win/tty.c

@@ -149,13 +149,9 @@ static char uv_tty_default_fg_bright = 0;
 static char uv_tty_default_bg_bright = 0;
 static char uv_tty_default_inverse = 0;
 
-typedef enum {
-  UV_SUPPORTED,
-  UV_UNCHECKED,
-  UV_UNSUPPORTED
-} uv_vtermstate_t;
 /* Determine whether or not ANSI support is enabled. */
-static uv_vtermstate_t uv__vterm_state = UV_UNCHECKED;
+static BOOL uv__need_check_vterm_state = TRUE;
+static uv_tty_vtermstate_t uv__vterm_state = UV_TTY_UNSUPPORTED;
 static void uv__determine_vterm_state(HANDLE handle);
 
 void uv_console_init(void) {
@@ -223,7 +219,7 @@ int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, uv_file fd, int unused) {
      * between all uv_tty_t handles. */
     uv_sem_wait(&uv_tty_output_lock);
 
-    if (uv__vterm_state == UV_UNCHECKED)
+    if (uv__need_check_vterm_state)
       uv__determine_vterm_state(handle);
 
     /* Remember the original console text attributes. */
@@ -1675,7 +1671,7 @@ static int uv_tty_write_bufs(uv_tty_t* handle,
     uv_buf_t buf = bufs[i];
     unsigned int j;
 
-    if (uv__vterm_state == UV_SUPPORTED && buf.len > 0) {
+    if (uv__vterm_state == UV_TTY_SUPPORTED && buf.len > 0) {
       utf16_buf_used = MultiByteToWideChar(CP_UTF8,
                                            0,
                                            buf.base,
@@ -2280,18 +2276,17 @@ int uv_tty_reset_mode(void) {
 static void uv__determine_vterm_state(HANDLE handle) {
   DWORD dwMode = 0;
 
+  uv__need_check_vterm_state = FALSE;
   if (!GetConsoleMode(handle, &dwMode)) {
-    uv__vterm_state = UV_UNSUPPORTED;
     return;
   }
 
   dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
   if (!SetConsoleMode(handle, dwMode)) {
-    uv__vterm_state = UV_UNSUPPORTED;
     return;
   }
 
-  uv__vterm_state = UV_SUPPORTED;
+  uv__vterm_state = UV_TTY_SUPPORTED;
 }
 
 static DWORD WINAPI uv__tty_console_resize_message_loop_thread(void* param) {
@@ -2383,3 +2378,17 @@ static void uv__tty_console_signal_resize(void) {
     uv_mutex_unlock(&uv__tty_console_resize_mutex);
   }
 }
+
+void uv_tty_set_vterm_state(uv_tty_vtermstate_t state) {
+  uv_sem_wait(&uv_tty_output_lock);
+  uv__need_check_vterm_state = FALSE;
+  uv__vterm_state = state;
+  uv_sem_post(&uv_tty_output_lock);
+}
+
+int uv_tty_get_vterm_state(uv_tty_vtermstate_t* state) {
+  uv_sem_wait(&uv_tty_output_lock);
+  *state = uv__vterm_state;
+  uv_sem_post(&uv_tty_output_lock);
+  return 0;
+}