win,tty: support consoles with non-default colors

Use the console text color set by the user rather than assuming the
Windows default (white foreground on black background).

PR-URL: libuv#431
Reviewed-By: Bert Belder <[email protected]>

src/win/tty.c

@@ -55,6 +55,7 @@
 #define MAX_INPUT_BUFFER_LENGTH 8192
 
 
+static void uv_tty_capture_initial_style(CONSOLE_SCREEN_BUFFER_INFO* info);
 static void uv_tty_update_virtual_window(CONSOLE_SCREEN_BUFFER_INFO* info);
 
 
@@ -96,6 +97,15 @@ static CRITICAL_SECTION uv_tty_output_lock;
 
 static HANDLE uv_tty_output_handle = INVALID_HANDLE_VALUE;
 
+static WORD uv_tty_default_text_attributes =
+    FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
+
+static char uv_tty_default_fg_color = 7;
+static char uv_tty_default_bg_color = 0;
+static char uv_tty_default_fg_bright = 0;
+static char uv_tty_default_bg_bright = 0;
+static char uv_tty_default_inverse = 0;
+
 
 void uv_console_init() {
   InitializeCriticalSection(&uv_tty_output_lock);
@@ -143,6 +153,9 @@ int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, uv_file fd, int readable) {
     /* is received. */
     uv_tty_output_handle = handle;
 
+    /* Remember the original console text attributes. */
+    uv_tty_capture_initial_style(&screen_buffer_info);
+
     uv_tty_update_virtual_window(&screen_buffer_info);
 
     LeaveCriticalSection(&uv_tty_output_lock);
@@ -188,6 +201,62 @@ int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, uv_file fd, int readable) {
 }
 
 
+/* Set the default console text attributes based on how the console was
+ * configured when libuv started.
+ */
+static void uv_tty_capture_initial_style(CONSOLE_SCREEN_BUFFER_INFO* info) {
+  static int style_captured = 0;
+
+  /* Only do this once.
+  /* Assumption: Caller has acquired uv_tty_output_lock. */
+  if (style_captured)
+    return;
+
+  /* Save raw win32 attributes. */
+  uv_tty_default_text_attributes = info->wAttributes;
+
+  /* Convert black text on black background to use white text. */
+  if (uv_tty_default_text_attributes == 0)
+    uv_tty_default_text_attributes = 7;
+
+  /* Convert Win32 attributes to ANSI colors. */
+  uv_tty_default_fg_color = 0;
+  uv_tty_default_bg_color = 0;
+  uv_tty_default_fg_bright = 0;
+  uv_tty_default_bg_bright = 0;
+  uv_tty_default_inverse = 0;
+
+  if (uv_tty_default_text_attributes & FOREGROUND_RED)
+    uv_tty_default_fg_color |= 1;
+
+  if (uv_tty_default_text_attributes & FOREGROUND_GREEN)
+    uv_tty_default_fg_color |= 2;
+
+  if (uv_tty_default_text_attributes & FOREGROUND_BLUE)
+    uv_tty_default_fg_color |= 4;
+
+  if (uv_tty_default_text_attributes & BACKGROUND_RED)
+    uv_tty_default_bg_color |= 1;
+
+  if (uv_tty_default_text_attributes & BACKGROUND_GREEN)
+    uv_tty_default_bg_color |= 2;
+
+  if (uv_tty_default_text_attributes & BACKGROUND_BLUE)
+    uv_tty_default_bg_color |= 4;
+
+  if (uv_tty_default_text_attributes & FOREGROUND_INTENSITY)
+    uv_tty_default_fg_bright = 1;
+
+  if (uv_tty_default_text_attributes & BACKGROUND_INTENSITY)
+    uv_tty_default_bg_bright = 1;
+
+  if (uv_tty_default_text_attributes & COMMON_LVB_REVERSE_VIDEO)
+    uv_tty_default_inverse = 1;
+
+  style_captured = 1;
+}
+
+
 int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
   DWORD flags;
   unsigned char was_reading;
@@ -1022,7 +1091,7 @@ static int uv_tty_move_caret(uv_tty_t* handle, int x, unsigned char x_relative,
 
 static int uv_tty_reset(uv_tty_t* handle, DWORD* error) {
   const COORD origin = {0, 0};
-  const WORD char_attrs = FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
+  const WORD char_attrs = uv_tty_default_text_attributes;
   CONSOLE_SCREEN_BUFFER_INFO info;
   DWORD count, written;
 
@@ -1178,23 +1247,23 @@ static int uv_tty_set_style(uv_tty_t* handle, DWORD* error) {
 
   if (argc == 0) {
     /* Reset mode */
-    fg_color = 7;
-    bg_color = 0;
-    fg_bright = 0;
-    bg_bright = 0;
-    inverse = 0;
+    fg_color = uv_tty_default_fg_color;
+    bg_color = uv_tty_default_bg_color;
+    fg_bright = uv_tty_default_fg_bright;
+    bg_bright = uv_tty_default_bg_bright;
+    inverse = uv_tty_default_inverse;
   }
 
   for (i = 0; i < argc; i++) {
     short arg = argv[i];
 
     if (arg == 0) {
       /* Reset mode */
-      fg_color = 7;
-      bg_color = 0;
-      fg_bright = 0;
-      bg_bright = 0;
-      inverse = 0;
+      fg_color = uv_tty_default_fg_color;
+      bg_color = uv_tty_default_bg_color;
+      fg_bright = uv_tty_default_fg_bright;
+      bg_bright = uv_tty_default_bg_bright;
+      inverse = uv_tty_default_inverse;
 
     } else if (arg == 1) {
       /* Foreground bright on */
@@ -1231,17 +1300,17 @@ static int uv_tty_set_style(uv_tty_t* handle, DWORD* error) {
 
     } else if (arg == 39) {
       /* Default text color */
-      fg_color = 7;
-      fg_bright = 0;
+      fg_color = uv_tty_default_fg_color;
+      fg_bright = uv_tty_default_fg_bright;
 
     } else if (arg >= 40 && arg <= 47) {
       /* Set background color */
       bg_color = arg - 40;
 
     } else if (arg ==  49) {
       /* Default background color */
-      bg_color = 0;
-      bg_bright = 0;
+      bg_color = uv_tty_default_bg_color;
+      bg_bright = uv_tty_default_bg_bright;
 
     } else if (arg >= 90 && arg <= 97) {
       /* Set bold foreground color */