[dart:io] Move Platform.ansiSupported to {Stdin,Stdout}.supportsAnsiEscapes

runtime/bin/stdio_android.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(HOST_OS_ANDROID)
 
 #include "bin/stdio.h"
@@ skipping 65 matching lines @@
   if (enabled) {
     term.c_lflag |= ICANON;
   } else {
     term.c_lflag &= ~(ICANON);
   }
   status = NO_RETRY_EXPECTED(tcsetattr(STDIN_FILENO, TCSANOW, &term));
   return (status == 0);
 }
 
 
+static bool TermHasXTerm() {
+  const char* term = getenv("TERM");
+  if (term == NULL) {
+    return false;
+  }
+  return strstr(term, "xterm") != NULL;
+}
+
+
+bool Stdin::AnsiSupported(bool* supported) {
+  *supported = isatty(STDIN_FILENO) && TermHasXTerm();
+  return true;
+}
+
+
 bool Stdout::GetTerminalSize(intptr_t fd, int size[2]) {
   struct winsize w;
   int status = NO_RETRY_EXPECTED(ioctl(fd, TIOCGWINSZ, &w));
   if ((status == 0) && ((w.ws_col != 0) || (w.ws_row != 0))) {
     size[0] = w.ws_col;
     size[1] = w.ws_row;
     return true;
   }
   return false;
 }
 
+
+bool Stdout::AnsiSupported(intptr_t fd, bool* supported) {
+  *supported = isatty(fd) && TermHasXTerm();
+  return true;
+}
+
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(HOST_OS_ANDROID)
 
 #endif  // !defined(DART_IO_DISABLED)