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

runtime/bin/stdio_patch.dart

 // 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.
 
 @patch class _StdIOUtils {
   @patch static Stdin _getStdioInputStream() {
     switch (_getStdioHandleType(0)) {
       case _STDIO_HANDLE_TYPE_TERMINAL:
       case _STDIO_HANDLE_TYPE_PIPE:
       case _STDIO_HANDLE_TYPE_SOCKET:
@@ skipping 65 matching lines @@
     }
     return result;
   }
   @patch void set lineMode(bool enabled) {
     var result = _setLineMode(enabled);
     if (result is OSError) {
       throw new StdinException("Error setting terminal line mode", result);
     }
   }
 
+  @patch bool get supportsAnsiEscapes {
+    var result = _supportsAnsiEscapes();
+    if (result is OSError) {
+      throw new StdinException("Error determining ANSI support", result);
+    }
+    return result;
+  }
+
   static _echoMode() native "Stdin_GetEchoMode";
   static _setEchoMode(bool enabled) native "Stdin_SetEchoMode";
   static _lineMode() native "Stdin_GetLineMode";
   static _setLineMode(bool enabled) native "Stdin_SetLineMode";
   static _readByte() native "Stdin_ReadByte";
+  static _supportsAnsiEscapes() native "Stdin_AnsiSupported";
 }
 
 @patch class Stdout {
   @patch bool _hasTerminal(int fd) {
     try {
       _terminalSize(fd);
       return true;
     } catch (_) {
       return false;
     }
   }
 
   @patch int _terminalColumns(int fd) => _terminalSize(fd)[0];
   @patch int _terminalLines(int fd) => _terminalSize(fd)[1];
 
   static List _terminalSize(int fd) {
     var size = _getTerminalSize(fd);
     if (size is! List) {
       throw new StdoutException("Could not get terminal size", size);
     }
     return size;
   }
 
   static _getTerminalSize(int fd) native "Stdout_GetTerminalSize";
+
+  @patch static bool _supportsAnsiEscapes(int fd) {
+    var result = _getAnsiSupported(fd);
+    if (result is! bool) {
+      throw new StdoutException("Error determining ANSI support", result);

[siva, 2017/03/17 23:54:24]

Would it make sense to include the 'fd' in the exception error message?

+    }
+    return result;
+  }
+
+  static _getAnsiSupported(int fd) native "Stdout_AnsiSupported";
 }
 
 
 _getStdioHandle(_NativeSocket socket, int num) native "Socket_GetStdioHandle";
 _getSocketType(_NativeSocket nativeSocket) native "Socket_GetType";