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

runtime/bin/stdio_win.cc

Index: runtime/bin/stdio_win.cc
diff --git a/runtime/bin/stdio_win.cc b/runtime/bin/stdio_win.cc
index 8f2a72cf23d0bf89a3d7be248139697249486cd9..40df3a707beb4370409dba5e6298a84a76f8b04f 100644
--- a/runtime/bin/stdio_win.cc
+++ b/runtime/bin/stdio_win.cc
@@ -9,6 +9,16 @@
 
 #include "bin/stdio.h"
 
+// These are not always defined in the header files. See:
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms686033(v=vs.85).aspx
+#ifndef ENABLE_VIRTUAL_TERMINAL_INPUT
+#define ENABLE_VIRTUAL_TERMINAL_INPUT 0x0200
+#endif
+
+#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
+#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
+#endif
+
 namespace dart {
 namespace bin {
 
@@ -77,6 +87,23 @@ bool Stdin::SetLineMode(bool enabled) {
 }
 
 
+bool Stdin::AnsiSupported(bool* supported) {
+  ASSERT(supported != NULL);
+  HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
+  if (h == INVALID_HANDLE_VALUE) {
+    *supported = false;
+    return false;
+  }
+  DWORD mode;
+  if (!GetConsoleMode(h, &mode)) {
+    *supported = false;
+    return false;
+  }
+  *supported = (mode & ENABLE_VIRTUAL_TERMINAL_INPUT) != 0;
+  return true;
+}
+
+
 bool Stdout::GetTerminalSize(intptr_t fd, int size[2]) {
   HANDLE h;
   if (fd == 1) {
@@ -93,6 +120,28 @@ bool Stdout::GetTerminalSize(intptr_t fd, int size[2]) {
   return true;
 }
 
+
+bool Stdout::AnsiSupported(intptr_t fd, bool* supported) {
+  ASSERT(supported != NULL);
+  HANDLE h;
+  if (fd == 1) {
+    h = GetStdHandle(STD_OUTPUT_HANDLE);
+  } else {
+    h = GetStdHandle(STD_ERROR_HANDLE);
+  }
+  if (h == INVALID_HANDLE_VALUE) {
+    *supported = false;
+    return false;
+  }
+  DWORD mode;
+  if (!GetConsoleMode(h, &mode)) {
+    *supported = false;
+    return false;
+  }
+  *supported = (mode & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0;
+  return true;
+}
+
 }  // namespace bin
 }  // namespace dart