Dart:io stdin raw character codes - dart

Question

I've created a Dart console app and need to process keycodes like Arrow keys and function keys from stdin? The samples I've seen are typically String based :
Stream readLine() => stdin.transform(UTF8.decoder).transform(new LineSplitter());
readLine().listen(processLine);
I modified the above sample hoping to get the raw ints like this:
Stream readInts() => stdin;
readInts().listen(processInts);
void processInts(List<int> kbinput) {
for (int i=0;i<kbinput.length;i++){
print ("kbinput:${kbinput[i]}");
}
}
It seems stdin provides only printable characters and not all ascii keycodes. If it is not possible from stdin, can I create & load a stream within my native extension with the keycodes? How can my console app get to the ascii keycodes of any keypress? Thanks for your help!

Answer 1

One way would be
import 'dart:io' as io;
import 'dart:convert' show UTF8;
void main() {
io.stdin.echoMode = false;
var input;
while(input != 32) { // leave program with [Space][Enter]
input = io.stdin.readByteSync();
if(input != 10) print(input); // ignore [Enter]
}
io.stdin.echoMode = true;
}
but it only returns a value after Enter is pressed.
For one key press it returns from one up to three bytes.
It seems it's not easy to get a keystroke from console without pressing Enter
see Capture characters from standard input without waiting for enter to be pressed for more details.
You could create a native extension that implements the suggested solution in the linked question.