1 files changed, 30 insertions, 0 deletions
diff --git a/util/telchars.js b/util/telchars.js
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index 0000000..8cf414c
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+++ b/util/telchars.js
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+// Useful telnet key detection.
+
+const telchars = {
+  isSpace: buf => buf[0] === 0x20,
+  isEnter: buf => buf[0] === 0x0d && buf[1] === 0x00,
+  isTab: buf => buf[0] === 0x09,
+  isBackTab: buf => buf[0] === 0x1b && buf[2] === 0x5A,
+
+  // isEscape is hard because it's just send as ESC (the ANSI escape code),
+  // so we need to make sure that the escape code is all on its own
+  // (i.e. the length is 1)
+  isEscape: buf => buf[0] === 0x1b && buf.length === 1,
+
+  // Use this for when you'd like to detect the user confirming or issuing a
+  // command, like the X button on your PlayStation controller, or the mouse
+  // when you click on a button.
+  isSelect: buf => telchars.isSpace(buf) || telchars.isEnter(buf),
+
+  // Use this for when you'd like to detect the user cancelling an action,
+  // like the O button on your PlayStation controller, or the Escape key on
+  // your keyboard.
+  isCancel: buf => telchars.isEscape(buf),
+
+  isUp: buf => buf[0] === 0x1b && buf[2] === 0x41,
+  isDown: buf => buf[0] === 0x1b && buf[2] === 0x42,
+  isRight: buf => buf[0] === 0x1b && buf[2] === 0x43,
+  isLeft: buf => buf[0] === 0x1b && buf[2] === 0x44,
+}
+
+module.exports = telchars