Added beep and fontType commands

lib/src/commands.dart

@@ -3,6 +3,7 @@ const gs = '\x1D';
 
 // Miscellaneous
 const cInit = '$esc@'; // Initialize printer
+const cBeep = '${esc}B'; // Beeper [count] [duration]
 
 // Mech. Control
 const cCut = '${gs}V0'; // Cut paper
@@ -19,6 +20,8 @@ const cUnderline1dot = '$esc-1'; // Turns on underline mode (1-dot thick)
 const cUnderline2dots = '$esc-2'; // Turns on underline mode (2-dots thick)
 const cBoldOn = '${esc}E1'; // Turn emphasized mode on
 const cBoldOff = '${esc}E0'; // Turn emphasized mode off
+const cFontA = '${esc}M0'; // Font A
+const cFontB = '${esc}M1'; // Font B
 
 // Print Position
 const cAlignLeft = '${esc}a0'; // Left justification

lib/src/printer.dart

@@ -4,6 +4,7 @@ import 'commands.dart';
 
 enum PosTextAlign { left, center, right }
 enum PosCutMode { normal, partial, full }
+enum PosFontType { fontA, fontB }
 
 class PosTextSize {
   final int value;
@@ -21,6 +22,20 @@ class PosTextSize {
       16 * (width.value - 1) + (height.value - 1);
 }
 
+class PosBeepDuration {
+  final int value;
+  const PosBeepDuration._internal(this.value);
+  static const beep50ms = const PosBeepDuration._internal(1);
+  static const beep100ms = const PosBeepDuration._internal(2);
+  static const beep150ms = const PosBeepDuration._internal(3);
+  static const beep200ms = const PosBeepDuration._internal(4);
+  static const beep250ms = const PosBeepDuration._internal(5);
+  static const beep300ms = const PosBeepDuration._internal(6);
+  static const beep350ms = const PosBeepDuration._internal(7);
+  static const beep400ms = const PosBeepDuration._internal(8);
+  static const beep450ms = const PosBeepDuration._internal(9);
+}
+
 /// Abstract printer.
 class Printer {
   Printer(this._socket) {
@@ -66,6 +81,7 @@ class Printer {
     PosTextAlign align = PosTextAlign.left,
     PosTextSize height = PosTextSize.size1,
     PosTextSize width = PosTextSize.size1,
+    PosFontType fontType = PosFontType.fontA,
     int linesAfter = 0,
   }) {
     _socket.write(bold ? cBoldOn : cBoldOff);
@@ -74,7 +90,7 @@ class Printer {
     _socket.write(align == PosTextAlign.left
         ? cAlignLeft
         : (align == PosTextAlign.center ? cAlignCenter : cAlignRight));
-
+    _socket.write(fontType == PosFontType.fontA ? cFontA : cFontB);
     // Text size
     _socket.add(
       Uint8List.fromList(
@@ -87,6 +103,26 @@ class Printer {
     reset();
   }
 
+  void beep(
+      {int count = 3, PosBeepDuration duration = PosBeepDuration.beep450ms}) {
+    if (count <= 0) {
+      return;
+    }
+
+    int beepCount = count;
+    if (beepCount > 9) {
+      beepCount = 9;
+    }
+
+    _socket.add(
+      Uint8List.fromList(
+        List.from(cBeep.codeUnits)..addAll([beepCount, duration.value]),
+      ),
+    );
+
+    beep(count: count - 9, duration: duration);
+  }
+
   void reset() {
     _socket.write(cInit);
   }