EOS thermal printer does not print Arabic characters properly when using Flutter framework

Issue

Context:

I have an EOS thermal printer, but it does not print Arabic characters properly like in this image below:

Incorrect Arabic encoding

As you can see, the Arabic text is printed incorrectly and from Left-to-Right (LTR), (it should be Right-to-Left – RTL).

Note: You can clearly see the English text is printed perfectly at the end of the page.

Question:

How can I print Arabic text the right way in flutter?

Additional Info:

Flutter version: 2.5.3 (Stable)

Package Used: escpos

Tested on multiple Android devices running Android version (8, 9 ,10)

Solution

first I have used the esc_pos package and it didn’t work.
In the end, I’ve used the printing package to print an Arabic invoice and it works fine, and the explanation below

This is the full code to use the printing package.
first, create a class to pass the parameters to it(the parameters that you need to print) in my case 4 required param.

class HtmlGeneratorParamsAccount {
  final String daybet, payable, balance;
  final List<AccountStatmentModel> list;

  HtmlGeneratorParamsAccount({
    required this.daybet,
    required this.payable,
    required this.balance,
    required this.list,
  });
}

String generateHtmlA(HtmlGeneratorParamsAccount p) {
  String items = '''
    ''';

  for (var i = 0; i < p.list.length; i++) {
    DateFormat datee = DateFormat('yyyy/MM/dd', 'en');
    DateTime forFormat = p.list[i].date;
    final String formatted = datee.format(forFormat);
    double amount = p.list[i].debitAmount + p.list[i].payableAmount;
    items += '''<tr class = "item">''';

    items += '''<td>${p.list[i].description}</td>''';
    items += '''<td>${formatted}</td>''';
    items += '''<td>${p.list[i].opName}</td>''';
    items += '''<td>${double.parse(amount.toStringAsFixed(1))}</td>''';
    items += '''</tr>''';
  }
  var pay = double.parse(p.payable).toStringAsFixed(1);
  var day = double.parse(p.daybet).toStringAsFixed(1);
  var html = """ 

then you need to use HTML to build the body of your invoice(shape)

    <!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href=
"https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" />
    <style>

      .invoice-box {
        max-width:1000px;
        margin: auto;
        padding: 8px;
        border: 1px solid #eee;
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
        font-size: 8px;
        line-height: 24px;
        font-family: 'Helvetica Neue', 'Helvetica', Helvetica, Arial, sans-serif;
        color: #555;
      }
        .invoice-box table {
        width: 100%;
        line-height: inherit;
        text-align: center;
      }

      .invoice-box table td {
        padding: 10px;
        vertical-align: top;
      }
 
      .invoice-box table tr.top table td {
        padding-bottom: 5px;
      }

* {
  box-sizing: border-box;
}


.column {
  float: right;
  width:23%;
  
  padding: 16px;
 
}
.header{
text-align:center;
}


.row:after {
  content: "";
  display: table;
  clear: both;
}
 
</style>
</head>
<body>
<h2 class="header">كشف حساب</h2>
<h3 class="header">بيانات الزبون</h3>
<table>
<tr>
<div class="row">
  <div class="column" >
    <h4>المبلغ</h4>
    <p></p>
  </div>
 
  <div class="column" >

    <h4>نوع العملية</h4>
    
  </div>

  <div class="column" >
    <h4>تاريخ</h4>
   
  </div>
  <div class="column" >
    <h4>وصف</h4>
    
  </div>
</div>
</tr>
$items
</table>
<div>
<p class="header">------------------------</p>
<p class="header">:مجموع ${day}</p>
<p class="header">:مجموع $pay</p>
<p class="header">:المبلغ ${p.balance}</p>
<p>---</p>
<p>--</p>
<p>-</p>
</div>
</body>
</html>""";
  return html;

'''

create a function

when you need to use it (in button for example)

printDoc(HtmlGeneratorParamsAccount params) async {

await Printing.layoutPdf(
  onLayout: (format) async => await Printing.convertHtml(
    format: format,
    html: generateHtmlA(params),
  ),
);

}
now we will use the printDoc function inside IconButton

the params is the class we’ve made in the beginning, and we will pass the required parameters

 IconButton(
          onPressed: () {
            HtmlGeneratorParamsAccount params=
                HtmlGeneratorParamsAccount(
              list: list,
              payable: payableAmount.toString(),
              daybet: debitTxt.toString(),
              balance: balance.toString(),
            );
            printDoc(params);
          },
          icon: Icon(
            Icons.print,
          )),

Answered By – ِِAbdallah Al Hallak

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0

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