How to print the text right aligned in a Bluetooth POS Printer?

I have been trying to do a POS app in android where I am printing the receipt on a Bluetooth printer connected to the app. I am able to print 'large', 'small' and QR code with the HOINSDK provided with the device and also I am able to align then 'left' and 'centre' but unable to align it to the 'right'. Any help is appreciated.

Below are the codes for respective things:

//For Large Text

cmd[0] = 27;
cmd[1] = 97;
cmd[2] &= 0xEF;
mService.write(cmd);
mService.sendMessage("" + large_txt.getText().toString(), "GBK");

//For Small Text
cmd[0] = 0x1b;
cmd[1] = 0x21;
cmd[2] &= 0xEF;
mService.write(cmd);
mService.sendMessage("" + small_txt.getText().toString(), "GBK");

//For Center Alignment small text
cmd[0] = 27;
cmd[1] = 97;
cmd[2] |= 1;
mService.write(cmd);
cmd[0] = 27;
cmd[1] = 97;
cmd[2] = 1;
mService.write(cmd);
mService.sendMessage("" + center_txt.getText().toString(), "GBK");

//For centre alignment Large Text
cmd[1] = 97;
cmd[2] |= 1;
mService.write(cmd);
cmd[0] = 0x1b;
cmd[1] = 0x21;
cmd[2] = 0x10;
mService.write(cmd);
mService.sendMessage("" + center_txt.getText().toString(), "GBK");

//For Left alignment
cmd[0] = 27;
cmd[1] = 97;
cmd[2] |= 1;
mService.write(cmd);
cmd[0] = 27;
cmd[1] = 97;
cmd[2] = 0;
mService.write(cmd);
mService.sendMessage("" + left_txt.getText().toString(), "GBK");


If anybody can help me with the right alignment code, it would be helpful.

1 Answer
1

I faced same issue before but I did not found any solution so, I am using below method as a solution,

Example,

String largetext = "Title";
String largeFontMessage = getWhiteSpace(24 - largetext.length()) + largetext;
String smalltext = "Message";
String smallFontMessage = getWhiteSpace(42 - smalltext.length()) + smalltext;

// print largeFontMessage;
// print smallFontMessage;

public static String getWhiteSpace(int size) {
StringBuilder builder = new StringBuilder(size);
for (int i = 0; i < size; i++) {
builder.append(' ');
}
return builder.toString();
}


In my case in single line small text contains 42 characters and large text contains 24 characters.

Thanks.

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