Slow printing text

[niktses]

Resetting the image after every added text slows printing but changing the styling every time does not.
Removed reset() from here:
void textEncoded(
Uint8List textBytes, {
PosStyles styles = const PosStyles(),
int linesAfter = 0,
}) {
_text(textBytes, styles: styles);
// Ensure at least one line break after the text
emptyLines(linesAfter + 1);
reset();
}

and changed this:
bytes += styles.bold ? cBoldOn.codeUnits : [];
bytes += styles.turn90 ? cTurn90On.codeUnits : [];
bytes += styles.reverse ? cReverseOn.codeUnits : [];
bytes += styles.underline ? cUnderline1dot.codeUnits : [];
bytes += styles.fontType == PosFontType.fontB ? cFontB.codeUnits : [];
// Characters size
if (styles.height.value != PosTextSize.size1.value ||
styles.width.value != PosTextSize.size1.value) {
bytes += Uint8List.fromList(
List.from(cSizeGSn.codeUnits)
..add(PosTextSize.decSize(styles.height, styles.width)),
);
}

to this:
bytes += styles.bold ? cBoldOn.codeUnits : cBoldOff.codeUnits;
bytes += styles.turn90 ? cTurn90On.codeUnits : cTurn90Off.codeUnits;
bytes += styles.reverse ? cReverseOn.codeUnits : cReverseOff.codeUnits;
bytes += styles.underline ? cUnderline1dot.codeUnits : cUnderlineOff.codeUnits;
bytes += styles.fontType == PosFontType.fontB ? cFontB.codeUnits : cFontA.codeUnits;
// Characters size
bytes += Uint8List.fromList(
List.from(cSizeGSn.codeUnits)
..add(PosTextSize.decSize(styles.height, styles.width)),
);

and performance improvements were huge.
Consider testing this and if it works for you too consider changing it.

[andrey-ushakov]

Thank you for this!
It seems that it may explain this issue!

Actually, with my Xprinter XP-N160I I have no performance issues, that's why I haven't noticed this.
I will try to test soon and improve the library!

BTW, I'm not sure if you have mentioned it somewhere already, but what's your printer brand and model, please?

[niktses]

I'm using an Epson TM-T20ii-003. I also use a rongta rpp300 for its bluetooth but this one is pretty much garbage. Actually if you are interested the rongst has an issue that for some unknown to me reason exposes 2 bluetooth signals one of which does absolutely nothing and unfortunately this is the one your bluetooth library catches. The other one requires password so it probably affects it somehow. I fix this by bonding it beforehand and using this library as well "flutter_bluetooth_serial" to get the already bonded devices. The epson works fine. I have only tested in android so far.

[andrey-ushakov]

Resetting the image after every added text slows printing but changing the styling every time does not.

Unfortunately, changing the styling every time creates this issue (for some printers only): andrey-ushakov/esc_pos_bluetooth#1

However, it seems I've found a way how to avoid this. Could you please test the performance issue using your Epson TM-T20ii-003 and the latest library?

Here there is a good test: andrey-ushakov/esc_pos_printer#39 (comment)

Thanks!

[niktses]

In my case it works fine now.

[andrey-ushakov]

Ok! I'm closing this issue

[Fethi-Hamdani]

I'm having the same performance issue with an SPRT L31 printer, any help