如何在 Flutter 上实现打印队列？

Question

I´m using esc_pos_bluetooth 0.2.8 library and connect the printer by bluetooth Is ok when I send one order at a time, but when there are simultaneous orders, it print just the first and ignore the others. I try implement a print queue but I was not successful.

List printQueue = [];

insertPrintQueue(Schema item) {
    printQueue.add(item);
    printTicket(printQueue[0]);
  }

  verifyPrintQueue() {
    if (printQueue.length > 0) {
      printTicket(printQueue[0]);
    }
  }

  printTicket(Schema item) async {
      if (printerDevices != null) {
        printerManager.selectPrinter(printerDevices[0]);
        await printerManager
            .printTicket(await ticket.templateTicket(item))
            .then((value) => {
                  printQueue.removeAt(0),
                  if (printQueue.length > 0)
                    {
                      printTicket(printQueue[0])
                    }
                });
      } else {
      print("None Printer Found");
  }

I think this is happening because I'm trying to print while the printer is busy, have a way to check the status of the printer? and just order the print when the printer is not printing

Answer 1

insertPrintQueue(Schema item) {
  printQueue.add(item);
  printTicket(printQueue[0]); // Here
}

You are trying to print the first item always. So it works as expected. You can do it like this:

insertPrintQueue(Schema item) {
  printQueue.add(item);
  //printTicket(printQueue[0]);

  for (var ticket in printQueue) {
      printTicket(ticket);
  }
}