Flutter desktop about dart_pdf HOT 29 CLOSED

https://docs.microsoft.com/en-us/windows/win32/dlgbox/using-common-dialog-boxes#displaying-the-print-dialog-box

from dart_pdf.

Here is a dart code using FFI to list the printers on a Windows machine.

import 'dart:convert';
import 'dart:ffi' as ffi;

typedef CEnumPrinters = ffi.Int32 Function(
  ffi.Int32 flags,
  ffi.Pointer<ffi.Uint8> name,
  ffi.Int32 level,
  ffi.Pointer<ffi.Uint8> printerEnum,
  ffi.Int32 buf,
  ffi.Pointer<ffi.Int32> needed,
  ffi.Pointer<ffi.Int32> returned,
);

typedef EnumPrinters = int Function(
  int flags,
  ffi.Pointer<ffi.Uint8> name,
  int level,
  ffi.Pointer<ffi.Uint8> printerEnum,
  int buf,
  ffi.Pointer<ffi.Int32> needed,
  ffi.Pointer<ffi.Int32> returned,
);

// Example of handling a simple C struct
class PrintInfo extends ffi.Struct<PrintInfo> {
  @ffi.Int32()
  int flags;

  @ffi.Uint64()
  int _description;

  @ffi.Uint64()
  int _name;

  @ffi.Uint64()
  int _comment;

  String _utf16ToString(int address) {
    final ptr = ffi.Pointer<ffi.Uint16>.fromAddress(address);
    final units = List<int>();
    var len = 0;
    while (true) {
      final char = ptr.elementAt(len++).load<int>();
      if (char == 0) break;
      units.add(char);
    }
    return Utf8Decoder().convert(units);
  }

  String get description => _utf16ToString(_description);

  String get name => _utf16ToString(_name);

  String get comment => _utf16ToString(_comment);

  @override
  String toString() =>
      '$runtimeType\n  Flags=$flags\n  Name=$name\n  Description=$description\n  Comment=$comment';
}

void main() {
  final dylib = ffi.DynamicLibrary.open('winspool.drv');
  final enumPrintersPointer =
      dylib.lookup<ffi.NativeFunction<CEnumPrinters>>('EnumPrintersW');
  final enumPrinters = enumPrintersPointer.asFunction<EnumPrinters>();

  final needed = ffi.Pointer<ffi.Int32>.allocate()..store(0);
  final returned = ffi.Pointer<ffi.Int32>.allocate()..store(0);
  enumPrinters(2, ffi.Pointer.fromAddress(0), 1, ffi.Pointer.fromAddress(0), 0,
      needed, returned);

  final bufferSize = needed.load<int>();
  final buffer = ffi.Pointer<ffi.Uint8>.allocate(count: bufferSize);
  final result = enumPrinters(
      2, ffi.Pointer.fromAddress(0), 1, buffer, bufferSize, needed, returned);

  if (result == 0) throw ('Error listing the printers');

  final count = returned.load<int>();

  final a = ffi.Pointer<PrintInfo>.fromAddress(buffer.address);
  for (int i = 0; i < count; i++) {
    print(a.elementAt(i).load<PrintInfo>());
  }

  buffer.free();
}

from dart_pdf.

macOS desktop support is fully implemented in printing 3.0.0

from dart_pdf.

We're almost there!

from dart_pdf.

That's just great @DavBfr. I will test few use cases and we can get in out in next release.

from dart_pdf.

It's been long time with no activity on this issue. Anyone working on getting windows support for printing ?

please share the progress so that we can make this plugin cross-platform.

from dart_pdf.

@viveknimkarde yes I saw it, but it's really limited.

from dart_pdf.

Are you talking about https://github.com/google/flutter-desktop-embedding ?
This thing is not ready for production yet.

from dart_pdf.

Hey @DavBfr
Thats it..
I have gotten it workng on Mac and Windows. Its very nice to use. I was very surprised how fast and smooth it is.
The PDF code will work today.
The PDF plugin for Printing will need to be replaced. They do have plugins working today.

EDIT:
I presume your Flutter mobile sends the pdf out to the native PDF Reader and then the user gets to se it, presses print, and then it hooks into each system print spooler ?

from dart_pdf.

@gedw99, any update on this issue?

from dart_pdf.

hey @DavBfr Not yet !
Have been in a rush - wil get to this next week and integrate it with your package.

Just had an issue with IOS and printing :)

from dart_pdf.

Has this stalled?

from dart_pdf.

Hello, any news about this?

from dart_pdf.

Do we have a stable plugin api now for desktop-shells? I think MacOS and Linux should be easy to do using cups. But Windows will require a conversion from PDF to native print.

from dart_pdf.

Could you give me a light on how to do this? I need it to work at least on windows

from dart_pdf.

The most simple way to print a pdf on windows would be to generate the pdf, save it on a temporary folder and print using sumatrapdf as an external command line.

from dart_pdf.

Great, I'll study it better, thank you very much

from dart_pdf.

Here is a branch with a windows plugin, if some C++ / windows experts want to help.

https://github.com/DavBfr/dart_pdf/tree/windows

The goal is to use Pdfium for the rendering and share as much code as possible with the Linux implementation, which is not the case yet.

from dart_pdf.

Thanks for the update @DavBfr .

I will try to work on C++ part, although I am not a windows expert.

This plugin is very essential to make cross-platform apps.

from dart_pdf.

@DavBfr did you take a look at https://pub.dev/packages/windows_printing

Any learnings from this plugin implementation.

from dart_pdf.

Here you are: printing version 3.7.0 has Windows Desktop support, for x64 builds.

It's beta quality for now, full of memory leaks and missing bits, but the feature is there.

from dart_pdf.

Hey @DavBfr thanks for your work. My problem is that I am using thermal printer for print billing receipt but it always print blank receipts. Any help would be appreciated..

from dart_pdf.

I am printing simple hello world but it does not print anything.
``final font = await rootBundle.load("fonts/Helvetica.ttf");
final ttf = pw.Font.ttf(font);

    final doc = pw.Document();

    doc.addPage(
      pw.Page(
        pageFormat: PdfPageFormat.letter,
        build: (pw.Context context) {
          return pw.Text(
            "Hello World",
            style : pw.TextStyle(font: ttf, fontSize: 40)
          );
        },
      ),
    );

    final output = await getTemporaryDirectory();
    final file = File("${output.path}/example.pdf");
    await file.writeAsBytes(doc.save());

    await Printing.layoutPdf(
      onLayout: (PdfPageFormat format) async => doc.save(),
    );

from dart_pdf.

@rizirf-connect

Look at the windows CPP code. And adapt to your situation. I don't have a thermal printer.

from dart_pdf.

Sir I dont understand anything can you guide me plzz how to solve this problem.

from dart_pdf.

Hey @DavBfr can you please tell me what kind of problem i am facing right now..??

from dart_pdf.

@rizirf-connect I don't know. Please share more code.

from dart_pdf.

@DavBfr sir I am using all this code to simply print hello world in my thermal printer, but It is printing blank paper.

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Closing this issue as #468 is the last OS to support.

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