Getting grey Diagonal line in Dark mode

[kisrar]

After following this doc : https://github.com/espresso3389/pdfrx/blob/master/doc/Dark-Night-Mode-Support.md , in some users device, the PDF is getting a grey Diagonal line (from Top-Right to Bottom-Left) in Dark mode. Although in some device it works perfectly fine.

Screenshot:

Details:

Device: Samsung Galaxy M34 5G
Android : 15
pdfrx: 2.1.22
flutter: 3.35.2

Relevant code:

ColorFiltered(
          colorFilter: ColorFilter.mode(Colors.white, _darkModePDF ? BlendMode.difference : BlendMode.dst),
          child: _buildPDFViwer(),
        ),

[aiviapp]

This issue also occurs on the Samsung Galaxy S10 running Android 12.

[espresso3389]

It's very interesting.

And the line is from the top-right edge of the screen, and it implies that this is not the problem with the buffers allocated by PdfViewer or such, but it's a problem of buffer (or texture?) used by the app.

[espresso3389]

I've found that even a simplest Flutter app (just newly created by flutter create) exhibits this if I added ColorFiltered on the top of build function:

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return ColorFiltered(
      colorFilter: ColorFilter.mode(Colors.white, BlendMode.difference),
      child: MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          // This is the theme of your application
...

So, this is apparently an issue with Flutter framework.

[espresso3389]

I've filed this as flutter/flutter#176949.

[Ezor]

Instead of using a ColorFilter.mode, you can use this ColorFilter matrix, it's achieving the same result without the diagonal line bug on Android devices

ColorFilter.matrix([
                -1,
                0,
                0,
                0,
                255,
                0,
                -1,
                0,
                0,
                255,
                0,
                0,
                -1,
                0,
                255,
                0,
                0,
                0,
                1,
                0,
              ])

[kisrar]

@Ezor Thanks. Surprisingly the above solution is a nice workaround and working fine for me.

Although flutter team needs to fix the actual issue.