Add support for Flutter

[joaortk]

Would be great to see a Flutter compatible plugin out of the box

[lambdapioneer]

Hi @joaortk, thanks for raising this issue :) we, the maintainer team, don't have any real experience with Flutter. Therefore, this wouldn't be something that we are adding to the project ourselves. Quite frankly, we wouldn't have the resources to maintain it properly going forward.

However, we would be very happy to welcome contributions in form of PRs or external packaging projects 👋 I absolutely see that Spectrum – due to it's xplat support – would be a great candidate for any mobile xplat framework.

Cross-referencing two other issues due to similarity: #10 (ReactNative) and #16 (NativeScript)

[juliocbcotta]

I wrote something. :-)
Currently only support Android, but you can resize, crop and rotate your images.
I managed to create the classes in a way that I think it will be super easy to use them in a React Native project
.
https://github.com/BugsBunnyBR/spectrum_plugin

Any feedbacks are welcome.

[juliocbcotta]

So I am not an ios developer, but I gave it a try...
It looks like flutter uses use_frameworks!in the project podfile, I tried using use_modular_headers!. I also tried to use moduler_headers just to spectrum, but it failed to compile in all configs. I don't know if it is something I did wrong so If anyone with iOS expertise could try this to compile the sample in this branch
https://github.com/BugsBunnyBR/spectrum_plugin/tree/ios it would be great.