Kingfisher: Adding Aspect Fit/Fill to Image Resizing Processor

[TimOliver]

Hi @onevcat!

Thanks for this awesome library! It's really impressive! :)

I was playing with the ResizingImageProcessor in my app to resize images preload in a UITableView, and there were 2 resizing modes I was looking to use:

• Aspect fit: where the image stays at the same aspect ratio, but it scaled down to completely fit inside `targetSize.
• Aspect fill: where the image is kept at the same ratio, but scaled to fill the bounds of targetSize, with the outlying edges getting cropped.

I'd be happy to volunteer to add these. If you'd like that, would it be worth extending ResizingImageProcessor, or making them separate structs?

Thanks!

[onevcat]

Hi, thanks for considering contributing!

That's great if you could implement it! I think just extending the ResizingImageProcessor to contains additional properties would be a totally fine and better way.

Since it should not be a breaking change, so please add this as an option and keep current implementation for default using. Currently, the input size will be respected without aspect fitting or filling. So I guess just add an enum in the ResizingImageProcessor to indicate the resizing strategy might be a good idea. I suggest an interface like:

struct ResizingImageProcessor {
    enum ContentMode {
        case none // This will be the default one
        case aspectFit
        case aspectFill
    }

    init(targetSize: CGSize, mode: ContentMode = .none) { ... }
}

How do you think about it?

[Drusy]

Hi @onevcat, @TimOliver,

I just had to implement this feature this morning for my project functional scope.
Would you like me to share and make the PR for this or @TimOliver do you want to implement this one ?

Let me know

[onevcat]

👍 @Drusy It's great to hear that you are interested in it too. I'd like to receive a p-r from you!

However, since @TimOliver was earlier and might be still working on this, let's keep for a while to see Tim's comment now. :)

[Drusy]

@onevcat of course, keep me updated :)

[TimOliver]

Hey @Drusy, and @onevcat! Thanks for that!

Oh cool! No, I hadn't started it yet. I'm on a deadline to ship an app this week, so I would have had to have started it next week at the earliest.

If you've already got an implementation, then by all means, don't let me stand in the way! :)

[onevcat]

@TimOliver Great! Thank you.

@Drusy :)

[BrikerMan]

added #599

[Drusy]

@onevcat After reading @BrikerMan PR, I actually didn't know the existence of a such method func resize(to size: CGSize, for contentMode: UIViewContentMode) -> Image. If I would, I would probably have done the same.

Here is my PR #600 for this feature using your size proxy (no UIKit)

[onevcat]

@TimOliver @BrikerMan @Drusy Thank you all! #600 was merged and I will prepare a release for it later today.

func resize(to size: CGSize, for contentMode: UIViewContentMode) -> Image is now a UIKit specified helper method and we could merge it to the general resize one with new ContentMode enum, to improve readability. That should be another story and maybe I could find some time later for it.

[TimOliver]

Awesome! Great work all! :D