Feature progressiveJPEG for SwiftUI

[onevcat]

This allows SwiftUI uses the progressive JPEG modifier to display an image with progressive support.

Solve #1554

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2025-03-04.at.01.08.10.mp4

[gemini-code-assist]

Hello @onevcat, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

Summary of Changes

This pull request introduces progressive JPEG support for SwiftUI in Kingfisher. It adds a new ProgressiveJPEGDemo view to the demo app, showcasing the progressive loading of a JPEG image. The progressiveJPEG modifier is now available as a KFOptionSetter, and the KingfisherManager is updated to handle progressive image setting during image retrieval. This resolves issue #1554.

Highlights

• Feature: Adds progressive JPEG support to SwiftUI's KFImage, allowing images to load progressively.
• Demo: Introduces a new ProgressiveJPEGDemo view in the demo app to demonstrate the progressive JPEG loading feature.
• API: The progressiveJPEG modifier is now available as a KFOptionSetter, providing a convenient way to enable progressive loading.

Changelog

Click here to see the changelog

• Demo/Demo/Kingfisher-Demo/SwiftUIViews/MainView.swift
  • Added a NavigationLink to the new ProgressiveJPEGDemo view.
• Demo/Demo/Kingfisher-Demo/SwiftUIViews/ProgressiveJPEGDemo.swift
  • Created a new SwiftUI view ProgressiveJPEGDemo to display a progressive JPEG image using KFImage.
  • Uses KFImage with the progressiveJPEG() modifier.
  • Displays the received and total image sizes during loading using the onProgress callback.
• Demo/Kingfisher-Demo.xcodeproj/project.pbxproj
  • Added ProgressiveJPEGDemo.swift to the project.
  • Added ProgressiveJPEGDemo.swift to the build file.
  • Added ProgressiveJPEGDemo.swift to the sources build phase.
• Sources/General/KF.swift
  • Removed the progressiveJPEG function from the KF.Builder extension.
• Sources/General/KFOptionsSetter.swift
  • Added the progressiveJPEG function to the KFOptionSetter extension, allowing it to be used with SwiftUI.
• Sources/General/KingfisherManager.swift
  • Modified retrieveImage to accept a progressiveImageSetter closure.
  • The progressiveImageSetter closure is called when a progressively loaded image is available.
• Sources/SwiftUI/ImageBinder.swift
  • Added progressiveImageSetter to the retrieveImage call, which updates the loadedImage property with the progressively loaded image.

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Trivia time!

What does JPEG stand for?

Click here for the answer

JPEG stands for Joint Photographic Experts Group.

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[gemini-code-assist]

Code Review

This pull request introduces progressive JPEG support to SwiftUI views in Kingfisher. The changes involve adding a new demo view, modifying the KFImage and KingfisherManager to handle progressive images, and updating project files. Overall, the implementation seems reasonable, but there are a few areas that could be improved for clarity and maintainability.

Merge Readiness

The pull request introduces a new feature and seems generally well-implemented. I am unable to directly approve the pull request, and recommend that others review and approve this code before merging. Given the absence of any CRITICAL or HIGH severity issues, the pull request is a good candidate for merging after addressing the MEDIUM and LOW severity issues. I recommend that the pull request not be merged until those are addressed (at a minimum).