SCRLCanvasPrototype

An iOS prototype that simulates a canvas-based editor with overlay elements, snapping functionality, and zooming support.

It was created as a test assignment.

Features

• Scrollable and zoomable canvas (CanvasViewController, CanvasView)
• Overlays fetched from a remote API (OverlayFetcher)
• Overlay selection sheet (OverlaySelectionViewController)
• Snapping to guidelines and other overlays (SnapDetector)
• Visual snap lines with haptic feedback
• In-memory image caching (ImageCache)
• Custom overlay views with interactive dragging (OverlayItemView)

Project Structure

• CanvasViewController.swift: Manages the canvas, overlays, zoom, and snapping logic.
• CanvasView.swift: Renders static guidelines and dynamic snap lines.
• OverlayFetcher.swift: Fetches overlay data from a remote API.
• OverlaySelectionViewController.swift: Displays a modal with available overlays to add.
• OverlayItemView.swift: Interactive overlay views with drag and tap gestures.
• SnapDetector.swift: Logic for detecting snapping to guidelines and other overlays.
• OverlayCell.swift: UICollectionViewCell for displaying overlay thumbnails.
• OverlayItem.swift: Models for overlay categories and items.
• ImageCache.swift: Lightweight in-memory cache for images.

Notes

• UIKit-based, targeting iOS 16+
• Uses Swift concurrency (async/await) for network and image loading
• Includes SwiftUI previews for debugging UI in Xcode

Author

Created by Sergey Slobodenyuk on March 2025