From ce3b8ba4b34241d77de0b8c5f3d539abcc65bca0 Mon Sep 17 00:00:00 2001 From: Shadowfacts Date: Sun, 30 Apr 2023 11:55:00 -0400 Subject: [PATCH] Add zooming to focused attachment view --- .../FocusedAttachmentController.swift | 14 ++- .../ComposeUI/Views/ZoomableScrollView.swift | 111 ++++++++++++++++++ 2 files changed, 122 insertions(+), 3 deletions(-) create mode 100644 Packages/ComposeUI/Sources/ComposeUI/Views/ZoomableScrollView.swift diff --git a/Packages/ComposeUI/Sources/ComposeUI/Controllers/FocusedAttachmentController.swift b/Packages/ComposeUI/Sources/ComposeUI/Controllers/FocusedAttachmentController.swift index fd769710..2e227d19 100644 --- a/Packages/ComposeUI/Sources/ComposeUI/Controllers/FocusedAttachmentController.swift +++ b/Packages/ComposeUI/Sources/ComposeUI/Controllers/FocusedAttachmentController.swift @@ -35,9 +35,17 @@ class FocusedAttachmentController: ViewController { VStack(spacing: 0) { Spacer(minLength: 0) - ControllerView(controller: { controller.thumbnailController }) - .environment(\.attachmentThumbnailConfiguration, .init(contentMode: .fit, fullSize: true)) - .matchedGeometryDestination(id: attachment.id) + let attachmentView = + ControllerView(controller: { controller.thumbnailController }) + .environment(\.attachmentThumbnailConfiguration, .init(contentMode: .fit, fullSize: true)) + .matchedGeometryDestination(id: attachment.id) + if #available(iOS 16.0, *) { + ZoomableScrollView { + attachmentView + } + } else { + attachmentView + } Spacer(minLength: 0) diff --git a/Packages/ComposeUI/Sources/ComposeUI/Views/ZoomableScrollView.swift b/Packages/ComposeUI/Sources/ComposeUI/Views/ZoomableScrollView.swift new file mode 100644 index 00000000..54b4f7eb --- /dev/null +++ b/Packages/ComposeUI/Sources/ComposeUI/Views/ZoomableScrollView.swift @@ -0,0 +1,111 @@ +// +// ZoomableScrollView.swift +// ComposeUI +// +// Created by Shadowfacts on 4/29/23. +// + +import SwiftUI + +@available(iOS 16.0, *) +struct ZoomableScrollView: UIViewControllerRepresentable { + let content: Content + + init(@ViewBuilder content: () -> Content) { + self.content = content() + } + + func makeUIViewController(context: Context) -> Controller { + return Controller(content: content) + } + + func updateUIViewController(_ uiViewController: Controller, context: Context) { + uiViewController.host.rootView = content + } + + class Controller: UIViewController, UIScrollViewDelegate { + let scrollView = UIScrollView() + let host: UIHostingController + + private var lastIntrinsicSize: CGSize? + private var contentViewTopConstraint: NSLayoutConstraint! + private var contentViewLeadingConstraint: NSLayoutConstraint! + private var hostBoundsObservation: NSKeyValueObservation? + + init(content: Content) { + self.host = UIHostingController(rootView: content) + + super.init(nibName: nil, bundle: nil) + } + + required init?(coder: NSCoder) { + fatalError("init(coder:) has not been implemented") + } + + override func viewDidLoad() { + super.viewDidLoad() + + scrollView.delegate = self + scrollView.bouncesZoom = true + scrollView.translatesAutoresizingMaskIntoConstraints = false + view.addSubview(scrollView) + + host.sizingOptions = .intrinsicContentSize + host.view.backgroundColor = .clear + host.view.translatesAutoresizingMaskIntoConstraints = false + addChild(host) + scrollView.addSubview(host.view) + host.didMove(toParent: self) + + contentViewLeadingConstraint = host.view.leadingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.leadingAnchor) + contentViewTopConstraint = host.view.topAnchor.constraint(equalTo: scrollView.contentLayoutGuide.topAnchor) + + NSLayoutConstraint.activate([ + scrollView.frameLayoutGuide.leadingAnchor.constraint(equalTo: view.leadingAnchor), + scrollView.frameLayoutGuide.trailingAnchor.constraint(equalTo: view.trailingAnchor), + scrollView.frameLayoutGuide.topAnchor.constraint(equalTo: view.topAnchor), + scrollView.frameLayoutGuide.bottomAnchor.constraint(equalTo: view.bottomAnchor), + + contentViewLeadingConstraint, + contentViewTopConstraint, + ]) + } + + override func viewDidLayoutSubviews() { + super.viewDidLayoutSubviews() + + if host.view.intrinsicContentSize != lastIntrinsicSize { + self.lastIntrinsicSize = host.view.intrinsicContentSize + + let maxHeight = view.bounds.height - view.safeAreaInsets.top - view.safeAreaInsets.bottom + let maxWidth = view.bounds.width - view.safeAreaInsets.left - view.safeAreaInsets.right + let heightScale = maxHeight / host.view.intrinsicContentSize.height + let widthScale = maxWidth / host.view.intrinsicContentSize.width + let minScale = min(widthScale, heightScale) + let maxScale = minScale >= 1 ? minScale + 2 : 2 + print("min: \(minScale), max: \(maxScale)") + scrollView.minimumZoomScale = minScale + scrollView.maximumZoomScale = maxScale + scrollView.zoomScale = minScale + } + + centerImage() + } + + func viewForZooming(in scrollView: UIScrollView) -> UIView? { + return host.view + } + + func scrollViewDidZoom(_ scrollView: UIScrollView) { + centerImage() + } + + func centerImage() { + let yOffset = max(0, (view.bounds.size.height - host.view.bounds.height * scrollView.zoomScale) / 2) + contentViewTopConstraint.constant = yOffset + + let xOffset = max(0, (view.bounds.size.width - host.view.bounds.width * scrollView.zoomScale) / 2) + contentViewLeadingConstraint.constant = xOffset + } + } +}