NetNewsWire/iOS/Article/WebViewController.swift

620 lines
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Swift
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//
// WebViewController.swift
// NetNewsWire-iOS
//
// Created by Maurice Parker on 12/28/19.
// Copyright © 2019 Ranchero Software. All rights reserved.
//
import UIKit
import WebKit
import Account
import Articles
import SafariServices
protocol WebViewControllerDelegate: class {
func webViewController(_: WebViewController, articleExtractorButtonStateDidUpdate: ArticleExtractorButtonState)
}
class WebViewController: UIViewController {
private struct MessageName {
static let imageWasClicked = "imageWasClicked"
static let imageWasShown = "imageWasShown"
}
private var topShowBarsView: UIView!
private var bottomShowBarsView: UIView!
private var topShowBarsViewConstraint: NSLayoutConstraint!
private var bottomShowBarsViewConstraint: NSLayoutConstraint!
private var webView: WKWebView!
private lazy var contextMenuInteraction = UIContextMenuInteraction(delegate: self)
private var isFullScreenAvailable: Bool {
return traitCollection.userInterfaceIdiom == .phone && coordinator.isRootSplitCollapsed
}
private lazy var transition = ImageTransition(controller: self)
private var clickedImageCompletion: (() -> Void)?
private var articleExtractor: ArticleExtractor? = nil
private var extractedArticle: ExtractedArticle?
private var isShowingExtractedArticle = false {
didSet {
if isShowingExtractedArticle != oldValue {
reloadHTML()
}
}
}
var articleExtractorButtonState: ArticleExtractorButtonState = .off {
didSet {
delegate.webViewController(self, articleExtractorButtonStateDidUpdate: articleExtractorButtonState)
}
}
weak var coordinator: SceneCoordinator!
weak var delegate: WebViewControllerDelegate!
var article: Article? {
didSet {
stopArticleExtractor()
if article?.webFeed?.isArticleExtractorAlwaysOn ?? false {
startArticleExtractor()
}
if article != oldValue {
reloadHTML()
}
}
}
var restoreOffset = 0
deinit {
if webView != nil {
webView?.evaluateJavaScript("cancelImageLoad();")
webView.configuration.userContentController.removeScriptMessageHandler(forName: MessageName.imageWasClicked)
webView.configuration.userContentController.removeScriptMessageHandler(forName: MessageName.imageWasShown)
webView.removeFromSuperview()
WebViewProvider.shared.enqueueWebView(webView)
webView = nil
}
}
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(webFeedIconDidBecomeAvailable(_:)), name: .WebFeedIconDidBecomeAvailable, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(avatarDidBecomeAvailable(_:)), name: .AvatarDidBecomeAvailable, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(faviconDidBecomeAvailable(_:)), name: .FaviconDidBecomeAvailable, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(contentSizeCategoryDidChange(_:)), name: UIContentSizeCategory.didChangeNotification, object: nil)
WebViewProvider.shared.dequeueWebView() { webView in
// Add the webview
self.webView = webView
webView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(webView)
NSLayoutConstraint.activate([
self.view.leadingAnchor.constraint(equalTo: webView.leadingAnchor),
self.view.trailingAnchor.constraint(equalTo: webView.trailingAnchor),
self.view.topAnchor.constraint(equalTo: webView.topAnchor),
self.view.bottomAnchor.constraint(equalTo: webView.bottomAnchor)
])
self.configureTopShowBarsView()
self.configureBottomShowBarsView()
// Configure the webview
webView.navigationDelegate = self
webView.uiDelegate = self
self.configureContextMenuInteraction()
webView.configuration.userContentController.add(WrapperScriptMessageHandler(self), name: MessageName.imageWasClicked)
webView.configuration.userContentController.add(WrapperScriptMessageHandler(self), name: MessageName.imageWasShown)
// Even though page.html should be loaded into this webview, we have to do it again
// to work around this bug: http://www.openradar.me/22855188
let url = Bundle.main.url(forResource: "page", withExtension: "html")!
webView.loadFileURL(url, allowingReadAccessTo: url.deletingLastPathComponent())
self.view.setNeedsLayout()
self.view.layoutIfNeeded()
}
}
func reloadHTML() {
guard let webView = webView else { return }
let style = ArticleStylesManager.shared.currentStyle
let rendering: ArticleRenderer.Rendering
if let articleExtractor = articleExtractor, articleExtractor.state == .processing {
rendering = ArticleRenderer.loadingHTML(style: style)
} else if let article = article, let extractedArticle = extractedArticle {
if isShowingExtractedArticle {
rendering = ArticleRenderer.articleHTML(article: article, extractedArticle: extractedArticle, style: style, useImageIcon: true)
} else {
rendering = ArticleRenderer.articleHTML(article: article, style: style, useImageIcon: true)
}
} else if let article = article {
rendering = ArticleRenderer.articleHTML(article: article, style: style, useImageIcon: true)
} else {
rendering = ArticleRenderer.noSelectionHTML(style: style)
}
let templateData = TemplateData(style: rendering.style, body: rendering.html)
let encoder = JSONEncoder()
var render = "error();"
if let data = try? encoder.encode(templateData) {
let json = String(data: data, encoding: .utf8)!
render = "render(\(json), \(restoreOffset));"
}
restoreOffset = 0
WebViewProvider.shared.articleIconSchemeHandler.currentArticle = article
webView.scrollView.setZoomScale(1.0, animated: false)
webView.evaluateJavaScript(render)
}
// MARK: Notifications
@objc func webFeedIconDidBecomeAvailable(_ note: Notification) {
reloadArticleImage()
}
@objc func avatarDidBecomeAvailable(_ note: Notification) {
reloadArticleImage()
}
@objc func faviconDidBecomeAvailable(_ note: Notification) {
reloadArticleImage()
}
@objc func contentSizeCategoryDidChange(_ note: Notification) {
reloadHTML()
}
// MARK: Actions
@objc func showBars(_ sender: Any) {
showBars()
}
// MARK: API
func focus() {
webView.becomeFirstResponder()
}
func finalScrollPosition() -> CGFloat {
return webView.scrollView.contentSize.height - webView.scrollView.bounds.size.height + webView.scrollView.contentInset.bottom
}
func canScrollDown() -> Bool {
return webView.scrollView.contentOffset.y < finalScrollPosition()
}
func scrollPageDown() {
let scrollToY: CGFloat = {
let fullScroll = webView.scrollView.contentOffset.y + webView.scrollView.bounds.size.height
let final = finalScrollPosition()
return fullScroll < final ? fullScroll : final
}()
let convertedPoint = self.view.convert(CGPoint(x: 0, y: 0), to: webView.scrollView)
let scrollToPoint = CGPoint(x: convertedPoint.x, y: scrollToY)
webView.scrollView.setContentOffset(scrollToPoint, animated: true)
}
func hideClickedImage() {
webView?.evaluateJavaScript("hideClickedImage();")
}
func showClickedImage(completion: @escaping () -> Void) {
clickedImageCompletion = completion
webView?.evaluateJavaScript("showClickedImage();")
}
func fullReload() {
if let offset = webView?.scrollView.contentOffset.y {
restoreOffset = Int(offset)
webView?.reload()
}
}
func showBars() {
if isFullScreenAvailable {
AppDefaults.articleFullscreenEnabled = false
coordinator.showStatusBar()
topShowBarsViewConstraint.constant = 0
bottomShowBarsViewConstraint.constant = 0
navigationController?.setNavigationBarHidden(false, animated: true)
navigationController?.setToolbarHidden(false, animated: true)
configureContextMenuInteraction()
}
}
func hideBars() {
if isFullScreenAvailable {
AppDefaults.articleFullscreenEnabled = true
coordinator.hideStatusBar()
topShowBarsViewConstraint.constant = -44.0
bottomShowBarsViewConstraint.constant = 44.0
navigationController?.setNavigationBarHidden(true, animated: true)
navigationController?.setToolbarHidden(true, animated: true)
configureContextMenuInteraction()
}
}
func toggleArticleExtractor() {
guard let article = article else {
return
}
guard articleExtractor?.state != .processing else {
stopArticleExtractor()
return
}
guard !isShowingExtractedArticle else {
isShowingExtractedArticle = false
articleExtractorButtonState = .off
return
}
if let articleExtractor = articleExtractor {
if article.preferredLink == articleExtractor.articleLink {
isShowingExtractedArticle = true
articleExtractorButtonState = .on
}
} else {
startArticleExtractor()
}
}
func showActivityDialog(popOverBarButtonItem: UIBarButtonItem? = nil) {
guard let preferredLink = article?.preferredLink, let url = URL(string: preferredLink) else {
return
}
let itemSource = ArticleActivityItemSource(url: url, subject: article!.title)
let activityViewController = UIActivityViewController(activityItems: [itemSource], applicationActivities: nil)
activityViewController.popoverPresentationController?.barButtonItem = popOverBarButtonItem
present(activityViewController, animated: true)
}
}
// MARK: ArticleExtractorDelegate
extension WebViewController: ArticleExtractorDelegate {
func articleExtractionDidFail(with: Error) {
stopArticleExtractor()
articleExtractorButtonState = .error
}
func articleExtractionDidComplete(extractedArticle: ExtractedArticle) {
if articleExtractor?.state != .cancelled {
self.extractedArticle = extractedArticle
isShowingExtractedArticle = true
articleExtractorButtonState = .on
}
}
}
// MARK: UIContextMenuInteractionDelegate
extension WebViewController: UIContextMenuInteractionDelegate {
func contextMenuInteraction(_ interaction: UIContextMenuInteraction, configurationForMenuAtLocation location: CGPoint) -> UIContextMenuConfiguration? {
return UIContextMenuConfiguration(identifier: nil, previewProvider: contextMenuPreviewProvider) { [weak self] suggestedActions in
guard let self = self else { return nil }
var actions = [UIAction]()
if let action = self.prevArticleAction() {
actions.append(action)
}
if let action = self.nextArticleAction() {
actions.append(action)
}
actions.append(self.toggleReadAction())
actions.append(self.toggleStarredAction())
if let action = self.nextUnreadArticleAction() {
actions.append(action)
}
actions.append(self.toggleArticleExtractorAction())
actions.append(self.shareAction())
return UIMenu(title: "", children: actions)
}
}
func contextMenuInteraction(_ interaction: UIContextMenuInteraction, willPerformPreviewActionForMenuWith configuration: UIContextMenuConfiguration, animator: UIContextMenuInteractionCommitAnimating) {
coordinator.showBrowserForCurrentArticle()
}
}
// MARK: WKNavigationDelegate
extension WebViewController: WKNavigationDelegate {
func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
if navigationAction.navigationType == .linkActivated {
guard let url = navigationAction.request.url else {
decisionHandler(.allow)
return
}
let components = URLComponents(url: url, resolvingAgainstBaseURL: false)
if components?.scheme == "http" || components?.scheme == "https" {
let vc = SFSafariViewController(url: url)
present(vc, animated: true)
decisionHandler(.cancel)
} else {
decisionHandler(.allow)
}
} else {
decisionHandler(.allow)
}
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
self.reloadHTML()
}
}
// MARK: WKUIDelegate
extension WebViewController: WKUIDelegate {
func webView(_ webView: WKWebView, contextMenuForElement elementInfo: WKContextMenuElementInfo, willCommitWithAnimator animator: UIContextMenuInteractionCommitAnimating) {
// We need to have at least an unimplemented WKUIDelegate assigned to the WKWebView. This makes the
// link preview launch Safari when the link preview is tapped. In theory, you shoud be able to get
// the link from the elementInfo above and transition to SFSafariViewController instead of launching
// Safari. As the time of this writing, the link in elementInfo is always nil. ¯\_()_/¯
}
}
// MARK: WKScriptMessageHandler
extension WebViewController: WKScriptMessageHandler {
func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
switch message.name {
case MessageName.imageWasShown:
clickedImageCompletion?()
case MessageName.imageWasClicked:
imageWasClicked(body: message.body as? String)
default:
return
}
}
}
class WrapperScriptMessageHandler: NSObject, WKScriptMessageHandler {
// We need to wrap a message handler to prevent a circlular reference
private weak var handler: WKScriptMessageHandler?
init(_ handler: WKScriptMessageHandler) {
self.handler = handler
}
func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
handler?.userContentController(userContentController, didReceive: message)
}
}
// MARK: UIViewControllerTransitioningDelegate
extension WebViewController: UIViewControllerTransitioningDelegate {
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.presenting = true
return transition
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.presenting = false
return transition
}
}
// MARK: JSON
private struct TemplateData: Codable {
let style: String
let body: String
}
private struct ImageClickMessage: Codable {
let x: Float
let y: Float
let width: Float
let height: Float
let imageTitle: String?
let imageURL: String
}
// MARK: Private
private extension WebViewController {
func startArticleExtractor() {
if let link = article?.preferredLink, let extractor = ArticleExtractor(link) {
extractor.delegate = self
extractor.process()
articleExtractor = extractor
articleExtractorButtonState = .animated
}
}
func stopArticleExtractor() {
articleExtractor?.cancel()
articleExtractor = nil
isShowingExtractedArticle = false
articleExtractorButtonState = .off
}
func reloadArticleImage() {
webView?.evaluateJavaScript("reloadArticleImage()")
}
func imageWasClicked(body: String?) {
guard let body = body,
let data = body.data(using: .utf8),
let clickMessage = try? JSONDecoder().decode(ImageClickMessage.self, from: data),
let range = clickMessage.imageURL.range(of: ";base64,")
else { return }
let base64Image = String(clickMessage.imageURL.suffix(from: range.upperBound))
if let imageData = Data(base64Encoded: base64Image), let image = UIImage(data: imageData) {
let y = CGFloat(clickMessage.y) + webView.safeAreaInsets.top
let rect = CGRect(x: CGFloat(clickMessage.x), y: y, width: CGFloat(clickMessage.width), height: CGFloat(clickMessage.height))
transition.originFrame = webView.convert(rect, to: nil)
if navigationController?.navigationBar.isHidden ?? false {
transition.maskFrame = webView.convert(webView.frame, to: nil)
} else {
transition.maskFrame = webView.convert(webView.safeAreaLayoutGuide.layoutFrame, to: nil)
}
transition.originImage = image
coordinator.showFullScreenImage(image: image, imageTitle: clickMessage.imageTitle, transitioningDelegate: self)
}
}
func configureTopShowBarsView() {
topShowBarsView = UIView()
topShowBarsView.backgroundColor = .clear
topShowBarsView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(topShowBarsView)
if AppDefaults.articleFullscreenEnabled {
topShowBarsViewConstraint = view.topAnchor.constraint(equalTo: topShowBarsView.bottomAnchor, constant: -44.0)
} else {
topShowBarsViewConstraint = view.topAnchor.constraint(equalTo: topShowBarsView.bottomAnchor, constant: 0.0)
}
NSLayoutConstraint.activate([
topShowBarsViewConstraint,
view.leadingAnchor.constraint(equalTo: topShowBarsView.leadingAnchor),
view.trailingAnchor.constraint(equalTo: topShowBarsView.trailingAnchor),
topShowBarsView.heightAnchor.constraint(equalToConstant: 44.0)
])
topShowBarsView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(showBars(_:))))
}
func configureBottomShowBarsView() {
bottomShowBarsView = UIView()
topShowBarsView.backgroundColor = .clear
bottomShowBarsView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(bottomShowBarsView)
if AppDefaults.articleFullscreenEnabled {
bottomShowBarsViewConstraint = view.bottomAnchor.constraint(equalTo: bottomShowBarsView.topAnchor, constant: 44.0)
} else {
bottomShowBarsViewConstraint = view.bottomAnchor.constraint(equalTo: bottomShowBarsView.topAnchor, constant: 0.0)
}
NSLayoutConstraint.activate([
bottomShowBarsViewConstraint,
view.leadingAnchor.constraint(equalTo: bottomShowBarsView.leadingAnchor),
view.trailingAnchor.constraint(equalTo: bottomShowBarsView.trailingAnchor),
bottomShowBarsView.heightAnchor.constraint(equalToConstant: 44.0)
])
bottomShowBarsView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(showBars(_:))))
}
func configureContextMenuInteraction() {
if isFullScreenAvailable {
if navigationController?.isNavigationBarHidden ?? false {
webView?.addInteraction(contextMenuInteraction)
} else {
webView?.removeInteraction(contextMenuInteraction)
}
}
}
func contextMenuPreviewProvider() -> UIViewController {
let previewProvider = UIStoryboard.main.instantiateController(ofType: ContextMenuPreviewViewController.self)
previewProvider.article = article
return previewProvider
}
func prevArticleAction() -> UIAction? {
guard coordinator.isPrevArticleAvailable else { return nil }
let title = NSLocalizedString("Previous Article", comment: "Previous Article")
return UIAction(title: title, image: AppAssets.prevArticleImage) { [weak self] action in
self?.coordinator.selectPrevArticle()
}
}
func nextArticleAction() -> UIAction? {
guard coordinator.isNextArticleAvailable else { return nil }
let title = NSLocalizedString("Next Article", comment: "Next Article")
return UIAction(title: title, image: AppAssets.nextArticleImage) { [weak self] action in
self?.coordinator.selectNextArticle()
}
}
func toggleReadAction() -> UIAction {
let read = article?.status.read ?? false
let title = read ? NSLocalizedString("Mark as Unread", comment: "Mark as Unread") : NSLocalizedString("Mark as Read", comment: "Mark as Read")
let readImage = read ? AppAssets.circleClosedImage : AppAssets.circleOpenImage
return UIAction(title: title, image: readImage) { [weak self] action in
self?.coordinator.toggleReadForCurrentArticle()
}
}
func toggleStarredAction() -> UIAction {
let starred = article?.status.starred ?? false
let title = starred ? NSLocalizedString("Mark as Unstarred", comment: "Mark as Unstarred") : NSLocalizedString("Mark as Starred", comment: "Mark as Starred")
let starredImage = starred ? AppAssets.starOpenImage : AppAssets.starClosedImage
return UIAction(title: title, image: starredImage) { [weak self] action in
self?.coordinator.toggleStarredForCurrentArticle()
}
}
func nextUnreadArticleAction() -> UIAction? {
guard coordinator.isAnyUnreadAvailable else { return nil }
let title = NSLocalizedString("Next Unread Article", comment: "Next Unread Article")
return UIAction(title: title, image: AppAssets.nextUnreadArticleImage) { [weak self] action in
self?.coordinator.selectNextUnread()
}
}
func toggleArticleExtractorAction() -> UIAction {
let extracted = articleExtractorButtonState == .on
let title = extracted ? NSLocalizedString("Show Feed Article", comment: "Show Feed Article") : NSLocalizedString("Show Reader View", comment: "Show Reader View")
let extractorImage = extracted ? AppAssets.articleExtractorOffSF : AppAssets.articleExtractorOnSF
return UIAction(title: title, image: extractorImage) { [weak self] action in
self?.toggleArticleExtractor()
}
}
func shareAction() -> UIAction {
let title = NSLocalizedString("Share", comment: "Share")
return UIAction(title: title, image: AppAssets.shareImage) { [weak self] action in
self?.showActivityDialog()
}
}
}