From 0402bd607f27c102a37876e38bbcd9d3cbe222a8 Mon Sep 17 00:00:00 2001
From: Brent Simmons <brent@ranchero.com>
Date: Mon, 10 Jul 2023 21:19:28 -0700
Subject: [PATCH] Continue adopting async/await.

---
 .../Detail/DetailViewController.swift         | 10 ++---
 .../Detail/DetailWebViewController.swift      | 43 ++++++++++---------
 Mac/MainWindow/MainWindowController.swift     | 17 +++++---
 3 files changed, 39 insertions(+), 31 deletions(-)

diff --git a/Mac/MainWindow/Detail/DetailViewController.swift b/Mac/MainWindow/Detail/DetailViewController.swift
index e4b099bf4..fb1aa1917 100644
--- a/Mac/MainWindow/Detail/DetailViewController.swift
+++ b/Mac/MainWindow/Detail/DetailViewController.swift
@@ -63,13 +63,13 @@ enum DetailState: Equatable {
 	func stopMediaPlayback() {
 		currentWebViewController.stopMediaPlayback()
 	}
-	
-	func canScrollDown(_ callback: @escaping (Bool) -> Void) {
-		currentWebViewController.canScrollDown(callback)
+
+	func canScrollDown() async -> Bool {
+		await currentWebViewController.canScrollDown()
 	}
 
-	func canScrollUp(_ callback: @escaping (Bool) -> Void) {
-		currentWebViewController.canScrollUp(callback)
+	func canScrollUp() async -> Bool {
+		await currentWebViewController.canScrollUp()
 	}
 
 	override func scrollPageDown(_ sender: Any?) {
diff --git a/Mac/MainWindow/Detail/DetailWebViewController.swift b/Mac/MainWindow/Detail/DetailWebViewController.swift
index 07f50a461..c365727c6 100644
--- a/Mac/MainWindow/Detail/DetailWebViewController.swift
+++ b/Mac/MainWindow/Detail/DetailWebViewController.swift
@@ -161,16 +161,14 @@ protocol DetailWebViewControllerDelegate: AnyObject {
 	
 	// MARK: Scrolling
 
-	func canScrollDown(_ completion: @escaping (Bool) -> Void) {
-		fetchScrollInfo { (scrollInfo) in
-			completion(scrollInfo?.canScrollDown ?? false)
-		}
+	func canScrollDown() async -> Bool {
+		let scrollInfo = await scrollInfo()
+		return scrollInfo?.canScrollDown ?? false
 	}
 
-	func canScrollUp(_ completion: @escaping (Bool) -> Void) {
-		fetchScrollInfo { (scrollInfo) in
-			completion(scrollInfo?.canScrollUp ?? false)
-		}
+	func canScrollUp() async -> Bool {
+		let scrollInfo = await scrollInfo()
+		return scrollInfo?.canScrollUp ?? false
 	}
 
 	override func scrollPageDown(_ sender: Any?) {
@@ -292,7 +290,8 @@ private extension DetailWebViewController {
 	}
 	
 	func reloadHTMLMaintainingScrollPosition() {
-		fetchScrollInfo() { scrollInfo in
+		Task { @MainActor in
+			let scrollInfo = await scrollInfo()
 			self.windowScrollY = scrollInfo?.offsetY
 			self.reloadHTML()
 		}
@@ -330,21 +329,23 @@ private extension DetailWebViewController {
 		webView.loadHTMLString(html, baseURL: ArticleRenderer.page.baseURL)
 	}
 
-	func fetchScrollInfo(_ completion: @escaping (ScrollInfo?) -> Void) {
+	func scrollInfo() async -> ScrollInfo? {
 		let javascriptString = "var x = {contentHeight: document.body.scrollHeight, offsetY: window.pageYOffset}; x"
 
-		webView.evaluateJavaScript(javascriptString) { (info, error) in
-			guard let info = info as? [String: Any] else {
-				completion(nil)
-				return
-			}
-			guard let contentHeight = info["contentHeight"] as? CGFloat, let offsetY = info["offsetY"] as? CGFloat else {
-				completion(nil)
-				return
-			}
+		return await withCheckedContinuation { continuation in
+			webView.evaluateJavaScript(javascriptString) { (info, error) in
+				guard let info = info as? [String: Any] else {
+					continuation.resume(returning: nil)
+					return
+				}
+				guard let contentHeight = info["contentHeight"] as? CGFloat, let offsetY = info["offsetY"] as? CGFloat else {
+					continuation.resume(returning: nil)
+					return
+				}
 
-			let scrollInfo = ScrollInfo(contentHeight: contentHeight, viewHeight: self.webView.frame.height, offsetY: offsetY)
-			completion(scrollInfo)
+				let scrollInfo = ScrollInfo(contentHeight: contentHeight, viewHeight: self.webView.frame.height, offsetY: offsetY)
+				continuation.resume(returning: scrollInfo)
+			}
 		}
 	}
 
diff --git a/Mac/MainWindow/MainWindowController.swift b/Mac/MainWindow/MainWindowController.swift
index 23478446a..32d57548a 100644
--- a/Mac/MainWindow/MainWindowController.swift
+++ b/Mac/MainWindow/MainWindowController.swift
@@ -310,9 +310,15 @@ enum TimelineSourceMode {
 		guard let detailViewController = detailViewController else {
 			return
 		}
-		detailViewController.canScrollDown { (canScroll) in
+
+		Task { @MainActor in
+			let canScroll = await detailViewController.canScrollDown()
 			NSCursor.setHiddenUntilMouseMoves(true)
-			canScroll ? detailViewController.scrollPageDown(sender) : self.nextUnread(sender)
+			if canScroll {
+				detailViewController.scrollPageDown(sender)
+			} else {
+				nextUnread(sender)
+			}
 		}
 	}
 
@@ -320,13 +326,14 @@ enum TimelineSourceMode {
 		guard let detailViewController = detailViewController else {
 			return
 		}
-		detailViewController.canScrollUp { (canScroll) in
-			if (canScroll) {
+
+		Task { @MainActor in
+			let canScroll = await detailViewController.canScrollUp()
+			if canScroll {
 				NSCursor.setHiddenUntilMouseMoves(true)
 				detailViewController.scrollPageUp(sender)
 			}
 		}
-
 	}
 
 	@IBAction func copyArticleURL(_ sender: Any?) {