font size setting

mac/Sources/Byre/Fonts.swift

@@ -1,7 +1,41 @@
 import CoreText
+import Foundation
 import Synchronization
+import SwiftData
 import SwiftUI
 
+@MainActor
+@Observable
+final class FontSize {
+    static let shared = FontSize()
+    static let range = 9...20
+
+    private(set) var body = PrefsRecord.defaultFontSize
+
+    private init() {
+        load()
+    }
+
+    func load() {
+        body = record()?.fontSize ?? PrefsRecord.defaultFontSize
+    }
+
+    func set(_ size: Int) {
+        if let r = record() {
+            r.fontSize = size
+            r.saved = Date()
+        } else {
+            persistence.insert(PrefsRecord(fontSize: size))
+        }
+        saveRecords()
+        body = size
+    }
+
+    private func record() -> PrefsRecord? {
+        fetchRecords(FetchDescriptor<PrefsRecord>(sortBy: [SortDescriptor(\.saved, order: .reverse)])).first
+    }
+}
+
 enum Fonts {
     private static func file(_ subset: String, _ italic: Bool, _ weight: CGFloat) -> CTFontDescriptor {
         let url = Bundle.main.resourceURL!.appending(path: "fonts/atkinson-hyperlegible-mono-\(subset)-wght-\(italic ? "italic" : "normal").woff2")
@@ -17,7 +51,10 @@ enum Fonts {
 
     private static let fonts = Mutex<[String: CTFont]>([:])
 
+    // Call sites give sizes relative to a 13pt body; the user's font size shifts them all.
+    @MainActor
     private static func cached(_ size: CGFloat, _ weight: CGFloat, _ italic: Bool) -> CTFont {
+        let size = size + CGFloat(FontSize.shared.body - 13)
         let key = "\(size) \(weight) \(italic)"
         return fonts.withLock { fonts in
             if let f = fonts[key] {
@@ -29,10 +66,12 @@ enum Fonts {
         }
     }
 
+    @MainActor
     static func font(_ size: CGFloat, weight: CGFloat = 400, italic: Bool = false) -> Font {
         Font(cached(size, weight, italic))
     }
 
+    @MainActor
     static func ns(_ size: CGFloat, weight: CGFloat = 400, italic: Bool = false) -> NSFont {
         cached(size, weight, italic) as NSFont
     }