jumpy scroll 3

mac/Sources/Byre/Chat.swift

@@ -1,6 +1,5 @@
 import AppKit
 import ByreAPI
-import os
 import SwiftUI
 
 enum ChatKind: Equatable {
@@ -18,6 +17,7 @@ final class ChatModel {
     private(set) var fetching = false
     private(set) var olderGeneration = 0
     private(set) var hasUnmerged = false
+    var scannerDrop: CGFloat = 0
     @ObservationIgnored var stuck = true
     @ObservationIgnored private var unmergedTimer: Task<Void, Never>?
     @ObservationIgnored private var offs: [() -> Void] = []
@@ -486,13 +486,10 @@ struct CompactButton: View {
     }
 }
 
-let scrollLog = Logger(subsystem: "run.fc.byre.mac", category: "scroll")
-
 private struct ScrollMetrics: Equatable {
     let content: CGFloat
     let visible: CGFloat
     let distance: CGFloat
-    let offset: CGFloat
 }
 
 private struct TranscriptScroll: View {
@@ -532,44 +529,39 @@ private struct TranscriptScroll: View {
                 }
             }
             .scrollTargetLayout()
-            .overlay(alignment: .bottomLeading) {
-                if running && model.key != nil {
-                    Scanner(color: accent)
-                        .offset(y: 8)
-                }
-            }
             .padding(16)
         }
+        .overlay(alignment: .bottomLeading) {
+            if running && model.key != nil {
+                ScannerOverlay(model: model, color: accent)
+            }
+        }
         .scrollPosition($position)
         .defaultScrollAnchor(.bottom)
         .onScrollGeometryChange(for: ScrollMetrics.self) { g in
-            ScrollMetrics(content: g.contentSize.height, visible: g.visibleRect.height, distance: g.contentSize.height - g.visibleRect.maxY, offset: g.contentOffset.y)
+            ScrollMetrics(content: g.contentSize.height, visible: g.visibleRect.height, distance: g.contentSize.height - g.visibleRect.maxY)
         } action: { old, new in
-            let snap = !scrolling && model.stuck && new.distance > 1 && (new.content != old.content || new.visible != old.visible)
+            model.scannerDrop = new.distance
-            scrollLog.notice("geom rows=\(model.builder.root.rows.count) content=\(new.content) dContent=\(new.content - old.content) offset=\(new.offset) dOffset=\(new.offset - old.offset) visible=\(new.visible) distance=\(new.distance) scrolling=\(scrolling) stuck=\(model.stuck) snap=\(snap)")
             if scrolling {
                 model.stuck = new.distance < 80
                 return
             }
-            if snap {
+            if model.stuck && new.distance > 1 && (new.content != old.content || new.visible != old.visible) {
                 position.scrollTo(edge: .bottom)
             }
         }
-        .onScrollPhaseChange { old, phase in
+        .onScrollPhaseChange { _, phase in
-            scrollLog.notice("phase \(String(describing: old), privacy: .public) -> \(String(describing: phase), privacy: .public)")
             scrolling = phase.isScrolling
         }
         .onChange(of: model.builder.pending.last?.id) { old, new in
             guard let new, new > old ?? 0 else {
                 return
             }
-            scrollLog.notice("pending scrollTo bottom")
             model.stuck = true
             position.scrollTo(edge: .bottom)
         }
         .onChange(of: model.scrollRequest?.seq, initial: true) {
             if let r = model.scrollRequest {
-                scrollLog.notice("request scrollTo \(String(describing: r.id), privacy: .public)")
                 position.scrollTo(id: r.id, anchor: r.anchor)
             }
         }
@@ -580,6 +572,21 @@ private struct TranscriptScroll: View {
     }
 }
 
+private struct ScannerOverlay: View {
+    let model: ChatModel
+    let color: Color
+
+    var body: some View {
+        Scanner(color: color)
+            .padding(.leading, 16)
+            .padding(.bottom, 8)
+            .offset(y: model.scannerDrop)
+            .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .bottomLeading)
+            .clipped()
+            .allowsHitTesting(false)
+    }
+}
+
 private struct Scanner: View {
     let color: Color
 

mac/Sources/Byre/MarkdownView.swift

@@ -1,4 +1,3 @@
-import os
 import SwiftUI
 
 enum MDSegment {
@@ -536,10 +535,8 @@ private struct FlowText: NSViewRepresentable {
         func size(_ text: NSAttributedString, _ width: CGFloat?) -> CGSize {
             let same = measured.map { $0.text === text || $0.text.isEqual(to: text) } ?? false
             if same, let m = measured, m.width == width {
-                scrollLog.notice("measure hit len=\(text.length) width=\(width ?? -1) height=\(m.size.height)")
                 return m.size
             }
-            let start = ContinuousClock.now
             if !same {
                 storage.setAttributedString(text)
             }
@@ -547,7 +544,6 @@ private struct FlowText: NSViewRepresentable {
             layout.ensureLayout(for: container)
             let used = layout.usedRect(for: container)
             let size = CGSize(width: width ?? ceil(used.width), height: ceil(used.height))
-            scrollLog.notice("measure miss len=\(text.length) width=\(width ?? -1) oldWidth=\(self.measured?.width ?? -1) newText=\(!same) height=\(size.height) ms=\((ContinuousClock.now - start) / .milliseconds(1))")
             measured = (text, width, size)
             return size
         }