Settings › Display: now line, glucose scale and time window

Loop/Models/LoopConstants.swift

@@ -35,6 +35,13 @@ enum LoopConstants {
 
     static let statusChartMinimumHistoryDisplay: TimeInterval = .hours(1)
 
+    /// Chart width the time window options are sized for: a portrait iPhone.
+    static let statusChartReferenceWidth: CGFloat = 360
+
+    static let statusChartMaximumWidthScale: CGFloat = 2
+
+    static let chartMinimumWidthPerTimeLabel: CGFloat = 44
+
     static let glucoseChartDefaultDisplayBound =
         LoopQuantity(unit: .milligramsPerDeciliter, doubleValue: 100)...LoopQuantity(unit: .milligramsPerDeciliter, doubleValue: 175)
 

Loop/View Controllers/StatusTableViewController.swift

@@ -96,18 +96,23 @@ final class StatusTableViewController: LoopChartsTableViewController {
         tableView.register(InsulinSuspendedTableViewCell.nib(), forCellReuseIdentifier: InsulinSuspendedTableViewCell.className)
         tableView.register(RecentGlucoseTableViewCell.nib(), forCellReuseIdentifier: RecentGlucoseTableViewCell.className)
 
-        if FeatureFlags.predictedGlucoseChartClampEnabled {
-            statusCharts.glucose.glucoseDisplayRange = LoopConstants.glucoseChartDefaultDisplayBoundClamped
-        } else {
-            statusCharts.glucose.glucoseDisplayRange = LoopConstants.glucoseChartDefaultDisplayBound
-        }
+        applyDisplayPreferences()
 
         registerPumpManager()
         registerCGMManager()
 
         let notificationCenter = NotificationCenter.default
 
         notificationObservers += [
+            notificationCenter.addObserver(forName: UserDefaults.didChangeNotification, object: nil, queue: .main) { [weak self] _ in
+                MainActor.assumeIsolated {
+                    guard let self, self.displayPreferencesSnapshot != self.currentDisplayPreferences else { return }
+                    self.applyDisplayPreferences()
+                    self.refreshContext = RefreshContext.all
+                    self.tableView.reloadSections(IndexSet(integer: Section.charts.rawValue), with: .none)
+                    Task { await self.reloadData() }
+                }
+            },
             notificationCenter.addObserver(forName: .LoopDataUpdated, object: nil, queue: nil) { note in
                 let rawContext = note.userInfo?[LoopDataManager.LoopUpdateContextKey] as! LoopUpdateContext.RawValue
                 let context = LoopUpdateContext(rawValue: rawContext)
@@ -439,13 +444,45 @@ final class StatusTableViewController: LoopChartsTableViewController {
         deviceManager.cgmManager == nil || deviceManager.cgmManager?.isInoperable == true || deviceManager.cgmManager?.inSignalLoss == true || deviceManager.pumpManager == nil || deviceManager.pumpManager?.isInoperable == true || deviceManager.pumpManager?.inSignalLoss == true || deviceManager.hasBluetoothIssue
     }
 
+    private var displayPreferencesSnapshot: [AnyHashable] = []
+
+    private var currentDisplayPreferences: [AnyHashable] {
+        let defaults = UserDefaults.standard
+        return [
+            defaults.bool(forKey: DisplayPreference.nowLine),
+            defaults.bool(forKey: DisplayPreference.fixedGlucoseScale),
+            defaults.integer(forKey: DisplayPreference.historyHours)
+        ]
+    }
+
+    private func applyDisplayPreferences() {
+        displayPreferencesSnapshot = currentDisplayPreferences
+        let defaults = UserDefaults.standard
+        ChartDisplayOptions.showsNowLine = defaults.bool(forKey: DisplayPreference.nowLine)
+        statusCharts.glucose.usesFixedScale = defaults.bool(forKey: DisplayPreference.fixedGlucoseScale)
+        if FeatureFlags.predictedGlucoseChartClampEnabled {
+            statusCharts.glucose.glucoseDisplayRange = LoopConstants.glucoseChartDefaultDisplayBoundClamped
+        } else {
+            statusCharts.glucose.glucoseDisplayRange = LoopConstants.glucoseChartDefaultDisplayBound
+        }
+        StatusChartsManager.ChartIndex.allCases.forEach { statusCharts.invalidateChart(atIndex: $0.rawValue) }
+    }
+
     private func updateChartDateRange() {
         // How far back should we show data? Use the screen size as a guide.
         let availableWidth = (refreshContext.newSize ?? tableView.bounds.size).width - charts.fixedHorizontalMargin
 
-        let totalHours = floor(Double(availableWidth / LoopConstants.minimumChartWidthPerHour))
+        var totalHours = floor(Double(availableWidth / LoopConstants.minimumChartWidthPerHour))
         let futureHours = ceil(doseStore.longestEffectDuration.hours)
-        let historyHours = max(LoopConstants.statusChartMinimumHistoryDisplay.hours, totalHours - futureHours)
+        var historyHours = max(LoopConstants.statusChartMinimumHistoryDisplay.hours, totalHours - futureHours)
+        let preferredHistoryHours = UserDefaults.standard.integer(forKey: DisplayPreference.historyHours)
+        if preferredHistoryHours > 0 {
+            let forecastHours = preferredHistoryHours <= 3 ? 3 : futureHours
+            let widthScale = min(LoopConstants.statusChartMaximumWidthScale, max(1, availableWidth / LoopConstants.statusChartReferenceWidth))
+            totalHours = (Double(preferredHistoryHours) + forecastHours) * Double(widthScale)
+            historyHours = totalHours - forecastHours
+        }
+        charts.labelStepHours = max(1, Int(ceil(totalHours * Double(LoopConstants.chartMinimumWidthPerTimeLabel / availableWidth))))
 
         let date = Date(timeIntervalSinceNow: -TimeInterval(hours: historyHours))
         let chartStartDate = Calendar.current.nextDate(after: date, matching: DateComponents(minute: 0), matchingPolicy: .strict, direction: .backward) ?? date

Loop/Views/SettingsView.swift

@@ -321,6 +321,18 @@ extension SettingsView {
                 )
                 .accessibilityIdentifier("settingsViewLiveActivity")
             }
+            NavigationLink(destination: DisplaySettingsView()) {
+                LargeButton(
+                    action: {},
+                    includeArrow: false,
+                    imageView: Image(systemName: "chart.line.uptrend.xyaxis")
+                        .resizable()
+                        .aspectRatio(contentMode: .fit)
+                        .frame(width: 30),
+                    label: NSLocalizedString("Display", comment: "Display settings button text"),
+                    descriptiveText: NSLocalizedString("Chart scale, time window and now line", comment: "Display settings descriptive text")
+                )
+            }
         }
     }
 
@@ -820,3 +832,56 @@ public struct SettingsView_Previews: PreviewProvider {
         }
     }
 }
+
+enum DisplayPreference {
+    static let nowLine = "DisplayNowLine"
+    static let fixedGlucoseScale = "DisplayFixedGlucoseScale"
+    static let historyHours = "DisplayHistoryHours"
+}
+
+struct DisplaySettingsView: View {
+    @AppStorage(DisplayPreference.nowLine) private var nowLine = false
+    @AppStorage(DisplayPreference.fixedGlucoseScale) private var fixedGlucoseScale = false
+    @AppStorage(DisplayPreference.historyHours) private var historyHours = 0
+    @EnvironmentObject private var displayGlucosePreference: DisplayGlucosePreference
+
+    private var fixedScaleRange: String {
+        let values = GlucoseChart.fixedScaleAxisValues(for: displayGlucosePreference.unit)
+        let formatter = displayGlucosePreference.formatter.numberFormatter
+        return "\(formatter.string(from: values.first! as NSNumber) ?? "")–\(formatter.string(from: values.last! as NSNumber) ?? "")"
+    }
+
+    var body: some View {
+        List {
+            Section(footer: Text("A vertical line marking the current time on each chart.")) {
+                Toggle("Now Line", isOn: $nowLine)
+            }
+            Section(header: Text("Glucose Scale"), footer: Text("Fixed keeps the glucose chart at \(fixedScaleRange) \(displayGlucosePreference.unit.localizedShortUnitString) so every glance uses the same scale. Auto zooms to fit recent and forecast glucose.")) {
+                Picker("Glucose Scale", selection: $fixedGlucoseScale) {
+                    Text("Auto").tag(false)
+                    Text("Fixed \(fixedScaleRange)").tag(true)
+                }
+                .pickerStyle(.segmented)
+            }
+            Section(header: Text("Time Window"), footer: Text("The full forecast covers your insulin action time.")) {
+                Picker("Time Window", selection: $historyHours) {
+                    timeWindowRow("Full Forecast", detail: "As much history as fits").tag(0)
+                    timeWindowRow("3 Hours", detail: "3 h back, 3 h ahead").tag(3)
+                    timeWindowRow("6 Hours", detail: "6 h back, full forecast").tag(6)
+                    timeWindowRow("12 Hours", detail: "12 h back, full forecast").tag(12)
+                }
+                .pickerStyle(.inline)
+                .labelsHidden()
+            }
+        }
+        .insetGroupedListStyle()
+        .navigationTitle("Display")
+    }
+
+    private func timeWindowRow(_ title: LocalizedStringKey, detail: LocalizedStringKey) -> some View {
+        VStack(alignment: .leading) {
+            Text(title)
+            Text(detail).font(.footnote).foregroundColor(.secondary)
+        }
+    }
+}