delta calculation/representation re-write for mmol/L

Related to #JohanDegraeve#544

although the previous commits fixed the issue of erroneous (0 or close to 0) delta changes in mg/dL (the calculation was originally ported from an early xDrip+ many years ago), the mmol/L calculation has never been sufficiently accurate due to the conversion/rounding of mmol/L meaning that sometimes a +0.2mmol/L delta was actually calculated to +0.1mmol/L.

This changes fixes that and also updates the calculation and string representation methods for all instances in the app, Watch, Widgets etc

Also renamed a bunch of stuff to keep things constant over the whole project

xDrip Notification Context Extension/NotificationView.swift

@@ -14,7 +14,7 @@ struct NotificationView: View {
     var bgReadingDates: [Date]?
     var isMgDl: Bool?
     var slopeOrdinal: Int?
-    var deltaChangeInMgDl: Double?
+    var deltaValueInUserUnit: Double?
     var urgentLowLimitInMgDl: Double?
     var lowLimitInMgDl: Double?
     var highLimitInMgDl: Double?
@@ -104,17 +104,13 @@ struct NotificationView: View {
     /// convert the optional delta change int (in mg/dL) to a formatted change value in the user chosen unit making sure all zero values are shown as a positive change to follow Nightscout convention
     /// - Returns: a string holding the formatted delta change value (i.e. +0.4 or -6)
     func deltaChangeStringInUserChosenUnit() -> String {
-        if let deltaChangeInMgDl = deltaChangeInMgDl, let isMgDl = isMgDl {
-            let deltaSign: String = deltaChangeInMgDl > 0 ? "+" : ""
-            let valueAsString = deltaChangeInMgDl.mgdlToMmolAndToString(mgdl: isMgDl)
+        if let deltaValueInUserUnit = deltaValueInUserUnit, let isMgDl = isMgDl {
+            let deltaSign: String = deltaValueInUserUnit > 0 ? "+" : ""
+            let deltaValueAsString = isMgDl ? deltaValueInUserUnit.mgDlToMmolAndToString(mgDl: isMgDl) : deltaValueInUserUnit.mmolToString()
 
             // quickly check "value" and prevent "-0mg/dl" or "-0.0mmol/l" being displayed
             // show unitized zero deltas as +0 or +0.0 as per Nightscout format
-            if isMgDl {
-                return (deltaChangeInMgDl > -1 && deltaChangeInMgDl < 1) ?  "+0" : (deltaSign + valueAsString)
-            } else {
-                return (deltaChangeInMgDl > -0.1 && deltaChangeInMgDl < 0.1) ? "+0.0" : (deltaSign + valueAsString)
-            }
+            return deltaValueInUserUnit == 0.0 ? (isMgDl ? "+0" : "+0.0") : (deltaSign + deltaValueAsString)
         } else {
             return (isMgDl ?? true) ? "-" : "-.-"
         }

xDrip Notification Context Extension/NotificationViewController.swift

@@ -21,7 +21,7 @@ class NotificationViewController: UIViewController, UNNotificationContentExtensi
     var bgReadingDates: [Date]?
     var isMgDl: Bool?
     var slopeOrdinal: Int?
-    var deltaChangeInMgDl: Double?
+    var deltaValueInUserUnit: Double?
     var urgentLowLimitInMgDl: Double?
     var lowLimitInMgDl: Double?
     var highLimitInMgDl: Double?
@@ -50,7 +50,7 @@ class NotificationViewController: UIViewController, UNNotificationContentExtensi
         bgReadingValues = userInfo["bgReadingValues"] as? [Double] ?? [0]
         isMgDl = userInfo["isMgDl"] as? Bool ?? true
         slopeOrdinal = userInfo["slopeOrdinal"] as? Int ?? 0
-        deltaChangeInMgDl = userInfo["deltaChangeInMgDl"] as? Double ?? 0
+        deltaValueInUserUnit = userInfo["deltaValueInUserUnit"] as? Double ?? 0
         urgentLowLimitInMgDl = userInfo["urgentLowLimitInMgDl"] as? Double ?? 0
         lowLimitInMgDl = userInfo["lowLimitInMgDl"] as? Double ?? 0
         highLimitInMgDl = userInfo["highLimitInMgDl"] as? Double ?? 0
@@ -65,15 +65,15 @@ class NotificationViewController: UIViewController, UNNotificationContentExtensi
         bgValueInMgDl = (bgReadingValues?.count ?? 0) > 0 ? bgReadingValues?[0] : nil
         bgReadingDate = (bgReadingDates?.count ?? 0) > 0 ? bgReadingDates?[0] : nil
 
-        bgValueStringInUserChosenUnit = (bgReadingValues?.count ?? 0) > 0 ? bgReadingValues?[0].mgdlToMmolAndToString(mgdl: isMgDl ?? true) ?? "" : ""
+        bgValueStringInUserChosenUnit = (bgReadingValues?.count ?? 0) > 0 ? bgReadingValues?[0].mgDlToMmolAndToString(mgDl: isMgDl ?? true) ?? "" : ""
 
         let vc = UIHostingController(rootView: NotificationView(
             alertTitle: alertTitle,
             bgReadingValues: bgReadingValues,
             bgReadingDates: bgReadingDates,
             isMgDl: isMgDl,
             slopeOrdinal: slopeOrdinal,
-            deltaChangeInMgDl: deltaChangeInMgDl,
+            deltaValueInUserUnit: deltaValueInUserUnit,
             urgentLowLimitInMgDl: urgentLowLimitInMgDl,
             lowLimitInMgDl: lowLimitInMgDl,
             highLimitInMgDl: highLimitInMgDl,

xDrip Watch App/DataModels/NotificationController.swift

@@ -16,7 +16,7 @@ class NotificationController: WKUserNotificationHostingController<NotificationVi
     var bgReadingDates: [Date]?
     var isMgDl: Bool?
     var slopeOrdinal: Int?
-    var deltaChangeInMgDl: Double?
+    var deltaValueInUserUnit: Double?
     var urgentLowLimitInMgDl: Double?
     var lowLimitInMgDl: Double?
     var highLimitInMgDl: Double?
@@ -35,7 +35,7 @@ class NotificationController: WKUserNotificationHostingController<NotificationVi
             bgReadingDates: bgReadingDates,
             isMgDl: isMgDl,
             slopeOrdinal: slopeOrdinal,
-            deltaChangeInMgDl: deltaChangeInMgDl,
+            deltaValueInUserUnit: deltaValueInUserUnit,
             urgentLowLimitInMgDl: urgentLowLimitInMgDl,
             lowLimitInMgDl: lowLimitInMgDl,
             highLimitInMgDl: highLimitInMgDl,
@@ -61,7 +61,7 @@ class NotificationController: WKUserNotificationHostingController<NotificationVi
         bgReadingValues = userInfo["bgReadingValues"] as? [Double] ?? [0]
         isMgDl = userInfo["isMgDl"] as? Bool ?? true
         slopeOrdinal = userInfo["slopeOrdinal"] as? Int ?? 0
-        deltaChangeInMgDl = userInfo["deltaChangeInMgDl"] as? Double ?? 0
+        deltaValueInUserUnit = userInfo["deltaValueInUserUnit"] as? Double ?? 0
         urgentLowLimitInMgDl = userInfo["urgentLowLimitInMgDl"] as? Double ?? 0
         lowLimitInMgDl = userInfo["lowLimitInMgDl"] as? Double ?? 0
         highLimitInMgDl = userInfo["highLimitInMgDl"] as? Double ?? 0
@@ -76,7 +76,7 @@ class NotificationController: WKUserNotificationHostingController<NotificationVi
         bgValueInMgDl = (bgReadingValues?.count ?? 0) > 0 ? bgReadingValues?[0] : nil
         bgReadingDate = (bgReadingDates?.count ?? 0) > 0 ? bgReadingDates?[0] : nil
 
-        bgValueStringInUserChosenUnit = (bgReadingValues?.count ?? 0) > 0 ? bgReadingValues?[0].mgdlToMmolAndToString(mgdl: isMgDl ?? true) ?? "" : ""
+        bgValueStringInUserChosenUnit = (bgReadingValues?.count ?? 0) > 0 ? bgReadingValues?[0].mgDlToMmolAndToString(mgDl: isMgDl ?? true) ?? "" : ""
 
     }
 }

xDrip Watch App/DataModels/WatchStateModel.swift

@@ -32,7 +32,7 @@ final class WatchStateModel: NSObject, ObservableObject {
 
     @Published var isMgDl: Bool = true
     @Published var slopeOrdinal: Int = 2
-    @Published var deltaChangeInMgDl: Double = 0
+    @Published var deltaValueInUserUnit: Double = 0
     @Published var urgentLowLimitInMgDl: Double = 60
     @Published var lowLimitInMgDl: Double = 80
     @Published var highLimitInMgDl: Double = 170
@@ -85,7 +85,7 @@ final class WatchStateModel: NSObject, ObservableObject {
     /// - Returns: a string with bgValueInMgDl() converted into the user unit
     func bgValueStringInUserChosenUnit() -> String {
         if let bgReadingDate = bgReadingDate(), let bgValueInMgDl = bgValueInMgDl(), bgReadingDate > Date().addingTimeInterval(-60 * 20) {
-            return bgReadingValues.isEmpty ? (isMgDl ? "---" : "-.-") : bgValueInMgDl.mgdlToMmolAndToString(mgdl: isMgDl)
+            return bgReadingValues.isEmpty ? (isMgDl ? "---" : "-.-") : bgValueInMgDl.mgDlToMmolAndToString(mgDl: isMgDl)
         } else {
             return isMgDl ? "---" : "-.-"
         }
@@ -181,26 +181,17 @@ final class WatchStateModel: NSObject, ObservableObject {
     /// - Returns: a string holding the formatted delta change value (i.e. +0.4 or -6)
     func deltaChangeStringInUserChosenUnit() -> String {
         if let bgReadingDate = bgReadingDate(), bgReadingDate > Date().addingTimeInterval(-60 * 20) {
-            let valueAsString = deltaChangeInMgDl.mgdlToMmolAndToString(mgdl: isMgDl)
+            let deltaValueAsString = isMgDl ? deltaValueInUserUnit.mgDlToMmolAndToString(mgDl: isMgDl) : deltaValueInUserUnit.mmolToString()
 
             var deltaSign: String = ""
-            if (deltaChangeInMgDl > 0) { deltaSign = "+"; }
+
+            if deltaValueInUserUnit > 0 {
+                deltaSign = "+"
+            }
 
             // quickly check "value" and prevent "-0mg/dl" or "-0.0mmol/l" being displayed
             // show unitized zero deltas as +0 or +0.0 as per Nightscout format
-            if (isMgDl) {
-                if (deltaChangeInMgDl > -1) && (deltaChangeInMgDl < 1) {
-                    return "+0"
-                } else {
-                    return deltaSign + valueAsString
-                }
-            } else {
-                if (deltaChangeInMgDl > -0.1) && (deltaChangeInMgDl < 0.1) {
-                    return "+0.0"
-                } else {
-                    return deltaSign + valueAsString
-                }
-            }
+            return deltaValueInUserUnit == 0.0 ? (isMgDl ? "+0" : "+0.0") : (deltaSign + deltaValueAsString)
         } else {
             return "-"
         }
@@ -353,7 +344,7 @@ final class WatchStateModel: NSObject, ObservableObject {
 
             isMgDl = dictionary["isMgDl"] as? Bool ?? true
             slopeOrdinal = dictionary["slopeOrdinal"] as? Int ?? 0
-            deltaChangeInMgDl = dictionary["deltaChangeInMgDl"] as? Double ?? 0
+            deltaValueInUserUnit = dictionary["deltaValueInUserUnit"] as? Double ?? 0
             urgentLowLimitInMgDl = dictionary["urgentLowLimitInMgDl"] as? Double ?? 60
             lowLimitInMgDl = dictionary["lowLimitInMgDl"] as? Double ?? 70
             highLimitInMgDl = dictionary["highLimitInMgDl"] as? Double ?? 180
@@ -399,7 +390,7 @@ final class WatchStateModel: NSObject, ObservableObject {
             date.timeIntervalSince1970
         }
 
-        let complicationSharedUserDefaultsModel = ComplicationSharedUserDefaultsModel(bgReadingValues: bgReadingValues, bgReadingDatesAsDouble: bgReadingDatesAsDouble, isMgDl: isMgDl, slopeOrdinal: slopeOrdinal, deltaChangeInMgDl: deltaChangeInMgDl, urgentLowLimitInMgDl: urgentLowLimitInMgDl, lowLimitInMgDl: lowLimitInMgDl, highLimitInMgDl: highLimitInMgDl, urgentHighLimitInMgDl: urgentHighLimitInMgDl, keepAliveIsDisabled: keepAliveIsDisabled, liveDataIsEnabled: liveDataIsEnabled)
+        let complicationSharedUserDefaultsModel = ComplicationSharedUserDefaultsModel(bgReadingValues: bgReadingValues, bgReadingDatesAsDouble: bgReadingDatesAsDouble, isMgDl: isMgDl, slopeOrdinal: slopeOrdinal, deltaValueInUserUnit: deltaValueInUserUnit, urgentLowLimitInMgDl: urgentLowLimitInMgDl, lowLimitInMgDl: lowLimitInMgDl, highLimitInMgDl: highLimitInMgDl, urgentHighLimitInMgDl: urgentHighLimitInMgDl, keepAliveIsDisabled: keepAliveIsDisabled, liveDataIsEnabled: liveDataIsEnabled)
 
         // store the model in the shared user defaults using a name that is uniquely specific to this copy of the app as installed on
         // the user's device - this allows several copies of the app to be installed without cross-contamination of widget/complication data

xDrip Watch App/Views/BigNumberView/BigNumberView.swift

@@ -170,7 +170,7 @@ struct BigNumberView_Previews: PreviewProvider {
         watchState.bgReadingDates = bgDateArray()
         watchState.isMgDl = true
         watchState.slopeOrdinal = 5
-        watchState.deltaChangeInMgDl = -2
+        watchState.deltaValueInUserUnit = -2
         watchState.urgentLowLimitInMgDl = 60
         watchState.lowLimitInMgDl = 80
         watchState.highLimitInMgDl = 180

xDrip Watch App/Views/MainView/MainView.swift

@@ -136,7 +136,7 @@ struct ContentView_Previews: PreviewProvider {
         watchState.bgReadingDates = bgDateArray()
         watchState.isMgDl = false
         watchState.slopeOrdinal = 3
-        watchState.deltaChangeInMgDl = 2
+        watchState.deltaValueInUserUnit = 2
         watchState.urgentLowLimitInMgDl = 60
         watchState.lowLimitInMgDl = 80
         watchState.highLimitInMgDl = 140

xDrip Watch App/Views/MainView/SubViews/MainViewDataSourceView.swift

@@ -118,7 +118,7 @@ struct MainViewDataSourceView_Previews: PreviewProvider {
         watchState.bgReadingDates = bgDateArray()
         watchState.isMgDl = true
         watchState.slopeOrdinal = 5
-        watchState.deltaChangeInMgDl = -2
+        watchState.deltaValueInUserUnit = -2
         watchState.urgentLowLimitInMgDl = 60
         watchState.lowLimitInMgDl = 80
         watchState.highLimitInMgDl = 140

xDrip Watch App/Views/MainView/SubViews/MainViewHeaderView.swift

@@ -107,7 +107,7 @@ struct MainViewHeaderView_Previews: PreviewProvider {
         watchState.bgReadingDates = bgDateArray()
         watchState.isMgDl = true
         watchState.slopeOrdinal = 5
-        watchState.deltaChangeInMgDl = -2
+        watchState.deltaValueInUserUnit = -2
         watchState.urgentLowLimitInMgDl = 60
         watchState.lowLimitInMgDl = 80
         watchState.highLimitInMgDl = 140

xDrip Watch App/Views/MainView/SubViews/MainViewInfoView.swift

@@ -92,7 +92,7 @@ struct MainViewInfoView_Previews: PreviewProvider {
         watchState.bgReadingDates = bgDateArray()
         watchState.isMgDl = true
         watchState.slopeOrdinal = 5
-        watchState.deltaChangeInMgDl = -2
+        watchState.deltaValueInUserUnit = -2
         watchState.urgentLowLimitInMgDl = 60
         watchState.lowLimitInMgDl = 80
         watchState.highLimitInMgDl = 140

xDrip Watch App/Views/NotificationView.swift

@@ -17,7 +17,7 @@ struct NotificationView: View {
     var bgReadingDates: [Date]?
     var isMgDl: Bool?
     var slopeOrdinal: Int?
-    var deltaChangeInMgDl: Double?
+    var deltaValueInUserUnit: Double?
     var urgentLowLimitInMgDl: Double?
     var lowLimitInMgDl: Double?
     var highLimitInMgDl: Double?
@@ -110,17 +110,13 @@ struct NotificationView: View {
     /// convert the optional delta change int (in mg/dL) to a formatted change value in the user chosen unit making sure all zero values are shown as a positive change to follow Nightscout convention
     /// - Returns: a string holding the formatted delta change value (i.e. +0.4 or -6)
     func deltaChangeStringInUserChosenUnit() -> String {
-        if let deltaChangeInMgDl = deltaChangeInMgDl, let isMgDl = isMgDl {
-            let deltaSign: String = deltaChangeInMgDl > 0 ? "+" : ""
-            let valueAsString = deltaChangeInMgDl.mgdlToMmolAndToString(mgdl: isMgDl)
+        if let deltaValueInUserUnit = deltaValueInUserUnit, let isMgDl = isMgDl {
+            let deltaSign: String = deltaValueInUserUnit > 0 ? "+" : ""
+            let deltaValueAsString = isMgDl ? deltaValueInUserUnit.mgDlToMmolAndToString(mgDl: isMgDl) : deltaValueInUserUnit.mmolToString()
 
             // quickly check "value" and prevent "-0mg/dl" or "-0.0mmol/l" being displayed
             // show unitized zero deltas as +0 or +0.0 as per Nightscout format
-            if isMgDl {
-                return (deltaChangeInMgDl > -1 && deltaChangeInMgDl < 1) ?  "+0" : (deltaSign + valueAsString)
-            } else {
-                return (deltaChangeInMgDl > -0.1 && deltaChangeInMgDl < 0.1) ? "+0.0" : (deltaSign + valueAsString)
-            }
+            return deltaValueInUserUnit == 0.0 ? (isMgDl ? "+0" : "+0.0") : (deltaSign + deltaValueAsString)
         } else {
             return (isMgDl ?? true) ? "-" : "-.-"
         }

xDrip Watch Complication/DataModels/ComplicationSharedUserDefaultsModel.swift

@@ -14,7 +14,7 @@ struct ComplicationSharedUserDefaultsModel: Codable {
     var bgReadingDatesAsDouble: [Double]
     var isMgDl: Bool
     var slopeOrdinal: Int
-    var deltaChangeInMgDl: Double
+    var deltaValueInUserUnit: Double
     var urgentLowLimitInMgDl: Double
     var lowLimitInMgDl: Double
     var highLimitInMgDl: Double

xDrip Watch Complication/Views/AccessoryCircularView.swift

@@ -21,12 +21,12 @@ extension XDripWatchComplication.EntryView {
                     .minimumScaleFactor(0.2)
                     .lineLimit(1)
             } minimumValueLabel: {
-                Text(entry.widgetState.gaugeModel().minValue.mgdlToMmolAndToString(mgdl: entry.widgetState.isMgDl))
+                Text(entry.widgetState.gaugeModel().minValue.mgDlToMmolAndToString(mgDl: entry.widgetState.isMgDl))
                     .font(.system(size: 8))
                     .foregroundStyle(.colorPrimary)
                     .minimumScaleFactor(0.2)
             } maximumValueLabel: {
-                Text(entry.widgetState.gaugeModel().maxValue.mgdlToMmolAndToString(mgdl: entry.widgetState.isMgDl))
+                Text(entry.widgetState.gaugeModel().maxValue.mgDlToMmolAndToString(mgDl: entry.widgetState.isMgDl))
                     .font(.system(size: 8))
                     .foregroundStyle(.colorPrimary)
                     .minimumScaleFactor(0.2)

xDrip Watch Complication/Views/AccessoryCornerView.swift

@@ -24,12 +24,12 @@ extension XDripWatchComplication.EntryView {
                     } currentValueLabel: {
                         Text("Not shown")
                     } minimumValueLabel: {
-                        Text(entry.widgetState.gaugeModel().minValue.mgdlToMmolAndToString(mgdl: entry.widgetState.isMgDl))
+                        Text(entry.widgetState.gaugeModel().minValue.mgDlToMmolAndToString(mgDl: entry.widgetState.isMgDl))
                             .font(.system(size: 8))
                             .foregroundStyle(.colorPrimary)
                             .minimumScaleFactor(0.2)
                     } maximumValueLabel: {
-                        Text(entry.widgetState.gaugeModel().maxValue.mgdlToMmolAndToString(mgdl: entry.widgetState.isMgDl))
+                        Text(entry.widgetState.gaugeModel().maxValue.mgDlToMmolAndToString(mgDl: entry.widgetState.isMgDl))
                             .font(.system(size: 8))
                             .foregroundStyle(.colorPrimary)
                             .minimumScaleFactor(0.2)