Merge pull request #232 from JeremyStorring/189-carb-cap

Added ability to add min and max values to decimals in preferences page

FreeAPS/Sources/Modules/PreferencesEditor/PreferencesEditorDataFlow.swift

@@ -11,7 +11,11 @@ enum PreferencesEditor {
 
     enum FieldType {
         case boolean(keypath: WritableKeyPath<Preferences, Bool>)
-        case decimal(keypath: WritableKeyPath<Preferences, Decimal>)
+        case decimal(
+            keypath: WritableKeyPath<Preferences, Decimal>,
+            minVal: WritableKeyPath<Preferences, Decimal>? = nil,
+            maxVal: WritableKeyPath<Preferences, Decimal>? = nil
+        )
         case insulinCurve(keypath: WritableKeyPath<Preferences, InsulinCurve>)
     }
 
@@ -34,7 +38,7 @@ enum PreferencesEditor {
         var decimalValue: Decimal {
             get {
                 switch type {
-                case let .decimal(keypath):
+                case let .decimal(keypath, _, _):
                     return settable?.get(keypath) ?? 0
                 default: return 0
                 }
@@ -57,8 +61,18 @@ enum PreferencesEditor {
             switch (type, value) {
             case let (.boolean(keypath), value as Bool):
                 settable?.set(keypath, value: value)
-            case let (.decimal(keypath), value as Decimal):
-                settable?.set(keypath, value: value)
+            case let (.decimal(keypath, minVal, maxVal), value as Decimal):
+                let constrainedValue: Decimal
+                if let minValue = minVal, let minValueDecimal: Decimal = settable?.get(minValue), let maxValue = maxVal, let maxValueDecimal: Decimal = settable?.get(maxValue) {
+                    constrainedValue = min(max(value, minValueDecimal), maxValueDecimal)
+                } else if let minValue = minVal, let minValueDecimal: Decimal = settable?.get(minValue) {
+                    constrainedValue = max(value, minValueDecimal)
+                } else if let maxValue = maxVal, let maxValueDecimal: Decimal = settable?.get(maxValue) {
+                    constrainedValue = min(value, maxValueDecimal)
+                } else {
+                    constrainedValue = value
+                }
+                settable?.set(keypath, value: constrainedValue)
             case let (.insulinCurve(keypath), value as InsulinCurve):
                 settable?.set(keypath, value: value)
             default: break