Update DoubleTextField.swift

src/ShowyEdge/swift/Views/DoubleTextField.swift

@@ -2,32 +2,43 @@ import SwiftUI
 
 struct DoubleTextField: View {
   @Binding var value: Double
+  // Specifying a formatter directly in a TextField makes it difficult to enter numbers less than 1.0.
+  // Specifically, if a user wants to enter "0.2" and enters a value of "0.", the value becomes "0.0".
+  // To avoid this, do not specify the formatter directly in the TextField, but use onChange to format the value.
+  @State private var text = ""
+  @State private var error = false
 
   private let step: Double
   private let range: ClosedRange<Double>
   private let width: CGFloat
+  private let maximumFractionDigits: Int
   private let formatter: NumberFormatter
 
   init(
     value: Binding<Double>,
     range: ClosedRange<Double>,
     step: Double,
+    maximumFractionDigits: Int,
     width: CGFloat
   ) {
     _value = value
+    text = String(value.wrappedValue)
+
     self.step = step
     self.range = range
     self.width = width
+    self.maximumFractionDigits = maximumFractionDigits
 
     formatter = NumberFormatter()
-    formatter.numberStyle = .decimal
+    formatter.numberStyle = .decimal  // Use .decimal number style for double values
     formatter.minimum = NSNumber(value: range.lowerBound)
     formatter.maximum = NSNumber(value: range.upperBound)
+    formatter.maximumFractionDigits = maximumFractionDigits
   }
 
   var body: some View {
     HStack(spacing: 0) {
-      TextField("", value: $value, formatter: formatter).frame(width: width)
+      TextField("", text: $text).frame(width: width)
 
       Stepper(
         value: $value,
@@ -44,6 +55,58 @@ struct DoubleTextField: View {
           }
         }
       }
+
+      if error {
+        Text(
+          String(
+            format: "must be between %.\(maximumFractionDigits)f and %.\(maximumFractionDigits)f",
+            range.lowerBound,
+            range.upperBound)
+        )
+        .foregroundColor(Color.errorForeground)
+        .background(Color.errorBackground)
+      }
+    }
+    .onChange(of: text) { newText in
+      update(byText: newText)
+    }
+    .onChange(of: value) { newValue in
+      update(byValue: newValue)
+    }
+  }
+
+  private func update(byValue newValue: Double) {
+    if let newText = formatter.string(for: newValue) {
+      error = false
+
+      Task { @MainActor in
+        if value != newValue {
+          value = newValue
+        }
+        if text != newText {
+          text = newText
+        }
+      }
+    } else {
+      error = true
+    }
+  }
+
+  private func update(byText newText: String) {
+    if let number = formatter.number(from: newText) {
+      error = false
+
+      let newValue = number.doubleValue
+      Task { @MainActor in
+        if value != newValue {
+          value = newValue
+        }
+        if text != newText {
+          text = newText
+        }
+      }
+    } else {
+      error = true
     }
   }
 }

src/ShowyEdge/swift/Views/Settings/SettingsCustomFrameView.swift

@@ -35,6 +35,7 @@ struct SettingsCustomFrameView: View {
             value: $userSettings.customFrameWidth,
             range: 0...10000,
             step: 10,
+            maximumFractionDigits: 1,
             width: 50)
 
           CustomFrameUnitPicker(value: $userSettings.customFrameWidthUnit)
@@ -45,6 +46,7 @@ struct SettingsCustomFrameView: View {
             value: $userSettings.customFrameHeight,
             range: 0...10000,
             step: 10,
+            maximumFractionDigits: 1,
             width: 50)
 
           CustomFrameUnitPicker(value: $userSettings.customFrameHeightUnit)
@@ -69,6 +71,7 @@ struct SettingsCustomFrameView: View {
               value: $userSettings.customFrameLeft,
               range: -10000...10000,
               step: 100,
+              maximumFractionDigits: 1,
               width: 50)
 
             Text("pt")
@@ -79,6 +82,7 @@ struct SettingsCustomFrameView: View {
               value: $userSettings.customFrameTop,
               range: -10000...10000,
               step: 100,
+              maximumFractionDigits: 1,
               width: 50)
 
             Text("pt")

src/ShowyEdge/swift/Views/Settings/SettingsIndicatorView.swift

@@ -13,6 +13,7 @@ struct SettingsIndicatorView: View {
             value: $userSettings.indicatorHeightPx,
             range: 0...10000,
             step: 5,
+            maximumFractionDigits: 1,
             width: 50)
 
           Text("pt")