Implement textContentType modifier

Sources/AppKitBackend/AppKitBackend.swift

@@ -641,6 +641,22 @@ public final class AppKitBackend: AppBackend {
             onChange(textField.stringValue)
         }
         textField.onSubmit = onSubmit
+
+        if #available(macOS 14, *) {
+            textField.contentType =
+                switch environment.textContentType {
+                    case .url:
+                        .URL
+                    case .phoneNumber:
+                        .telephoneNumber
+                    case .name:
+                        .name
+                    case .emailAddress:
+                        .emailAddress
+                    default:
+                        nil
+                }
+        }
     }
 
     public func getContent(ofTextField textField: Widget) -> String {

Sources/SwiftCrossUI/Environment/EnvironmentValues.swift

@@ -38,6 +38,9 @@ public struct EnvironmentValues {
     /// The scale factor of the current window.
     public var windowScaleFactor: Double
 
+    /// The type of on-screen keyboard to show when a text field is focused.
+    public var textContentType: TextContentType
+
     /// Called by view graph nodes when they resize due to an internal state
     /// change and end up changing size. Each view graph node sets its own
     /// handler when passing the environment on to its children, setting up
@@ -143,6 +146,7 @@ public struct EnvironmentValues {
         multilineTextAlignment = .leading
         colorScheme = .light
         windowScaleFactor = 1
+        textContentType = .text
         window = nil
         extraValues = [:]
     }

Sources/SwiftCrossUI/Modifiers/TextContentTypeModifier.swift

@@ -0,0 +1,11 @@
+extension View {
+    /// Set the content type of text fields.
+    /// 
+    /// This controls autocomplete suggestions, and on mobile devices, which on-screen keyboard
+    /// is shown.
+    public func textContentType(_ type: TextContentType) -> some View {
+        EnvironmentModifier(self) { environment in
+            environment.with(\.textContentType, type)
+        }
+    }
+}

Sources/SwiftCrossUI/TextContentType.swift

@@ -0,0 +1,38 @@
+public enum TextContentType {
+    /// Plain text.
+    /// 
+    /// This is the default value.
+    case text
+    /// Just digits.
+    ///
+    /// For numbers that may include decimals or negative numbers, see ``decimal(signed:)``.
+    ///
+    /// If `ascii` is true, the user should only enter the ASCII digits 0-9. If `ascii` is
+    /// false, on mobile devices they may see a different numeric keypad depending on their
+    /// locale settings (for example, they may see the digits ० १ २ ३ ४ ५ ६ ७ ८ ९ instead
+    /// if the language is set to Hindi).
+    case digits(ascii: Bool)
+    /// A URL.
+    ///
+    /// On mobile devices, this type shows a keyboard with prominent buttons for "/" and ".com",
+    /// and might not include a spacebar.
+    case url
+    /// A phone number.
+    case phoneNumber
+    /// A person's name.
+    ///
+    /// This typically uses the default keyboard, but informs autocomplete to use contact
+    /// names rather than regular words.
+    case name
+    /// A number.
+    ///
+    /// If `signed` is false, on mobile devices it shows a numeric keypad with a decimal point,
+    /// but not necessarily plus and minus signs. If `signed` is true then more punctuation can
+    /// be entered.
+    case decimal(signed: Bool)
+    /// An email address.
+    ///
+    /// This informs autocomplete that the input is an email address, and on mobile devices,
+    /// displays a keyboard with prominent "@" and "." buttons.
+    case emailAddress
+}

Sources/UIKitBackend/UIKitBackend+Control.swift

@@ -240,6 +240,36 @@ extension UIKitBackend {
         textFieldWidget.child.textColor = UIColor(color: environment.suggestedForegroundColor)
         textFieldWidget.onChange = onChange
         textFieldWidget.onSubmit = onSubmit
+
+        switch environment.textContentType {
+            case .text:
+                textFieldWidget.child.keyboardType = .default
+                textFieldWidget.child.textContentType = nil
+            case .digits(ascii: false):
+                textFieldWidget.child.keyboardType = .numberPad
+                textFieldWidget.child.textContentType = nil
+            case .digits(ascii: true):
+                textFieldWidget.child.keyboardType = .asciiCapableNumberPad
+                textFieldWidget.child.textContentType = nil
+            case .url:
+                textFieldWidget.child.keyboardType = .URL
+                textFieldWidget.child.textContentType = .URL
+            case .phoneNumber:
+                textFieldWidget.child.keyboardType = .phonePad
+                textFieldWidget.child.textContentType = .telephoneNumber
+            case .name:
+                textFieldWidget.child.keyboardType = .namePhonePad
+                textFieldWidget.child.textContentType = .name
+            case .decimal(signed: false):
+                textFieldWidget.child.keyboardType = .decimalPad
+                textFieldWidget.child.textContentType = nil
+            case .decimal(signed: true):
+                textFieldWidget.child.keyboardType = .numbersAndPunctuation
+                textFieldWidget.child.textContentType = nil
+            case .emailAddress:
+                textFieldWidget.child.keyboardType = .emailAddress
+                textFieldWidget.child.textContentType = .emailAddress
+        }
 
         #if os(iOS)
             if let updateToolbar = environment.updateToolbar {

Sources/WinUIBackend/WinUIBackend.swift

@@ -801,6 +801,38 @@ public final class WinUIBackend: AppBackend {
         }
 
         missing("text field font handling")
+
+        let inputScope: InputScopeNameValue =
+            switch environment.textContentType {
+                case .decimal(_):
+                    .number
+                case .digits(_):
+                    .digits
+                case .emailAddress:
+                    .emailSmtpAddress
+                case .name:
+                    .personalFullName
+                case .phoneNumber:
+                    .telephoneNumber
+                case .text:
+                    .default
+                case .url:
+                    .url
+            }
+
+        setInputScope(for: textField, to: inputScope)
+    }
+
+    private func setInputScope(for textField: TextBox, to value: InputScopeNameValue) {
+        if let inputScope = textField.inputScope,
+            inputScope.names.count == 1
+        {
+            inputScope.names[0] = value
+        } else {
+            let inputScope = InputScope()
+            inputScope.names.add(value)
+            textField.inputScope = inputScope
+        }
     }
 
     public func setContent(ofTextField textField: Widget, to content: String) {