Add support fot handling delete key presses.

Using a sub-class with an overridden deleteBackward() allows detection
of delete presses on empty fields which can be useful for navigating
back to a previous field.

Author: lukeredpath

Demo Project/ResponsiveTextFieldDemo/ContentView.swift

@@ -51,7 +51,8 @@ struct ContentView: View {
                         isEditing: $isEditingPassword.animation(),
                         isSecure: hidePassword,
                         configuration: .combine(.password, .lastOfChain),
-                        handleReturn: { isEditingPassword = false }
+                        handleReturn: { isEditingPassword = false },
+                        handleDelete: { isEditingEmail = $0.isEmpty }
                     )
                     .fixedSize(horizontal: false, vertical: true)
                     .disabled(!isEnabled)

ResponsiveTextField.xcworkspace/xcshareddata/xcschemes/ResponsiveTextField.xcscheme

@@ -29,7 +29,8 @@
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
          <TestableReference
-            skipped = "NO">
+            skipped = "NO"
+            testExecutionOrdering = "random">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "ResponsiveTextFieldTests"

Sources/ResponsiveTextField/ResponsiveTextField.swift

@@ -59,6 +59,20 @@ public struct ResponsiveTextField {
     /// If this is not set, the textfield delegate will indicate that the return key is not handled.
     var handleReturn: (() -> Void)?
 
+    /// A callback function that will be called when the user deletes backwards.
+    ///
+    /// Takes a single argument - a `String` - which will be the current text when the user
+    /// hits the delete key (but before any deletion occurs).
+    ///
+    /// If this is an empty string, it indicates that the user tapped delete inside an empty field.
+    var handleDelete: ((String) -> Void)?
+
+    /// A callback function that can be used to control whether or not text should change.
+    ///
+    /// Takes two `String` arguments - the text prior to the change and the new text if
+    /// the change is permitted.
+    ///
+    /// Return `true` to allow the change or `false` to prevent the change.
     var shouldChange: ((String, String) -> Bool)?
 
     public init(
@@ -68,6 +82,7 @@ public struct ResponsiveTextField {
         isSecure: Bool = false,
         configuration: Configuration = .empty,
         handleReturn: (() -> Void)? = nil,
+        handleDelete: ((String) -> Void)? = nil,
         shouldChange: ((String, String) -> Bool)? = nil
     ) {
         self.placeholder = placeholder
@@ -76,6 +91,7 @@ public struct ResponsiveTextField {
         self.isSecure = isSecure
         self.configuration = configuration
         self.handleReturn = handleReturn
+        self.handleDelete = handleDelete
         self.shouldChange = shouldChange
     }
 }
@@ -84,9 +100,10 @@ public struct ResponsiveTextField {
 
 extension ResponsiveTextField: UIViewRepresentable {
     public func makeUIView(context: Context) -> UITextField {
-        let textField = UITextField()
+        let textField = DeleteHandlingTextField()
         configuration.configure(textField)
         // This stops the text field from expanding if the text overflows the frame width
+        textField.handleDelete = handleDelete
         textField.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
         textField.placeholder = placeholder
         textField.text = text.wrappedValue
@@ -181,6 +198,15 @@ extension ResponsiveTextField: UIViewRepresentable {
     }
 }
 
+private class DeleteHandlingTextField: UITextField {
+    var handleDelete: ((String) -> Void)?
+
+    override func deleteBackward() {
+        handleDelete?(text ?? "")
+        super.deleteBackward()
+    }
+}
+
 // MARK: - TextField Configurations
 
 extension ResponsiveTextField {