Added UIKeyInput

Sources/Cacao/UIKeyInput.swift

@@ -0,0 +1,32 @@
+//
+//  UIKeyInput.swift
+//  Cacao
+//
+//  Created by Alsey Coleman Miller on 11/26/17.
+//
+
+import Foundation
+
+/// A set of methods a subclass of `UIResponder` uses to implement simple text entry.
+///
+/// When instances of this subclass are the first responder, the system keyboard is displayed.
+/// Only a small subset of the available keyboards and languages are available to classes that adopt this protocol.
+public protocol UIKeyInput: UITextInputTraits {
+
+    /// Insert a character into the displayed text.
+    ///
+    /// - Parameter text: A string object representing the character typed on the system keyboard.
+    ///
+    /// Add the character text to your class’s backing store at the index corresponding to the cursor and redisplay the text.
+    func insertText(_ text: String)
+
+    /// Delete a character from the displayed text.
+    ///
+    /// Remove the character just before the cursor from your class’s backing store and redisplay the text.
+    func deleteBackward()
+
+    /// A Boolean value that indicates whether the text-entry objects has any text.
+    ///
+    /// - Returns: `true` if the backing store has textual content, `false` otherwise.
+    var hasText: Bool { get }
+}