Generic Placeholders

dreymonde · Apr 17, 2017 · 72aea1a · 72aea1a
1 parent 28d03f7
commit 72aea1a
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Showing 4 changed files with 122 additions and 33 deletions.
diff --git a/Placeholders/Placeholders+UIKit.swift b/Placeholders/Placeholders+UIKit.swift
@@ -8,6 +8,28 @@
 
 import UIKit
 
+public protocol TextFieldPlaceholder {
+
+    func set(on textField: UITextField)
+
+}
+
+extension String : TextFieldPlaceholder {
+
+    public func set(on textField: UITextField) {
+        textField.placeholder = self
+    }
+
+}
+
+extension NSAttributedString : TextFieldPlaceholder {
+
+    public func set(on textField: UITextField) {
+        textField.attributedPlaceholder = self
+    }
+
+}
+
 extension UITextField {
 
     var isTextEmpty: Bool {
@@ -17,16 +39,16 @@ extension UITextField {
         return true
     }
 
-    public struct PlaceholderChange {
+    public struct PlaceholderChange<Placeholder : TextFieldPlaceholder> {
 
-        private let _setNewPlaceholder: (String, UITextField) -> ()
+        private let _setNewPlaceholder: (Placeholder, UITextField) -> ()
 
-        public func setNewPlaceholder(_ placeholder: String, on textField: UITextField) {
+        public func setNewPlaceholder(_ placeholder: Placeholder, on textField: UITextField) {
             guard textField.isTextEmpty else { return }
             _setNewPlaceholder(placeholder, textField)
         }
 
-        public init(setNewPlaceholder: @escaping (String, UITextField) -> ()) {
+        public init(setNewPlaceholder: @escaping (Placeholder, UITextField) -> ()) {
             self._setNewPlaceholder = setNewPlaceholder
         }
 
@@ -36,11 +58,11 @@ extension UITextField {
 
 extension UITextField.PlaceholderChange {
 
-    public static func caTransition(_ transition: @escaping () -> CATransition) -> UITextField.PlaceholderChange {
+    public static func caTransition(_ transition: @escaping () -> CATransition) -> UITextField.PlaceholderChange<Placeholder> {
         return UITextField.PlaceholderChange { (placeholder, textField) in
             let transition = transition()
             textField.subviews.first(where: { NSStringFromClass(type(of: $0)) == "UITextFieldLabel" })?.layer.add(transition, forKey: nil)
-            textField.placeholder = placeholder
+            placeholder.set(on: textField)
         }
     }
 
@@ -66,7 +88,7 @@ extension UITextField.PlaceholderChange {
 
     public static func pushTransition(_ direction: TransitionPushDirection,
                             duration: TimeInterval = 0.35,
-                            timingFunction: CAMediaTimingFunction = .init(name: kCAMediaTimingFunctionEaseInEaseOut)) -> UITextField.PlaceholderChange {
+                            timingFunction: CAMediaTimingFunction = .init(name: kCAMediaTimingFunctionEaseInEaseOut)) -> UITextField.PlaceholderChange<Placeholder> {
         return .caTransition {
             let transition = CATransition()
             transition.duration = duration
@@ -79,12 +101,12 @@ extension UITextField.PlaceholderChange {
 
 }
 
-extension Placeholders {
+extension Placeholders where Element : TextFieldPlaceholder {
 
     public func start(interval: TimeInterval,
                       fireInitial: Bool = true,
                       textField: UITextField,
-                      animation change: UITextField.PlaceholderChange) {
+                      animation change: UITextField.PlaceholderChange<Element>) {
         self.start(interval: interval, fireInitial: fireInitial) { [weak textField, weak self] (placeholder) in
             if let textField = textField {
                 change.setNewPlaceholder(placeholder, on: textField)

diff --git a/Placeholders/Placeholders.swift b/Placeholders/Placeholders.swift
@@ -8,17 +8,30 @@
 
 import Foundation
 
-final public class Placeholders {
+public struct PlaceholdersOptions : OptionSet {
 
-    public var iterator: AnyIterator<String>
+    public var rawValue: Int
+
+    public init(rawValue: Int) {
+        self.rawValue = rawValue
+    }
+
+    public static var infinite = PlaceholdersOptions(rawValue: 1 << 0)
+    public static var shuffle = PlaceholdersOptions(rawValue: 1 << 1)
+
+}
+
+final public class Placeholders<Element> {
+
+    public var iterator: AnyIterator<Element>
     var timer: Timer?
-    var action: (String) -> () = { _ in }
+    var action: (Element) -> () = { _ in }
 
-    public init<StringIterator : IteratorProtocol>(iterator: StringIterator) where StringIterator.Element == String {
+    public init<Iterator : IteratorProtocol>(iterator: Iterator) where Iterator.Element == Element {
         self.iterator = AnyIterator(iterator)
     }
 
-    public convenience init(placeholders: [String], options: Options = []) {
+    public convenience init(placeholders: [Element], options: PlaceholdersOptions = []) {
         var finalPlaceholders = placeholders
         if options.contains(.shuffle) { finalPlaceholders.shuffle() }
         if options.contains(.infinite) {
@@ -28,24 +41,11 @@ final public class Placeholders {
         }
     }
 
-    public struct Options : OptionSet {
-
-        public var rawValue: Int
-
-        public init(rawValue: Int) {
-            self.rawValue = rawValue
-        }
-
-        public static var infinite = Options(rawValue: 1 << 0)
-        public static var shuffle = Options(rawValue: 1 << 1)
-
-    }
-
     deinit {
         timer?.invalidate()
     }
 
-    public func start(interval: TimeInterval, fireInitial: Bool, action: @escaping (String) -> ()) {
+    public func start(interval: TimeInterval, fireInitial: Bool, action: @escaping (Element) -> ()) {
         self.action = action
         let timer = Timer(timeInterval: interval,
                           target: self,

diff --git a/PlaceholdersTests/PlaceholdersTests.swift b/PlaceholdersTests/PlaceholdersTests.swift
@@ -9,8 +9,35 @@
 import XCTest
 @testable import Placeholders
 
+extension UITextField.PlaceholderChange {
+
+    static var fade_a: UITextField.PlaceholderChange<Placeholder> {
+        return UITextField.PlaceholderChange { (placeholder, textField) in
+            let transition = CATransition()
+            transition.duration = 0.35
+            transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
+            transition.type = kCATransitionFade
+            textField.subviews.first(where: { NSStringFromClass(type(of: $0)) == "UITextFieldLabel" })?.layer.add(transition, forKey: nil)
+            placeholder.set(on: textField)
+        }
+    }
+
+    static var fade: UITextField.PlaceholderChange<Placeholder> {
+        return .caTransition {
+            let transition = CATransition()
+            transition.duration = 0.35
+            transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
+            transition.type = kCATransitionFade
+            return transition
+        }
+    }
+
+}
+
 class PlaceholdersTests: XCTestCase {
 
+    let placeholders = Placeholders(placeholders: ["First", "Second", "Third"], options: [.infinite, .shuffle])
+
     override func setUp() {
         super.setUp()
         // Put setup code here. This method is called before the invocation of each test method in the class.
@@ -26,6 +53,25 @@ class PlaceholdersTests: XCTestCase {
         // Use XCTAssert and related functions to verify your tests produce the correct results.
     }
 
+    func testREADME2() {
+        let textField = UITextField()
+        placeholders.start(interval: 3.0,
+                           fireInitial: true,
+                           textField: textField,
+                           animation: .pushTransition(.fromBottom))
+        placeholders.start(interval: 3.0,
+                           fireInitial: true,
+                           textField: textField,
+                           animation: .fade)
+    }
+
+    func testREADME1() {
+        let placeholders = Placeholders(placeholders: ["A", "B", "C"], options: .infinite)
+        placeholders.start(interval: 2.0, fireInitial: true, action: { next in
+            print(next)
+        })
+    }
+
     func testPerformanceExample() {
         // This is an example of a performance test case.
         self.measure {

diff --git a/README.md b/README.md
@@ -1,4 +1,8 @@
 # Placeholders
+
+[![Swift][swift-badge]][swift-url]
+[![Platform][platform-badge]][platform-url]
+
 **Placeholders** gives you the ability to define multiple placeholders for `UITextField`, and also animate their change in the way you like. The result looks like that:
 
 ![Demo](Resources/Demo.gif)
@@ -50,26 +54,28 @@ To define your custom `animation` as, for example, `.pushTransition`, you can ex
 ```swift
 extension UITextField.PlaceholderChange {
 
-    static var fade: UITextField.PlaceholderChange {
+    static var fade: UITextField.PlaceholderChange<Placeholder> {
         return UITextField.PlaceholderChange { (placeholder, textField) in
             let transition = CATransition()
             transition.duration = 0.35
             transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
             transition.type = kCATransitionFade
             textField.subviews.first(where: { NSStringFromClass(type(of: $0)) == "UITextFieldLabel" })?.layer.add(transition, forKey: nil)
-            textField.placeholder = placeholder
+            placeholder.set(on: textField)
         }
     }
 
 }
 ```
 
-Or you can use convenience `.caTransition` static function to make your life a bit easier:
+This generic `Placeholder` type and `placeholder.set(on: textField)` syntax exists in order to support `NSAttributedString` as a placeholder.
+
+You can also use convenience `.caTransition` static function to make your life a bit easier:
 
 ```swift
 extension UITextField.PlaceholderChange {
 
-    static var fade: UITextField.PlaceholderChange {
+    static var fade: UITextField.PlaceholderChange<Placeholder> {
         return .caTransition {
             let transition = CATransition()
             transition.duration = 0.35
@@ -91,4 +97,19 @@ placeholders.start(interval: 3.0,
                    animation: .fade)
 ```
 
-Neat!
+Neat!
+
+## Installation
+**Placeholders** is available through [Carthage][carthage-url]. To install, just write into your Cartfile:
+
+```ruby
+github "dreymonde/Placeholders" ~> 0.1.0
+```
+
+We also encourage you to write your very own implementation that fits your needs best. Our source code is there to help.
+
+[carthage-url]: https://github.com/Carthage/Carthage
+[swift-badge]: https://img.shields.io/badge/Swift-3.0-orange.svg?style=flat
+[swift-url]: https://swift.org
+[platform-badge]: https://img.shields.io/badge/Platform-iOS-lightgray.svg?style=flat
+[platform-url]: https://developer.apple.com/swift/