[CM-1318] Add key command for navigation (#7)

* rebase

* [UPDATE] review comments resolved

* [UPDATE] resolved review comment

* [UPDATE] added test file

Author: SahilSainiYML

Package.swift

@@ -4,6 +4,7 @@ import PackageDescription
 
 let package = Package(
     name: "YCarousel",
+    defaultLocalization: "en",
     platforms: [
         .iOS(.v14)
     ],
@@ -16,7 +17,7 @@ let package = Package(
     dependencies: [
         .package(
             url: "https://github.com/yml-org/YCoreUI.git",
-            from: "1.5.0"
+            from: "1.6.0"
         )
     ],
     targets: [

Sources/YCarousel/Assets/Strings/en.lproj/Localizable.strings

@@ -0,0 +1,9 @@
+/* 
+  Localizable.strings
+  
+
+  Created by Sahil Saini on 05/04/23.
+  
+*/
+"Previous_Arrow_Button" = "Previous";
+"Next_Arrow_Button" = "Next";

Sources/YCarousel/CarouselView.swift

@@ -50,7 +50,7 @@ public class CarouselView: UIView {
             }
         }
     }
-    
+
     private let pageControlBottomSpacing: CGFloat = 16
     private var viewProvider: CarouselViewProvider?
 
@@ -118,6 +118,16 @@ public class CarouselView: UIView {
         }
         return nil
     }
+
+    /// Load view at index
+    /// - Parameter index: index of view to load
+    public func loadView(at index: Int) {
+        guard 0..<numberOfPages ~= index else {
+            return
+        }
+        currentPage = index
+        gotoPage(at: index)
+    }
 }
 
 internal extension CarouselView {

Sources/YCarousel/CarouselViewController.swift

@@ -12,6 +12,9 @@ import UIKit
 public class CarouselViewController: UIViewController, CarouselViewDelegate, CarouselViewDataSource {
     private let pages: [CarouselPage]
 
+    /// Enables keyboard navigation. Default is `true`.
+    public var isKeyboardNavigationEnabled: Bool = true
+
     /// The carousel view managed by this controller
     public var carouselView: CarouselView! { view as? CarouselView }
 
@@ -37,6 +40,7 @@ public class CarouselViewController: UIViewController, CarouselViewDelegate, Car
         carouselView.dataSource = self
         carouselView.delegate = self
         self.view = carouselView
+        configureKeys()
     }
 
     // MARK: - CarouselViewDelegate
@@ -95,3 +99,32 @@ public class CarouselViewController: UIViewController, CarouselViewDelegate, Car
     /// - Returns: UIView
     public func carouselView(pageAt index: Int) -> UIView { pages[index].view }
 }
+
+// MARK: - UIKeyCommand
+
+internal extension CarouselViewController {
+    func configureKeys() {
+        let rightArrow = UIKeyCommand(
+            title: CarouselViewController.Strings.next.localized,
+            action: #selector(rightArrowKeyPressed),
+            input: UIKeyCommand.inputRightArrow
+        )
+        let leftArrow = UIKeyCommand(
+            title: CarouselViewController.Strings.previous.localized,
+            action: #selector(leftArrowKeyPressed),
+            input: UIKeyCommand.inputLeftArrow
+        )
+        addKeyCommand(leftArrow)
+        addKeyCommand(rightArrow)
+    }
+
+    @objc func leftArrowKeyPressed() {
+        guard isKeyboardNavigationEnabled else { return }
+        carouselView.loadView(at: carouselView.currentPage - 1)
+    }
+
+    @objc func rightArrowKeyPressed() {
+        guard isKeyboardNavigationEnabled else { return }
+        carouselView.loadView(at: carouselView.currentPage + 1)
+    }
+}

Sources/YCarousel/Enums/CarouselViewController+Strings.swift

@@ -0,0 +1,22 @@
+//
+//  CarouselViewController+Strings.swift
+//  YCarousel
+//
+//  Created by Sahil Saini on 05/04/23.
+//  Copyright © 2023 Y Media Labs. All rights reserved.
+//
+
+import Foundation
+import YCoreUI
+
+extension CarouselViewController {
+    /// Strings
+    enum Strings: String, Localizable, CaseIterable {
+        /// Buttons
+        case previous = "Previous_Arrow_Button"
+        case next = "Next_Arrow_Button"
+
+        /// Bundle
+        static var bundle: Bundle { .module }
+    }
+}

Tests/YCarouselTests/CarouselViewControllerTests.swift

@@ -82,6 +82,67 @@ final class CarouselViewControllerTests: XCTestCase {
         XCTAssertTrue(sut.pageWillUnload)
         XCTAssertTrue(sut.pageWillUnload)
     }
+
+    func test_pressKeyboardLeft_deliversPreviousPage() {
+        // Given
+        let sut = makeSUT(withViews: [UIView(), UIView()])
+        sut.carouselView.loadPage(at: 1)
+        // When
+        sut.leftArrowKeyPressed()
+        // Then
+        XCTAssertEqual(sut.carouselView.currentPage, 0)
+    }
+
+    func test_pressKeyboardLeftOnFirstPage_deliversNothing() {
+        // Given
+        let sut = makeSUT(withViews: [UIView(), UIView()])
+        XCTAssertEqual(sut.carouselView.currentPage, 0)
+        // When
+        sut.leftArrowKeyPressed()
+        // Then
+        XCTAssertEqual(sut.carouselView.currentPage, 0)
+    }
+
+    func test_pressKeyboardRight_deliversNextPage() {
+        // Given
+        let sut = makeSUT(withViews: [UIView(), UIView()])
+        XCTAssertEqual(sut.carouselView.currentPage, 0)
+        // When
+        sut.rightArrowKeyPressed()
+        // Then
+        XCTAssertEqual(sut.carouselView.currentPage, 1)
+    }
+
+    func test_pressKeyboardRightFromLastPage_deliversNothing() {
+        // Given
+        let sut = makeSUT(withViews: [UIView(), UIView()])
+        sut.carouselView.loadView(at: 1)
+        // When
+        sut.rightArrowKeyPressed()
+        // Then
+        XCTAssertEqual(sut.carouselView.currentPage, 1)
+    }
+
+    func test_pressKeyboardLeftWhenDisabled_deliversNothing() {
+        // Given
+        let sut = makeSUT(withViews: [UIView(), UIView()])
+        sut.carouselView.loadView(at: 1)
+        sut.isKeyboardNavigationEnabled = false
+        // When
+        sut.leftArrowKeyPressed()
+        // Then
+        XCTAssertEqual(sut.carouselView.currentPage, 1)
+    }
+
+    func test_pressKeyboardRightWhenDisabled_deliversNothing() {
+        // Given
+        let sut = makeSUT(withViews: [UIView(), UIView()])
+        sut.isKeyboardNavigationEnabled = false
+        // When
+        sut.rightArrowKeyPressed()
+        // Then
+        XCTAssertEqual(sut.carouselView.currentPage, 0)
+    }
 }
 
 private extension CarouselViewControllerTests {

Tests/YCarouselTests/Enums/CarouselViewController+StringsTests.swift

@@ -0,0 +1,23 @@
+//
+//  CarouselViewController+StringsTests.swift
+//  YCarousel
+//
+//  Created by Sahil Saini on 07/04/23.
+//  Copyright © 2023 Y Media Labs. All rights reserved.
+//
+
+import XCTest
+@testable import YCarousel
+
+final class CarouselViewControllerStringsTests: XCTestCase {
+    func testLoadStrings() {
+        CarouselViewController.Strings.allCases.forEach {
+            // Given a localized string constant
+            let string = $0.localized
+            // should not be empty
+            XCTAssertFalse(string.isEmpty)
+            // should not equal its key
+            XCTAssertNotEqual($0.rawValue, string)
+        }
+    }
+}