add deleteAtPosition method (#105)

mac-gallagher · Jul 13, 2020 · 2be4f20 · 2be4f20
1 parent 8ae0c30
commit 2be4f20
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Showing 8 changed files with 270 additions and 121 deletions.
diff --git a/Shuffle-iOS.podspec b/Shuffle-iOS.podspec
@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
 s.name         = "Shuffle-iOS"
-s.version      = "0.3.2"
+s.version      = "0.3.3"
 s.platform     = :ios, "9.0"
 s.summary      = "A multi-directional card swiping library inspired by Tinder"
 
@@ -13,7 +13,7 @@ s.homepage     = "https://github.com/mac-gallagher/Shuffle"
 s.documentation_url = "https://github.com/mac-gallagher/Shuffle/tree/master/README.md"
 s.license      = { :type => 'MIT', :file => 'LICENSE' }
 s.author       = { "Mac Gallagher" => "[email protected]" }
-s.source       = { :git => "https://github.com/mac-gallagher/Shuffle.git", :tag => "v0.3.2" }
+s.source       = { :git => "https://github.com/mac-gallagher/Shuffle.git", :tag => "v0.3.3" }
 
 s.swift_version = "5.0"
 s.source_files = "Sources/**/*.{h,swift}"

diff --git a/Sources/Shuffle/SwipeCardStack/CardStackStateManager.swift b/Sources/Shuffle/SwipeCardStack/CardStackStateManager.swift
@@ -24,7 +24,10 @@
 
 import Foundation
 
-typealias Swipe = (index: Int, direction: SwipeDirection)
+struct Swipe: Equatable {
+  var index: Int
+  var direction: SwipeDirection
+}
 
 protocol CardStackStateManagable {
   var remainingIndices: [Int] { get }
@@ -33,6 +36,7 @@ protocol CardStackStateManagable {
 
   func insert(_ index: Int, at position: Int)
   func delete(_ index: Int)
+  func delete(indexAtPosition position: Int)
 
   func swipe(_ direction: SwipeDirection)
   func undoSwipe() -> Swipe?
@@ -67,7 +71,7 @@ class CardStackStateManager: CardStackStateManagable {
 
     // Increment all stored indices greater than or equal to index by 1
     remainingIndices = remainingIndices.map { $0 >= index ? $0 + 1 : $0 }
-    swipes = swipes.map { $0.index >= index ? Swipe($0.index + 1, $0.direction) : $0 }
+    swipes = swipes.map { $0.index >= index ? Swipe(index: $0.index + 1, direction: $0.direction) : $0 }
 
     remainingIndices.insert(index, at: position)
   }
@@ -85,13 +89,23 @@ class CardStackStateManager: CardStackStateManagable {
 
     // Decrement all stored indices greater than or equal to index by 1
     remainingIndices = remainingIndices.map { $0 >= index ? $0 - 1 : $0 }
-    swipes = swipes.map { $0.index >= index ? Swipe($0.index - 1, $0.direction) : $0 }
+    swipes = swipes.map { $0.index >= index ? Swipe(index: $0.index - 1, direction: $0.direction) : $0 }
+  }
+
+  func delete(indexAtPosition position: Int) {
+    precondition(position >= 0, "Attempt to delete card at position \(position)")
+    //swiftlint:disable:next line_length
+    precondition(position < remainingIndices.count, "Attempt to delete card at position \(position), but there are only \(remainingIndices.count) cards remaining in the stack before the update")
+
+    // Decrement all stored indices greater than or equal to index by 1
+    let index = remainingIndices.remove(at: position)
+    remainingIndices = remainingIndices.map { $0 >= index ? $0 - 1 : $0 }
   }
 
   func swipe(_ direction: SwipeDirection) {
     if remainingIndices.isEmpty { return }
     let firstIndex = remainingIndices.removeFirst()
-    let swipe = Swipe(direction: direction, index: firstIndex)
+    let swipe = Swipe(index: firstIndex, direction: direction)
     swipes.append(swipe)
   }
 

diff --git a/Sources/Shuffle/SwipeCardStack/SwipeCardStack.swift b/Sources/Shuffle/SwipeCardStack/SwipeCardStack.swift
@@ -24,11 +24,14 @@
 
 import UIKit
 
-/// A typealias for a `SwipeCard` and it's corresponding index in the card stack's `dataSource`.
-typealias Card = (index: Int, card: SwipeCard)
-
 open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegate {
 
+  /// A internal structure for a `SwipeCard` and it's corresponding index in the card stack's `dataSource`.
+  struct Card {
+    var index: Int
+    var card: SwipeCard
+  }
+
   open var animationOptions: CardStackAnimatableOptions = CardStackAnimationOptions.default
 
   /// Return `false` if you wish to ignore all horizontal gestures on the card stack.
@@ -201,7 +204,7 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
     if (stateManager.remainingIndices.count - visibleCards.count) > 0 {
       let bottomCardIndex = stateManager.remainingIndices[visibleCards.count]
       if let card = loadCard(at: bottomCardIndex) {
-        insertCard(Card(bottomCardIndex, card), at: visibleCards.count)
+        insertCard(Card(index: bottomCardIndex, card: card), at: visibleCards.count)
       }
     }
 
@@ -290,6 +293,34 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
     return nil
   }
 
+  func reloadVisibleCards() {
+    visibleCards.forEach { $0.card.removeFromSuperview() }
+    visibleCards.removeAll()
+
+    let numberOfCards = min(stateManager.remainingIndices.count, numberOfVisibleCards)
+    for position in 0..<numberOfCards {
+      let index = stateManager.remainingIndices[position]
+      if let card = loadCard(at: index) {
+        insertCard(Card(index: index, card: card), at: position)
+      }
+    }
+  }
+
+  func insertCard(_ value: Card, at position: Int) {
+    cardContainer.insertSubview(value.card, at: visibleCards.count - position)
+    layoutCard(value.card, at: position)
+    visibleCards.insert(value, at: position)
+  }
+
+  func loadCard(at index: Int) -> SwipeCard? {
+    let card = dataSource?.cardStack(self, cardForIndexAt: index)
+    card?.delegate = self
+    card?.panGestureRecognizer.delegate = self
+    return card
+  }
+
+  // MARK: - State Management
+
   /// Returns the current position of the card at the specified index.
   ///
   /// A returned value of `0` indicates that the card is the topmost card in the stack.
@@ -309,8 +340,7 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
   /// Inserts a new card with the given index at the specified position.
   /// - Parameters:
   ///   - index: The index of the card in the data source.
-  ///   - position: The position of the new card in the card stack. This position should be determined on
-  ///   the returned value of `numberOfRemainingCards`.
+  ///   - position: The position of the new card in the card stack.
   public func insertCard(atIndex index: Int, position: Int) {
     guard let dataSource = dataSource else { return }
 
@@ -351,8 +381,8 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
     reloadVisibleCards()
   }
 
-  /// Deletes the card at the specified index. Removes swipes
-  /// - Parameter index: The index of the card in the data source
+  /// Deletes the card at the specified index.
+  /// - Parameter index: The index of the card in the data source.
   public func deleteCard(atIndex index: Int) {
     guard let dataSource = dataSource else { return }
 
@@ -371,30 +401,24 @@ open class SwipeCardStack: UIView, SwipeCardDelegate, UIGestureRecognizerDelegat
     reloadVisibleCards()
   }
 
-  func reloadVisibleCards() {
-    visibleCards.forEach { $0.card.removeFromSuperview() }
-    visibleCards.removeAll()
+  /// Deletes the card at the specified position in the card stack.
+  /// - Parameter position: The position of the card to delete in the card stack.
+  public func deleteCard(atPosition position: Int) {
+    guard let dataSource = dataSource else { return }
 
-    let numberOfCards = min(stateManager.remainingIndices.count, numberOfVisibleCards)
-    for position in 0..<numberOfCards {
-      let index = stateManager.remainingIndices[position]
-      if let card = loadCard(at: index) {
-        insertCard(Card(index, card), at: position)
-      }
-    }
-  }
+    let oldNumberOfCards = stateManager.totalIndexCount
+    let newNumberOfCards = dataSource.numberOfCards(in: self)
 
-  func insertCard(_ value: Card, at position: Int) {
-    cardContainer.insertSubview(value.card, at: visibleCards.count - position)
-    layoutCard(value.card, at: position)
-    visibleCards.insert(value, at: position)
-  }
+    stateManager.delete(indexAtPosition: position)
 
-  func loadCard(at index: Int) -> SwipeCard? {
-    let card = dataSource?.cardStack(self, cardForIndexAt: index)
-    card?.delegate = self
-    card?.panGestureRecognizer.delegate = self
-    return card
+    if newNumberOfCards != oldNumberOfCards - 1 {
+      let errorString = StringUtils.createInvalidUpdateErrorString(newCount: newNumberOfCards,
+                                                                   oldCount: oldNumberOfCards,
+                                                                   deletedCount: 1)
+      fatalError(errorString)
+    }
+
+    reloadVisibleCards()
   }
 
   // MARK: - Notifications

diff --git a/Tests/ShuffleTests/SwipeCardStack/Mocks/MockCardStackStateManager.swift b/Tests/ShuffleTests/SwipeCardStack/Mocks/MockCardStackStateManager.swift
@@ -41,12 +41,20 @@ class MockCardStackStateManager: CardStackStateManagable {
     insertPositions.append(position)
   }
 
-  var deleteCalled: Bool = false
-  var deleteIndex: Int?
+  var deleteAtIndexCalled: Bool = false
+  var deleteAtIndexIndex: Int?
 
   func delete(_ index: Int) {
-    deleteCalled = true
-    deleteIndex = index
+    deleteAtIndexCalled = true
+    deleteAtIndexIndex = index
+  }
+
+  var deleteAtPositionCalled: Bool = false
+  var deleteAtPositionPosition: Int?
+
+  func delete(indexAtPosition position: Int) {
+    deleteAtPositionCalled = true
+    deleteAtPositionPosition = position
   }
 
   var swipeCalled = false