Add prepareCellForSkeleton for UITableView and UICollectionView (#415)

* Add prepareCellForSkeleton for UITableView and UICollectionView

* Update README to add collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath)

* Update README.md

Co-authored-by: Juanpe Catalán <juanpecm@gmail.com>

.github/workflows/main.yml

@@ -16,4 +16,4 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Build
-        run: xcodebuild clean -target '${{ matrix.build-config['target'] }}' -sdk '${{ matrix.build-config['sdk'] }}' -destination '${{ matrix.build-config['destination'] }}'
+        run: xcodebuild clean build -target '${{ matrix.build-config['target'] }}' -sdk '${{ matrix.build-config['sdk'] }}' -destination '${{ matrix.build-config['destination'] }}'

Example/CollectionView/ViewController.swift

@@ -174,6 +174,12 @@ extension ViewController: SkeletonCollectionViewDataSource {
     func collectionSkeletonView(_ skeletonView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
         return 10
     }
+
+    func collectionSkeletonView(_ skeletonView: UICollectionView, skeletonCellForItemAt indexPath: IndexPath) -> UICollectionViewCell? {
+        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionViewCell", for: indexPath) as? CollectionViewCell
+        cell?.isSkeletonable = indexPath.row != 0
+        return cell
+    }
     
     // MARK: - UICollectionViewDataSource
     
@@ -184,6 +190,10 @@ extension ViewController: SkeletonCollectionViewDataSource {
     func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
         let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionViewCell", for: indexPath) as! CollectionViewCell
         return cell
-        
+    }
+
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath) {
+        let cell = cell as? CollectionViewCell
+        cell?.isSkeletonable = indexPath.row != 0
     }
 }

Example/TableView/ViewController.swift

@@ -183,6 +183,17 @@ extension ViewController: SkeletonTableViewDataSource {
         cell.label1.text = "cell -> \(indexPath.row)"
         return cell
     }
+    
+    func collectionSkeletonView(_ skeletonView: UITableView, skeletonCellForRowAt indexPath: IndexPath) -> UITableViewCell? {
+        let cell = skeletonView.dequeueReusableCell(withIdentifier: "CellIdentifier", for: indexPath) as? Cell
+        cell?.textField.isHidden = indexPath.row == 0
+        return cell
+    }
+
+    func collectionSkeletonView(_ skeletonView: UITableView, prepareCellForSkeleton cell: UITableViewCell, at indexPath: IndexPath) {
+        let cell = cell as? Cell
+        cell?.textField.isHidden = indexPath.row == 0
+    }
 }
 
 extension ViewController: SkeletonTableViewDelegate {

README.md

@@ -169,19 +169,16 @@ If you want to show the skeleton in a ```UITableView```, you need to conform to
 
 ``` swift
 public protocol SkeletonTableViewDataSource: UITableViewDataSource {
-    func numSections(in collectionSkeletonView: UITableView) -> Int
+    func numSections(in collectionSkeletonView: UITableView) -> Int // Default: 1
     func collectionSkeletonView(_ skeletonView: UITableView, numberOfRowsInSection section: Int) -> Int
     func collectionSkeletonView(_ skeletonView: UITableView, cellIdentifierForRowAt indexPath: IndexPath) -> ReusableCellIdentifier
+    func collectionSkeletonView(_ skeletonView: UITableView, skeletonCellForRowAt indexPath: IndexPath) -> UITableViewCell? // Default: nil
+    func collectionSkeletonView(_ skeletonView: UITableView, prepareCellForSkeleton cell: UITableViewCell, at indexPath: IndexPath)
 }
 ```
 As you can see, this protocol inherits from ```UITableViewDataSource```, so you can replace this protocol with the skeleton protocol.
 
-This protocol has a default implementation:
-
-``` swift
-func numSections(in collectionSkeletonView: UITableView) -> Int
-// Default: 1
-```
+This protocol has a default implementation for some methods. For example, the number of rows for each section is calculated in runtime:
 
 ``` swift
 func collectionSkeletonView(_ skeletonView: UITableView, numberOfRowsInSection section: Int) -> Int
@@ -189,18 +186,35 @@ func collectionSkeletonView(_ skeletonView: UITableView, numberOfRowsInSection s
 // It calculates how many cells need to populate whole tableview
 ```
 
-There is only one method you need to implement to let Skeleton know the cell identifier. This method doesn't have default implementation:
- ``` swift
- func collectionSkeletonView(_ skeletonView: UITableView, cellIdentifierForRowAt indexPath: IndexPath) -> ReusableCellIdentifier
- ```
+> 📣 **IMPORTANT!** 
+>
+> If you return `UITableView.automaticNumberOfSkeletonRows` in the above method, it acts like the default behavior (i.e. it calculates how many cells needed to populate the whole tableview).
 
-**Example**
+There is only one method you need to implement to let Skeleton know the cell identifier. This method doesn't have default implementation:
  ``` swift
  func collectionSkeletonView(_ skeletonView: UITableView, cellIdentifierForRowAt indexPath: IndexPath) -> ReusableCellIdentifier {
     return "CellIdentifier"
 }
  ```
  
+ By default, the library dequeues the cells from each indexPath, but you can also do this if you want to make some changes before the skeleton appears:
+ ``` swift
+ func collectionSkeletonView(_ skeletonView: UITableView, skeletonCellForRowAt indexPath: IndexPath) -> UITableViewCell? {
+     let cell = skeletonView.dequeueReusableCell(withIdentifier: "CellIdentifier", for: indexPath) as? Cell
+     cell?.textField.isHidden = indexPath.row == 0
+     return cell
+ }
+ ```
+ 
+If you prefer to leave the deque part to the library you can configure the cell using this method:
+ ``` swift
+ func collectionSkeletonView(_ skeletonView: UITableView, prepareCellForSkeleton cell: UITableViewCell, at indexPath: IndexPath) {
+     let cell = cell as? Cell
+     cell?.textField.isHidden = indexPath.row == 0
+ }
+ ```
+
+ 
 Besides, you can skeletonize both the headers and footers. You need to conform to `SkeletonTableViewDelegate` protocol.
 
 ```swift
@@ -228,10 +242,12 @@ For `UICollectionView`, you need to conform to `SkeletonCollectionViewDataSource
 
 ``` swift
 public protocol SkeletonCollectionViewDataSource: UICollectionViewDataSource {
-    func numSections(in collectionSkeletonView: UICollectionView) -> Int // default: 1
+    func numSections(in collectionSkeletonView: UICollectionView) -> Int  // default: 1
     func collectionSkeletonView(_ skeletonView: UICollectionView, numberOfItemsInSection section: Int) -> Int
     func collectionSkeletonView(_ skeletonView: UICollectionView, cellIdentifierForItemAt indexPath: IndexPath) -> ReusableCellIdentifier
     func collectionSkeletonView(_ skeletonView: UICollectionView, supplementaryViewIdentifierOfKind: String, at indexPath: IndexPath) -> ReusableCellIdentifier? // default: nil
+    func collectionSkeletonView(_ skeletonView: UICollectionView, skeletonCellForItemAt indexPath: IndexPath) -> UICollectionViewCell?  // default: nil
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath)
 }
 ```
 
@@ -491,6 +507,33 @@ Sometimes you wanna hide some view when the animation starts, so there is a quic
 view.isHiddenWhenSkeletonIsActive = true  // This works only when isSkeletonable = true
 ```
 
+**Don't modify user interaction when the skeleton is active**
+
+
+By default, the user interaction is disabled for skeletonized items, but if you don't want to modify the user interaction indicator when skeleton is active, you can use the `isUserInteractionDisabledWhenSkeletonIsActive` property:
+
+```swift
+view.isUserInteractionDisabledWhenSkeletonIsActive = false  // The view will be active when the skeleton will be active.
+```
+
+**Delayed show skeleton**
+
+You can delay the presentation of the skeleton if the views update quickly.
+
+```swift
+func showSkeleton(usingColor: UIColor,
+                  animated: Bool,
+                  delay: TimeInterval,
+                  transition: SkeletonTransitionStyle)
+```
+
+```swift
+func showGradientSkeleton(usingGradient: SkeletonGradient,
+                          animated: Bool,
+                          delay: TimeInterval,
+                          transition: SkeletonTransitionStyle)
+```
+
 **Debug**
 
 To facilitate the debug tasks when something is not working fine. **`SkeletonView`** has some new tools.

SkeletonView.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "SkeletonView"
-  s.version      = "1.15.0"
+  s.version      = "1.18.0"
   s.summary      = "An elegant way to show users that something is happening and also prepare them to which contents he is waiting"
   s.description  = <<-DESC
   Today almost all apps have async processes, as API requests, long runing processes, etc. And while the processes are working, usually developers place a loading view to show users that something is going on.

SkeletonView.xcodeproj/project.pbxproj

@@ -619,6 +619,7 @@
 					52D6D97B1BEFF229002C0205 = {
 						CreatedOnToolsVersion = 7.1;
 						LastSwiftMigration = 1000;
+						ProvisioningStyle = Automatic;
 					};
 					F5F899F11FABA607002E8FDA = {
 						CreatedOnToolsVersion = 9.1;
@@ -1117,8 +1118,10 @@
 			buildSettings = {
 				APPLICATION_EXTENSION_API_ONLY = NO;
 				CLANG_ENABLE_MODULES = YES;
-				CODE_SIGN_IDENTITY = "iPhone Developer";
+				CODE_SIGN_IDENTITY = "Apple Development";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
+				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				DEFINES_MODULE = YES;
 				DEVELOPMENT_TEAM = "";
 				DYLIB_COMPATIBILITY_VERSION = 1;
@@ -1131,6 +1134,8 @@
 				ONLY_ACTIVE_ARCH = NO;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.SkeletonView.SkeletonView-iOS";
 				PRODUCT_NAME = SkeletonView;
+				PROVISIONING_PROFILE_SPECIFIER = "";
+				"PROVISIONING_PROFILE_SPECIFIER[sdk=macosx*]" = "";
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_VERSION = 5.0;
@@ -1142,8 +1147,10 @@
 			buildSettings = {
 				APPLICATION_EXTENSION_API_ONLY = NO;
 				CLANG_ENABLE_MODULES = YES;
-				CODE_SIGN_IDENTITY = "iPhone Developer";
+				CODE_SIGN_IDENTITY = "Apple Development";
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "";
+				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "Apple Development";
+				CODE_SIGN_STYLE = Automatic;
 				DEFINES_MODULE = YES;
 				DEVELOPMENT_TEAM = "";
 				DYLIB_COMPATIBILITY_VERSION = 1;
@@ -1155,6 +1162,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.SkeletonView.SkeletonView-iOS";
 				PRODUCT_NAME = SkeletonView;
+				PROVISIONING_PROFILE_SPECIFIER = "";
+				"PROVISIONING_PROFILE_SPECIFIER[sdk=macosx*]" = "";
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 				SWIFT_VERSION = 5.0;

Sources/Collections/CollectionSkeletonProtocol.swift

@@ -31,12 +31,16 @@ extension CollectionSkeleton where Self: UIScrollView {
     func removeDummyDataSource(reloadAfter: Bool) {}
 
     func disableUserInteraction() {
-        isUserInteractionEnabled = false
-        isScrollEnabled = false
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = false
+            isScrollEnabled = false
+        }
     }
     
     func enableUserInteraction() {
-        isUserInteractionEnabled = true
-        isScrollEnabled = true
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = true
+            isScrollEnabled = true
+        }
     }
 }

Sources/Collections/CollectionViews/SkeletonCollectionViewProtocols.swift

@@ -13,20 +13,28 @@ public protocol SkeletonCollectionViewDataSource: UICollectionViewDataSource {
     func collectionSkeletonView(_ skeletonView: UICollectionView, numberOfItemsInSection section: Int) -> Int
     func collectionSkeletonView(_ skeletonView: UICollectionView, cellIdentifierForItemAt indexPath: IndexPath) -> ReusableCellIdentifier
     func collectionSkeletonView(_ skeletonView: UICollectionView, supplementaryViewIdentifierOfKind: String, at indexPath: IndexPath) -> ReusableCellIdentifier?
+    func collectionSkeletonView(_ skeletonView: UICollectionView, skeletonCellForItemAt indexPath: IndexPath) -> UICollectionViewCell?
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath)
 }
 
 public extension SkeletonCollectionViewDataSource {
     func collectionSkeletonView(_ skeletonView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
-        return skeletonView.estimatedNumberOfRows
+        UICollectionView.automaticNumberOfSkeletonItems
     }
     
-    func collectionSkeletonView(_ skeletonView: UICollectionView,
-                                supplementaryViewIdentifierOfKind: String,
-                                at indexPath: IndexPath) -> ReusableCellIdentifier? {
-        return nil
+    func collectionSkeletonView(_ skeletonView: UICollectionView, supplementaryViewIdentifierOfKind: String, at indexPath: IndexPath) -> ReusableCellIdentifier? {
+        nil
     }
     
-    func numSections(in collectionSkeletonView: UICollectionView) -> Int { return 1 }
+    func numSections(in collectionSkeletonView: UICollectionView) -> Int {
+        1
+    }
+    
+    func collectionSkeletonView(_ skeletonView: UICollectionView, skeletonCellForItemAt indexPath: IndexPath) -> UICollectionViewCell? {
+        nil
+    }
+
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath) { }
 }
 
 public protocol SkeletonCollectionViewDelegate: UICollectionViewDelegate { }

Sources/Collections/CollectionViews/UICollectionView+CollectionSkeleton.swift

@@ -9,6 +9,8 @@
 import UIKit
  
 extension UICollectionView: CollectionSkeleton {
+    public static let automaticNumberOfSkeletonItems = -1
+
     var estimatedNumberOfRows: Int {
         guard let flowlayout = collectionViewLayout as? UICollectionViewFlowLayout else { return 0 }
         switch flowlayout.scrollDirection {

Sources/Collections/SkeletonCollectionDataSource.swift

@@ -32,12 +32,31 @@ extension SkeletonCollectionDataSource: UITableViewDataSource {
     }
     
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        originalTableViewDataSource?.collectionSkeletonView(tableView, numberOfRowsInSection: section) ?? 0
+        guard let originalTableViewDataSource = originalTableViewDataSource else {
+            return 0
+        }
+
+        let numberOfRows = originalTableViewDataSource.collectionSkeletonView(tableView, numberOfRowsInSection: section)
+
+        if numberOfRows == UITableView.automaticNumberOfSkeletonRows {
+            return tableView.estimatedNumberOfRows
+        } else {
+            return numberOfRows
+        }
     }
     
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
-        let cellIdentifier = originalTableViewDataSource?.collectionSkeletonView(tableView, cellIdentifierForRowAt: indexPath) ?? ""
-        let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath)
+        guard let cell = originalTableViewDataSource?.collectionSkeletonView(tableView, skeletonCellForRowAt: indexPath) else {
+            let cellIdentifier = originalTableViewDataSource?.collectionSkeletonView(tableView, cellIdentifierForRowAt: indexPath) ?? ""
+            let fakeCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath)
+
+            originalTableViewDataSource?.collectionSkeletonView(tableView, prepareCellForSkeleton: fakeCell, at: indexPath)
+            skeletonViewIfContainerSkeletonIsActive(container: tableView, view: fakeCell)
+            
+            return fakeCell
+        }
+
+        originalTableViewDataSource?.collectionSkeletonView(tableView, prepareCellForSkeleton: cell, at: indexPath)
         skeletonViewIfContainerSkeletonIsActive(container: tableView, view: cell)
         return cell
     }
@@ -50,12 +69,31 @@ extension SkeletonCollectionDataSource: UICollectionViewDataSource {
     }
     
     func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
-        originalCollectionViewDataSource?.collectionSkeletonView(collectionView, numberOfItemsInSection: section) ?? 0
+        guard let originalCollectionViewDataSource = originalCollectionViewDataSource else {
+            return 0
+        }
+
+        let numberOfItems = originalCollectionViewDataSource.collectionSkeletonView(collectionView, numberOfItemsInSection: section)
+
+        if numberOfItems == UICollectionView.automaticNumberOfSkeletonItems {
+            return collectionView.estimatedNumberOfRows
+        } else {
+            return numberOfItems
+        }
     }
     
     func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
-        let cellIdentifier = originalCollectionViewDataSource?.collectionSkeletonView(collectionView, cellIdentifierForItemAt: indexPath) ?? ""
-        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath)
+        guard let cell = originalCollectionViewDataSource?.collectionSkeletonView(collectionView, skeletonCellForItemAt: indexPath) else {
+            let cellIdentifier = originalCollectionViewDataSource?.collectionSkeletonView(collectionView, cellIdentifierForItemAt: indexPath) ?? ""
+            let fakeCell = collectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath)
+
+            originalCollectionViewDataSource?.collectionSkeletonView(collectionView, prepareCellForSkeleton: fakeCell, at: indexPath)
+            skeletonViewIfContainerSkeletonIsActive(container: collectionView, view: fakeCell)
+            
+            return fakeCell
+        }
+
+        originalCollectionViewDataSource?.collectionSkeletonView(collectionView, prepareCellForSkeleton: cell, at: indexPath)
         skeletonViewIfContainerSkeletonIsActive(container: collectionView, view: cell)
         return cell
     }

Sources/Collections/TableViews/SkeletonTableViewProtocols.swift

@@ -12,11 +12,13 @@ public protocol SkeletonTableViewDataSource: UITableViewDataSource {
     func numSections(in collectionSkeletonView: UITableView) -> Int
     func collectionSkeletonView(_ skeletonView: UITableView, numberOfRowsInSection section: Int) -> Int
     func collectionSkeletonView(_ skeletonView: UITableView, cellIdentifierForRowAt indexPath: IndexPath) -> ReusableCellIdentifier
+    func collectionSkeletonView(_ skeletonView: UITableView, skeletonCellForRowAt indexPath: IndexPath) -> UITableViewCell?
+    func collectionSkeletonView(_ skeletonView: UITableView, prepareCellForSkeleton cell: UITableViewCell, at indexPath: IndexPath)
 }
 
 public extension SkeletonTableViewDataSource {
     func collectionSkeletonView(_ skeletonView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        return skeletonView.estimatedNumberOfRows
+        return UITableView.automaticNumberOfSkeletonRows
     }
     
     func numSections(in collectionSkeletonView: UITableView) -> Int { return 1 }
@@ -27,6 +29,12 @@ public extension SkeletonTableViewDataSource {
     func collectionSkeletonView(_ skeletonView: UITableView, cellIdenfierForRowAt indexPath: IndexPath) -> ReusableCellIdentifier {
         return collectionSkeletonView(skeletonView, cellIdentifierForRowAt: indexPath)
     }
+    
+    func collectionSkeletonView(_ skeletonView: UITableView, skeletonCellForRowAt indexPath: IndexPath) -> UITableViewCell? {
+        nil
+    }
+
+    func collectionSkeletonView(_ skeletonView: UITableView, prepareCellForSkeleton cell: UITableViewCell, at indexPath: IndexPath) { }
 }
 
 public protocol SkeletonTableViewDelegate: UITableViewDelegate {

Sources/Collections/TableViews/UITableView+CollectionSkeleton.swift

@@ -11,6 +11,8 @@ import UIKit
 public typealias ReusableHeaderFooterIdentifier = String
 
 extension UITableView: CollectionSkeleton {
+    public static let automaticNumberOfSkeletonRows = -1
+
     var estimatedNumberOfRows: Int {
         return Int(ceil(frame.height / rowHeight))
     }

Sources/Extensions/UIView+Autolayout.swift

@@ -12,9 +12,17 @@ extension UIView {
         nonContentSizeLayoutConstraints.filter { $0.firstAttribute == NSLayoutConstraint.Attribute.height }
     }
     
+    var skeletonHeightConstraints: [NSLayoutConstraint] {
+        nonContentSizeLayoutConstraints.filter {
+            $0.firstAttribute == NSLayoutConstraint.Attribute.height
+                && $0.identifier?.contains("SkeletonView.Constraint.Height") ?? false
+        }
+    }
+    
     @discardableResult
     func setHeight(equalToConstant constant: CGFloat) -> NSLayoutConstraint {
         let heightConstraint = heightAnchor.constraint(equalToConstant: constant)
+        heightConstraint.identifier = "SkeletonView.Constraint.Height.\(constant)"
         NSLayoutConstraint.activate([heightConstraint])
         return heightConstraint
     }

Sources/Extensions/UIView+Extension.swift

@@ -16,6 +16,8 @@ enum ViewAssociatedKeys {
     static var buttonViewState = "buttonViewState"
     static var currentSkeletonConfig = "currentSkeletonConfig"
     static var skeletonCornerRadius = "skeletonCornerRadius"
+    static var disabledWhenSkeletonIsActive = "disabledWhenSkeletonIsActive"
+    static var delayedShowSkeletonWorkItem = "delayedShowSkeletonWorkItem"
 }
 // codebeat:enable[TOO_MANY_IVARS]
 
@@ -53,4 +55,9 @@ extension UIView {
     var isSuperviewAStackView: Bool {
         superview is UIStackView
     }
+    
+    var delayedShowSkeletonWorkItem: DispatchWorkItem? {
+        get { return ao_get(pkey: &ViewAssociatedKeys.delayedShowSkeletonWorkItem) as? DispatchWorkItem }
+        set { ao_setOptional(newValue, pkey: &ViewAssociatedKeys.delayedShowSkeletonWorkItem) }
+    }
 }

Sources/Extensions/UIView+IBInspectable.swift

@@ -14,6 +14,12 @@ public extension UIView {
         get { return hiddenWhenSkeletonIsActive }
         set { hiddenWhenSkeletonIsActive = newValue }
     }
+    
+    @IBInspectable
+    var isUserInteractionDisabledWhenSkeletonIsActive: Bool {
+        get { return disabledWhenSkeletonIsActive }
+        set { disabledWhenSkeletonIsActive = newValue }
+    }
 
     @IBInspectable
     var skeletonCornerRadius: Float {
@@ -34,6 +40,11 @@ public extension UIView {
         get { return ao_get(pkey: &ViewAssociatedKeys.hiddenWhenSkeletonIsActive) as? Bool ?? false }
         set { ao_set(newValue, pkey: &ViewAssociatedKeys.hiddenWhenSkeletonIsActive) }
     }
+    
+    private var disabledWhenSkeletonIsActive: Bool {
+        get { return ao_get(pkey: &ViewAssociatedKeys.disabledWhenSkeletonIsActive) as? Bool ?? true }
+        set { ao_set(newValue, pkey: &ViewAssociatedKeys.disabledWhenSkeletonIsActive) }
+    }
 
     private var skeletonableCornerRadius: Float {
         get { return ao_get(pkey: &ViewAssociatedKeys.skeletonCornerRadius) as? Float ?? 0.0 }

Sources/Helpers/PrepareForSkeletonProtocol.swift

@@ -10,7 +10,10 @@ import UIKit
 
 extension UIView {
     @objc func prepareViewForSkeleton() {
-        isUserInteractionEnabled = false
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = false
+        }
+        
         startTransition { [weak self] in
             self?.backgroundColor = .clear
         }
@@ -19,7 +22,6 @@ extension UIView {
 
 extension UILabel {
     var desiredHeightBasedOnNumberOfLines: CGFloat {
-        let lineHeight = constraintHeight ?? SkeletonAppearance.default.multilineHeight
         let spaceNeededForEachLine = lineHeight * CGFloat(numberOfLines)
         let spaceNeededForSpaces = skeletonLineSpacing * CGFloat(numberOfLines - 1)
         let padding = paddingInsets.top + paddingInsets.bottom
@@ -44,10 +46,7 @@ extension UILabel {
         }
     }
     
-    func restoreBackupHeightConstraints() {
-        heightConstraints.forEach {
-            removeConstraint($0)
-        }
+    func restoreBackupHeightConstraintsIfNeeded() {
         guard !backupHeightConstraints.isEmpty else { return }
         NSLayoutConstraint.activate(backupHeightConstraints)
         backupHeightConstraints.removeAll()
@@ -55,7 +54,11 @@ extension UILabel {
     
     override func prepareViewForSkeleton() {
         backgroundColor = .clear
-        isUserInteractionEnabled = false
+        
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = false
+        }
+        
         resignFirstResponder()
         startTransition { [weak self] in
             self?.updateHeightConstraintsIfNeeded()
@@ -67,7 +70,11 @@ extension UILabel {
 extension UITextView {
     override func prepareViewForSkeleton() {
         backgroundColor = .clear
-        isUserInteractionEnabled = false
+        
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = false
+        }
+        
         resignFirstResponder()
         startTransition { [weak self] in
             self?.textColor = .clear
@@ -90,7 +97,11 @@ extension UITextField {
 extension UIImageView {
     override func prepareViewForSkeleton() {
         backgroundColor = .clear
-        isUserInteractionEnabled = false
+        
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = false
+        }
+        
         startTransition { [weak self] in
             self?.image = nil
         }
@@ -100,7 +111,11 @@ extension UIImageView {
 extension UIButton {
     override func prepareViewForSkeleton() {
         backgroundColor = .clear
-        isUserInteractionEnabled = false
+        
+        if isUserInteractionDisabledWhenSkeletonIsActive {
+            isUserInteractionEnabled = false
+        }
+        
         startTransition { [weak self] in
             self?.setTitle(nil, for: .normal)
         }

Sources/Multilines/ContainsMultilineText.swift

@@ -11,8 +11,8 @@ enum MultilineAssociatedKeys {
 }
 
 protocol ContainsMultilineText {
-    var constraintHeight: CGFloat? { get }
-    var numLines: Int { get }
+    var lineHeight: CGFloat { get }
+    var numberOfLines: Int { get }
     var lastLineFillingPercent: Int { get }
     var multilineCornerRadius: Int { get }
     var multilineSpacing: CGFloat { get }

Sources/Multilines/UILabel+Multiline.swift

@@ -27,15 +27,11 @@ public extension UILabel {
     }
 }
 
-extension UILabel: ContainsMultilineText {
-    var constraintHeight: CGFloat? {
-        backupHeightConstraints.first?.constant
+extension UILabel: ContainsMultilineText {    
+    var lineHeight: CGFloat {
+        backupHeightConstraints.first?.constant ?? SkeletonAppearance.default.multilineHeight
     }
-
-    var numLines: Int {
-        return numberOfLines
-    }
-
+    
     var lastLineFillingPercent: Int {
         get { return ao_get(pkey: &MultilineAssociatedKeys.lastLineFillingPercent) as? Int ?? SkeletonAppearance.default.multilineLastLineFillPercent }
         set { ao_set(newValue, pkey: &MultilineAssociatedKeys.lastLineFillingPercent) }

Sources/Multilines/UITextView+Multiline.swift

@@ -28,11 +28,19 @@ public extension UITextView {
 }
 
 extension UITextView: ContainsMultilineText {
-    var constraintHeight: CGFloat? {
-        heightConstraints.first?.constant
+    var lineHeight: CGFloat {
+        if let fontLineHeight = font?.lineHeight {
+            if let heightConstraints = heightConstraints.first?.constant {
+                return (fontLineHeight > heightConstraints) ? heightConstraints : fontLineHeight
+            }
+            
+            return fontLineHeight
+        }
+        
+        return SkeletonAppearance.default.multilineHeight
     }
     
-    var numLines: Int {
+    var numberOfLines: Int {
         -1
     }
 	

Sources/Recoverable/Recoverable.swift

@@ -27,12 +27,17 @@ extension UIView: Recoverable {
         guard let storedViewState = viewState else { return }
         
         startTransition { [weak self] in
-            self?.layer.cornerRadius = storedViewState.cornerRadius
-            self?.layer.masksToBounds = storedViewState.clipToBounds
-            self?.isUserInteractionEnabled = storedViewState.isUserInteractionsEnabled
+            guard let self = self else { return }
             
-            if self?.backgroundColor == .clear || forced {
-                self?.backgroundColor = storedViewState.backgroundColor
+            self.layer.cornerRadius = storedViewState.cornerRadius
+            self.layer.masksToBounds = storedViewState.clipToBounds
+            
+            if self.isUserInteractionDisabledWhenSkeletonIsActive {
+                self.isUserInteractionEnabled = storedViewState.isUserInteractionsEnabled
+            }
+            
+            if self.backgroundColor == .clear || forced {
+                self.backgroundColor = storedViewState.backgroundColor
             }
         }
     }
@@ -52,12 +57,16 @@ extension UILabel {
     override func recoverViewState(forced: Bool) {
         super.recoverViewState(forced: forced)
         startTransition { [weak self] in
-            guard let storedLabelState = self?.labelState else { return }
+            guard let self = self,
+                  let storedLabelState = self.labelState else {
+                return
+            }
             
-            self?.restoreBackupHeightConstraints()
+            NSLayoutConstraint.deactivate(self.skeletonHeightConstraints)
+            self.restoreBackupHeightConstraintsIfNeeded()
             
-            if self?.textColor == .clear || forced {
-                self?.textColor = storedLabelState.textColor
+            if self.textColor == .clear || forced {
+                self.textColor = storedLabelState.textColor
             }
         }
     }

Sources/SkeletonLayer.swift

@@ -83,9 +83,8 @@ struct SkeletonLayer {
     /// If there is more than one line, or custom preferences have been set for a single line, draw custom layers
     func addTextLinesIfNeeded() {
         guard let textView = holderAsTextView else { return }
-        let lineHeight = textView.constraintHeight ?? SkeletonAppearance.default.multilineHeight
-        let config = SkeletonMultilinesLayerConfig(lines: textView.numLines,
-                                                   lineHeight: lineHeight,
+        let config = SkeletonMultilinesLayerConfig(lines: textView.numberOfLines,
+                                                   lineHeight: textView.lineHeight,
                                                    type: type,
                                                    lastLineFillPercent: textView.lastLineFillingPercent,
                                                    multilineCornerRadius: textView.multilineCornerRadius,
@@ -98,9 +97,8 @@ struct SkeletonLayer {
     
     func updateLinesIfNeeded() {
         guard let textView = holderAsTextView else { return }
-        let lineHeight = textView.constraintHeight ?? SkeletonAppearance.default.multilineHeight
-        let config = SkeletonMultilinesLayerConfig(lines: textView.numLines,
-                                                   lineHeight: lineHeight,
+        let config = SkeletonMultilinesLayerConfig(lines: textView.numberOfLines,
+                                                   lineHeight: textView.lineHeight,
                                                    type: type,
                                                    lastLineFillPercent: textView.lastLineFillingPercent,
                                                    multilineCornerRadius: textView.multilineCornerRadius,
@@ -113,7 +111,7 @@ struct SkeletonLayer {
     
     var holderAsTextView: ContainsMultilineText? {
         guard let textView = holder as? ContainsMultilineText,
-            (textView.numLines == -1 || textView.numLines == 0 || textView.numLines > 1 || textView.numLines == 1 && !SkeletonAppearance.default.renderSingleLineAsView) else {
+            (textView.numberOfLines == -1 || textView.numberOfLines == 0 || textView.numberOfLines > 1 || textView.numberOfLines == 1 && !SkeletonAppearance.default.renderSingleLineAsView) else {
                 return nil
         }
         return textView

Sources/SkeletonView.swift

@@ -9,20 +9,63 @@ public extension UIView {
     ///   - color: The color of the skeleton. Defaults to `SkeletonAppearance.default.tintColor`.
     ///   - transition: The style of the transition when the skeleton appears. Defaults to `.crossDissolve(0.25)`.
     func showSkeleton(usingColor color: UIColor = SkeletonAppearance.default.tintColor, transition: SkeletonTransitionStyle = .crossDissolve(0.25)) {
+        delayedShowSkeletonWorkItem?.cancel()
         let config = SkeletonConfig(type: .solid, colors: [color], transition: transition)
         showSkeleton(skeletonConfig: config)
     }
     
+    /// Shows the skeleton using the view that calls this method as root view.
+    ///
+    /// - Parameters:
+    ///   - color: The color of the skeleton. Defaults to `SkeletonAppearance.default.tintColor`.
+    ///   - animated: If the skeleton is animated or not. Defaults to `true`.
+    ///   - delay: The amount of time (measured in seconds) to wait before show the skeleton.
+    ///   - transition: The style of the transition when the skeleton appears. Defaults to `.crossDissolve(0.25)`.
+    func showSkeleton(usingColor color: UIColor = SkeletonAppearance.default.tintColor, animated: Bool = true, delay: TimeInterval, transition: SkeletonTransitionStyle = .crossDissolve(0.25)) {
+        delayedShowSkeletonWorkItem?.cancel()
+        
+        delayedShowSkeletonWorkItem = DispatchWorkItem { [weak self] in
+            let config = SkeletonConfig(type: .solid, colors: [color], animated: animated, transition: transition)
+            self?.showSkeleton(skeletonConfig: config)
+        }
+        
+        DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: delayedShowSkeletonWorkItem!)
+    }
+    
     /// Shows the gradient skeleton without animation using the view that calls this method as root view.
     ///
     /// - Parameters:
     ///   - gradient: The gradient of the skeleton. Defaults to `SkeletonAppearance.default.gradient`.
     ///   - transition: The style of the transition when the skeleton appears. Defaults to `.crossDissolve(0.25)`.
     func showGradientSkeleton(usingGradient gradient: SkeletonGradient = SkeletonAppearance.default.gradient, transition: SkeletonTransitionStyle = .crossDissolve(0.25)) {
+        delayedShowSkeletonWorkItem?.cancel()
         let config = SkeletonConfig(type: .gradient, colors: gradient.colors, transition: transition)
         showSkeleton(skeletonConfig: config)
     }
     
+    /// Shows the gradient skeleton using the view that calls this method as root view.
+    ///
+    /// - Parameters:
+    ///   - gradient: The gradient of the skeleton. Defaults to `SkeletonAppearance.default.gradient`.
+    ///   - animated: If the skeleton is animated or not. Defaults to `true`.
+    ///   - delay: The amount of time (measured in seconds) to wait before show the skeleton.
+    ///   - transition: The style of the transition when the skeleton appears. Defaults to `.crossDissolve(0.25)`.
+    func showGradientSkeleton(
+        usingGradient gradient: SkeletonGradient = SkeletonAppearance.default.gradient,
+        animated: Bool = true,
+        delay: TimeInterval,
+        transition: SkeletonTransitionStyle = .crossDissolve(0.25)
+    ) {
+        delayedShowSkeletonWorkItem?.cancel()
+        
+        delayedShowSkeletonWorkItem = DispatchWorkItem { [weak self] in
+            let config = SkeletonConfig(type: .gradient, colors: gradient.colors, animated: animated, transition: transition)
+            self?.showSkeleton(skeletonConfig: config)
+        }
+        
+        DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: delayedShowSkeletonWorkItem!)
+    }
+    
     /// Shows the animated skeleton using the view that calls this method as root view.
     ///
     /// If animation is nil, sliding animation will be used, with direction left to right.
@@ -32,6 +75,7 @@ public extension UIView {
     ///   - animation: The animation of the skeleton. Defaults to `nil`.
     ///   - transition: The style of the transition when the skeleton appears. Defaults to `.crossDissolve(0.25)`.
     func showAnimatedSkeleton(usingColor color: UIColor = SkeletonAppearance.default.tintColor, animation: SkeletonLayerAnimation? = nil, transition: SkeletonTransitionStyle = .crossDissolve(0.25)) {
+        delayedShowSkeletonWorkItem?.cancel()
         let config = SkeletonConfig(type: .solid, colors: [color], animated: true, animation: animation, transition: transition)
         showSkeleton(skeletonConfig: config)
     }
@@ -45,6 +89,7 @@ public extension UIView {
     ///   - animation: The animation of the skeleton. Defaults to `nil`.
     ///   - transition: The style of the transition when the skeleton appears. Defaults to `.crossDissolve(0.25)`.
     func showAnimatedGradientSkeleton(usingGradient gradient: SkeletonGradient = SkeletonAppearance.default.gradient, animation: SkeletonLayerAnimation? = nil, transition: SkeletonTransitionStyle = .crossDissolve(0.25)) {
+        delayedShowSkeletonWorkItem?.cancel()
         let config = SkeletonConfig(type: .gradient, colors: gradient.colors, animated: true, animation: animation, transition: transition)
         showSkeleton(skeletonConfig: config)
     }
@@ -75,6 +120,7 @@ public extension UIView {
     }
     
     func hideSkeleton(reloadDataAfter reload: Bool = true, transition: SkeletonTransitionStyle = .crossDissolve(0.25)) {
+        delayedShowSkeletonWorkItem?.cancel()
         flowDelegate?.willBeginHidingSkeletons(rootView: self)
         recursiveHideSkeleton(reloadDataAfter: reload, transition: transition, root: self)
     }
@@ -277,14 +323,22 @@ extension UIView {
             .setHolder(self)
             .build()
             else { return }
-
+        
         self.skeletonLayer = skeletonLayer
-        layer.insertSublayer(skeletonLayer,
-                             at: UInt32.max,
-                             transition: config.transition) { [weak self] in
-                                if config.animated {
-                                    self?.startSkeletonAnimation(config.animation)
-                                }
+        layer.insertSkeletonLayer(
+            skeletonLayer,
+            atIndex: UInt32.max,
+            transition: config.transition
+        ) { [weak self] in
+            guard let self = self else { return }
+            
+            /// Workaround to fix the problem when inserting a sublayer and
+            /// the content offset is modified by the system.
+            (self as? UITextView)?.setContentOffset(.zero, animated: false)
+            
+            if config.animated {
+                self.startSkeletonAnimation(config.animation)
+            }
         }
         status = .on
     }

Sources/SubviewsSkeletonables.swift

@@ -18,7 +18,7 @@ extension UITableView {
 		// Some developer trying to call `view.showAnimatedSkeleton()`
 		// when the request or data is loading which sometimes happens before the ViewDidAppear
 		guard window != nil else { return [] }
-		return visibleCells + visibleSectionHeaders + visibleSectionFooters
+        return subviews
     }
 }
 

Sources/Transitions/UIView+Transitions.swift

@@ -3,13 +3,13 @@
 import UIKit
 
 extension CALayer {
-    func insertSublayer(_ layer: SkeletonLayer, at idx: UInt32, transition: SkeletonTransitionStyle, completion: (() -> Void)? = nil) {
-        insertSublayer(layer.contentLayer, at: idx)
+    func insertSkeletonLayer(_ sublayer: SkeletonLayer, atIndex index: UInt32, transition: SkeletonTransitionStyle, completion: (() -> Void)? = nil) {
+        insertSublayer(sublayer.contentLayer, at: index)
         switch transition {
         case .none:
             completion?()
         case .crossDissolve(let duration):
-			layer.contentLayer.setOpacity(from: 0, to: 1, duration: duration, completion: completion)
+            sublayer.contentLayer.setOpacity(from: 0, to: 1, duration: duration, completion: completion)
         }
     }
 }