Delay the presentation of the skeletons (#411)

README.md

@@ -504,6 +504,24 @@ By default, the user interaction is disabled for skeletonized items, but if you
 view.isUserInteractionDisabledWhenSkeletonIsActive = false  // The view will be active when the skeleton will be active.
 ```
 
+**Delayed show skeleton**
+
+You can delay the showIf the views are updated quickly you canAn optional delay applied to the transition, like the transition duration.
+
+```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.

Sources/Extensions/UIView+Extension.swift

@@ -17,6 +17,7 @@ enum ViewAssociatedKeys {
     static var currentSkeletonConfig = "currentSkeletonConfig"
     static var skeletonCornerRadius = "skeletonCornerRadius"
     static var disabledWhenSkeletonIsActive = "disabledWhenSkeletonIsActive"
+    static var delayedShowSkeletonWorkItem = "delayedShowSkeletonWorkItem"
 }
 // codebeat:enable[TOO_MANY_IVARS]
 
@@ -54,4 +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/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)
     }