Add dragging handler (#8)

FluidGroup · Feb 27, 2024 · 3e460c1 · 3e460c1
1 parent 6a6d1cb
commit 3e460c1
Show file tree

Hide file tree

Showing 2 changed files with 58 additions and 17 deletions.
diff --git a/Development/Development/ContentView.swift b/Development/Development/ContentView.swift
@@ -25,10 +25,16 @@ struct ShortBar: View {
 private struct DemoContent: View {
 
   @State var value: Double = 0
+  @State var isDragging: Bool = false
 
   var body: some View {
     VStack {
-      Text("\(value)")
+      HStack {
+        Circle()
+          .frame(width: 8, height: 8)
+          .foregroundStyle(isDragging ? Color.green : Color.gray)
+        Text("\(value)").monospacedDigit()
+      }
       SwiftUIPrecisionLevelSlider(
         value: $value,
         haptics: .init(trigger: { value in
@@ -38,7 +44,10 @@ private struct DemoContent: View {
           return nil
         }),
         range: .init(range: -45...45, transform: { $0.rounded(.toNearestOrEven) }),
-        centerLevel: { value in
+        draggingHandler: { value in
+          isDragging = value
+        },
+        centerLevel: { value, isDragging in
           HStack {
             Spacer()
             VStack {
@@ -50,7 +59,7 @@ private struct DemoContent: View {
           }
           .foregroundStyle(.tint)
         },
-        track: { value in
+        track: { value, isDragging in
           VStack {
             HStack {
               Spacer()

diff --git a/Sources/PrecisionLevelSlider/PrecisionLevelSlider.swift b/Sources/PrecisionLevelSlider/PrecisionLevelSlider.swift
@@ -58,29 +58,31 @@ open class PrecisionLevelSlider: UIControl {
 
   private final class Proxy: ObservableObject {
     @Published var value: Double = 0
+    @Published var isDragging: Bool = false
   }
 
   private struct Provider<Content: View>: View {
 
     @ObservedObject var proxy: Proxy
 
-    private let content: (Double) -> Content
+    private let content: (Double, Bool) -> Content
 
     init(
       proxy: Proxy,
-      @ViewBuilder content: @escaping (Double) -> Content
+      @ViewBuilder content: @escaping (Double, Bool) -> Content
     ) {
       self.content = content
       self.proxy = proxy
     }
 
     var body: some View {
-      content(proxy.value)
+      content(proxy.value, proxy.isDragging)
     }
 
   }
 
-  var onChangeValue: (Double) -> Void = { _ in }
+  public var onChangeValue: (Double) -> Void = { _ in }
+  public var onChangeDragState: (Bool) -> Void = { _ in }
 
   private let haptics: Haptics?
 
@@ -133,6 +135,15 @@ open class PrecisionLevelSlider: UIControl {
 
   open var isContinuous: Bool = true
 
+  private var isDragging: Bool = false {
+    didSet {
+      if oldValue != isDragging {
+        proxy?.isDragging = isDragging
+      }
+      onChangeDragState(isDragging)
+    }
+  }
+
   private let scrollView = UIScrollView()
   private let contentView = UIView()
 
@@ -157,8 +168,8 @@ open class PrecisionLevelSlider: UIControl {
   public convenience init(
     range: ValueRange,
     haptics: Haptics?,
-    @ViewBuilder centerLevel: @escaping (Double) -> some View,
-    @ViewBuilder track: @escaping (Double) -> some View
+    @ViewBuilder centerLevel: @escaping (Double, Bool) -> some View,
+    @ViewBuilder track: @escaping (Double, Bool) -> some View
   ) {
 
     let proxy = Proxy()
@@ -168,12 +179,12 @@ open class PrecisionLevelSlider: UIControl {
       haptics: haptics,
       centerLevelView: SwiftUIHostingView(content: {
         Provider(proxy: proxy) {
-          centerLevel($0)
+          centerLevel($0, $1)
         }
       }),
       trackView: SwiftUIHostingView(content: {
         Provider(proxy: proxy) {
-          track($0)
+          track($0, $1)
         }
       })
     )
@@ -307,8 +318,16 @@ extension PrecisionLevelSlider: UIScrollViewDelegate {
     }
   }
 
+  public func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
+    isDragging = true
+  }
+
   public func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+
+    isDragging = false
+
     if isContinuous == false {
+
       let oldValue = value
       value = offsetToValue()
       if oldValue != value {
@@ -318,9 +337,14 @@ extension PrecisionLevelSlider: UIScrollViewDelegate {
     }
   }
 
-  public func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool)
-  {
+  public func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
+
+    if decelerate == false {
+      isDragging = false
+    }
+
     if decelerate == false && isContinuous == false {
+
       let oldValue = value
       value = offsetToValue()
       if oldValue != value {
@@ -363,21 +387,24 @@ public struct SwiftUIPrecisionLevelSlider<CenterLevel: View, Track: View>: UIVie
 
   @Binding var value: Double
 
-  private let centerLevel: (Double) -> CenterLevel
-  private let track: (Double) -> Track
+  private let centerLevel: (Double, Bool) -> CenterLevel
+  private let track: (Double, Bool) -> Track
   private let range: PrecisionLevelSlider.ValueRange
   private let haptics: PrecisionLevelSlider.Haptics?
+  private let draggingHandler: (Bool) -> Void
 
   public init(
     value: Binding<Double>,
     haptics: PrecisionLevelSlider.Haptics?,
     range: PrecisionLevelSlider.ValueRange,
-    @ViewBuilder centerLevel: @escaping (Double) -> CenterLevel,
-    @ViewBuilder track: @escaping (Double) -> Track
+    draggingHandler: @escaping (Bool) -> Void = { _ in },
+    @ViewBuilder centerLevel: @escaping (Double, Bool) -> CenterLevel,
+    @ViewBuilder track: @escaping (Double, Bool) -> Track
   ) {
     self._value = value
     self.haptics = haptics
     self.centerLevel = centerLevel
+    self.draggingHandler = draggingHandler
     self.track = track
     self.range = range
   }
@@ -396,6 +423,11 @@ public struct SwiftUIPrecisionLevelSlider<CenterLevel: View, Track: View>: UIVie
         self.value = value
       }
     }
+
+    view.onChangeDragState = { value in
+      self.draggingHandler(value)
+    }
+
     return view
   }