refactor: updatePositions timing

Author: tomosaaan

Example/Example/ContentView.swift

@@ -17,7 +17,8 @@ struct ContentView: View {
             id: \.x,
             selectedData: $selectedData
         )
-        .frame(height: 300, alignment: .bottom)
+        .hiddenChart(true)
+//        .frame(height: 300, alignment: .bottom)
 //        .hiddenChart(true)
 //        .minCount(3)
 //        .graph(width: .ratio(0.8), height: .fixed(50))

Sources/GraphRangeSlider/GraphRangeSlider.swift

@@ -28,14 +28,22 @@ public struct GraphRangeSlider<Data, ID>: View where Data: RandomAccessCollectio
     public var body: some View {
         Group {
             if isHiddenChart {
-                if !positions.isEmpty {
-                    Slider(
-                        positions: positions,
-                        onEnded: { builder.onEnded.call(selectedData) },
-                        leftCurrentIndex: $leftCurrentIndex,
-                        rightCurrentIndex: $rightCurrentIndex
-                    )
-                    .frame(height: toggleRadius * 2)
+                Group {
+                    if !positions.isEmpty {
+                        Slider(
+                            positions: positions,
+                            onEnded: { builder.onEnded.call(selectedData) },
+                            leftCurrentIndex: $leftCurrentIndex,
+                            rightCurrentIndex: $rightCurrentIndex
+                        )
+                        .frame(height: toggleRadius * 2)
+                    }
+                }
+                .onAppear {
+                    if positions.isEmpty {
+                        updatePositions()
+                        updateIndices()
+                    }
                 }
             } else {
                 Chart(data, id: id) { data in