auto rotate wheel when tapping icon

app/src/main/java/sh/sar/basedbank/ui/home/CircularNavFragment.kt

@@ -23,6 +23,8 @@ import kotlin.math.*
 
 class CircularNavFragment : Fragment() {
 
+    private var wheelView: CircularWheelView? = null
+
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
@@ -47,9 +49,10 @@ class CircularNavFragment : Fragment() {
                 android.widget.LinearLayout.LayoutParams.MATCH_PARENT, 0, 1f
             )
         }
-        val wheelView = CircularWheelView(ctx).apply {
+        val prefs = ctx.getSharedPreferences("prefs", Context.MODE_PRIVATE)
+        wheelView = CircularWheelView(ctx).apply {
             layoutParams = FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT)
-            val prefs = ctx.getSharedPreferences("prefs", Context.MODE_PRIVATE)
+            wheelAngle = prefs.getFloat("circular_wheel_angle", 0f)
             val savedSlots = NavCustomization.getCircularSlots(prefs).map { id ->
                 val def = NavCustomization.ALL_SWAPPABLE.find { it.id == id }!!
                 CircularWheelView.WheelItem(def.id, def.iconRes, ctx.getString(def.titleRes))
@@ -112,6 +115,10 @@ class CircularNavFragment : Fragment() {
 
     override fun onPause() {
         super.onPause()
+        wheelView?.let { wv ->
+            requireContext().getSharedPreferences("prefs", Context.MODE_PRIVATE)
+                .edit().putFloat("circular_wheel_angle", wv.wheelAngle).apply()
+        }
         val toolbar = requireActivity().findViewById<com.google.android.material.appbar.MaterialToolbar>(R.id.toolbar)
         toolbar.findViewWithTag<android.view.View>("wheel_title")?.let { toolbar.removeView(it) }
         requireActivity().invalidateOptionsMenu()
@@ -181,7 +188,7 @@ class CircularWheelView @JvmOverloads constructor(
 
     // ---- touch & fling ----------------------------------------------------
 
-    private var wheelAngle    = 0f
+    var wheelAngle    = 0f
     private var isDragging    = false
     private var snapAnimator: ValueAnimator? = null
 
@@ -358,7 +365,7 @@ class CircularWheelView @JvmOverloads constructor(
                         dist <= innerRadius -> onCenterClick?.invoke()
                         dist <= outerRadius -> {
                             val idx = segmentAt(event.x, event.y)
-                            if (idx in items.indices) onItemClick?.invoke(items[idx].navId)
+                            if (idx in items.indices) animateToSixOClock(idx) { onItemClick?.invoke(items[idx].navId) }
                         }
                     }
                 } else {
@@ -423,6 +430,30 @@ class CircularWheelView @JvmOverloads constructor(
         return (a / (360f / items.size)).toInt() % items.size
     }
 
+    private fun animateToSixOClock(index: Int, onDone: () -> Unit) {
+        val segDeg = 360f / items.size.coerceAtLeast(1)
+        val midDeg = index * segDeg + segDeg / 2f
+        // delta needed so this segment's midpoint lands at 90° (6 o'clock in math coords)
+        var delta = (90f - midDeg) - wheelAngle
+        // normalise to shortest path [-180, 180]
+        delta = ((delta % 360f) + 360f) % 360f
+        if (delta > 180f) delta -= 360f
+        val endAngle = wheelAngle + delta
+
+        snapAnimator?.cancel()
+        snapAnimator = ValueAnimator.ofFloat(wheelAngle, endAngle).apply {
+            duration = 350
+            interpolator = DecelerateInterpolator()
+            addUpdateListener { wheelAngle = it.animatedValue as Float; invalidate() }
+            addListener(object : AnimatorListenerAdapter() {
+                private var cancelled = false
+                override fun onAnimationCancel(a: Animator) { cancelled = true }
+                override fun onAnimationEnd(a: Animator) { if (!cancelled) onDone() }
+            })
+            start()
+        }
+    }
+
     private fun snapToNearest() {
         val segDeg = 360f / items.size.coerceAtLeast(1)
         val target = (wheelAngle / segDeg).roundToInt() * segDeg