fix: 滚轮选择器仅在滚动停止后触发选中变更和触觉反馈

快速滑动时不再每帧更新 selectedIndex，改为等滚动停止后
计算最终中心项再触发回调，消除来回抽搐问题。

core/src/main/kotlin/plus/rua/project/ui/WheelPicker.kt

@@ -1,6 +1,7 @@
 package plus.rua.project.ui
 
-import android.os.Build
+import android.view.HapticFeedbackConstants
+import android.view.View
 import androidx.compose.foundation.gestures.snapping.SnapLayoutInfoProvider
 import androidx.compose.foundation.gestures.snapping.rememberSnapFlingBehavior
 import androidx.compose.foundation.layout.Box
@@ -16,32 +17,31 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalView
-import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
-import kotlinx.coroutines.launch
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.filter
 import kotlin.math.abs
-import kotlin.math.roundToInt
 
 private val ItemHeight = 48.dp
 private const val VisibleItemCount = 5
 private val WheelHeight = ItemHeight * VisibleItemCount
+private const val PaddingItems = VisibleItemCount / 2
 
 /**
  * 通用滚轮选择器，支持惯性吸附和触觉反馈。
  *
+ * 滚动停止后才触发选中变更和触觉反馈，避免快速滑动时抖动。
+ *
  * @param items 显示的项目列表
  * @param selectedIndex 当前选中项索引
- * @param onSelectedChange 选中项变化回调
+ * @param onSelectedChange 选中项变化回调（仅在滚动停止后触发）
  * @param modifier 外部布局修饰符
- * @param itemContent 单个项目渲染，[isSelected] 为 true 表示中心选中项
  */
 @Composable
 fun WheelPicker(
@@ -49,65 +49,41 @@ fun WheelPicker(
     selectedIndex: Int,
     onSelectedChange: (Int) -> Unit,
     modifier: Modifier = Modifier,
-    itemContent: @Composable (index: Int, item: String, isSelected: Boolean) -> Unit = { _, item, isSelected ->
-        Text(
-            text = item,
-            color = if (isSelected) MaterialTheme.colorScheme.onSurface
-            else MaterialTheme.colorScheme.onSurface.copy(alpha = 0.4f),
-            fontSize = if (isSelected) 20.sp else 16.sp,
-            fontWeight = if (isSelected) FontWeight.Bold else FontWeight.Normal,
-            style = LocalTextStyle.current
-        )
-    }
 ) {
-    val paddingItems = VisibleItemCount / 2
-    val totalItems = items.size + paddingItems * 2
     val listState = rememberLazyListState(
-        initialFirstVisibleItemIndex = (selectedIndex - paddingItems).coerceAtLeast(0)
+        initialFirstVisibleItemIndex = (selectedIndex - PaddingItems).coerceAtLeast(0)
     )
-    val coroutineScope = rememberCoroutineScope()
     val view = LocalView.current
 
-    fun centerForLayoutIndex(layoutIndex: Int): Int = layoutIndex - paddingItems
-
-    fun layoutIndexForCenter(center: Int): Int = center + paddingItems
-
-    // 检测中心选中项变化 → 触觉反馈
-    val currentCenter by remember {
+    // 视觉中心项（实时，仅用于渲染高亮）
+    val visualCenter by remember {
         derivedStateOf {
             val viewportCenter = listState.layoutInfo.viewportSize.height / 2f
             listState.layoutInfo.visibleItemsInfo.minByOrNull {
                 abs(it.offset + it.size / 2f - viewportCenter)
-            }?.index?.let { centerForLayoutIndex(it) } ?: -1
-        }
-    }
-
-    LaunchedEffect(currentCenter) {
-        if (currentCenter in items.indices && currentCenter != selectedIndex) {
-            onSelectedChange(currentCenter)
-            performHapticFeedback(view)
+            }?.index?.let { it - PaddingItems } ?: selectedIndex
         }
     }
 
     // 初始滚动到选中项
     LaunchedEffect(selectedIndex) {
-        val target = layoutIndexForCenter(selectedIndex)
-        if (centerForLayoutIndex(listState.firstVisibleItemIndex) != selectedIndex) {
-            listState.scrollToItem((target - paddingItems).coerceAtLeast(0))
+        val target = (selectedIndex - PaddingItems).coerceAtLeast(0)
+        if (listState.firstVisibleItemIndex != target) {
+            listState.scrollToItem(target)
         }
     }
 
-    // 滚动停止后吸附到最近项
+    // 滚动停止后：计算最终中心项 → 触发选中变更 + 触觉反馈
     LaunchedEffect(listState) {
-        snapshotFlow { listState.isScrollInProgress }
-            .collect { scrolling ->
+        var lastSettled = selectedIndex
+        snapshotFlow { listState.isScrollInProgress to listState.layoutInfo}
+            .collect { (scrolling, _) ->
                 if (!scrolling) {
-                    val target = layoutIndexForCenter(currentCenter.coerceIn(0, items.lastIndex))
-                    val current = listState.firstVisibleItemIndex + paddingItems
-                    if (target != current) {
-                        coroutineScope.launch {
-                            listState.animateScrollToItem((target - paddingItems).coerceAtLeast(0))
-                        }
+                    val center = visualCenter.coerceIn(0, items.lastIndex)
+                    if (center != lastSettled) {
+                        lastSettled = center
+                        onSelectedChange(center)
+                        view.performHapticFeedback(HapticFeedbackConstants.CLOCK_TICK)
                     }
                 }
             }
@@ -124,8 +100,8 @@ fun WheelPicker(
         horizontalAlignment = Alignment.CenterHorizontally,
         userScrollEnabled = true
     ) {
-        items(totalItems) { layoutIndex ->
-            val centerIndex = centerForLayoutIndex(layoutIndex)
+        items(items.size + PaddingItems * 2) { layoutIndex ->
+            val centerIndex = layoutIndex - PaddingItems
             val isValid = centerIndex in items.indices
             Box(
                 modifier = Modifier
@@ -134,18 +110,17 @@ fun WheelPicker(
                 contentAlignment = Alignment.Center
             ) {
                 if (isValid) {
-                    itemContent(centerIndex, items[centerIndex], centerIndex == currentCenter)
+                    val isSelected = centerIndex == visualCenter
+                    Text(
+                        text = items[centerIndex],
+                        color = if (isSelected) MaterialTheme.colorScheme.onSurface
+                        else MaterialTheme.colorScheme.onSurface.copy(alpha = 0.4f),
+                        fontSize = if (isSelected) 20.sp else 16.sp,
+                        fontWeight = if (isSelected) FontWeight.Bold else FontWeight.Normal,
+                        style = LocalTextStyle.current
+                    )
                 }
             }
         }
     }
 }
-
-private fun performHapticFeedback(view: android.view.View) {
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O_MR1) {
-        view.performHapticFeedback(android.view.HapticFeedbackConstants.CLOCK_TICK)
-    } else {
-        @Suppress("DEPRECATION")
-        view.performHapticFeedback(android.view.HapticFeedbackConstants.CLOCK_TICK)
-    }
-}