fix drag scroll exclusion

Calvin-LL · May 13, 2024 · 3563c55 · 3563c55
1 parent 71c0973
commit 3563c55
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Showing 2 changed files with 25 additions and 25 deletions.
diff --git a/reorderable/src/commonMain/kotlin/sh/calvin/reorderable/ReorderableLazyCollection.kt b/reorderable/src/commonMain/kotlin/sh/calvin/reorderable/ReorderableLazyCollection.kt
@@ -405,13 +405,7 @@ open class ReorderableLazyCollectionState<out T> internal constructor(
     internal fun onDrag(offset: Offset) {
         draggingItemDraggedDelta += offset
 
-        if (!onMoveStateMutex.tryLock()) return
-
-        val draggingItem = draggingItemLayoutInfo
-        if (draggingItem == null) {
-            onMoveStateMutex.unlock()
-            return
-        }
+        val draggingItem = draggingItemLayoutInfo ?: return
         // how far the dragging item is from the original position
         val dragOffset = draggingItemOffset.reverseAxisIfNecessary()
             .reverseAxisWithLayoutDirectionIfLazyVerticalStaggeredGridRtlFix()
@@ -421,20 +415,6 @@ open class ReorderableLazyCollectionState<out T> internal constructor(
             scrollThresholdPadding
         )
 
-        if (!scroller.isScrolling) {
-            val draggingItemRect = Rect(startOffset, endOffset)
-            // find a target item to move with
-            val targetItem = findTargetItem(draggingItemRect) {
-                it.index != draggingItem.index
-            }
-            if (targetItem != null) {
-                scope.launch {
-                    moveItems(draggingItem, targetItem)
-                }
-            }
-        }
-        onMoveStateMutex.unlock()
-
         // the distance from the top or left of the list to the center of the dragging item handle
         val handleOffset =
             when (state.layoutInfo.reverseLayout ||
@@ -453,7 +433,7 @@ open class ReorderableLazyCollectionState<out T> internal constructor(
         val distanceFromEnd = (contentEndOffset - handleOffset.getAxis(orientation))
             .coerceAtLeast(0f)
 
-        if (distanceFromStart < scrollThreshold) {
+        val isScrollingStarted = if (distanceFromStart < scrollThreshold) {
             scroller.start(
                 Scroller.Direction.BACKWARD,
                 getScrollSpeedMultiplier(distanceFromStart),
@@ -492,7 +472,26 @@ open class ReorderableLazyCollectionState<out T> internal constructor(
             )
         } else {
             scroller.tryStop()
+            false
+        }
+
+        if (!onMoveStateMutex.tryLock()) return
+        if (!scroller.isScrolling && !isScrollingStarted) {
+            val draggingItemRect = Rect(startOffset, endOffset)
+            // find a target item to move with
+            val targetItem = findTargetItem(
+                draggingItemRect,
+                items = state.layoutInfo.visibleItemsInfo,
+            ) {
+                it.index != draggingItem.index
+            }
+            if (targetItem != null) {
+                scope.launch {
+                    moveItems(draggingItem, targetItem)
+                }
+            }
         }
+        onMoveStateMutex.unlock()
     }
 
     // keep dragging item in visible area to prevent it from disappearing

diff --git a/reorderable/src/commonMain/kotlin/sh/calvin/reorderable/Scroller.kt b/reorderable/src/commonMain/kotlin/sh/calvin/reorderable/Scroller.kt
@@ -134,7 +134,7 @@ class Scroller internal constructor(
 
     private var programmaticScrollJob: Job? = null
     val isScrolling: Boolean
-        get() = programmaticScrollJob != null
+        get() = programmaticScrollJob?.isActive == true
 
     private val scrollInfoChannel = Channel<ScrollInfo>(Channel.CONFLATED)
 
@@ -143,8 +143,8 @@ class Scroller internal constructor(
         speedMultiplier: Float = 1f,
         maxScrollDistanceProvider: () -> Float = { Float.MAX_VALUE },
         onScroll: suspend () -> Unit = {},
-    ) {
-        if (!canScroll(direction)) return
+    ): Boolean {
+        if (!canScroll(direction)) return false
 
         if (programmaticScrollJob == null) {
             programmaticScrollJob = scope.launch {
@@ -156,6 +156,7 @@ class Scroller internal constructor(
             ScrollInfo(direction, speedMultiplier, maxScrollDistanceProvider, onScroll)
 
         scrollInfoChannel.trySend(scrollInfo)
+        return true
     }
 
     private suspend fun scrollLoop() {