PPJG-2914 Remove last callback (#24)

* Remove last callback if we set new items.
We have to remove the previous callback if we set new items, since the callback could break the logic with the predictive animations(namely supportsPredictiveItemAnimations) which are calculated via a few onLayout callbacks

* Set callback as null after we already removed the callback and remove redundant volatile annotation

delegates/gradle.properties

@@ -1,5 +1,5 @@
 POM_ARTIFACT_ID=delegates
-VERSION_NAME=1.1.2
+VERSION_NAME=1.1.3
 POM_NAME=delegates
 POM_PACKAGING=jar
 GROUP=com.revolut.recyclerkit

delegates/src/main/java/com/revolut/recyclerkit/delegates/DiffAdapter.kt

@@ -116,6 +116,8 @@ open class DiffAdapter(
             private set
         override val items = mutableListOf<ListItem>()
 
+        private var lastDispatchDiffCallback: Runnable? = null
+
         override fun attachRecyclerView(recyclerView: RecyclerView) {
             this.recyclerView = WeakReference(recyclerView)
         }
@@ -133,6 +135,7 @@ open class DiffAdapter(
             val firstVisiblePosition = recyclerView.layoutManager.findFirstCompletelyVisibleItemPosition(autoScrollToTop)
 
             val dispatchDiff: () -> Unit = {
+                lastDispatchDiffCallback = null
                 items.clear()
                 items.addAll(newList)
 
@@ -143,8 +146,13 @@ open class DiffAdapter(
                 }
             }
 
+            lastDispatchDiffCallback?.let {
+                recyclerView.removeCallbacks(it)
+            }
             if (recyclerView.isComputingLayout) {
-                recyclerView.post { dispatchDiff() }
+                val newDispatchDiffCallback = Runnable { dispatchDiff() }
+                lastDispatchDiffCallback = newDispatchDiffCallback
+                recyclerView.post(newDispatchDiffCallback)
             } else {
                 dispatchDiff()
             }