From a7c73724c56619fdda7d42276743c2712c9bd483 Mon Sep 17 00:00:00 2001
From: yarolegovich <yarolegovich@gmail.com>
Date: Sat, 1 Aug 2020 17:35:22 +0300
Subject: [PATCH] Fixed onItemChanged not being called after scrollToPosition
 re #147

---
 .../DiscreteScrollView.java                   | 30 ++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/library/src/main/java/com/yarolegovich/discretescrollview/DiscreteScrollView.java b/library/src/main/java/com/yarolegovich/discretescrollview/DiscreteScrollView.java
index 759c8d3..560e5d0 100644
--- a/library/src/main/java/com/yarolegovich/discretescrollview/DiscreteScrollView.java
+++ b/library/src/main/java/com/yarolegovich/discretescrollview/DiscreteScrollView.java
@@ -30,6 +30,12 @@ public class DiscreteScrollView extends RecyclerView {
 
     private List<ScrollStateChangeListener> scrollStateChangeListeners;
     private List<OnItemChangedListener> onItemChangedListeners;
+    private Runnable notifyItemChangedRunnable = new Runnable() {
+        @Override
+        public void run() {
+            notifyCurrentItemChanged();
+        }
+    };
 
     private boolean isOverScrollEnabled;
 
@@ -97,6 +103,15 @@ public ViewHolder getViewHolder(int position) {
         return view != null ? getChildViewHolder(view) : null;
     }
 
+    @Override
+    public void scrollToPosition(int position) {
+        int currentPosition = layoutManager.getCurrentPosition();
+        super.scrollToPosition(position);
+        if (currentPosition != position) {
+            notifyCurrentItemChanged();
+        }
+    }
+
     /**
      * @return adapter position of the current item or -1 if nothing is selected
      */
@@ -197,12 +212,17 @@ private void notifyCurrentItemChanged(ViewHolder holder, int current) {
     }
 
     private void notifyCurrentItemChanged() {
+        removeCallbacks(notifyItemChangedRunnable);
         if (onItemChangedListeners.isEmpty()) {
             return;
         }
         int current = layoutManager.getCurrentPosition();
         ViewHolder currentHolder = getViewHolder(current);
-        notifyCurrentItemChanged(currentHolder, current);
+        if (currentHolder == null) {
+            post(notifyItemChangedRunnable);
+        } else {
+            notifyCurrentItemChanged(currentHolder, current);
+        }
     }
 
     private class ScrollStateListener implements DiscreteScrollLayoutManager.ScrollStateListener {
@@ -216,6 +236,7 @@ public void onIsBoundReachedFlagChange(boolean isBoundReached) {
 
         @Override
         public void onScrollStart() {
+            removeCallbacks(notifyItemChangedRunnable);
             if (scrollStateChangeListeners.isEmpty()) {
                 return;
             }
@@ -256,12 +277,7 @@ public void onScroll(float currentViewPosition) {
 
         @Override
         public void onCurrentViewFirstLayout() {
-            post(new Runnable() {
-                @Override
-                public void run() {
-                    notifyCurrentItemChanged();
-                }
-            });
+            notifyCurrentItemChanged();
         }
 
         @Override