From 72e8aba1a189b0ec1dc2b2ea1a7ddeacf0eff4c5 Mon Sep 17 00:00:00 2001
From: tomoima525 <tomoima525@gmail.com>
Date: Mon, 14 Aug 2017 22:28:22 -0700
Subject: [PATCH] less memory usage

---
 .../infiniterotation/InfiniteRotationAdapter.kt   | 10 +++++-----
 .../infiniterotation/InfiniteRotationView.kt      | 15 +++++++--------
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationAdapter.kt b/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationAdapter.kt
index bd366dd..a05315b 100644
--- a/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationAdapter.kt
+++ b/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationAdapter.kt
@@ -11,8 +11,10 @@ import butterknife.ButterKnife
 /**
  * Created by tomoaki on 2017/08/13.
  */
-class InfiniteRotationAdapter(val list: List<ItemInfo>)
-    : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
+class InfiniteRotationAdapter(itemList: List<ItemInfo>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
+
+    private val list: List<ItemInfo> = listOf(itemList.last()) + itemList + listOf(itemList.first())
+
     override fun onBindViewHolder(holder: RecyclerView.ViewHolder?, position: Int) {
         (holder as? ItemViewHolder)?.let {
             it.pageName.text = list[position % list.size].page
@@ -29,9 +31,7 @@ class InfiniteRotationAdapter(val list: List<ItemInfo>)
         return ItemViewHolder(view)
     }
 
-    override fun getItemCount() = list.size * 3
-
-    fun getListSize() = list.size
+    override fun getItemCount() = list.size
 
     internal class ItemViewHolder(view: View): RecyclerView.ViewHolder(view) {
         @BindView(R.id.page_name)
diff --git a/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationView.kt b/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationView.kt
index 69d4fa4..0978dcb 100644
--- a/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationView.kt
+++ b/app/src/main/java/com/tomoima/infiniterotation/InfiniteRotationView.kt
@@ -35,12 +35,12 @@ class InfiniteRotationView(context: Context, attributeSet: AttributeSet)
         val snapHelper = PagerSnapHelper()
         snapHelper.attachToRecyclerView(recyclerView)
 
-        adapter.getListSize()
+        adapter.itemCount
                 .takeIf { it > 1 }
                 ?.apply {
-                    onScrollListener = OnScrollListener(adapter.getListSize(), layoutManager)
+                    onScrollListener = OnScrollListener(adapter.itemCount, layoutManager)
                     recyclerView.addOnScrollListener(onScrollListener)
-                    recyclerView.scrollToPosition(adapter.getListSize())
+                    recyclerView.scrollToPosition(1)
                 }
     }
 
@@ -51,13 +51,12 @@ class InfiniteRotationView(context: Context, attributeSet: AttributeSet)
             super.onScrolled(recyclerView, dx, dy)
             val firstItemVisible = layoutManager.findFirstVisibleItemPosition()
 
-
-            if (firstItemVisible > itemCount && firstItemVisible % itemCount == 0) {
+            if (firstItemVisible > 0 && firstItemVisible % (itemCount - 1) == 0) {
                 // When position reaches end of the list, it should go back to the beginning
-                recyclerView?.scrollToPosition(itemCount)
-            } else if (firstItemVisible == itemCount - 1) {
+                recyclerView?.scrollToPosition(1)
+            } else if (firstItemVisible == 0) {
                 // When position reaches beginning of the list, it should go back to the end
-                recyclerView?.scrollToPosition(itemCount * 2)
+                recyclerView?.scrollToPosition(itemCount - 1)
             }
         }
     }