feat(chat-original): 원작 상세 화면 및 캐릭터 무한 스크롤 로딩 구현

app/src/main/java/kr/co/vividnext/sodalive/common/GridSpacingItemDecoration.kt

@@ -5,11 +5,14 @@ import android.view.View
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.RecyclerView.ItemDecoration
 
-
+/**
+ * Grid 간격 데코레이션. 헤더가 있는 경우 headerCount로 보정하여 첫 행 판단 및 컬럼 계산을 정확히 수행한다.
+ */
 class GridSpacingItemDecoration(
     private val spanCount: Int,
     private val spacing: Int,
-    private val includeEdge: Boolean
+    private val includeEdge: Boolean,
+    private val headerCount: Int = 0
 ) : ItemDecoration() {
     override fun getItemOffsets(
         outRect: Rect,
@@ -17,19 +20,26 @@ class GridSpacingItemDecoration(
         parent: RecyclerView,
         state: RecyclerView.State
     ) {
-        val position = parent.getChildAdapterPosition(view) // Item position
-        val column = position % spanCount // Current column
+        val position = parent.getChildAdapterPosition(view)
+        // 헤더 범위는 간격을 적용하지 않음
+        val adjustedPosition = position - headerCount
+        if (adjustedPosition < 0) {
+            outRect.set(0, 0, 0, 0)
+            return
+        }
+
+        val column = adjustedPosition % spanCount
         if (includeEdge) {
             outRect.left = spacing - column * spacing / spanCount
             outRect.right = (column + 1) * spacing / spanCount
-            if (position < spanCount) { // Top edge
+            if (adjustedPosition < spanCount) { // Top edge (헤더 제외 첫 행)
                 outRect.top = spacing
             }
             outRect.bottom = spacing // Item bottom
         } else {
             outRect.left = column * spacing / spanCount
             outRect.right = spacing - (column + 1) * spacing / spanCount
-            if (position >= spanCount) {
+            if (adjustedPosition >= spanCount) {
                 outRect.top = spacing // Item top
             }
         }