Merge pull request #143 from Ryosuke839/#142-recyclerview-performance

#142 Improve RecyclerView performance
Ryosuke839 · Sep 17, 2023 · b71f5cf · b71f5cf
2 parents 5f3a23d + 5375b35
commit b71f5cf
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Showing 2 changed files with 44 additions and 8 deletions.
diff --git a/app/src/main/java/jp/ddo/hotmist/unicodepad/ListAdapter.kt b/app/src/main/java/jp/ddo/hotmist/unicodepad/ListAdapter.kt
@@ -665,8 +665,10 @@ internal class ListAdapter(activity: Activity, pref: SharedPreferences, db: Name
                     runOnUiThread {
                         highTarget?.setBackgroundColor(resnormal)
                         highTarget = null
-                        notifyItemChanged(highlight)
-                        highlight = -1
+                        if (highlight != -1) {
+                            notifyItemChanged(highlight)
+                            highlight = -1
+                        }
                     }
                     false
                 }
@@ -708,6 +710,34 @@ internal class ListAdapter(activity: Activity, pref: SharedPreferences, db: Name
         }
     }
 
+    override fun instantiateSpanSizeLookup(context: Context, spanCount: Int): GridLayoutManager.SpanSizeLookup {
+        return object : GridLayoutManager.SpanSizeLookup() {
+            override fun getSpanSize(position: Int): Int {
+                return if (getItemViewType(position) != 1 || single) 1 else spanCount
+            }
+
+            override fun getSpanIndex(position: Int, spanCount: Int): Int {
+                val (itemIndex, titleIndex) = getItemIndex(position)
+                return if (titleIndex != -1) {
+                    0
+                } else {
+                    itemIndex % spanCount
+                }
+            }
+
+            override fun getSpanGroupIndex(adapterPosition: Int, spanCount: Int): Int {
+                val (itemIndex, titleIndex) = getItemIndex(adapterPosition)
+                return if (titleIndex != -1) {
+                    titleIndex + (adapterPosition - titleIndex) / spanCount
+                } else {
+                    adapterPosition - itemIndex + itemIndex / spanCount
+                }
+            }
+        }.also {
+            it.isSpanIndexCacheEnabled = false
+        }
+    }
+
     override fun destroy() {
         jump = null
         mark = null

diff --git a/app/src/main/java/jp/ddo/hotmist/unicodepad/UnicodeAdapter.kt b/app/src/main/java/jp/ddo/hotmist/unicodepad/UnicodeAdapter.kt
@@ -94,7 +94,7 @@ abstract class UnicodeAdapter(protected val activity: Activity, private val db:
         return if (itemIndex == -1) -1L - titleIndex else getItemCodePoint(itemIndex)
     }
 
-    private fun getItemIndex(position: Int): Pair<Int, Int> {
+    protected fun getItemIndex(position: Int): Pair<Int, Int> {
         val titleIndex = searchTitlePosition(position)
         return if (titleIndex >= 0 && position == getTitlePosition(titleIndex) + titleIndex)
             -1 to titleIndex
@@ -282,13 +282,19 @@ abstract class UnicodeAdapter(protected val activity: Activity, private val db:
 
     private var layoutManager: GridLayoutManager? = null
 
+    open fun instantiateSpanSizeLookup(context: Context, spanCount: Int): GridLayoutManager.SpanSizeLookup {
+        return object : GridLayoutManager.SpanSizeLookup() {
+            override fun getSpanSize(position: Int): Int {
+                return if (getItemViewType(position) != 1 || single) 1 else spanCount
+            }
+        }.also {
+            it.isSpanIndexCacheEnabled = true
+        }
+    }
+
     fun getLayoutManager(context: Context, spanCount: Int): GridLayoutManager {
         return GridLayoutManager(context, if (single) 1 else spanCount).also {
-            it.spanSizeLookup = object : GridLayoutManager.SpanSizeLookup() {
-                override fun getSpanSize(position: Int): Int {
-                    return if (getItemViewType(position) != 1 || single) 1 else spanCount
-                }
-            }
+            it.spanSizeLookup = instantiateSpanSizeLookup(context, spanCount)
             layoutManager = it
         }
     }