resources: smoother list diffing (fixes #8993) (#8950)

Author: dogi

app/build.gradle

@@ -9,8 +9,8 @@ android {
         applicationId "org.ole.planet.myplanet"
         minSdk = 26
         targetSdk = 36
-        versionCode = 3709
-        versionName = "0.37.9"
+        versionCode = 3710
+        versionName = "0.37.10"
         ndkVersion = '26.3.11579264'
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables.useSupportLibrary = true

app/src/main/java/org/ole/planet/myplanet/ui/resources/AdapterResource.kt

@@ -309,10 +309,22 @@ class AdapterResource(
             areItemsTheSame = { old, new -> old?.id == new?.id },
             areContentsTheSame = { old, new ->
                 old?.title == new?.title &&
-                    old?.description == new?.description &&
-                    old?.createdDate == new?.createdDate &&
-                    old?.averageRating == new?.averageRating &&
-                    old?.timesRated == new?.timesRated
+                        old?.description == new?.description &&
+                        old?.createdDate == new?.createdDate &&
+                        old?.averageRating == new?.averageRating &&
+                        old?.timesRated == new?.timesRated
+            },
+            getChangePayload = { old, new ->
+                val ratingChanged = old?.averageRating != new?.averageRating || old?.timesRated != new?.timesRated
+                val otherContentChanged = old?.title != new?.title ||
+                        old?.description != new?.description ||
+                        old?.createdDate != new?.createdDate
+
+                if (ratingChanged && !otherContentChanged) {
+                    RATING_PAYLOAD
+                } else {
+                    null
+                }
             }
         )
         libraryList = newList

app/src/main/java/org/ole/planet/myplanet/utilities/DiffUtils.kt

@@ -17,7 +17,8 @@ object DiffUtils {
         oldList: List<T>,
         newList: List<T>,
         areItemsTheSame: (oldItem: T, newItem: T) -> Boolean,
-        areContentsTheSame: (oldItem: T, newItem: T) -> Boolean
+        areContentsTheSame: (oldItem: T, newItem: T) -> Boolean,
+        getChangePayload: ((oldItem: T, newItem: T) -> Any?)? = null
     ): RecyclerDiffUtil.DiffResult {
         val callback = object : RecyclerDiffUtil.Callback() {
             override fun getOldListSize() = oldList.size
@@ -26,6 +27,9 @@ object DiffUtils {
                 areItemsTheSame(oldList[oldItemPosition], newList[newItemPosition])
             override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int) =
                 areContentsTheSame(oldList[oldItemPosition], newList[newItemPosition])
+            override fun getChangePayload(oldItemPosition: Int, newItemPosition: Int): Any? {
+                return getChangePayload?.invoke(oldList[oldItemPosition], newList[newItemPosition])
+            }
         }
         return RecyclerDiffUtil.calculateDiff(callback)
     }