Improve: Fix weird behaviour on scroll

I wonder why nobody noticed but scrolling is weird in App Detail page

src/main/kotlin/com/looker/droidify/screen/ProductAdapter.kt

@@ -87,7 +87,7 @@ class ProductAdapter(private val callbacks: Callbacks) :
         data class Downloading(val read: Long, val total: Long?) : Status()
     }
 
-    enum class ViewType { APP_INFO, SWITCH, SECTION, EXPAND, TEXT, LINK, PERMISSIONS, RELEASE, EMPTY }
+    enum class ViewType { APP_INFO, SCREENSHOT, SWITCH, SECTION, EXPAND, TEXT, LINK, PERMISSIONS, RELEASE, EMPTY }
 
     private enum class SwitchType(val titleResId: Int) {
         IGNORE_ALL_UPDATES(R.string.ignore_all_updates),
@@ -105,7 +105,7 @@ class ProductAdapter(private val callbacks: Callbacks) :
 
     internal enum class ExpandType {
         NOTHING, DESCRIPTION, CHANGES,
-        LINKS, DONATES, PERMISSIONS, SCREENSHOTS, VERSIONS
+        LINKS, DONATES, PERMISSIONS, VERSIONS
     }
 
     private enum class TextType { DESCRIPTION, ANTI_FEATURES, CHANGES }
@@ -131,7 +131,6 @@ class ProductAdapter(private val callbacks: Callbacks) :
             val repository: Repository,
             val product: Product,
             val packageName: String,
-            val screenshots: List<Product.Screenshot>,
         ) : Item() {
             override val descriptor: String
                 get() = "app_info.${product.name}"
@@ -140,6 +139,18 @@ class ProductAdapter(private val callbacks: Callbacks) :
                 get() = ViewType.APP_INFO
         }
 
+        class ScreenshotItem(
+            val screenshots: List<Product.Screenshot>,
+            val packageName: String,
+            val repository: Repository,
+        ) : Item() {
+            override val descriptor: String
+                get() = "screenshot.${screenshots.size}"
+            override val viewType: ViewType
+                get() = ViewType.SCREENSHOT
+
+        }
+
         class SwitchItem(
             val switchType: SwitchType,
             val packageName: String,
@@ -314,12 +325,6 @@ class ProductAdapter(private val callbacks: Callbacks) :
         val statusLayout = itemView.findViewById<View>(R.id.status_layout)!!
         val status = itemView.findViewById<MaterialTextView>(R.id.status)!!
         val progress = itemView.findViewById<LinearProgressIndicator>(R.id.progress)!!
-        val screenshotsSection =
-            itemView.findViewById<LinearLayoutCompat>(R.id.screenshots_section)!!
-        val screenshotsSectionIcon =
-            itemView.findViewById<ShapeableImageView>(R.id.screenshots_section_icon)!!
-        val screenshotsView = itemView.findViewById<NestedScrollView>(R.id.screenshots_view)!!
-        val screenshotsRecycler = itemView.findViewById<RecyclerView>(R.id.screenshots_recycler)!!
 
         val progressIcon: Drawable
         val defaultIcon: Drawable
@@ -346,6 +351,16 @@ class ProductAdapter(private val callbacks: Callbacks) :
         val dev = itemView.findViewById<MaterialCardView>(R.id.dev_block)!!
     }
 
+    private class ScreenShotViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+
+        val screenshotsSection =
+            itemView.findViewById<LinearLayoutCompat>(R.id.screenshots_section)!!
+        val screenshotsSectionIcon =
+            itemView.findViewById<ShapeableImageView>(R.id.screenshots_section_icon)!!
+        val screenshotsView = itemView.findViewById<NestedScrollView>(R.id.screenshots_view)!!
+        val screenshotsRecycler = itemView.findViewById<RecyclerView>(R.id.screenshots_recycler)!!
+    }
+
     private class SwitchViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
         val enabled = itemView.findViewById<SwitchMaterial>(R.id.enabled)!!
 
@@ -554,8 +569,12 @@ class ProductAdapter(private val callbacks: Callbacks) :
             items += Item.AppInfoItem(
                 productRepository.second,
                 productRepository.first,
+                packageName
+            )
+            items += Item.ScreenshotItem(
+                productRepository.first.screenshots,
                 packageName,
-                productRepository.first.screenshots
+                productRepository.second
             )
 
             if (installedItem != null) {
@@ -892,6 +911,7 @@ class ProductAdapter(private val callbacks: Callbacks) :
             ViewType.APP_INFO -> AppInfoViewHolder(parent.inflate(R.layout.item_app_info_x)).apply {
                 action.setOnClickListener { this@ProductAdapter.action?.let(callbacks::onActionClick) }
             }
+            ViewType.SCREENSHOT -> ScreenShotViewHolder(parent.inflate(R.layout.screenshot_scrollview))
             ViewType.SWITCH -> SwitchViewHolder(parent.inflate(R.layout.switch_item)).apply {
                 itemView.setOnClickListener {
                     val switchItem = items[adapterPosition] as Item.SwitchItem
@@ -1074,25 +1094,6 @@ class ProductAdapter(private val callbacks: Callbacks) :
                         iconTint = if (action == Action.CANCEL) holder.actionTintOnCancel
                         else holder.actionTintOnNormal
                     }
-                    if (item.screenshots.isEmpty()) {
-                        holder.screenshotsSection.visibility = View.GONE
-                        holder.screenshotsView.visibility = View.GONE
-                    } else {
-                        holder.screenshotsSection.visibility = View.VISIBLE
-                        holder.screenshotsView.visibility = View.VISIBLE
-                        holder.screenshotsSection.setOnClickListener {
-                            val isExpanded = holder.screenshotsView.visibility == View.VISIBLE
-                            holder.screenshotsSectionIcon.scaleY = if (isExpanded) -1f else 1f
-                            holder.screenshotsView.visibility =
-                                if (isExpanded) View.GONE else View.VISIBLE
-                        }
-                        holder.screenshotsRecycler.layoutManager =
-                            LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
-                        holder.screenshotsRecycler.adapter =
-                            ScreenshotsAdapter { callbacks.onScreenshotClick(it) }.apply {
-                                setScreenshots(item.repository, item.packageName, item.screenshots)
-                            }
-                    }
                 }
                 if (updateAll || updateStatus) {
                     val status = status
@@ -1165,6 +1166,29 @@ class ProductAdapter(private val callbacks: Callbacks) :
                     true
                 }
             }
+            ViewType.SCREENSHOT -> {
+                holder as ScreenShotViewHolder
+                item as Item.ScreenshotItem
+                if (item.screenshots.isEmpty()) {
+                    holder.screenshotsSection.visibility = View.GONE
+                    holder.screenshotsView.visibility = View.GONE
+                } else {
+                    holder.screenshotsSection.visibility = View.VISIBLE
+                    holder.screenshotsView.visibility = View.VISIBLE
+                    holder.screenshotsSection.setOnClickListener {
+                        val isExpanded = holder.screenshotsView.visibility == View.VISIBLE
+                        holder.screenshotsSectionIcon.scaleY = if (isExpanded) -1f else 1f
+                        holder.screenshotsView.visibility =
+                            if (isExpanded) View.GONE else View.VISIBLE
+                    }
+                    holder.screenshotsRecycler.layoutManager =
+                        LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
+                    holder.screenshotsRecycler.adapter =
+                        ScreenshotsAdapter { callbacks.onScreenshotClick(it) }.apply {
+                            setScreenshots(item.repository, item.packageName, item.screenshots)
+                        }
+                }
+            }
             ViewType.SWITCH -> {
                 holder as SwitchViewHolder
                 item as Item.SwitchItem

src/main/res/layout/item_app_info_x.xml

@@ -235,54 +235,9 @@
         android:layout_height="56dp"
         android:layout_marginHorizontal="12dp"
         app:iconGravity="textStart"
-        app:layout_constraintBottom_toTopOf="@id/screenshots_section"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/status_layout"
         app:shapeAppearanceOverlay="@style/PillShapeAppearance" />
 
-    <androidx.appcompat.widget.LinearLayoutCompat
-        android:id="@+id/screenshots_section"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:background="?android:attr/selectableItemBackground"
-        android:orientation="horizontal"
-        android:padding="16dp"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/action">
-
-        <com.google.android.material.textview.MaterialTextView
-            android:id="@+id/title"
-            android:layout_width="0dp"
-            android:layout_height="wrap_content"
-            android:layout_weight="1"
-            android:singleLine="true"
-            android:text="@string/screenshots"
-            android:textColor="?attr/colorAccent" />
-
-        <com.google.android.material.imageview.ShapeableImageView
-            android:id="@+id/screenshots_section_icon"
-            android:layout_width="wrap_content"
-            android:layout_height="match_parent"
-            android:scaleType="center"
-            android:src="@drawable/ic_arrow_down"
-            android:tint="?attr/colorAccent"
-            tools:ignore="ContentDescription" />
-    </androidx.appcompat.widget.LinearLayoutCompat>
-
-    <androidx.core.widget.NestedScrollView
-        android:id="@+id/screenshots_view"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/screenshots_section">
-
-        <androidx.recyclerview.widget.RecyclerView
-            android:id="@+id/screenshots_recycler"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:orientation="horizontal" />
-    </androidx.core.widget.NestedScrollView>
 </androidx.constraintlayout.widget.ConstraintLayout>

src/main/res/layout/screenshot_scrollview.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.appcompat.widget.LinearLayoutCompat xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical">
+
+    <androidx.appcompat.widget.LinearLayoutCompat
+        android:id="@+id/screenshots_section"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:background="?android:attr/selectableItemBackground"
+        android:orientation="horizontal"
+        android:padding="16dp">
+
+        <com.google.android.material.textview.MaterialTextView
+            android:id="@+id/title"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:singleLine="true"
+            android:text="@string/screenshots"
+            android:textColor="?attr/colorAccent" />
+
+        <com.google.android.material.imageview.ShapeableImageView
+            android:id="@+id/screenshots_section_icon"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:scaleType="center"
+            android:src="@drawable/ic_arrow_down"
+            android:tint="?attr/colorAccent"
+            tools:ignore="ContentDescription" />
+    </androidx.appcompat.widget.LinearLayoutCompat>
+
+    <androidx.core.widget.NestedScrollView
+        android:id="@+id/screenshots_view"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/screenshots_recycler"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:orientation="horizontal" />
+    </androidx.core.widget.NestedScrollView>
+
+</androidx.appcompat.widget.LinearLayoutCompat>