Merge pull request #523 from squanchy-dev/diff_util_for_search

Use ListAdapter to dispatch adapter updates for the SearchActivity

Author: rock3r

app/src/main/java/net/squanchy/search/SearchService.kt

@@ -60,16 +60,16 @@ class SearchService(
         }
 
         return ArrayList<SearchListElement>(events.size + speakers.size).apply {
-            if (events.isNotEmpty()) {
-                add(EventHeader)
-                addAll(events.map(::EventElement))
-            }
-
             if (speakers.isNotEmpty()) {
                 add(SpeakerHeader)
                 addAll(speakers.map(::SpeakerElement))
             }
 
+            if (events.isNotEmpty()) {
+                add(EventHeader)
+                addAll(events.map(::EventElement))
+            }
+
             add(AlgoliaLogo)
         }
     }

app/src/main/java/net/squanchy/search/view/SearchAdapter.kt

@@ -3,8 +3,9 @@ package net.squanchy.search.view
 import android.app.Activity
 import android.support.annotation.IntDef
 import android.support.v7.app.AppCompatActivity
+import android.support.v7.recyclerview.extensions.ListAdapter
+import android.support.v7.util.DiffUtil
 import android.support.v7.widget.GridLayoutManager
-import android.support.v7.widget.RecyclerView
 import android.view.LayoutInflater
 import android.view.ViewGroup
 import net.squanchy.R
@@ -20,7 +21,7 @@ import net.squanchy.search.view.SearchItemViewHolder.HeaderViewHolder
 import net.squanchy.search.view.SearchItemViewHolder.SearchEventViewHolder
 import net.squanchy.search.view.SearchItemViewHolder.SpeakerViewHolder
 
-internal class SearchAdapter(activity: AppCompatActivity) : RecyclerView.Adapter<SearchItemViewHolder>() {
+internal class SearchAdapter(activity: AppCompatActivity) : ListAdapter<SearchListElement, SearchItemViewHolder>(DiffCallback) {
 
     private val imageLoader: ImageLoader
     private val activity: Activity
@@ -38,7 +39,7 @@ internal class SearchAdapter(activity: AppCompatActivity) : RecyclerView.Adapter
 
     @ViewTypeId
     override fun getItemViewType(position: Int): Int {
-        return when (searchResult.elements[position]) {
+        return when (getItem(position)) {
             is SearchListElement.EventHeader -> HEADER
             is SearchListElement.SpeakerHeader -> HEADER
             is EventElement -> EVENT
@@ -48,7 +49,7 @@ internal class SearchAdapter(activity: AppCompatActivity) : RecyclerView.Adapter
     }
 
     override fun getItemId(position: Int): Long {
-        val item = searchResult.elements[position]
+        val item = getItem(position)
         return when (item) {
             is EventElement -> item.event.numericId
             is SpeakerElement -> item.speaker.numericId
@@ -88,17 +89,15 @@ internal class SearchAdapter(activity: AppCompatActivity) : RecyclerView.Adapter
         }
     }
 
-    override fun getItemCount(): Int = searchResult.elements.size
-
     fun createSpanSizeLookup(columnsCount: Int): GridLayoutManager.SpanSizeLookup {
         return GridSpanSizeLookup(searchResult.elements, columnsCount)
     }
 
     fun updateWith(searchResult: SearchResult.Success, listener: SearchRecyclerView.OnSearchResultClickListener) {
-        this.searchResult = searchResult
         this.listener = listener
+        this.searchResult = searchResult
 
-        notifyDataSetChanged()
+        submitList(searchResult.elements)
     }
 
     companion object {
@@ -118,3 +117,17 @@ internal class SearchAdapter(activity: AppCompatActivity) : RecyclerView.Adapter
         private const val ITEM_ID_ALGOLIA_LOGO: Long = 3230264564
     }
 }
+
+private object DiffCallback : DiffUtil.ItemCallback<SearchListElement>() {
+    override fun areItemsTheSame(oldItem: SearchListElement?, newItem: SearchListElement?): Boolean {
+        return when {
+            oldItem is EventElement && newItem is EventElement -> oldItem.event.numericId == newItem.event.numericId
+            oldItem is SpeakerElement && newItem is SpeakerElement -> oldItem.speaker.numericId == newItem.speaker.numericId
+            else -> oldItem == newItem
+        }
+    }
+
+    override fun areContentsTheSame(oldItem: SearchListElement?, newItem: SearchListElement?): Boolean {
+        return oldItem == newItem
+    }
+}

app/src/main/java/net/squanchy/search/view/SearchRecyclerView.kt

@@ -24,10 +24,6 @@ class SearchRecyclerView @JvmOverloads constructor(
 
     private lateinit var adapter: SearchAdapter
 
-    init {
-        itemAnimator = null
-    }
-
     override fun onFinishInflate() {
         super.onFinishInflate()
 

app/src/main/res/layout/activity_search.xml

@@ -32,7 +32,7 @@
   <net.squanchy.search.view.SearchRecyclerView
     android:id="@+id/searchRecyclerView"
     android:layout_width="match_parent"
-    android:layout_height="wrap_content"
+    android:layout_height="match_parent"
     app:layout_behavior="@string/appbar_scrolling_view_behavior" />
 
   <FrameLayout

app/src/main/res/values/themes.xml

@@ -102,7 +102,9 @@
 
   <style name="Theme.Squanchy.SignIn" parent="Theme.Squanchy.BottomSheet" />
 
-  <style name="Theme.Squanchy.Search" parent="Theme.Squanchy.MostlyWhite" />
+  <style name="Theme.Squanchy.Search" parent="Theme.Squanchy.MostlyWhite">
+    <item name="android:windowBackground">@color/window_background</item>
+  </style>
 
   <style name="Theme.Squanchy.Settings" parent="Theme.Squanchy.PrimaryStatusBar">
     <item name="colorAccent">?attr/colorPrimary</item>