[fenix] For https://github.com/mozilla-mobile/fenix/issues/17542 - Removes flash on renaming top site and fixes title not being updated

app/src/androidTest/java/org/mozilla/fenix/ui/robots/HomeScreenRobot.kt

@@ -703,7 +703,7 @@ private fun assertExistingTopSitesList() =
 
 private fun assertExistingTopSitesTabs(title: String) =
     onView(allOf(withId(R.id.top_sites_list)))
-        .check(matches(hasItem(hasDescendant(withText(title)))))
+        .check(matches(hasDescendant(withText(title))))
         .check(matches(withEffectiveVisibility(Visibility.VISIBLE)))
 
 private fun assertNotExistingTopSitesList(title: String) =

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/SessionControlAdapter.kt

@@ -43,7 +43,12 @@ sealed class AdapterItem(@LayoutRes val viewType: Int) {
         ButtonTipViewHolder.LAYOUT_ID
     )
 
-    data class TopSitePager(val topSites: List<TopSite>) : AdapterItem(TopSitePagerViewHolder.LAYOUT_ID) {
+    data class TopSitePagerPayload(
+        val changed: Set<Pair<Int, TopSite>>
+    )
+
+    data class TopSitePager(val topSites: List<TopSite>) :
+        AdapterItem(TopSitePagerViewHolder.LAYOUT_ID) {
         override fun sameAs(other: AdapterItem): Boolean {
             val newTopSites = (other as? TopSitePager) ?: return false
             return newTopSites.topSites.size == this.topSites.size
@@ -56,6 +61,19 @@ sealed class AdapterItem(@LayoutRes val viewType: Int) {
             val oldTopSites = this.topSites.asSequence()
             return newSitesSequence.zip(oldTopSites).all { (new, old) -> new == old }
         }
+
+        override fun getChangePayload(newItem: AdapterItem): Any? {
+            val newTopSites = (newItem as? TopSitePager) ?: return null
+            val oldTopSites = (this as? TopSitePager) ?: return null
+
+            val changed = mutableSetOf<Pair<Int, TopSite>>()
+            for ((index, item) in newTopSites.topSites.withIndex()) {
+                if (oldTopSites.topSites.getOrNull(index) != item) {
+                    changed.add(Pair(index, item))
+                }
+            }
+            return if (changed.isNotEmpty()) TopSitePagerPayload(changed) else null
+        }
     }
 
     object PrivateBrowsingDescription : AdapterItem(PrivateBrowsingDescriptionViewHolder.LAYOUT_ID)
@@ -195,6 +213,25 @@ class SessionControlAdapter(
 
     override fun getItemViewType(position: Int) = getItem(position).viewType
 
+    override fun onBindViewHolder(
+        holder: RecyclerView.ViewHolder,
+        position: Int,
+        payloads: MutableList<Any>
+    ) {
+        if (payloads.isNullOrEmpty()) {
+            onBindViewHolder(holder, position)
+        } else {
+            when (holder) {
+                is TopSitePagerViewHolder -> {
+                    if (payloads[0] is AdapterItem.TopSitePagerPayload) {
+                        val payload = payloads[0] as AdapterItem.TopSitePagerPayload
+                        holder.update(payload)
+                    }
+                }
+            }
+        }
+    }
+
     @SuppressWarnings("ComplexMethod")
     override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
         val item = getItem(position)

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/viewholders/TopSitePagerViewHolder.kt

@@ -13,6 +13,7 @@ import mozilla.components.feature.top.sites.TopSite
 import org.mozilla.fenix.R
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.home.sessioncontrol.AdapterItem
 import org.mozilla.fenix.home.sessioncontrol.TopSiteInteractor
 import org.mozilla.fenix.home.sessioncontrol.viewholders.topsites.TopSitesPagerAdapter
 
@@ -28,7 +29,11 @@ class TopSitePagerViewHolder(
     private val topSitesPageChangeCallback = object : ViewPager2.OnPageChangeCallback() {
         override fun onPageSelected(position: Int) {
             if (currentPage != position) {
-                pageIndicator.context.components.analytics.metrics.track(Event.TopSiteSwipeCarousel(position))
+                pageIndicator.context.components.analytics.metrics.track(
+                    Event.TopSiteSwipeCarousel(
+                        position
+                    )
+                )
             }
 
             pageIndicator.setSelection(position)
@@ -43,6 +48,12 @@ class TopSitePagerViewHolder(
         }
     }
 
+    fun update(payload: AdapterItem.TopSitePagerPayload) {
+        for (item in payload.changed) {
+            topSitesPagerAdapter.notifyItemChanged(currentPage, payload)
+        }
+    }
+
     fun bind(topSites: List<TopSite>) {
         val chunkedTopSites = topSites.chunked(TOP_SITES_PER_PAGE)
         topSitesPagerAdapter.submitList(chunkedTopSites)

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/viewholders/topsites/TopSitesAdapter.kt

@@ -8,13 +8,14 @@ import android.view.LayoutInflater
 import android.view.ViewGroup
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ListAdapter
+import kotlinx.android.synthetic.main.top_site_item.view.*
 import mozilla.components.feature.top.sites.TopSite
 import org.mozilla.fenix.home.sessioncontrol.TopSiteInteractor
 import org.mozilla.fenix.perf.StartupTimeline
 
 class TopSitesAdapter(
     private val interactor: TopSiteInteractor
-) : ListAdapter<TopSite, TopSiteItemViewHolder>(DiffCallback) {
+) : ListAdapter<TopSite, TopSiteItemViewHolder>(TopSitesDiffCallback) {
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TopSiteItemViewHolder {
         val view = LayoutInflater.from(parent.context)
             .inflate(TopSiteItemViewHolder.LAYOUT_ID, parent, false)
@@ -26,11 +27,39 @@ class TopSitesAdapter(
         holder.bind(getItem(position))
     }
 
-    private object DiffCallback : DiffUtil.ItemCallback<TopSite>() {
+    override fun onBindViewHolder(
-        override fun areItemsTheSame(oldItem: TopSite, newItem: TopSite) =
+        holder: TopSiteItemViewHolder,
-            oldItem.id == newItem.id || oldItem.title == newItem.title || oldItem.url == newItem.url
+        position: Int,
+        payloads: MutableList<Any>
+    ) {
+        if (payloads.isNullOrEmpty()) {
+            onBindViewHolder(holder, position)
+        } else {
+            when (payloads[0]) {
+                is TopSite -> {
+                    holder.bind((payloads[0] as TopSite))
+                }
+                is TopSitePayload -> {
+                    holder.itemView.top_site_title.text = (payloads[0] as TopSitePayload).newTitle
+                }
+            }
+        }
+    }
+
+    data class TopSitePayload(
+        val newTitle: String?
+    )
+
+    internal object TopSitesDiffCallback : DiffUtil.ItemCallback<TopSite>() {
+        override fun areItemsTheSame(oldItem: TopSite, newItem: TopSite) = oldItem.id == newItem.id
 
         override fun areContentsTheSame(oldItem: TopSite, newItem: TopSite) =
-            oldItem.id == newItem.id || oldItem.title == newItem.title || oldItem.url == newItem.url
+            oldItem.id == newItem.id && oldItem.title == newItem.title && oldItem.url == newItem.url
+
+        override fun getChangePayload(oldItem: TopSite, newItem: TopSite): Any? {
+            return if (oldItem.id == newItem.id && oldItem.url == newItem.url && oldItem.title != newItem.title) {
+                TopSitePayload(newItem.title)
+            } else null
+        }
     }
 }

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/viewholders/topsites/TopSitesPagerAdapter.kt

@@ -10,12 +10,13 @@ import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ListAdapter
 import kotlinx.android.synthetic.main.component_top_sites.view.*
 import mozilla.components.feature.top.sites.TopSite
+import org.mozilla.fenix.home.sessioncontrol.AdapterItem
 import org.mozilla.fenix.home.sessioncontrol.TopSiteInteractor
 import org.mozilla.fenix.home.sessioncontrol.viewholders.TopSiteViewHolder
 
 class TopSitesPagerAdapter(
     private val interactor: TopSiteInteractor
-) : ListAdapter<List<TopSite>, TopSiteViewHolder>(DiffCallback) {
+) : ListAdapter<List<TopSite>, TopSiteViewHolder>(TopSiteListDiffCallback) {
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TopSiteViewHolder {
         val view = LayoutInflater.from(parent.context)
@@ -23,12 +24,30 @@ class TopSitesPagerAdapter(
         return TopSiteViewHolder(view, interactor)
     }
 
+    override fun onBindViewHolder(
+        holder: TopSiteViewHolder,
+        position: Int,
+        payloads: MutableList<Any>
+    ) {
+        if (payloads.isNullOrEmpty()) {
+            onBindViewHolder(holder, position)
+        } else {
+            if (payloads[0] is AdapterItem.TopSitePagerPayload) {
+                val adapter = holder.itemView.top_sites_list.adapter as TopSitesAdapter
+                val payload = payloads[0] as AdapterItem.TopSitePagerPayload
+                for (item in payload.changed) {
+                    adapter.notifyItemChanged(item.first, item.second)
+                }
+            }
+        }
+    }
+
     override fun onBindViewHolder(holder: TopSiteViewHolder, position: Int) {
         val adapter = holder.itemView.top_sites_list.adapter as TopSitesAdapter
         adapter.submitList(getItem(position))
     }
 
-    private object DiffCallback : DiffUtil.ItemCallback<List<TopSite>>() {
+    internal object TopSiteListDiffCallback : DiffUtil.ItemCallback<List<TopSite>>() {
         override fun areItemsTheSame(oldItem: List<TopSite>, newItem: List<TopSite>): Boolean {
             return oldItem.size == newItem.size
         }
@@ -36,5 +55,15 @@ class TopSitesPagerAdapter(
         override fun areContentsTheSame(oldItem: List<TopSite>, newItem: List<TopSite>): Boolean {
             return newItem.zip(oldItem).all { (new, old) -> new == old }
         }
+
+        override fun getChangePayload(oldItem: List<TopSite>, newItem: List<TopSite>): Any? {
+            val changed = mutableSetOf<Pair<Int, TopSite>>()
+            for ((index, item) in newItem.withIndex()) {
+                if (oldItem.getOrNull(index) != item) {
+                    changed.add(Pair(index, item))
+                }
+            }
+            return if (changed.isNotEmpty()) AdapterItem.TopSitePagerPayload(changed) else null
+        }
     }
 }

app/src/test/java/org/mozilla/fenix/home/sessioncontrol/viewholders/topsites/TopSitesAdapterTest.kt

@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.home.sessioncontrol.viewholders.topsites
+
+import mozilla.components.feature.top.sites.TopSite
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class TopSitesAdapterTest {
+
+    @Test
+    fun testDiffCallback() {
+        val topSite = TopSite(
+            id = 1L,
+            title = "Title1",
+            url = "https://mozilla.org",
+            null,
+            TopSite.Type.DEFAULT
+        )
+        val topSite2 = TopSite(
+            id = 1L,
+            title = "Title2",
+            url = "https://mozilla.org",
+            null,
+            TopSite.Type.DEFAULT
+        )
+
+        assertEquals(
+            TopSitesAdapter.TopSitesDiffCallback.getChangePayload(topSite, topSite2),
+            TopSitesAdapter.TopSitePayload("Title2")
+        )
+
+        val topSite3 = TopSite(
+            id = 2L,
+            title = "Title2",
+            url = "https://firefox.org",
+            null,
+            TopSite.Type.DEFAULT
+        )
+
+        assertEquals(
+            TopSitesAdapter.TopSitesDiffCallback.getChangePayload(topSite, topSite3),
+            null
+        )
+    }
+}

app/src/test/java/org/mozilla/fenix/home/sessioncontrol/viewholders/topsites/TopSitesPagerAdapterTest.kt

@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.home.sessioncontrol.viewholders.topsites
+
+import mozilla.components.feature.top.sites.TopSite
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.mozilla.fenix.home.sessioncontrol.AdapterItem
+
+class TopSitesPagerAdapterTest {
+    @Test
+    fun testDiffCallback() {
+        val topSite = TopSite(
+            id = 1L,
+            title = "Title1",
+            url = "https://mozilla.org",
+            null,
+            TopSite.Type.DEFAULT
+        )
+
+        val topSite2 = TopSite(
+            id = 2L,
+            title = "Title2",
+            url = "https://mozilla.org",
+            null,
+            TopSite.Type.DEFAULT
+        )
+
+        val topSite3 = TopSite(
+            id = 3L,
+            title = "Title2",
+            url = "https://firefox.org",
+            null,
+            TopSite.Type.DEFAULT
+        )
+
+        assertEquals(
+            TopSitesPagerAdapter.TopSiteListDiffCallback.getChangePayload(
+                listOf(topSite, topSite3),
+                listOf(topSite, topSite2)
+            ),
+            AdapterItem.TopSitePagerPayload(setOf(Pair(1, topSite2)))
+        )
+    }
+}