Use list adapter in app drawer

app/src/main/kotlin/org/fossify/launcher/adapters/LaunchersAdapter.kt

@@ -1,9 +1,12 @@
 package org.fossify.launcher.adapters
 
+import android.annotation.SuppressLint
 import android.graphics.drawable.Drawable
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.ListAdapter
 import androidx.recyclerview.widget.RecyclerView
 import com.bumptech.glide.Glide
 import com.bumptech.glide.load.engine.DiskCacheStrategy
@@ -21,78 +24,41 @@ import org.fossify.launcher.databinding.ItemLauncherLabelBinding
 import org.fossify.launcher.extensions.config
 import org.fossify.launcher.interfaces.AllAppsListener
 import org.fossify.launcher.models.AppLauncher
-import org.fossify.launcher.models.HomeScreenGridItem
 
 class LaunchersAdapter(
     val activity: SimpleActivity,
-    launchers: ArrayList<AppLauncher>,
     val allAppsListener: AllAppsListener,
     val itemClick: (Any) -> Unit
-) : RecyclerView.Adapter<LaunchersAdapter.ViewHolder>(), RecyclerViewFastScroller.OnPopupTextUpdate {
+) : ListAdapter<AppLauncher, LaunchersAdapter.ViewHolder>(AppLauncherDiffCallback()), RecyclerViewFastScroller.OnPopupTextUpdate {
 
     private var textColor = activity.getProperTextColor()
     private var iconPadding = 0
-    private var wereFreshIconsLoaded = false
-    private var filterQuery: String? = null
-    private var filteredLaunchers: List<AppLauncher> = launchers
-
-    var launchers: ArrayList<AppLauncher> = launchers
-        set(value) {
-            field = value
-            updateFilter()
-        }
 
     init {
+        setHasStableIds(true)
         calculateIconWidth()
     }
 
+    override fun getItemId(position: Int): Long {
+        return getItem(position).getLauncherIdentifier().hashCode().toLong()
+    }
+
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
         val binding = ItemLauncherLabelBinding.inflate(LayoutInflater.from(parent.context), parent, false)
         return ViewHolder(binding.root)
     }
 
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
-        holder.bindView(filteredLaunchers[position])
+        holder.bindView(getItem(position))
     }
 
-    override fun getItemCount() = filteredLaunchers.size
-
     private fun calculateIconWidth() {
         val currentColumnCount = activity.config.drawerColumnCount
-
         val iconWidth = activity.realScreenSize.x / currentColumnCount
         iconPadding = (iconWidth * 0.1f).toInt()
     }
 
-    fun hideIcon(item: HomeScreenGridItem) {
-        val itemToRemove = launchers.firstOrNull { it.getLauncherIdentifier() == item.getItemIdentifier() }
-        if (itemToRemove != null) {
-            val position = launchers.indexOfFirst { it.getLauncherIdentifier() == item.getItemIdentifier() }
-            val filteredPosition = filteredLaunchers.indexOfFirst { it.getLauncherIdentifier() == item.getItemIdentifier() }
-            launchers.removeAt(position)
-            updateFilter()
-            notifyItemRemoved(filteredPosition)
-        }
-    }
-
-    fun updateItems(newItems: ArrayList<AppLauncher>) {
-        val oldSum = launchers.sumOf { it.getHashToCompare() }
-        val newSum = newItems.sumOf { it.getHashToCompare() }
-        if (oldSum != newSum || !wereFreshIconsLoaded) {
-            launchers = newItems
-            notifyDataSetChanged()
-            wereFreshIconsLoaded = true
-        }
-    }
-
-    fun updateSearchQuery(newQuery: String?) {
-        if (filterQuery != newQuery) {
-            filterQuery = newQuery
-            updateFilter()
-            notifyDataSetChanged()
-        }
-    }
-
+    @SuppressLint("NotifyDataSetChanged")
     fun updateTextColor(newTextColor: Int) {
         if (newTextColor != textColor) {
             textColor = newTextColor
@@ -100,10 +66,6 @@ class LaunchersAdapter(
         }
     }
 
-    private fun updateFilter() {
-        filteredLaunchers = launchers.filter { filterQuery == null || it.title.contains(filterQuery!!, ignoreCase = true) }
-    }
-
     inner class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
         fun bindView(launcher: AppLauncher): View {
             val binding = ItemLauncherLabelBinding.bind(itemView)
@@ -112,7 +74,6 @@ class LaunchersAdapter(
                 binding.launcherLabel.setTextColor(textColor)
                 binding.launcherIcon.setPadding(iconPadding, iconPadding, iconPadding, 0)
 
-                // Once all images are loaded and crossfades are done, directly set drawables
                 if (launcher.drawable != null && binding.launcherIcon.tag == true) {
                     binding.launcherIcon.setImageDrawable(launcher.drawable)
                 } else {
@@ -127,14 +88,13 @@ class LaunchersAdapter(
                         .into(object : DrawableImageViewTarget(binding.launcherIcon) {
                             override fun onResourceReady(resource: Drawable, transition: Transition<in Drawable>?) {
                                 super.onResourceReady(resource, transition)
-                                // Set tag to true to mark that crossfade was already done on this view
                                 view.tag = true
                             }
                         })
                 }
 
                 setOnClickListener { itemClick(launcher) }
-                setOnLongClickListener { view ->
+                setOnLongClickListener {
                     val location = IntArray(2)
                     getLocationOnScreen(location)
                     allAppsListener.onAppLauncherLongPressed((location[0] + width / 2).toFloat(), location[1].toFloat(), launcher)
@@ -146,5 +106,13 @@ class LaunchersAdapter(
         }
     }
 
-    override fun onChange(position: Int) = filteredLaunchers.getOrNull(position)?.getBubbleText() ?: ""
+    override fun onChange(position: Int) = currentList.getOrNull(position)?.getBubbleText() ?: ""
+}
+
+private class AppLauncherDiffCallback : DiffUtil.ItemCallback<AppLauncher>() {
+    override fun areItemsTheSame(oldItem: AppLauncher, newItem: AppLauncher): Boolean {
+        return oldItem.getLauncherIdentifier().hashCode().toLong() == newItem.getLauncherIdentifier().hashCode().toLong()
+    }
+
+    override fun areContentsTheSame(oldItem: AppLauncher, newItem: AppLauncher) = oldItem == newItem
 }

app/src/main/kotlin/org/fossify/launcher/fragments/AllAppsFragment.kt

@@ -26,6 +26,8 @@ class AllAppsFragment(context: Context, attributeSet: AttributeSet) : MyFragment
     var ignoreTouches = false
     var hasTopPadding = false
 
+    private var launchers = emptyList<AppLauncher>()
+
     @SuppressLint("ClickableViewAccessibility")
     override fun setupFragment(activity: MainActivity) {
         this.activity = activity
@@ -61,7 +63,6 @@ class AllAppsFragment(context: Context, attributeSet: AttributeSet) : MyFragment
 
         val layoutManager = binding.allAppsGrid.layoutManager as MyGridLayoutManager
         layoutManager.spanCount = context.config.drawerColumnCount
-        val launchers = (binding.allAppsGrid.adapter as LaunchersAdapter).launchers
         setupAdapter(launchers)
     }
 
@@ -95,26 +96,27 @@ class AllAppsFragment(context: Context, attributeSet: AttributeSet) : MyFragment
         return shouldIntercept
     }
 
-    fun gotLaunchers(appLaunchers: ArrayList<AppLauncher>) {
-        val sorted = appLaunchers.sortedWith(
-            compareBy({
-                it.title.normalizeString().lowercase()
-            }, {
-                it.packageName
-            })
-        ).toMutableList() as ArrayList<AppLauncher>
+    fun gotLaunchers(appLaunchers: List<AppLauncher>) {
+        launchers = appLaunchers.sortedWith(
+            compareBy(
+                { it.title.normalizeString().lowercase() },
+                { it.packageName }
+            )
+        )
 
-        setupAdapter(sorted)
+        setupAdapter(launchers)
     }
 
-    private fun setupAdapter(launchers: ArrayList<AppLauncher>) {
+    private fun getAdapter() = binding.allAppsGrid.adapter as? LaunchersAdapter
+
+    private fun setupAdapter(launchers: List<AppLauncher>) {
         activity?.runOnUiThread {
             val layoutManager = binding.allAppsGrid.layoutManager as MyGridLayoutManager
             layoutManager.spanCount = context.config.drawerColumnCount
 
-            val currAdapter = binding.allAppsGrid.adapter
-            if (currAdapter == null) {
-                LaunchersAdapter(activity!!, launchers, this) {
+            var adapter = getAdapter()
+            if (adapter == null) {
+                adapter = LaunchersAdapter(activity!!, this) {
                     activity?.launchApp((it as AppLauncher).packageName, it.activityName)
                     if (activity?.config?.closeAppDrawer == true) {
                         activity?.closeAppDrawer(delayed = true)
@@ -124,14 +126,22 @@ class AllAppsFragment(context: Context, attributeSet: AttributeSet) : MyFragment
                 }.apply {
                     binding.allAppsGrid.adapter = this
                 }
-            } else {
-                (currAdapter as LaunchersAdapter).updateItems(launchers)
             }
+
+            adapter.submitList(launchers.toMutableList())
         }
     }
 
     fun hideIcon(item: HomeScreenGridItem) {
-        (binding.allAppsGrid.adapter as? LaunchersAdapter)?.hideIcon(item)
+        val itemToRemove = launchers.firstOrNull { it.getLauncherIdentifier() == item.getItemIdentifier() }
+        if (itemToRemove != null) {
+            val position = launchers.indexOfFirst { it.getLauncherIdentifier() == item.getItemIdentifier() }
+            launchers = launchers.toMutableList().apply {
+                removeAt(position)
+            }
+
+            getAdapter()?.submitList(launchers)
+        }
     }
 
     fun setupViews(addTopPadding: Boolean = hasTopPadding) {
@@ -172,21 +182,23 @@ class AllAppsFragment(context: Context, attributeSet: AttributeSet) : MyFragment
         val topPadding = if (addTopPadding) activity!!.statusBarHeight else 0
         setPadding(0, topPadding, 0, 0)
         background = ColorDrawable(context.getProperBackgroundColor())
-        (binding.allAppsGrid.adapter as? LaunchersAdapter)?.updateTextColor(context.getProperTextColor())
+        getAdapter()?.updateTextColor(context.getProperTextColor())
 
         binding.searchBar.beVisibleIf(context.config.showSearchBar)
         binding.searchBar.getToolbar().beGone()
         binding.searchBar.updateColors()
         binding.searchBar.setupMenu()
 
-        binding.searchBar.onSearchTextChangedListener = {
-            (binding.allAppsGrid.adapter as? LaunchersAdapter)?.updateSearchQuery(it)
-            showNoResultsPlaceholderIfNeeded()
+        binding.searchBar.onSearchTextChangedListener = { query ->
+            val filtered = launchers.filter { query.isEmpty() || it.title.contains(query, ignoreCase = true) }
+            getAdapter()?.submitList(filtered) {
+                showNoResultsPlaceholderIfNeeded()
+            }
         }
     }
 
     private fun showNoResultsPlaceholderIfNeeded() {
-        val itemCount = binding.allAppsGrid.adapter?.itemCount
+        val itemCount = getAdapter()?.itemCount
         binding.noResultsPlaceholder.beVisibleIf(itemCount != null && itemCount == 0)
     }