fix #212, アプリ設定画面のListViewが過剰に更新されるのを防ぐ

app/src/main/java/jp/juggler/subwaytooter/ActAppSetting.kt

@@ -18,15 +18,19 @@ import android.widget.*
 import androidx.annotation.ColorInt
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
-import androidx.appcompat.widget.SwitchCompat
 import androidx.core.content.ContextCompat
 import androidx.core.content.FileProvider
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
 import com.jrummyapps.android.colorpicker.ColorPickerDialog
 import com.jrummyapps.android.colorpicker.ColorPickerDialogListener
 import jp.juggler.subwaytooter.appsetting.AppDataExporter
 import jp.juggler.subwaytooter.appsetting.AppSettingItem
 import jp.juggler.subwaytooter.appsetting.SettingType
 import jp.juggler.subwaytooter.appsetting.appSettingRoot
+import jp.juggler.subwaytooter.databinding.ActAppSettingBinding
+import jp.juggler.subwaytooter.databinding.LvSettingItemBinding
 import jp.juggler.subwaytooter.dialog.DlgAppPicker
 import jp.juggler.subwaytooter.notification.restartAllWorker
 import jp.juggler.subwaytooter.pref.impl.BooleanPref
@@ -47,8 +51,10 @@ import java.io.File
 import java.io.FileOutputStream
 import java.io.InputStream
 import java.io.OutputStreamWriter
+import java.lang.ref.WeakReference
 import java.text.NumberFormat
 import java.util.*
+import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.TimeUnit
 import java.util.zip.ZipEntry
 import java.util.zip.ZipOutputStream
@@ -79,9 +85,14 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
 
     lateinit var pref: SharedPreferences
     lateinit var handler: Handler
-    private lateinit var lvList: ListView
+
-    private lateinit var adapter: MyAdapter
+    val views by lazy {
-    private lateinit var etSearch: EditText
+        ActAppSettingBinding.inflate(layoutInflater)
+    }
+
+    private val adapter by lazy {
+        MyAdapter()
+    }
 
     private val arNoop = ActivityResultHandler(log) { }
 
@@ -108,6 +119,18 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
         }
     }
 
+    private var pendingQuery: String? = null
+
+    private val procQuery: Runnable = Runnable {
+        if (pendingQuery != null) load(null, pendingQuery)
+    }
+
+    private val divider = Any()
+
+    private var lastSection: AppSettingItem? = null
+    private var lastQuery: String? = null
+    private var colorTarget: AppSettingItem? = null
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         backPressed {
@@ -151,17 +174,15 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
     }
 
     private fun initUi() {
-        setContentView(R.layout.act_app_setting)
+        setContentView(views.root)
         App1.initEdgeToEdge(this)
 
-        Styler.fixHorizontalPadding0(findViewById(R.id.llContent))
+        Styler.fixHorizontalPadding0(views.llContent)
-        lvList = findViewById(R.id.lvList)
 
-        adapter = MyAdapter()
+        views.lvList.layoutManager = LinearLayoutManager(this)
-        lvList.adapter = adapter
+        views.lvList.adapter = adapter
 
-        etSearch = findViewById<EditText>(R.id.etSearch).apply {
+        views.etSearch.addTextChangedListener(object : TextWatcher {
-            addTextChangedListener(object : TextWatcher {
             override fun afterTextChanged(p0: Editable?) {
                 pendingQuery = p0?.toString()
                 this@ActAppSetting.handler.removeCallbacks(procQuery)
@@ -184,9 +205,8 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
             ) {
             }
         })
-        }
 
-        findViewById<View>(R.id.btnSearchReset).setOnClickListener(this@ActAppSetting)
+        views.btnSearchReset.setOnClickListener(this)
     }
 
     private fun removeDefaultPref() {
@@ -215,34 +235,18 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
         when (v.id) {
             R.id.btnSearchReset -> {
                 handler.removeCallbacks(procQuery)
-                etSearch.setText("")
+                views.etSearch.setText("")
-                etSearch.hideKeyboard()
+                views.etSearch.hideKeyboard()
                 load(lastSection, null)
             }
         }
     }
 
-    ///////////////////////////////////////////////////////////////
-    private var pendingQuery: String? = null
-
-    private val procQuery: Runnable = Runnable {
-        if (pendingQuery != null) load(null, pendingQuery)
-    }
-
-    ///////////////////////////////////////////////////////////////
-
-    private val divider = Any()
-    private val list = ArrayList<Any>()
-
-    private var lastSection: AppSettingItem? = null
-    private var lastQuery: String? = null
-
     private fun load(section: AppSettingItem?, query: String?) {
-        list.clear()
+        adapter.items = buildList {
-
             var lastPath: String? = null
             fun addParentPath(item: AppSettingItem) {
-            list.add(divider)
+                add(divider)
 
                 val pathList = ArrayList<String>()
                 var parent = item.parent
@@ -253,12 +257,14 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                 val path = pathList.joinToString("/")
                 if (path != lastPath) {
                     lastPath = path
-                list.add(path)
+                    add(path)
-                list.add(divider)
+                    add(divider)
                 }
             }
 
-        if (query?.isNotEmpty() == true) {
+            when {
+                // 検索キーワードあり
+                query?.isNotBlank() == true -> {
                     lastQuery = query
                     fun scanGroup(level: Int, item: AppSettingItem) {
                         if (item.caption == 0) return
@@ -267,7 +273,9 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                             if (item.type == SettingType.Group) {
                                 for (child in item.items) {
                                     if (child.caption == 0) continue
-                            if (getString(item.caption).contains(query, ignoreCase = true)) {
+                                    if (getString(item.caption).contains(query,
+                                            ignoreCase = true)
+                                    ) {
                                         match = true
                                         break
                                     }
@@ -275,17 +283,15 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                                 if (match) {
                                     // put entire group
                                     addParentPath(item)
-                            list.add(item)
+                                    add(item)
-                            for (child in item.items) {
+                                    addAll(item.items)
-                                list.add(child)
-                            }
                                 }
                                 return
                             }
 
                             if (match) {
                                 addParentPath(item)
-                        list.add(item)
+                                add(item)
                             }
                         }
                         for (child in item.items) {
@@ -293,31 +299,29 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                         }
                     }
                     scanGroup(0, appSettingRoot)
-            if (list.isNotEmpty()) list.add(divider)
+                }
-        } else if (section == null) {
                 // show root page
+                section == null -> {
                     val root = appSettingRoot
                     lastQuery = null
                     lastSection = null
                     for (child in root.items) {
-                list.add(divider)
+                        add(divider)
-                list.add(child)
+                        add(child)
+                    }
                 }
-            list.add(divider)
-        } else {
                 // show section page
+                else -> {
                     lastSection = section
                     lastQuery = null
                     fun scanGroup(level: Int, parent: AppSettingItem?) {
                         parent ?: return
                         for (item in parent.items) {
-                    list.add(divider)
+                            add(divider)
-                    list.add(item)
+                            add(item)
                             if (item.items.isNotEmpty()) {
                                 if (item.type == SettingType.Group) {
-                            for (child in item.items) {
+                                    addAll(item.items)
-                                list.add(child)
-                            }
                                 } else {
                                     scanGroup(level + 1, item)
                                 }
@@ -325,41 +329,11 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                         }
                     }
                     scanGroup(0, section.cast())
-            if (list.isNotEmpty()) list.add(divider)
                 }
-        adapter.notifyDataSetChanged()
-        lvList.setSelectionFromTop(0, 0)
             }
-
+            if (isNotEmpty()) add(divider)
-    inner class MyAdapter : BaseAdapter() {
-
-        override fun getCount(): Int = list.size
-        override fun getItemId(position: Int): Long = 0
-        override fun getItem(position: Int): Any = list[position]
-        override fun getViewTypeCount(): Int = SettingType.values().maxByOrNull { it.id }!!.id + 1
-
-        override fun getItemViewType(position: Int): Int =
-            when (val item = list[position]) {
-                is AppSettingItem -> item.type.id
-                is String -> SettingType.Path.id
-                divider -> SettingType.Divider.id
-                else -> error("can't generate view for type $item")
-            }
-
-        // true if the item at the specified position is not a separator.
-        // (A separator is a non-selectable, non-clickable item).
-        override fun areAllItemsEnabled(): Boolean = false
-
-        override fun isEnabled(position: Int): Boolean = list[position] is AppSettingItem
-
-        override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View =
-            when (val item = list[position]) {
-                is AppSettingItem ->
-                    getViewSettingItem(item, convertView, parent)
-                is String -> getViewPath(item, convertView)
-                divider -> getViewDivider(convertView)
-                else -> error("can't generate view for type $item")
         }
+        views.lvList.scrollToPosition(0)
     }
 
     private fun dip(dp: Float): Int =
@@ -367,62 +341,6 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
 
     private fun dip(dp: Int): Int = dip(dp.toFloat())
 
-    private fun getViewDivider(convertView: View?): View =
-        convertView ?: FrameLayout(this@ActAppSetting).apply {
-            layoutParams = AbsListView.LayoutParams(
-                AbsListView.LayoutParams.MATCH_PARENT,
-                AbsListView.LayoutParams.WRAP_CONTENT
-            )
-            addView(View(this@ActAppSetting).apply {
-                layoutParams = FrameLayout.LayoutParams(
-                    AbsListView.LayoutParams.MATCH_PARENT,
-                    dip(1)
-                ).apply {
-                    val marginX = 0
-                    val marginY = dip(6)
-                    setMargins(marginX, marginY, marginX, marginY)
-                }
-                setBackgroundColor(context.attrColor(R.attr.colorSettingDivider))
-            })
-        }
-
-    private fun getViewPath(path: String, convertView: View?): View {
-        val tv: MyTextView =
-            convertView.cast() ?: MyTextView(this@ActAppSetting).apply {
-                layoutParams = AbsListView.LayoutParams(
-                    AbsListView.LayoutParams.MATCH_PARENT,
-                    AbsListView.LayoutParams.WRAP_CONTENT
-                )
-                val padX = 0
-                val padY = dip(3)
-                setTypeface(typeface, Typeface.BOLD)
-                setPaddingRelative(padX, padY, padX, padY)
-            }
-        tv.text = path
-        return tv
-    }
-
-    private fun getViewSettingItem(
-        item: AppSettingItem,
-        convertView: View?,
-        parent: ViewGroup?,
-    ): View {
-        val view: View
-        val holder: ViewHolderSettingItem
-        if (convertView != null) {
-            view = convertView
-            holder = convertView.tag.cast()!!
-        } else {
-            view = layoutInflater.inflate(R.layout.lv_setting_item, parent, false)
-            holder = ViewHolderSettingItem(view)
-            view.tag = holder
-        }
-        holder.bind(item)
-        return view
-    }
-
-    private var colorTarget: AppSettingItem? = null
-
     override fun onDialogDismissed(dialogId: Int) {
     }
 
@@ -438,40 +356,146 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
         colorTarget.changed(this)
     }
 
-    inner class ViewHolderSettingItem(viewRoot: View) :
+    inner class MyAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
+        var items: List<Any> = emptyList()
+            set(newItems) {
+                val oldItems = field
+                field = newItems
+                DiffUtil.calculateDiff(object : DiffUtil.Callback() {
+                    override fun getOldListSize() = oldItems.size
+                    override fun getNewListSize() = newItems.size
+                    override fun areItemsTheSame(
+                        oldItemPosition: Int,
+                        newItemPosition: Int,
+                    ) = oldItems.elementAtOrNull(oldItemPosition) == newItems.elementAtOrNull(
+                        newItemPosition)
+
+                    override fun areContentsTheSame(
+                        oldItemPosition: Int,
+                        newItemPosition: Int,
+                    ) = oldItems.elementAtOrNull(oldItemPosition) == newItems.elementAtOrNull(
+                        newItemPosition)
+                }, true).dispatchUpdatesTo(this)
+            }
+
+        private val settingHolderList =
+            ConcurrentHashMap<AppSettingItem, WeakReference<VhSettingItem>>()
+
+        override fun getItemCount() = items.size
+
+        override fun getItemViewType(position: Int) =
+            when (val item = items.elementAtOrNull(position)) {
+                divider -> SettingType.Divider.id
+                is String -> SettingType.Path.id
+                is AppSettingItem -> item.type.id
+                else -> error("can't generate view for type $item")
+            }
+
+        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+            when (SettingType.map[viewType]) {
+                SettingType.Divider -> VhDivider()
+                SettingType.Path -> VhPath(parent)
+                else -> VhSettingItem(this@ActAppSetting, parent)
+            }
+
+        override fun onBindViewHolder(viewHolder: RecyclerView.ViewHolder, position: Int) {
+            when (val item = items.elementAtOrNull(position)) {
+                divider -> viewHolder.cast<VhDivider>()
+                is String -> viewHolder.cast<VhPath>()?.bind(item)
+                is AppSettingItem -> if (viewHolder is VhSettingItem) {
+                    viewHolder.bind(item)
+                    // 古い紐付けを削除
+                    settingHolderList.entries.filter {
+                        when (it.value.get()) {
+                            null, viewHolder -> true
+                            else -> false
+                        }
+                    }.forEach { settingHolderList.remove(it.key) }
+                    // 新しい紐付けを覚える
+                    settingHolderList[item] = WeakReference(viewHolder)
+                }
+            }
+        }
+
+        fun findVhSetting(item: AppSettingItem) = settingHolderList[item]?.get()
+    }
+
+    private inner class VhDivider(
+        viewRoot: FrameLayout = FrameLayout(this@ActAppSetting).apply {
+            layoutParams = RecyclerView.LayoutParams(
+                RecyclerView.LayoutParams.MATCH_PARENT,
+                RecyclerView.LayoutParams.WRAP_CONTENT
+            )
+            addView(View(this@ActAppSetting).apply {
+                layoutParams = FrameLayout.LayoutParams(
+                    FrameLayout.LayoutParams.MATCH_PARENT,
+                    dip(1)
+                ).apply {
+                    val marginX = 0
+                    val marginY = dip(6)
+                    setMargins(marginX, marginY, marginX, marginY)
+                }
+                setBackgroundColor(context.attrColor(R.attr.colorSettingDivider))
+            })
+        },
+    ) : RecyclerView.ViewHolder(viewRoot)
+
+    private inner class VhPath(
+        val parent: ViewGroup,
+        val viewRoot: MyTextView = MyTextView(this@ActAppSetting).apply {
+            layoutParams = RecyclerView.LayoutParams(
+                RecyclerView.LayoutParams.MATCH_PARENT,
+                RecyclerView.LayoutParams.WRAP_CONTENT
+            )
+            val padX = 0
+            val padY = dip(3)
+            setTypeface(typeface, Typeface.BOLD)
+            setPaddingRelative(padX, padY, padX, padY)
+        },
+    ) : RecyclerView.ViewHolder(viewRoot) {
+        fun bind(path: String) {
+            viewRoot.text = path
+        }
+    }
+
+    // not private
+    class VhSettingItem(
+        val activity: ActAppSetting,
+        parent: ViewGroup,
+        private val views: LvSettingItemBinding = LvSettingItemBinding
+            .inflate(activity.layoutInflater, parent, false),
+    ) : RecyclerView.ViewHolder(views.root),
         TextWatcher,
         AdapterView.OnItemSelectedListener,
         CompoundButton.OnCheckedChangeListener {
 
-        private val tvCaption: TextView = viewRoot.findViewById(R.id.tvCaption)
+        private val btnAction = views.btnAction
-        private val btnAction: Button = viewRoot.findViewById(R.id.btnAction)
 
-        private val checkBox: CheckBox = viewRoot.findViewById<CheckBox>(R.id.checkBox)
+        private val checkBox = views.checkBox
             .also { it.setOnCheckedChangeListener(this) }
 
-        private val swSwitch: SwitchCompat = viewRoot.findViewById<SwitchCompat>(R.id.swSwitch)
+        private val swSwitch = views.swSwitch
             .also { it.setOnCheckedChangeListener(this) }
 
-        val llExtra: LinearLayout = viewRoot.findViewById(R.id.llExtra)
+        val llExtra = views.llExtra
 
-        val textView1: TextView = viewRoot.findViewById(R.id.textView1)
+        val textView1 = views.textView1
 
-        private val llButtonBar: LinearLayout = viewRoot.findViewById(R.id.llButtonBar)
+        private val llButtonBar = views.llButtonBar
-        private val vColor: View = viewRoot.findViewById(R.id.vColor)
+        private val vColor = views.vColor
-        private val btnEdit: Button = viewRoot.findViewById(R.id.btnEdit)
+        private val btnEdit = views.btnEdit
-        private val btnReset: Button = viewRoot.findViewById(R.id.btnReset)
+        private val btnReset = views.btnReset
 
-        private val spSpinner: Spinner = viewRoot.findViewById<Spinner>(R.id.spSpinner)
+        private val spSpinner = views.spSpinner
             .also { it.onItemSelectedListener = this }
 
-        private val etEditText: EditText = viewRoot.findViewById<EditText>(R.id.etEditText)
+        private val etEditText = views.etEditText
             .also { it.addTextChangedListener(this) }
 
-        private val tvDesc: TextView = viewRoot.findViewById(R.id.tvDesc)
+        private val tvDesc = views.tvDesc
-        private val tvError: TextView = viewRoot.findViewById(R.id.tvError)
+        private val tvError = views.tvError
 
-        val activity: ActAppSetting
+        private val pref = activity.pref
-            get() = this@ActAppSetting
 
         var item: AppSettingItem? = null
 
@@ -482,7 +506,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
             try {
                 this.item = item
 
-                tvCaption.vg(false)
+                views.tvCaption.vg(false)
                 btnAction.vg(false)
                 checkBox.vg(false)
                 swSwitch.vg(false)
@@ -495,11 +519,11 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                 tvDesc.vg(false)
                 tvError.vg(false)
 
-                val name = if (item.caption == 0) "" else getString(item.caption)
+                val name = if (item.caption == 0) "" else activity.getString(item.caption)
 
                 if (item.desc != 0) {
                     tvDesc.vg(true)
-                    tvDesc.text = getString(item.desc)
+                    tvDesc.text = activity.getString(item.desc)
                     if (item.descClickSet) {
                         tvDesc.background = ContextCompat.getDrawable(
                             activity,
@@ -520,7 +544,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                         btnAction.text = name
                         btnAction.isEnabledAlpha = item.enabled
                         btnAction.setOnClickListener {
-                            load(item.cast()!!, null)
+                            activity.load(item.cast()!!, null)
                         }
                     }
 
@@ -539,7 +563,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                         checkBox.vg(false) // skip animation
                         checkBox.text = name
                         checkBox.isEnabledAlpha = item.enabled
-                        checkBox.isChecked = bp(pref)
+                        checkBox.isChecked = bp(activity.pref)
                         checkBox.vg(true)
                     }
 
@@ -548,9 +572,9 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                             item.pref.cast() ?: error("$name has no boolean pref")
                         showCaption(name)
                         swSwitch.vg(false) // skip animation
-                        setSwitchColor(swSwitch)
+                        activity.setSwitchColor(swSwitch)
                         swSwitch.isEnabledAlpha = item.enabled
-                        swSwitch.isChecked = bp(pref)
+                        swSwitch.isChecked = bp(activity.pref)
                         swSwitch.vg(true)
                     }
 
@@ -561,7 +585,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                     SettingType.Sample -> {
                         llExtra.vg(true)
                         llExtra.removeAllViews()
-                        layoutInflater.inflate(item.sampleLayoutId, llExtra, true)
+                        activity.layoutInflater.inflate(item.sampleLayoutId, llExtra, true)
                         item.sampleUpdate(activity, llExtra)
                     }
 
@@ -570,12 +594,12 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                         showCaption(name)
                         llButtonBar.vg(true)
                         vColor.vg(true)
-                        vColor.setBackgroundColor(ip(pref))
+                        vColor.setBackgroundColor(ip(activity.pref))
                         btnEdit.isEnabledAlpha = item.enabled
                         btnReset.isEnabledAlpha = item.enabled
                         btnEdit.setOnClickListener {
-                            colorTarget = item
+                            activity.colorTarget = item
-                            val color = ip(pref)
+                            val color = ip(activity.pref)
                             val builder = ColorPickerDialog.newBuilder()
                                 .setDialogType(ColorPickerDialog.TYPE_CUSTOM)
                                 .setAllowPresets(true)
@@ -585,7 +609,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                             builder.show(activity)
                         }
                         btnReset.setOnClickListener {
-                            pref.edit().remove(ip).apply()
+                            activity.pref.edit().remove(ip).apply()
                             showColor()
                             item.changed.invoke(activity)
                         }
@@ -602,11 +626,12 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                             // 整数型の設定のSpinnerは全て選択肢を単純に覚える
                             val argsInt = item.spinnerArgs
                             if (argsInt != null) {
-                                initSpinner(spSpinner, argsInt.map { getString(it) })
+                                activity.initSpinner(spSpinner,
+                                    argsInt.map { activity.getString(it) })
                             } else {
-                                initSpinner(spSpinner, item.spinnerArgsProc(activity))
+                                activity.initSpinner(spSpinner, item.spinnerArgsProc(activity))
                             }
-                            spSpinner.setSelection(pi.invoke(pref))
+                            spSpinner.setSelection(pi.invoke(activity.pref))
                         } else {
                             item.spinnerInitializer.invoke(activity, spSpinner)
                         }
@@ -615,18 +640,13 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
                     SettingType.EditText -> {
                         showCaption(name)
                         etEditText.vg(true)
-
                             ?: error("EditText must have preference.")
                         etEditText.inputType = item.inputType
                         val text = when (val pi = item.pref) {
-                            is FloatPref -> {
+                            is FloatPref ->
-                                item.fromFloat.invoke(activity, pi(pref))
+                                item.fromFloat.invoke(activity, pi(activity.pref))
-                            }
+                            is StringPref ->
-
+                                pi(activity.pref)
-                            is StringPref -> {
-                                pi(pref)
-                            }
-
                             else -> error("EditText han incorrect pref $pi")
                         }
                         etEditText.setText(text)
@@ -662,8 +682,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
 
         private fun showCaption(caption: String) {
             if (caption.isNotEmpty()) {
-                tvCaption.vg(true)
+                views.tvCaption.vg(true)?.text = caption
-                tvCaption.text = caption
                 updateCaption()
             }
         }
@@ -672,16 +691,16 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
             val item = item ?: return
             val key = item.pref?.key ?: return
 
-            val sample: TextView = tvCaption
+            val sample = views.tvCaption
-            var defaultExtra = defaultLineSpacingExtra[key]
+            var defaultExtra = activity.defaultLineSpacingExtra[key]
             if (defaultExtra == null) {
                 defaultExtra = sample.lineSpacingExtra
-                defaultLineSpacingExtra[key] = defaultExtra
+                activity.defaultLineSpacingExtra[key] = defaultExtra
             }
-            var defaultMultiplier = defaultLineSpacingMultiplier[key]
+            var defaultMultiplier = activity.defaultLineSpacingMultiplier[key]
             if (defaultMultiplier == null) {
                 defaultMultiplier = sample.lineSpacingMultiplier
-                defaultLineSpacingMultiplier[key] = defaultMultiplier
+                activity.defaultLineSpacingMultiplier[key] = defaultMultiplier
             }
 
             val size = item.captionFontSize.invoke(activity)
@@ -705,7 +724,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
         fun showColor() {
             val item = item ?: return
             val ip = item.pref.cast<IntPref>() ?: return
-            val c = ip(pref)
+            val c = ip(activity.pref)
             vColor.setBackgroundColor(c)
         }
 
@@ -724,15 +743,15 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
             when (val pi = item.pref) {
 
                 is StringPref -> {
-                    pref.edit().put(pi, sv).apply()
+                    activity.pref.edit().put(pi, sv).apply()
                 }
 
                 is FloatPref -> {
                     val fv = item.toFloat.invoke(activity, sv)
                     if (fv.isFinite()) {
-                        pref.edit().put(pi, fv).apply()
+                        activity.pref.edit().put(pi, fv).apply()
                     } else {
-                        pref.edit().remove(pi.key).apply()
+                        activity.pref.edit().remove(pi.key).apply()
                     }
                 }
 
@@ -756,7 +775,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
             if (bindingBusy) return
             val item = item ?: return
             when (val pi = item.pref) {
-                is IntPref -> pref.edit().put(pi, spSpinner.selectedItemPosition).apply()
+                is IntPref -> activity.pref.edit().put(pi, spSpinner.selectedItemPosition).apply()
                 else -> item.spinnerOnSelected.invoke(activity, spSpinner, position)
             }
             item.changed.invoke(activity)
@@ -865,13 +884,9 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
         finish()
     }
 
-    fun findItemViewHolder(item: AppSettingItem?): ViewHolderSettingItem? {
+    fun findItemViewHolder(item: AppSettingItem?): VhSettingItem? {
         if (item != null) {
-            for (i in 0 until lvList.childCount) {
+            adapter.findVhSetting(item)
-                val view = lvList.getChildAt(i)
-                val holder: ViewHolderSettingItem? = view?.tag?.cast()
-                if (holder?.item == item) return holder
-            }
         }
         return null
     }
@@ -884,8 +899,7 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
     }
 
     // リスト内部のSwitchCompat全ての色を更新する
-    fun setSwitchColor() =
+    fun setSwitchColor() = setSwitchColor(views.lvList)
-        setSwitchColor(lvList)
 
     //////////////////////////////////////////////////////
 
@@ -914,8 +928,8 @@ class ActAppSetting : AppCompatActivity(), ColorPickerDialogListener, View.OnCli
         return Float.NaN
     }
 
-    private val defaultLineSpacingExtra = HashMap<String, Float>()
+    val defaultLineSpacingExtra = HashMap<String, Float>()
-    private val defaultLineSpacingMultiplier = HashMap<String, Float>()
+    val defaultLineSpacingMultiplier = HashMap<String, Float>()
 
     private fun handleFontResult(item: AppSettingItem?, data: Intent, fileName: String) {
         item ?: error("handleFontResult : setting item is null")

app/src/main/java/jp/juggler/subwaytooter/appsetting/AppSettingItem.kt

@@ -18,6 +18,7 @@ import jp.juggler.subwaytooter.util.CustomShareTarget
 import jp.juggler.subwaytooter.util.openBrowser
 import jp.juggler.util.*
 import org.jetbrains.anko.backgroundDrawable
+import java.util.concurrent.atomic.AtomicInteger
 
 enum class SettingType(val id: Int) {
     Path(0),
@@ -33,6 +34,12 @@ enum class SettingType(val id: Int) {
     TextWithSelector(10),
     CheckBox(11),
     Section(12)
+
+    ;
+
+    companion object {
+        val map = values().associateBy { it.id }
+    }
 }
 
 class AppSettingItem(
@@ -41,6 +48,7 @@ class AppSettingItem(
     @StringRes val caption: Int,
     val pref: BasePref<*>? = null,
 ) {
+    val id = idSeed.incrementAndGet()
 
     @StringRes
     var desc: Int = 0
@@ -191,7 +199,11 @@ class AppSettingItem(
         for (item in items) item.scan(block)
     }
 
+    override fun hashCode() = id
+    override fun equals(other: Any?) = (other as? AppSettingItem)?.id == this.id
+
     companion object {
+        var idSeed = AtomicInteger(0)
 
         var SAMPLE_CCD_HEADER: AppSettingItem? = null
         var SAMPLE_CCD_BODY: AppSettingItem? = null
@@ -467,7 +479,7 @@ val appSettingRoot = AppSettingItem(null, SettingType.Section, R.string.app_sett
 
         spinner(PrefI.ipMediaBackground, R.string.background_pattern) {
             MediaBackgroundDrawable.Kind.values()
-                .filter{it.isMediaBackground}
+                .filter { it.isMediaBackground }
                 .map { it.name }
         }
 

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

@@ -39,7 +39,7 @@
 
     </LinearLayout>
 
-    <ListView
+    <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/lvList"
         android:layout_width="match_parent"
         android:layout_height="0dp"