databinding: rewrite in kotlin

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-03-27 03:08:47 -06:00
parent 8669c01eaa
commit 48a9fd46a6
25 changed files with 533 additions and 919 deletions
@@ -0,0 +1,103 @@
+/*
+ * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package com.wireguard.android.databinding
+
+import android.content.Context
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.databinding.DataBindingUtil
+import androidx.databinding.ObservableList
+import androidx.databinding.ViewDataBinding
+import androidx.recyclerview.widget.RecyclerView
+import com.wireguard.android.BR
+import java.lang.ref.WeakReference
+
+/**
+ * A generic `RecyclerView.Adapter` backed by a `ObservableKeyedArrayList`.
+ */
+class ObservableKeyedRecyclerViewAdapter<K, E : Keyed<out K>> internal constructor(context: Context, private val layoutId: Int,
+                                                                                   list: ObservableKeyedArrayList<K, E>?) : RecyclerView.Adapter<ObservableKeyedRecyclerViewAdapter.ViewHolder>() {
+    private val callback = OnListChangedCallback(this)
+    private val layoutInflater: LayoutInflater = LayoutInflater.from(context)
+    private var list: ObservableKeyedArrayList<K, E>? = null
+    private var rowConfigurationHandler: RowConfigurationHandler<ViewDataBinding, Any>? = null
+
+    private fun getItem(position: Int): E? = if (list == null || position < 0 || position >= list!!.size) null else list?.get(position)
+
+    override fun getItemCount() = list?.size ?: 0
+
+    override fun getItemId(position: Int) = (getKey(position)?.hashCode() ?: -1).toLong()
+
+    private fun getKey(position: Int): K? = getItem(position)?.key
+
+    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+        holder.binding.setVariable(BR.collection, list)
+        holder.binding.setVariable(BR.key, getKey(position))
+        holder.binding.setVariable(BR.item, getItem(position))
+        holder.binding.executePendingBindings()
+        if (rowConfigurationHandler != null) {
+            val item = getItem(position)
+            if (item != null) {
+                rowConfigurationHandler?.onConfigureRow(holder.binding, item, position)
+            }
+        }
+    }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) = ViewHolder(DataBindingUtil.inflate(layoutInflater, layoutId, parent, false))
+
+    fun setList(newList: ObservableKeyedArrayList<K, E>?) {
+        list?.removeOnListChangedCallback(callback)
+        list = newList
+        list?.addOnListChangedCallback(callback)
+        notifyDataSetChanged()
+    }
+
+    fun setRowConfigurationHandler(rowConfigurationHandler: RowConfigurationHandler<*, *>?) {
+        this.rowConfigurationHandler = rowConfigurationHandler as? RowConfigurationHandler<ViewDataBinding, Any>
+    }
+
+    interface RowConfigurationHandler<B : ViewDataBinding, T> {
+        fun onConfigureRow(binding: B, item: T, position: Int)
+    }
+
+    private class OnListChangedCallback<E : Keyed<*>> constructor(adapter: ObservableKeyedRecyclerViewAdapter<*, E>) : ObservableList.OnListChangedCallback<ObservableList<E>>() {
+        private val weakAdapter: WeakReference<ObservableKeyedRecyclerViewAdapter<*, E>> = WeakReference(adapter)
+
+        override fun onChanged(sender: ObservableList<E>) {
+            val adapter = weakAdapter.get()
+            if (adapter != null)
+                adapter.notifyDataSetChanged()
+            else
+                sender.removeOnListChangedCallback(this)
+        }
+
+        override fun onItemRangeChanged(sender: ObservableList<E>, positionStart: Int,
+                                        itemCount: Int) {
+            onChanged(sender)
+        }
+
+        override fun onItemRangeInserted(sender: ObservableList<E>, positionStart: Int,
+                                         itemCount: Int) {
+            onChanged(sender)
+        }
+
+        override fun onItemRangeMoved(sender: ObservableList<E>, fromPosition: Int,
+                                      toPosition: Int, itemCount: Int) {
+            onChanged(sender)
+        }
+
+        override fun onItemRangeRemoved(sender: ObservableList<E>, positionStart: Int,
+                                        itemCount: Int) {
+            onChanged(sender)
+        }
+
+    }
+
+    class ViewHolder(val binding: ViewDataBinding) : RecyclerView.ViewHolder(binding.root)
+
+    init {
+        setList(list)
+    }
+}