仿微信朋友圈点击评论自动定位到相关行

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <TextView
        android:id="@+id/tv_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="12sp" />
    <TextView
        android:id="@+id/tv_comment"
        android:text="评论"
        android:textSize="14sp"
        android:layout_margin="5dip"
        android:textColor="@color/colorAccent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="300dip">
    <ImageView
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@mipmap/ic_launcher"/>
</RelativeLayout>

data class TopClass(val value: String)

class MainAdapter(private val beans: ArrayList<Any>, val context: Context) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
    var height = 0
    enum class TYPE(val value: Int) {
        TOP(0), NORMAL(1)
    }
    override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): RecyclerView.ViewHolder {
        when(viewType) {
            TYPE.NORMAL.value -> {
                val view = LayoutInflater.from(context).inflate(R.layout.adapter_main, parent, false)
                return MainNormalViewHolder(view)
            }
            TYPE.TOP.value -> {
                val view = LayoutInflater.from(context).inflate(R.layout.adapter_top, parent, false)
                return MainTopViewHolder(view)
            }
        }
        throw Exception()
    }
    override fun getItemCount() = beans.size
    override fun onBindViewHolder(holder: RecyclerView.ViewHolder?, position: Int) {
        if (holder != null) {
            when(getItemViewType(position)) {
                TYPE.NORMAL.value -> {
                    (holder as MainNormalViewHolder).setText(beans[position] as String)
                    holder.clickComment(holder.layoutPosition)
                }
                TYPE.TOP.value -> {}
            }
        }
    }
    override fun getItemViewType(position: Int): Int {
        when(beans[position]) {
            is String -> return TYPE.NORMAL.value
            is TopClass -> return TYPE.TOP.value
        }
        return super.getItemViewType(position)
    }
    inner class MainNormalViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun setText(text: String) {
            itemView.tv_title.text = text
        }
        fun clickComment(position: Int) {
            itemView.tv_comment.setOnClickListener {
                (context as MainActivity).showInputComment(itemView.tv_comment, position)
            }
        }
    }
    inner class MainTopViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1">
    </ScrollView>
    <View
        android:layout_width="match_parent"
        android:layout_height="0.5dip"
        android:background="#666666"></View>
    <LinearLayout
        android:id="@+id/dialog_layout_comment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="确认"/>
    </LinearLayout>
</LinearLayout>

fun showInputComment(commentView: View, position: Int) {
    // RV中评论区起始Y的位置
    val rvInputY = getY(commentView)
    val rvInputHeight = commentView.height
    dialog = Dialog(this, android.R.style.Theme_Translucent_NoTitleBar)
    dialog!!.setContentView(R.layout.dialog_comment)
    dialog!!.show()
    val handler = object : Handler() {}
    handler.postDelayed({
        // 对话框中的输入框Y的位置
        val dialogY = getY(dialog!!.findViewById<LinearLayout>(R.id.dialog_layout_comment))
        rv_main.smoothScrollBy(0, rvInputY - (dialogY - rvInputHeight))
    }, 300)
}
private fun getY(view: View): Int {
    val rect = IntArray(2)
    view.getLocationOnScreen(rect)
    return rect[1]
}

data class BottomClass(val value: String)

handler.postDelayed({
    // 对话框中的输入框Y的位置
    val dialogY = getY(dialog!!.findViewById<LinearLayout>(R.id.dialog_layout_comment))
    if (position == arrays.size - 1) {
        arrays.add(BottomClass(""))
        adapter?.height = dialog!!.findViewById<LinearLayout>(R.id.dialog_layout_comment).height
        adapter?.notifyDataSetChanged()
    }
    rv_main.smoothScrollBy(0, rvInputY - (dialogY - rvInputHeight))
}, 300)

window.decorView.viewTreeObserver.addOnGlobalLayoutListener {
    val rect = Rect()
    window.decorView.getWindowVisibleDisplayFrame(rect)
    val displayHeight = rect.bottom - rect.top
    val height = window.decorView.height
    val keyboardHeight = height - displayHeight
    if (previousKeyboardHeight != keyboardHeight) {
        val hide = displayHeight.toDouble() / height > 0.8
        if (hide) {
            if (arrays[arrays.size - 1] is BottomClass) {
                arrays.removeAt(arrays.size - 1)
                adapter?.notifyDataSetChanged()
            }
            dialog?.dismiss()
        }
    }
}