[lb9] LeftFragment.kt

package com.example.lb9

import android.annotation.SuppressLint
import android.content.Context
import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.*
import androidx.fragment.app.Fragment
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.MainScope
import kotlinx.coroutines.launch
import org.json.JSONObject
import org.w3c.dom.Text
import java.lang.Exception
import java.net.URL
import kotlin.math.ceil


class LeftFragment() : Fragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_left_n, container, false)
        val btn = view.findViewById<Button>(R.id.search_button)
        btn.setOnClickListener{

            val text = view.findViewById<TextView>(R.id.search_field).text ?: "example"
            GlobalScope.launch {
                val tUrl = URL("https://api.github.com/search/repositories?q=${text}")
                try {
                    val t = tUrl.readText()
                    val json = JSONObject(t)
                    val count = json.getInt("total_count")
                    val pages: Int = ceil(count.toDouble() / 100.0).toInt()

                    MainScope().launch {
                        var page: Int = 1
                        displayPage(view, page, text, pages)
                        val next = view.findViewById<Button>(R.id.next)
                        next.setOnClickListener {
                            if (page < pages) {
                                page += 1
                                displayPage(view, page, text, pages)
                            }
                        }
                        val prev = view.findViewById<Button>(R.id.prev)
                        prev.setOnClickListener {
                            if (page > 1) {
                                page -= 1
                                displayPage(view, page, text, pages)
                            }
                        }
                    }
                } catch (e: Exception) { Log.i("info_3", "$e") }
            }
        }
        return view
    }

    private fun displayPage(view: View, page: Int, url: CharSequence, pages: Int) {
        GlobalScope.launch {
            val tUrl = URL("https://api.github.com/search/repositories?q=${url}&page=${page}")
            Log.i("info_1", "$tUrl")
                val t = tUrl.readText()
            Log.i("info_2", "$t")
            val json = JSONObject(t)
            val jArray = json.getJSONArray("items")
            val array = MutableList(0) { " " }
            for (i in 0 until jArray.length()) {
                val o = jArray.getJSONObject(i)
                val s = o.getString("name")
                array.add(s)
            }
            MainScope().launch {
                val pageView = view.findViewById<TextView>(R.id.current_page)
                pageView.text = "$page / $pages"
                val listOptions = view.findViewById<ListView>(R.id.list_elements)
                listOptions.adapter = ArrayAdapter<String>(context!!,
                    R.layout.elements_list_item,array)
                listOptions.setOnItemClickListener { parent, view, position, id ->
                    val obj = jArray.getJSONObject(position)
                    val full_name = obj.getString("full_name")
                    val description = obj.getString("description")
                    val p_url = obj.getString("html_url")
                    val lang = obj.getString("language")
                    val avatar = obj.getJSONObject("owner").getString("avatar_url")
                    (mainContext as OnDataListener).onData(full_name, description, p_url, lang, avatar)
                }
            }
        }
    }

    override fun onAttach(context: Context) {
        super.onAttach(context)
        mainContext = context
    }
    private lateinit var mainContext: Context
}