File system surfing 2 (#39)

* primitive surfing

* navigation to Nihil

* created constant class

app/src/main/assets/Nihil/1

@@ -0,0 +1 @@
+[{"text":"Eсли вы здесь, значит, вы добрались до таксона, который ещё не был добавлен в наш справочник", "to":1}, {"text":"Вы можете помочь нам это сделать https://github.com/SomeAnonimCoder/TheBigMayevsky", "to":1}]

app/src/main/java/msu/ug/ChoiceFragment.kt

@@ -0,0 +1,72 @@
+package msu.ug
+
+import android.content.Context
+import android.view.View
+import android.widget.ListView
+import android.widget.SimpleAdapter
+import androidx.fragment.app.ListFragment
+import org.json.JSONArray
+import java.io.BufferedReader
+import java.io.InputStreamReader
+import java.lang.StringBuilder
+
+class ChoiceFragment(private val actContext: Context) : ListFragment() {
+    private val storage = Storage(actContext)
+    private val toIndices = ArrayList<Int>()
+    private val taxons = ArrayList<String>()
+
+    override fun onStart() {
+        super.onStart()
+
+        val from = arrayOf(Const.MAP_TEXT_KEY)
+        val to = intArrayOf(android.R.id.text1)
+        val displayData = ArrayList<Map<String, Any>>()
+        updateDisplayData(displayData)
+        val listAdapter = SimpleAdapter(context, displayData, android.R.layout.simple_list_item_1, from, to)
+        setListAdapter(listAdapter)
+        storage.addSwitchListener {
+            updateDisplayData(displayData)
+            listAdapter.notifyDataSetChanged()
+        }
+    }
+
+    override fun onListItemClick(l: ListView?, v: View?, position: Int, id: Long) {
+        super.onListItemClick(l, v, position, id)
+        if (toIndices[position] == 0) {
+            storage.appendPath(taxons[position])
+            storage.currentChoise = 1
+        } else {
+            storage.currentChoise = toIndices[position]
+        }
+
+    }
+
+    private fun getPlainText(statementFile : String) : String {
+        val statementStream = actContext.assets.open(statementFile)
+        val br = BufferedReader(InputStreamReader(statementStream))
+        var line : String? = br.readLine()
+        val sb = StringBuilder()
+
+        while (line != null) {
+            sb.append(line)
+            line = br.readLine()
+        }
+
+        return sb.toString()
+    }
+
+    private fun updateDisplayData(displayData: ArrayList<Map<String, Any>>) {
+        val file = storage.getPath().joinToString("/") + "/" + storage.currentChoise.toString()
+        val arr = JSONArray(getPlainText(file))
+        toIndices.clear()
+        displayData.clear()
+        (0 until arr.length()).forEach {i ->
+            val map = HashMap<String, Any>()
+            val thesa = arr.getJSONObject(i)
+            map[Const.MAP_TEXT_KEY] = thesa.getString(Const.JSON_TEXT_KEY)
+            toIndices.add(thesa.getInt(Const.TO_KEY))
+            taxons.add(thesa.optString(Const.TAXON_KEY, Const.DEFAULT_TAXON))
+            displayData.add(map)
+        }
+    }
+}

app/src/main/java/msu/ug/Const.kt

@@ -0,0 +1,21 @@
+package msu.ug
+
+class Const {
+    companion object {
+        const val CUR_CHOICE_KEY = "current_choise"
+        const val PATH_LEN_KEY = "path_len"
+
+        const val DEFAULT_TAXON = "Nihil"
+
+        const val MAP_TEXT_KEY = "text"
+        const val JSON_TEXT_KEY = "text"
+        const val TO_KEY = "to"
+        const val TAXON_KEY = "taxon"
+
+        const val SP_NAME = "my_shared_preferences"
+
+        fun folderKey(folderIndex : Int) : String {
+            return "folder_$folderIndex"
+        }
+    }
+}

app/src/main/java/msu/ug/MainActivity.kt

@@ -14,7 +14,7 @@ class MainActivity : AppCompatActivity() {
         setContentView(R.layout.activity_main)
 
         val transaction = supportFragmentManager.beginTransaction()
-        transaction.replace(R.id.fragment_frame, ChoiseFragment(this))
+        transaction.replace(R.id.fragment_frame, ChoiceFragment(this))
         transaction.commit()
     }
 }

app/src/main/java/msu/ug/Storage.kt

@@ -4,12 +4,43 @@ import android.content.Context
 import android.content.SharedPreferences
 
 class Storage (context : Context) {
-    private val sp : SharedPreferences = context.getSharedPreferences("MY_SP", Context.MODE_PRIVATE)
+    private val sp : SharedPreferences = context.getSharedPreferences(Const.SP_NAME, Context.MODE_PRIVATE)
+    private val switchListeners : ArrayList<() -> Unit> = ArrayList()
+
+    fun addSwitchListener(listener : () -> Unit) {
+        switchListeners.add(listener)
+    }
+
     var currentChoise : Int
         set(value) {
-            sp.edit().putInt("current_choise", value).apply()
+            if (value > 0) {
+                sp.edit().putInt(Const.CUR_CHOICE_KEY, value).apply()
+                switchListeners.forEach {
+                    it.invoke()
+                }
+            }
         }
         get() {
-            return sp.getInt("current_choise", 1)
+            return sp.getInt(Const.CUR_CHOICE_KEY, 1)
         }
+
+    fun getPath() : List<String> {
+        val pathLen = sp.getInt(Const.PATH_LEN_KEY, 0)
+        val ret = ArrayList<String>()
+
+        for (i in 0 until pathLen) {
+            val str = sp.getString(Const.folderKey(i), "")
+            if (str != null) {
+                ret.add(str)
+            }
+        }
+
+        return ret
+    }
+
+    fun appendPath(folder : String) {
+        val len = sp.getInt(Const.PATH_LEN_KEY, 0)
+        sp.edit().putString(Const.folderKey(len), folder).apply()
+        sp.edit().putInt(Const.PATH_LEN_KEY, len + 1).apply()
+    }
 }