Refactoring in MainActivity

app/src/main/java/com/paktalin/quickmax/MainActivity.kt

@@ -12,8 +12,7 @@ class MainActivity : AppCompatActivity() {
 
     private var secToSolve: Int = 4
     private var numDigits: Int = 3
-    private lateinit var checkedCard: MaterialCardView
-    private lateinit var cards: List<MaterialCardView>
+    private lateinit var cards: Map<Int, MaterialCardView>
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -22,7 +21,12 @@ class MainActivity : AppCompatActivity() {
         if (savedInstanceState == null) retrieveSharedPrefs()
         else restoreInstanceState(savedInstanceState)
 
-        checkedCard.isChecked = true
+        cards = mapOf(2 to card_2_digits, 3 to card_3_digits, 4 to card_4_digits)
+        cards.values.forEach { card ->
+            card.setOnClickListener { card.isChecked = true }
+            card.setOnCheckedChangeListener(checkedChangeListener)
+        }
+        cards.getValue(numDigits).isChecked = true
 
         seek_bar.apply {
             setMinStartValue(secToSolve.toFloat()).apply()
@@ -32,14 +36,10 @@ class MainActivity : AppCompatActivity() {
             }
         }
 
-        cards = listOf(card_2_digits, card_3_digits, card_4_digits)
-        cards.forEach { card -> card.setOnClickListener(cardOnClickListener) }
-
         btn_play.setOnClickListener(playClickListener)
     }
 
     private fun restoreInstanceState(savedInstanceState: Bundle) {
-        checkedCard = findViewById(savedInstanceState.getInt("checked_num_id"))
         secToSolve = savedInstanceState.getInt("sec_to_solve")
         numDigits = savedInstanceState.getInt("num_digits")
     }
@@ -48,24 +48,18 @@ class MainActivity : AppCompatActivity() {
         super.onSaveInstanceState(outState)
         outState.putInt("num_digits", numDigits)
         outState.putInt("sec_to_solve", secToSolve)
-        outState.putInt("checked_num_id", checkedCard.id)
     }
 
-    private val cardOnClickListener = View.OnClickListener { card ->
-        val cardM = card as MaterialCardView
-        if (!cardM.isChecked) {
-            checkedCard = cardM
-            checkedCard.isChecked = true
-            numDigits = numDigitsFromCard(checkedCard)
-            cards.forEach { c ->
-                if (c.id != checkedCard.id)
-                    c.isChecked = false
+    private val checkedChangeListener = MaterialCardView.OnCheckedChangeListener { card, isChecked ->
+        if (isChecked && card != cards.getValue(numDigits)) {
+            numDigits = getTextView(card).text.toString().toInt()
+            cards.values.forEach { c ->
+                if (c != card) c.isChecked = false
             }
         }
     }
 
     private val playClickListener = View.OnClickListener {
-        saveSelectedValues()
         val intent = Intent(this, TaskActivity::class.java).also { i ->
             i.putExtra("num_digits", numDigits)
             i.putExtra("sec_to_solve", secToSolve)
@@ -73,26 +67,21 @@ class MainActivity : AppCompatActivity() {
         startActivity(intent)
     }
 
+    override fun onStop() {
+        super.onStop()
+        saveSelectedValues()
+    }
+
     private fun saveSelectedValues() {
         val editor = getSharedPreferences("my_prefs", Context.MODE_PRIVATE).edit()
         editor.putInt("sec_to_solve", secToSolve)
-        editor.putInt("checked_num_id", checkedCard.id)
+        editor.putInt("num_digits", numDigits)
         editor.apply()
     }
 
     private fun retrieveSharedPrefs() {
         val prefs = getSharedPreferences("my_prefs", Context.MODE_PRIVATE)
         secToSolve = prefs.getInt("sec_to_solve", 4)
-        checkedCard = findViewById(
-            prefs.getInt(
-                "checked_num_id",
-                R.id.card_3_digits
-            )
-        )
-        numDigits = numDigitsFromCard(checkedCard)
-    }
-
-    private fun numDigitsFromCard(card: MaterialCardView): Int {
-        return getTextView(card).text.toString().toInt()
+        numDigits = prefs.getInt("num_digits", 3)
     }
 }
\ No newline at end of file