Use single live event to prevent false trigger after rotation. remove hilt (for the moment)

app/src/main/java/me/zobrist/tichucounter/MainActivity.kt

@@ -22,13 +22,8 @@ import me.zobrist.tichucounter.fragments.KeyboardViewModel
 import java.util.*
 import javax.inject.Inject
 
-@AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
 
-    private var updateOnChange: Boolean = true
-
-    @Inject
-    lateinit var history: History
     private var currentRound: Round = Round(null, null)
 
     private val keyboardViewModel: KeyboardViewModel by viewModels()
@@ -58,7 +53,6 @@ class MainActivity : AppCompatActivity() {
 
         val json = this.getSharedPreferences("Settings", MODE_PRIVATE)
             .getString("history", "{\"scores\":[]}")
-        history = Gson().fromJson(json, History::class.java)
         binding.contentMain.nameTeamA.setText(
             this.getSharedPreferences("Settings", MODE_PRIVATE).getString("nameTeamA", "TeamA")
         )
@@ -66,7 +60,7 @@ class MainActivity : AppCompatActivity() {
             this.getSharedPreferences("Settings", MODE_PRIVATE).getString("nameTeamB", "TeamB")
         )
 
-        keyboardViewModel.scoreA.observe(this, androidx.lifecycle.Observer { value ->
+        keyboardViewModel.scoreA.observe(this) { value ->
             val tichu = Tichu()
 
             val oldValue = currentRound.scoreA
@@ -83,9 +77,9 @@ class MainActivity : AppCompatActivity() {
 
                 keyboardViewModel.setSubmitButtonEnable(tichu.isValidRound(currentRound))
             }
-        })
+        }
 
-        keyboardViewModel.scoreB.observe(this, androidx.lifecycle.Observer { value ->
+        keyboardViewModel.scoreB.observe(this) { value ->
             val tichu = Tichu()
 
             val oldValue = currentRound.scoreB
@@ -102,28 +96,27 @@ class MainActivity : AppCompatActivity() {
 
                 keyboardViewModel.setSubmitButtonEnable(tichu.isValidRound(currentRound))
             }
-        })
+        }
 
-        keyboardViewModel.submitButtonClicked.observe(this, androidx.lifecycle.Observer {
+        keyboardViewModel.submitButtonClicked.observe(this) {
             historyListViewModel.logRound(currentRound)
             keyboardViewModel.setScoreA(null)
             keyboardViewModel.setScoreB(null)
-        })
+        }
 
-        historyListViewModel.totalScoreA.observe(this, androidx.lifecycle.Observer { value ->
+        historyListViewModel.totalScoreA.observe(this) { value ->
             binding.contentMain.scoreA.text = value.toString()
-        })
+        }
 
-        historyListViewModel.totalScoreB.observe(this, androidx.lifecycle.Observer { value ->
+        historyListViewModel.totalScoreB.observe(this) { value ->
             binding.contentMain.scoreB.text = value.toString()
-        })
+        }
     }
 
     override fun onSaveInstanceState(outState: Bundle) {
         super.onSaveInstanceState(outState)
 
         val prefs = this.getSharedPreferences("Settings", MODE_PRIVATE).edit()
-        prefs.putString("history", Gson().toJson(history))
         prefs.putString("nameTeamA", binding.contentMain.nameTeamA.text.toString())
         prefs.putString("nameTeamB", binding.contentMain.nameTeamB.text.toString())
         prefs.apply()
@@ -177,8 +170,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun clearAll() {
-
-        history.clearAll()
+        historyListViewModel.clearAll()
     }
 
 

app/src/main/java/me/zobrist/tichucounter/fragments/HistoryList.kt

@@ -1,19 +1,12 @@
 package me.zobrist.tichucounter.fragments
 
-import android.content.Context
 import android.os.Bundle
-import android.text.InputType
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import android.view.inputmethod.InputMethodManager
-import android.widget.EditText
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
-import androidx.lifecycle.Observer
-import dagger.hilt.android.AndroidEntryPoint
 import me.zobrist.tichucounter.databinding.FragmentHistoryListBinding
-import me.zobrist.tichucounter.databinding.FragmentKeyboardBinding
 
 class HistoryList : Fragment() {
 
@@ -46,13 +39,17 @@ class HistoryList : Fragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
 
-        viewModel.historyA.observe(viewLifecycleOwner, Observer { text ->
+        viewModel.historyA.observe(viewLifecycleOwner) { text ->
             binding.historyA.text = text
-        })
+        }
 
-        viewModel.historyB.observe(viewLifecycleOwner, Observer { text ->
+        viewModel.historyB.observe(viewLifecycleOwner) { text ->
             binding.historyB.text = text
-        })
+        }
+
+        viewModel.scrollDown.observe(viewLifecycleOwner) {
+            binding.scrollViewHistory.smoothScrollTo(0, binding.scrollViewHistory.height)
+        }
     }
 
 }

app/src/main/java/me/zobrist/tichucounter/fragments/HistoryListViewModel.kt

@@ -1,5 +1,6 @@
 package me.zobrist.tichucounter.fragments
 
+import SingleLiveEvent
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
@@ -13,6 +14,7 @@ class HistoryListViewModel : ViewModel() {
     private val _totalScoreB: MutableLiveData<Int> = MutableLiveData<Int>()
     private val _historyA: MutableLiveData<String> = MutableLiveData<String>()
     private val _historyB: MutableLiveData<String> = MutableLiveData<String>()
+    private val _scrollDown: SingleLiveEvent<Boolean> = SingleLiveEvent()
 
 
 
@@ -36,6 +38,11 @@ class HistoryListViewModel : ViewModel() {
             return _historyB
         }
 
+    val scrollDown: LiveData<Boolean>
+        get() {
+            return _scrollDown
+        }
+
     private fun getScoreA() {
         var tempScore = 0
         scores.forEach {
@@ -47,7 +54,7 @@ class HistoryListViewModel : ViewModel() {
     private fun getScoreB() {
         var tempScore = 0
         scores.forEach {
-            it.scoreB?.let {it -> tempScore += it}
+            it.scoreB?.let { it -> tempScore += it }
         }
         _totalScoreB.value = tempScore
     }
@@ -68,33 +75,33 @@ class HistoryListViewModel : ViewModel() {
         _historyB.value = tempHistory
     }
 
-    fun logRound(round: Round) {
-        scores.add(round.copy())
+    private fun updateAll() {
         getHistoryA()
         getHistoryB()
         getScoreA()
         getScoreB()
+        scrollDown()
+    }
+
+    fun logRound(round: Round) {
+        scores.add(round.copy())
+        updateAll()
     }
 
     fun revertLastRound() {
         if (scores.isNotEmpty()) {
             scores.removeAt(scores.size - 1)
         }
-        getHistoryA()
-        getHistoryB()
-        getScoreA()
-        getScoreB()
+        updateAll()
+    }
+
+    private fun scrollDown() {
+        _scrollDown.value = true
     }
 
     fun clearAll() {
         scores.clear()
+        updateAll()
     }
-
-    fun isEmpty(): Boolean {
-        return scores.isEmpty()
-    }
-
-
-
 }
 

app/src/main/java/me/zobrist/tichucounter/fragments/Keyboard.kt

@@ -11,7 +11,6 @@ import android.widget.EditText
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.Observer
-import dagger.hilt.android.AndroidEntryPoint
 import me.zobrist.tichucounter.databinding.FragmentKeyboardBinding
 
 class Keyboard : Fragment() {
@@ -56,13 +55,13 @@ class Keyboard : Fragment() {
             if (enabled) enableSubmitButton() else disableSubmitButton()
         })
 
-        viewModel.scoreA.observe(viewLifecycleOwner, Observer { value ->
+        viewModel.scoreA.observe(viewLifecycleOwner) { value ->
             updateScore(binding.inputTeamA, value)
-        })
+        }
 
-        viewModel.scoreB.observe(viewLifecycleOwner, Observer { value ->
+        viewModel.scoreB.observe(viewLifecycleOwner) { value ->
             updateScore(binding.inputTeamB, value)
-        })
+        }
 
         setListeners()
 

app/src/main/java/me/zobrist/tichucounter/fragments/KeyboardViewModel.kt

@@ -1,16 +1,15 @@
 package me.zobrist.tichucounter.fragments
 
+import SingleLiveEvent
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
-import dagger.hilt.android.lifecycle.HiltViewModel
-import javax.inject.Inject
 
-class KeyboardViewModel: ViewModel() {
-    private val _scoreA: MutableLiveData<Int?> = MutableLiveData<Int?>()
-    private val _scoreB: MutableLiveData<Int?> = MutableLiveData<Int?>()
-    private val _enableSubmitButton: MutableLiveData<Boolean> = MutableLiveData<Boolean>()
-    private val _submitButtonClicked: MutableLiveData<Boolean> = MutableLiveData<Boolean>()
+class KeyboardViewModel : ViewModel() {
+    private val _scoreA: MutableLiveData<Int?> = MutableLiveData()
+    private val _scoreB: MutableLiveData<Int?> = MutableLiveData()
+    private val _enableSubmitButton: MutableLiveData<Boolean> = MutableLiveData()
+    private val _submitButtonClicked: SingleLiveEvent<Boolean> = SingleLiveEvent()
 
     val scoreA: LiveData<Int?>
         get() {

app/src/main/java/me/zobrist/tichucounter/framework/SingleLiveEvent.kt

@@ -0,0 +1,53 @@
+import android.util.Log
+import androidx.annotation.MainThread
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.Observer
+import java.util.concurrent.atomic.AtomicBoolean
+
+/**
+ * A lifecycle-aware observable that sends only new updates after subscription, used for events like
+ * navigation and Snackbar messages.
+ *
+ *
+ * This avoids a common problem with events: on configuration change (like rotation) an update
+ * can be emitted if the observer is active. This LiveData only calls the observable if there's an
+ * explicit call to setValue() or call().
+ *
+ *
+ * Note that only one observer is going to be notified of changes.
+ */
+class SingleLiveEvent<T> : MutableLiveData<T>() {
+    private val pending = AtomicBoolean(false)
+
+    @MainThread
+    override fun observe(owner: LifecycleOwner, observer: Observer<in T>) {
+        if (hasActiveObservers()) {
+            Log.w(TAG, "Multiple observers registered but only one will be notified of changes.")
+        }
+        // Observe the internal MutableLiveData
+        super.observe(owner, Observer { t ->
+            if (pending.compareAndSet(true, false)) {
+                observer.onChanged(t)
+            }
+        })
+    }
+
+    @MainThread
+    override fun setValue(t: T?) {
+        pending.set(true)
+        super.setValue(t)
+    }
+
+    /**
+     * Used for cases where T is Void, to make calls cleaner.
+     */
+    @MainThread
+    fun call() {
+        value = null
+    }
+
+    companion object {
+        private val TAG = "SingleLiveEvent"
+    }
+}

app/src/main/java/me/zobrist/tichucounter/framework/TichuCounterApplication.kt

@@ -1,7 +0,0 @@
-package me.zobrist.tichucounter.framework
-
-import android.app.Application
-import dagger.hilt.android.HiltAndroidApp
-
-@HiltAndroidApp
-class TichuCounterApplication : Application()