implementing bio-metric pull

app/build.gradle

@@ -96,4 +96,7 @@ dependencies {
     //implementation "com.google.dagger:hilt-android-testing:$hilt_ver"
     implementation "androidx.hilt:hilt-common:1.0.0-alpha03"
     implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03"
+
+    //Bio-metric
+    implementation 'androidx.biometric:biometric:1.2.0-alpha03'
 }

app/src/main/AndroidManifest.xml

@@ -3,7 +3,8 @@
     package="dev.spikeysanju.expensetracker">
 
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
-
+    <uses-permission android:name="android.permission.USE_BIOMETRIC"
+        android:requiredFeature="true"/>
 
     <application
         android:name=".app.ExpenseTracker"

app/src/main/java/dev/spikeysanju/expensetracker/data/local/datastore/PrefsDataStore.kt

@@ -0,0 +1,11 @@
+package dev.spikeysanju.expensetracker.data.local.datastore
+
+import android.content.Context
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.createDataStore
+
+
+abstract class PrefsDataStore(context: Context, fileName: String) {
+    internal val dataStore: DataStore<Preferences> = context.createDataStore(fileName)
+}

app/src/main/java/dev/spikeysanju/expensetracker/data/local/datastore/SettingsDataStore.kt

@@ -0,0 +1,42 @@
+package dev.spikeysanju.expensetracker.data.local.datastore
+
+import android.content.Context
+import androidx.datastore.preferences.core.booleanPreferencesKey
+import androidx.datastore.preferences.core.edit
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import javax.inject.Singleton
+
+
+class SettingsDataStore(context: Context) :
+    PrefsDataStore(
+        context,
+        PREF_FILE_SETTINGS
+    ),
+    SettingsImpl {
+
+    // used to get the data from datastore
+    override val biometric: Flow<Boolean>
+        get() = dataStore.data.map { preferences ->
+            val biometric = preferences[BIOMETRIC_KEY] ?: false
+            biometric
+        }
+
+    // used to save the bio-metric preference to datastore
+    override suspend fun saveToDataStore(isBiometricEnabled: Boolean) {
+        dataStore.edit { preferences ->
+            preferences[BIOMETRIC_KEY] = isBiometricEnabled
+        }
+    }
+
+    companion object {
+        private const val PREF_FILE_SETTINGS = "settings_preference"
+        private val BIOMETRIC_KEY = booleanPreferencesKey("biometric_mode")
+    }
+}
+
+@Singleton
+interface SettingsImpl {
+    val biometric: Flow<Boolean>
+    suspend fun saveToDataStore(isBiometricEnabled: Boolean)
+}

app/src/main/java/dev/spikeysanju/expensetracker/data/local/datastore/UIModeDataStore.kt

@@ -1,18 +1,12 @@
 package dev.spikeysanju.expensetracker.data.local.datastore
 
 import android.content.Context
-import androidx.datastore.core.DataStore
-import androidx.datastore.preferences.core.Preferences
 import androidx.datastore.preferences.core.booleanPreferencesKey
 import androidx.datastore.preferences.core.edit
-import androidx.datastore.preferences.createDataStore
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 import javax.inject.Singleton
 
-abstract class PrefsDataStore(context: Context, fileName: String) {
-    internal val dataStore: DataStore<Preferences> = context.createDataStore(fileName)
-}
 
 class UIModeDataStore(context: Context) :
     PrefsDataStore(

app/src/main/java/dev/spikeysanju/expensetracker/model/Transaction.kt

@@ -26,7 +26,7 @@ data class Transaction(
         System.currentTimeMillis(),
     @PrimaryKey(autoGenerate = true)
     @ColumnInfo(name = "id")
-    var id: Int = 0,
+    var id: Int = 0
 ) : Serializable {
     val createdAtDateFormat: String
         get() = DateFormat.getDateTimeInstance()

app/src/main/java/dev/spikeysanju/expensetracker/view/auth/AuthFragment.kt

@@ -0,0 +1,69 @@
+package dev.spikeysanju.expensetracker.view.auth
+
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.biometric.BiometricPrompt
+import androidx.core.content.ContextCompat
+import androidx.fragment.app.viewModels
+import androidx.lifecycle.lifecycleScope
+import androidx.navigation.fragment.findNavController
+import dagger.hilt.android.AndroidEntryPoint
+import dev.spikeysanju.expensetracker.R
+import dev.spikeysanju.expensetracker.databinding.FragmentAuthBinding
+import dev.spikeysanju.expensetracker.view.base.BaseFragment
+import kotlinx.coroutines.flow.first
+import kotlin.system.exitProcess
+
+@AndroidEntryPoint
+class AuthFragment : BaseFragment<FragmentAuthBinding, AuthViewModel>() {
+    override val viewModel: AuthViewModel by viewModels()
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+
+        lifecycleScope.launchWhenStarted {
+            if(viewModel.bioMetricPreference.first())
+                authenticate()
+        }
+    }
+
+    override fun getViewBinding(inflater: LayoutInflater, container: ViewGroup?) =
+        FragmentAuthBinding.inflate(inflater, container, false)
+
+
+    private fun authenticate(){
+        val executor = ContextCompat.getMainExecutor(requireContext())
+        val biometricPrompt = BiometricPrompt(this, executor,
+            object : BiometricPrompt.AuthenticationCallback() {
+                override fun onAuthenticationSucceeded(
+                    result: BiometricPrompt.AuthenticationResult) {
+                    super.onAuthenticationSucceeded(result)
+                    findNavController().navigate(R.id.action_authFragment_to_dashboardFragment)
+                }
+
+                override fun onAuthenticationFailed() {
+                    super.onAuthenticationFailed()
+                    //todo: show message wait for a second; static err code
+                    exitProcess(-1)
+                }
+
+                override fun onAuthenticationError(errorCode: Int,
+                                                   errString: CharSequence) {
+                    super.onAuthenticationError(errorCode, errString)
+                    //todo: show message wait for a second; static err code
+                    exitProcess(-2)
+                }
+            })
+
+        val promptInfo = BiometricPrompt.PromptInfo.Builder()
+            .setTitle("Please complete bio-metric login to use Expenso")
+            .setNegativeButtonText("Exit")
+            .build()
+        biometricPrompt.authenticate(promptInfo)
+    }
+
+}

app/src/main/java/dev/spikeysanju/expensetracker/view/auth/AuthViewModel.kt

@@ -0,0 +1,24 @@
+package dev.spikeysanju.expensetracker.view.auth
+
+
+import android.app.Application
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import dev.spikeysanju.expensetracker.data.local.datastore.SettingsDataStore
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class AuthViewModel @Inject constructor(
+    application: Application
+) :
+    AndroidViewModel(application) {
+
+    // init datastore
+    private val settingsDataStore = SettingsDataStore(application)
+
+    // get bio-metric preference
+    val bioMetricPreference = settingsDataStore.biometric
+}

app/src/main/java/dev/spikeysanju/expensetracker/view/dashboard/DashboardFragment.kt

@@ -95,7 +95,7 @@ class DashboardFragment :
             override fun onMove(
                 recyclerView: RecyclerView,
                 viewHolder: RecyclerView.ViewHolder,
-                target: RecyclerView.ViewHolder,
+                target: RecyclerView.ViewHolder
             ): Boolean {
                 return true
             }
@@ -280,6 +280,10 @@ class DashboardFragment :
                 findNavController().navigate(R.id.action_dashboardFragment_to_aboutFragment)
                 true
             }
+            R.id.action_settings -> {
+                findNavController().navigate(R.id.action_dashboardFragment_to_settingsFragment)
+                true
+            }
             else -> super.onOptionsItemSelected(item)
         }
     }

app/src/main/java/dev/spikeysanju/expensetracker/view/main/MainActivity.kt

@@ -1,8 +1,12 @@
 package dev.spikeysanju.expensetracker.view.main
 
 import android.os.Bundle
+import android.widget.Toast
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
+import androidx.biometric.BiometricPrompt
+import androidx.core.content.ContextCompat
+import androidx.lifecycle.lifecycleScope
 import androidx.navigation.NavController
 import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.AppBarConfiguration
@@ -14,6 +18,10 @@ import dev.spikeysanju.expensetracker.databinding.ActivityMainBinding
 import dev.spikeysanju.expensetracker.repo.TransactionRepo
 import dev.spikeysanju.expensetracker.utils.viewModelFactory
 import dev.spikeysanju.expensetracker.view.main.viewmodel.TransactionViewModel
+import dev.spikeysanju.expensetracker.view.settings.SettingsViewModel
+import kotlinx.coroutines.flow.first
+import java.util.concurrent.Executor
+import kotlin.system.exitProcess
 
 @AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
@@ -79,4 +87,5 @@ class MainActivity : AppCompatActivity() {
         navHostFragment.navController.navigateUp()
         return super.onSupportNavigateUp()
     }
+
 }

app/src/main/java/dev/spikeysanju/expensetracker/view/settings/SettingsFragment.kt

@@ -0,0 +1,38 @@
+package dev.spikeysanju.expensetracker.view.settings
+
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.viewModels
+import androidx.lifecycle.lifecycleScope
+import dagger.hilt.android.AndroidEntryPoint
+import dev.spikeysanju.expensetracker.databinding.FragmentSettingsBinding
+import dev.spikeysanju.expensetracker.view.base.BaseFragment
+import kotlinx.coroutines.flow.first
+
+@AndroidEntryPoint
+class SettingsFragment : BaseFragment<FragmentSettingsBinding, SettingsViewModel>() {
+    override val viewModel: SettingsViewModel by viewModels()
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        // Set the item state
+        lifecycleScope.launchWhenStarted {
+            binding.biometric.isChecked = viewModel.bioMetricPreference.first()
+        }
+
+        initViews()
+    }
+
+    private fun initViews() = with(binding) {
+        biometric.setOnCheckedChangeListener { _, biometricEnabled ->
+            viewModel.setBioMetricLock(biometricEnabled)
+        }
+    }
+
+    override fun getViewBinding(inflater: LayoutInflater, container: ViewGroup?) =
+        FragmentSettingsBinding.inflate(inflater, container, false)
+}

app/src/main/java/dev/spikeysanju/expensetracker/view/settings/SettingsViewModel.kt

@@ -0,0 +1,31 @@
+package dev.spikeysanju.expensetracker.view.settings
+
+
+import android.app.Application
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import dev.spikeysanju.expensetracker.data.local.datastore.SettingsDataStore
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class SettingsViewModel @Inject constructor(
+    application: Application
+) :
+    AndroidViewModel(application) {
+
+    // init datastore
+    private val settingsDataStore = SettingsDataStore(application)
+
+    // get bio-metric preference
+    val bioMetricPreference = settingsDataStore.biometric
+
+    fun setBioMetricLock(bioMetricLock: Boolean) {
+        viewModelScope.launch(Dispatchers.IO) {
+            settingsDataStore.saveToDataStore(bioMetricLock)
+        }
+    }
+
+}