keep user choices

app/build.gradle

@@ -93,6 +93,9 @@ dependencies {
     implementation "androidx.camera:camera-view:$camerax_version"
     implementation "androidx.camera:camera-extensions:$camerax_version"
 
+    // preferences
+    implementation "androidx.datastore:datastore-preferences:1.0.0"
+
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'

app/src/main/java/org/fnives/android/qrcodetransfer/MainActivity.kt

@@ -26,11 +26,11 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import org.fnives.android.qrcodetransfer.create.CreateQRCode
 import org.fnives.android.qrcodetransfer.intent.LocalIntentTextProvider
 import org.fnives.android.qrcodetransfer.read.ReadQRCode
+import org.fnives.android.qrcodetransfer.storage.LocalAppPreferencesProvider
 import org.fnives.android.qrcodetransfer.ui.theme.QRCodeTransferTheme
 
 
@@ -39,25 +39,27 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
 
         setContent {
-            LocalIntentTextProvider(intent) {
+            LocalAppPreferencesProvider(this) {
-                QRCodeTransferTheme {
+                LocalIntentTextProvider(intent) {
-                    var writerSelected by rememberSaveable { mutableStateOf(true) }
+                    QRCodeTransferTheme {
-                    // A surface container using the 'background' color from the theme
+                        var writerSelected by rememberSaveable { mutableStateOf(true) }
-                    Surface(
+                        // A surface container using the 'background' color from the theme
-                        modifier = Modifier.fillMaxSize(),
+                        Surface(
-                        color = MaterialTheme.colors.background,
+                            modifier = Modifier.fillMaxSize(),
-                    ) {
+                            color = MaterialTheme.colors.background,
-                        Scaffold(bottomBar = {
+                        ) {
-                            NavBar(
+                            Scaffold(bottomBar = {
-                                writerSelected = writerSelected,
+                                NavBar(
-                                setWriterSelected = { writerSelected = it })
+                                    writerSelected = writerSelected,
-                        }) {
+                                    setWriterSelected = { writerSelected = it })
-                            Box(Modifier.padding(it)) {
+                            }) {
-                                AnimatedContent(targetState = writerSelected) { showWriter ->
+                                Box(Modifier.padding(it)) {
-                                    if (showWriter) {
+                                    AnimatedContent(targetState = writerSelected) { showWriter ->
-                                        CreateQRCode()
+                                        if (showWriter) {
-                                    } else {
+                                            CreateQRCode()
-                                        ReadQRCode()
+                                        } else {
+                                            ReadQRCode()
+                                        }
                                     }
                                 }
                             }

app/src/main/java/org/fnives/android/qrcodetransfer/create/CreateQRCode.kt

@@ -12,7 +12,6 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.sizeIn
-import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
@@ -22,6 +21,7 @@ import androidx.compose.material.CircularProgressIndicator
 import androidx.compose.material.OutlinedTextField
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -45,6 +45,7 @@ import kotlinx.coroutines.withContext
 import org.fnives.android.qrcodetransfer.R
 import org.fnives.android.qrcodetransfer.SequenceProtocol
 import org.fnives.android.qrcodetransfer.intent.LocalIntentText
+import org.fnives.android.qrcodetransfer.storage.LocalAppPreferences
 import org.fnives.android.qrcodetransfer.toBitmap
 
 
@@ -151,9 +152,10 @@ fun QRCodeContentInput(
 ) {
     val messageFromIntent = LocalIntentText.current
     var content by rememberSaveable(messageFromIntent) { mutableStateOf(messageFromIntent.orEmpty()) }
-    var number by rememberSaveable { mutableStateOf(SequenceProtocol.versionCode) }
+    val appPreferences = LocalAppPreferences.current
+    val number by appPreferences.versionCode.collectAsState(initial = SequenceProtocol.versionCode)
     SequenceProtocol.versionCode = number
-    var encodeBase64 by rememberSaveable { mutableStateOf(SequenceProtocol.encodeBase64) }
+    val encodeBase64 by appPreferences.encodeBase64.collectAsState(initial = SequenceProtocol.encodeBase64)
     SequenceProtocol.encodeBase64 = encodeBase64
     val keyboardController = LocalSoftwareKeyboardController.current
     val coroutineScope = rememberCoroutineScope { Dispatchers.IO }
@@ -198,13 +200,14 @@ fun QRCodeContentInput(
     ) {
         Column {
             QRCodeVersionNumberDropdown(number, setVersionNumber = {
-                number = it
+                // protocol does additional checks so we follow it's lead
                 SequenceProtocol.versionCode = it
+                appPreferences.setVersionCode(SequenceProtocol.versionCode)
                 createBitmaps()
             })
             Base64EncodeCheckbox(encode = encodeBase64, setEncode = {
-                encodeBase64 = it
                 SequenceProtocol.encodeBase64 = it
+                appPreferences.setEncodeBase64(SequenceProtocol.encodeBase64)
                 createBitmaps()
             })
         }

app/src/main/java/org/fnives/android/qrcodetransfer/read/ReadQRCode.kt

@@ -14,6 +14,7 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.LocalTextStyle
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -31,6 +32,7 @@ import java.time.Duration
 import org.fnives.android.qrcodetransfer.R
 import org.fnives.android.qrcodetransfer.SequenceProtocol
 import org.fnives.android.qrcodetransfer.create.Base64EncodeCheckbox
+import org.fnives.android.qrcodetransfer.storage.LocalAppPreferences
 import org.fnives.android.qrcodetransfer.toBinaryBitmap
 
 
@@ -49,7 +51,8 @@ fun ReadQRCode() {
 @Composable
 fun QRCodeReader() {
     var readState by remember { mutableStateOf<ReadState?>(null) }
-    var encodeBase64 by remember { mutableStateOf<Boolean>(SequenceProtocol.encodeBase64) }
+    val appPreferences = LocalAppPreferences.current
+    val encodeBase64 by appPreferences.encodeBase64.collectAsState(initial = SequenceProtocol.encodeBase64)
     val textScrollState = rememberScrollState()
 
     Column {
@@ -65,8 +68,8 @@ fun QRCodeReader() {
         Column {
             Base64EncodeCheckbox(encode = encodeBase64, setEncode = {
                 SequenceProtocol.encodeBase64 = it
+                appPreferences.setEncodeBase64(SequenceProtocol.encodeBase64)
                 readState = null
-                encodeBase64 = it
             })
             Column(
                 Modifier

app/src/main/java/org/fnives/android/qrcodetransfer/storage/AppPreferences.kt

@@ -0,0 +1,62 @@
+package org.fnives.android.qrcodetransfer.storage
+
+import android.content.Context
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.remember
+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.core.intPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.launch
+
+class AppPreferences(private val context: Context) {
+
+    private val scope = CoroutineScope(Dispatchers.IO)
+    private val Context.store: DataStore<Preferences> by preferencesDataStore(name = "settings")
+    private val dataStore get() = context.store
+    private val versionCodeKey = intPreferencesKey("versionCode")
+    val versionCode: Flow<Int> = dataStore.data
+        .map { preferences ->
+            preferences[versionCodeKey] ?: 4
+        }
+
+    fun setVersionCode(versionCode: Int) {
+        scope.launch {
+            dataStore.edit {
+                it[versionCodeKey] = versionCode
+            }
+        }
+    }
+
+    private val encodeBase64Key = booleanPreferencesKey("encodeBase64")
+    val encodeBase64: Flow<Boolean> = dataStore.data
+        .map { preferences ->
+            preferences[encodeBase64Key] ?: false
+        }
+
+    fun setEncodeBase64(encodeBase64: Boolean) {
+        scope.launch {
+            dataStore.edit {
+                it[encodeBase64Key] = encodeBase64
+            }
+        }
+    }
+}
+
+val LocalAppPreferences = compositionLocalOf<AppPreferences> {
+    error("CompositionLocal LocalIntentText not present")
+}
+
+@Composable
+fun LocalAppPreferencesProvider(context: Context, content: @Composable () -> Unit) {
+    val preferences = remember(context) { AppPreferences(context) }
+    CompositionLocalProvider(LocalAppPreferences provides preferences, content = content)
+}