Use Compose Multiplaform compatible dependencies

app/build.gradle.kts

@@ -2,6 +2,7 @@ plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.android)
     alias(libs.plugins.kotlin.compose)
+    kotlin("plugin.serialization") version "2.0.20"
 }
 
 android {
@@ -40,7 +41,8 @@ android {
 }
 
 dependencies {
-    implementation("com.google.code.gson:gson:2.8.9")
+    implementation(libs.kotlinx.datetime)
+    implementation(libs.kotlinx.serialization.json)
     implementation(libs.androidx.core.ktx)
     implementation(libs.androidx.lifecycle.runtime.ktx)
     implementation(libs.androidx.activity.compose)

app/src/main/java/com/example/dadflex/gamescreen/GameScreen.kt

@@ -37,7 +37,8 @@ import com.example.dadflex.preferences.HighscoreEntry
 import com.example.dadflex.preferences.PreferencesHelper
 import com.example.dadflex.ui.theme.DadflexTheme
 import kotlinx.coroutines.delay
-import java.util.Date
+import kotlinx.datetime.Clock
+import kotlinx.datetime.Instant
 
 
 @Composable
@@ -109,7 +110,7 @@ fun GameScreen(
                     val newHighScoreAdded = highscore.checkAndAddHighscore(HighscoreEntry(
                         name = name,
                         reactionTime = result,
-                        date = Date()
+                        date = Clock.System.now()
                     ))
 
                     if (newHighScoreAdded){

app/src/main/java/com/example/dadflex/preferences/Highscore.kt

@@ -1,13 +1,16 @@
 package com.example.dadflex.preferences
 
-import java.util.Date
+import kotlinx.datetime.Instant
+import kotlinx.serialization.Serializable
 
+@Serializable
 data class HighscoreEntry(
     val name : String,
     val reactionTime : Long,
-    val date : Date
+    val date : Instant
 )
 
+@Serializable
 class Highscore {
     private val highscoreList = mutableListOf<HighscoreEntry>()
 

app/src/main/java/com/example/dadflex/preferences/PreferencesHelper.kt

@@ -1,9 +1,9 @@
 package com.example.dadflex.preferences
 
-import com.google.gson.Gson
-
 import android.content.Context
 import android.content.SharedPreferences
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 
 object PreferencesHelper {
     private const val PREFS_NAME = "dadflex_prefs"
@@ -25,17 +25,24 @@ object PreferencesHelper {
     }
 
     fun saveHighscore(context: Context, highscore: Highscore) {
-        val gson = Gson()
-        val highscoreJson = gson.toJson(highscore)
+        // Convert to JSON with kotlin serialization
+        val highscoreJson = Json.encodeToString(highscore)
+
         val editor = getPreferences(context).edit()
 
         editor.putString(KEY_HIGHSCORE, highscoreJson)
         editor.apply()
     }
 
     fun getHighscore(context: Context): Highscore {
-        val gson = Gson()
         val json = getPreferences(context).getString(KEY_HIGHSCORE, null) ?: return Highscore()
-        return gson.fromJson(json, Highscore::class.java)
+        // Decode with kotlin serialization
+
+        return try {
+            Json.decodeFromString(json)
+        } catch (e: Exception) {
+            // Old java.util.Date format e.g 'Dec 10, 2024 4:42:44 PM' can't be parsed :(
+            Highscore()
+        }
     }
 }

gradle/libs.versions.toml

@@ -9,23 +9,28 @@ lifecycleRuntimeKtx = "2.6.1"
 activityCompose = "1.8.0"
 composeBom = "2024.04.01"
 navigationCompose = "2.8.4"
+kotlinxDatetime = "0.4.0"
+kotlinxSerializationJson = "1.7.3"
+
 
 [libraries]
+androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
+androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
-junit = { group = "junit", name = "junit", version.ref = "junit" }
-androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
+androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
-androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
-androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
+androidx-material3 = { group = "androidx.compose.material3", name = "material3" }
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
 androidx-ui = { group = "androidx.compose.ui", name = "ui" }
 androidx-ui-graphics = { group = "androidx.compose.ui", name = "ui-graphics" }
+androidx-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
+androidx-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
 androidx-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling" }
 androidx-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
-androidx-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
-androidx-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
-androidx-material3 = { group = "androidx.compose.material3", name = "material3" }
-androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
+junit = { group = "junit", name = "junit", version.ref = "junit" }
+kotlinx-datetime = { group = "org.jetbrains.kotlinx", name = "kotlinx-datetime", version.ref = "kotlinxDatetime" }
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerializationJson" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }