Add Datastore with Protobuf

Author: JanMalch

app/build.gradle.kts

@@ -2,6 +2,7 @@
 plugins {
     alias(libs.plugins.com.android.application)
     alias(libs.plugins.org.jetbrains.kotlin.android)
+    alias(libs.plugins.com.google.protobuf)
 }
 
 android {
@@ -60,11 +61,32 @@ dependencies {
     implementation(libs.ui.graphics)
     implementation(libs.ui.tooling.preview)
     implementation(libs.material3)
+    implementation(libs.bundles.datastore)
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.test.ext.junit)
     androidTestImplementation(libs.espresso.core)
     androidTestImplementation(platform(libs.compose.bom))
     androidTestImplementation(libs.ui.test.junit4)
     debugImplementation(libs.ui.tooling)
     debugImplementation(libs.ui.test.manifest)
+}
+
+protobuf {
+    protoc {
+        artifact = libs.protoc.get().toString()
+    }
+    // https://github.com/google/protobuf-gradle-plugin/issues/518#issuecomment-1273099797
+    // https://github.com/zhaobozhen/LibChecker/blob/c0c3bc7c661fe45cc44d5c6ab0202764652e0b7e/app/build.gradle.kts#L197
+    generateProtoTasks {
+        all().forEach {
+            it.builtins {
+                create("java") {
+                    option("lite")
+                }
+                create("kotlin") {
+                    option("lite")
+                }
+            }
+        }
+    }
 }

app/src/main/java/io/github/janmalch/composeprotosettings/preferences/UserPreferencesSerializer.kt

@@ -0,0 +1,20 @@
+package io.github.janmalch.composeprotosettings.preferences
+
+import androidx.datastore.core.CorruptionException
+import androidx.datastore.core.Serializer
+import com.google.protobuf.InvalidProtocolBufferException
+import java.io.InputStream
+import java.io.OutputStream
+
+object UserPreferencesSerializer : Serializer<UserPreferences> {
+    override val defaultValue: UserPreferences = UserPreferences.getDefaultInstance()
+    override suspend fun readFrom(input: InputStream): UserPreferences {
+        try {
+            return UserPreferences.parseFrom(input)
+        } catch (exception: InvalidProtocolBufferException) {
+            throw CorruptionException("Cannot read proto.", exception)
+        }
+    }
+
+    override suspend fun writeTo(t: UserPreferences, output: OutputStream) = t.writeTo(output)
+}

app/src/main/proto/user_prefs.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+option java_package = "io.github.janmalch.composeprotosettings.preferences";
+option java_multiple_files = true;
+
+message UserPreferences {
+  // filter for showing / hiding completed tasks
+  bool show_completed = 1;
+}

gradle/libs.versions.toml

@@ -1,13 +1,16 @@
 [versions]
 agp = "8.1.0-rc01"
 org-jetbrains-kotlin-android = "1.8.10"
-core-ktx = "1.9.0"
+core-ktx = "1.10.1"
 junit = "4.13.2"
 androidx-test-ext-junit = "1.1.5"
 espresso-core = "3.5.1"
 lifecycle-runtime-ktx = "2.6.1"
 activity-compose = "1.7.2"
-compose-bom = "2023.03.00"
+compose-bom = "2023.06.01"
+datastore = "1.0.0"
+protobuf = "3.23.2" # "3.23.3" is broken
+protobuf-plugin = "0.9.3"
 
 [libraries]
 core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "core-ktx" }
@@ -25,9 +28,16 @@ ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
 ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
 material3 = { group = "androidx.compose.material3", name = "material3" }
 
+datatore = { group = "androidx.datastore", name = "datastore", version.ref = "datastore" }
+protobuf-java = { group = "com.google.protobuf", name = "protobuf-javalite", version.ref = "protobuf" }
+protobuf-kotlin = { group = "com.google.protobuf", name = "protobuf-kotlin-lite", version.ref = "protobuf" }
+protoc = { group = "com.google.protobuf", name = "protoc", version.ref = "protobuf" }
+
+
 [plugins]
 com-android-application = { id = "com.android.application", version.ref = "agp" }
 org-jetbrains-kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "org-jetbrains-kotlin-android" }
+com-google-protobuf = { id = "com.google.protobuf", version.ref = "protobuf-plugin"}
 
 [bundles]
-
+datastore = ["datatore", "protobuf-java", "protobuf-kotlin"]