The lore

I have this data class UserSettingsModel, that I have moved to, because of a need to store some appSettings: Map<String, AppSettingsModel>. This is for an app that reads off user-specified notifications from user-specified apps.

Those data classes are defined thusly:

UserSettingsModel

package com.mikewarren.speakify.data

data class UserSettingsModel(
    val useDarkTheme: Boolean,
    val selectedTTSVoice: String,
    val appSettings: Map<String, AppSettingsModel>,
)

AppSettingsModel

package com.mikewarren.speakify.data

data class AppSettingsModel(
    val appName: String,
    val announcerVoice: String?, // Nullable if no voice is selected
    val notificationSources: List<String> = emptyList()
)

Ok, what's the problem?

I created this app/src/main/proto/app_settings.proto, originally defined to be:

protobuf
syntax = "proto3";

option java_package = "com.mikewarren.speakify.data";
option java_multiple_files = true;

message AppSettingsModel {
  string app_name = 1;
  string announcer_voice = 2;
  repeated string notification_sources = 3;
}

message UserSettingsModel {
  bool use_dark_theme = 1;
  string selected_tts_voice = 2;
  map<string, AppSettingsModel> app_settings = 3;
}

built the project, tried to use the stuff, but faced some confusion immediately. After asking the AI, it turns out that Proto generates its own data model classes, separate from yours, with their own methods. So I changed my app/src/main/proto/app_settings.proto:

protobuf
syntax = "proto3";

option java_package = "com.mikewarren.speakify.data";
option java_multiple_files = true;

message AppSettings {
  string app_name = 1;
  string announcer_voice = 2;
  repeated string notification_sources = 3;
}

message UserSettings {
  bool use_dark_theme = 4;
  string selected_tts_voice = 5;
  map<string, AppSettings> app_settings = 6;
}

tried to rebuild, but still didn't see any generated UserSettings or AppSettings classes!

Here's my app's build.gradle:

plugins {
    alias(libs.plugins.android.application)
    alias(libs.plugins.kotlin.android)
    alias(libs.plugins.kotlin.compose)

    id "kotlin-kapt"
    id 'com.google.dagger.hilt.android' // Add this line
}

final int androidSdkVersion = 35

android {
    namespace 'com.mikewarren.speakify'
    compileSdk androidSdkVersion

    defaultConfig {
        applicationId "com.mikewarren.speakify"
        minSdk 24
        targetSdk androidSdkVersion
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_11
        targetCompatibility JavaVersion.VERSION_11
    }
    kotlinOptions {
        jvmTarget = '11'
    }
    buildFeatures {
        compose true
    }
}

dependencies {

    implementation("com.google.dagger:hilt-android:2.51.1")
    implementation libs.androidx.media3.common.ktx
    kapt("com.google.dagger:hilt-compiler:2.51.1")
// If using Hilt with Compose Navigation:
    implementation("androidx.hilt:hilt-navigation-compose:1.2.0")
    implementation("com.google.protobuf:protobuf-javalite:3.18.0") // or latest version
    // Add this line:
    implementation("com.google.protobuf:protoc:3.17.2") // Use the same version as in your protobuf extension
    implementation("androidx.datastore:datastore:1.1.4")
    implementation libs.androidx.core.ktx
    implementation libs.androidx.lifecycle.runtime.ktx
    implementation libs.androidx.activity.compose
    implementation platform(libs.androidx.compose.bom)
    implementation libs.androidx.ui
    implementation libs.androidx.ui.graphics
    implementation libs.androidx.ui.tooling.preview
    implementation libs.androidx.material3
    implementation libs.androidx.navigation.runtime.ktx
    implementation libs.androidx.navigation.compose
    implementation libs.androidx.espresso.core

    // https://mvnrepository.com/artifact/androidx.datastore/datastore-preferences
    implementation "androidx.datastore:datastore-preferences:1.1.4"


    implementation libs.androidx.datastore.core.android
    implementation libs.androidx.datastore.preferences.core.jvm
    testImplementation libs.junit
    androidTestImplementation libs.androidx.junit
    androidTestImplementation libs.androidx.espresso.core
    androidTestImplementation platform(libs.androidx.compose.bom)
    androidTestImplementation libs.androidx.ui.test.junit4
    debugImplementation libs.androidx.ui.tooling
    debugImplementation libs.androidx.ui.test.manifest

    runtimeOnly libs.androidx.lifecycle

}

and the root-level one, for good measure:

buildscript {
    dependencies {
        classpath "com.android.tools.build:gradle:8.9.1"
        classpath "com.google.dagger:hilt-android-gradle-plugin:2.51.1" // Add this line with the correct version
        classpath 'com.google.protobuf:protobuf-javalite:4.30.2'
    }
}

// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
alias(libs.plugins.android.application) apply false
    alias(libs.plugins.kotlin.android) apply false
    alias(libs.plugins.kotlin.compose) apply false
}