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Rolf-SmitRolf-Smit
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Refactor: Replace kotlin-inject with Metro for dependency injection (#155)
Upside: - Metro is a Kotlin compiler plugin, so it generates .class files directly during IR transformation rather than producing source files like KSP. This removes the need for the KSP plugin and seems to also eliminate per iOS target wiring in the build script, this is nice. Downside: - `@Inject` on top-level functions works at compile time, but the generated types are not resolved by the IDE ("Unresolved reference" errors). Wrapper classes with `@Inject` on the constructor and a `@Composable operator fun invoke()` seem to be the recommended approach to avoid this. However, this is not ideal as it adds boilerplate (see: https://zacsweers.github.io/metro/latest/installation/#ide-support). - Metro graphs cannot have constructor parameters, and platform specific modules cannot extend the shared graph with additional bindings (only the reverse direction is supported via `@GraphExtension` it seems). So platform dependencies must be constructed manually. Currently there is only one (`PlatformFileDataSource`), but if more are added this might get messy. kotlin-inject avoided this through component inheritance.
1 parent 566354c commit 8896d5f

28 files changed

Lines changed: 193 additions & 275 deletions

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‎androidApp/build.gradle.kts‎

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Original file line numberDiff line numberDiff line change
@@ -18,6 +18,7 @@ val abysnerBuildNumber: String by project.properties
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plugins {
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alias(libs.plugins.androidApplication)
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alias(libs.plugins.compose.compiler)
21+
alias(libs.plugins.metro)
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alias(libs.plugins.screenshot)
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alias(libs.plugins.kover)
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id("screenshot-reference-cleanup")
@@ -116,6 +117,7 @@ screenshotTests {
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dependencies {
118119
implementation(project(":composeApp"))
120+
implementation(project(":data"))
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implementation(libs.androidx.activity.compose)
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screenshotTestImplementation(libs.screenshot.validation.api)

‎androidApp/src/main/kotlin/org/neotech/app/abysner/AbysnerApplication.kt‎

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@@ -1,6 +1,6 @@
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/*
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* Abysner - Dive planner
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* Copyright (C) 2024 Neotech
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* Copyright (C) 2024-2026 Neotech
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*
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* Abysner is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License version 3,
@@ -13,20 +13,26 @@
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package org.neotech.app.abysner
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import android.app.Application
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import dev.zacsweers.metro.createGraphFactory
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import org.neotech.app.abysner.data.PlatformFileDataSourceImpl
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import org.neotech.app.abysner.di.AppComponent
17-
import org.neotech.app.abysner.di.PlatformComponentImpl
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import org.neotech.app.abysner.di.create
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class AbysnerApplication: Application() {
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private lateinit var appComponent: AppComponent
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override fun onCreate() {
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super.onCreate()
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val platformComponent = PlatformComponentImpl::class.create(this.applicationContext)
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appComponent = AppComponent::class.create(platformComponent)
26+
// Metro graphs cannot have constructor parameters, and platform source sets cannot extend
27+
// the shared graph with additional bindings (only the reverse direction is supported via
28+
// @GraphExtension it seems). So platform dependencies must be constructed manually and
29+
// passed through a @DependencyGraph.Factory. Currently, there is only one
30+
// (PlatformFileDataSource), but if more platform-specific bindings are added this might get
31+
// messy? Each one needs a factory parameter, a @Provides function in AppComponent, and
32+
// manual construction at every call site (Android, iOS, JVM).
33+
// kotlin-inject avoided this through component inheritance.
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appComponent = createGraphFactory<AppComponent.Factory>().create(PlatformFileDataSourceImpl(this.applicationContext))
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}
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fun appComponent(): AppComponent = appComponent
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}
32-

‎composeApp/build.gradle.kts‎

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@@ -10,12 +10,8 @@
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* along with this program. If not, see https://www.gnu.org/licenses/.
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*/
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13-
import com.google.devtools.ksp.gradle.KspAATask
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import org.jetbrains.compose.desktop.application.dsl.TargetFormat
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import org.jetbrains.kotlin.gradle.dsl.JvmTarget
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import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
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import org.jetbrains.kotlin.gradle.plugin.KotlinTarget
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import org.neotech.gradle.capitalizeFirstCharacter
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import java.io.ByteArrayOutputStream
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// DMG distribution does not support "-beta", MSI requires at least MAJOR.MINOR.BUILD
@@ -29,7 +25,7 @@ plugins {
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alias(libs.plugins.androidKmpLibrary)
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alias(libs.plugins.jetbrainsCompose)
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alias(libs.plugins.compose.compiler)
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alias(libs.plugins.ksp)
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alias(libs.plugins.metro)
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alias(libs.plugins.kover)
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}
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@@ -114,7 +110,6 @@ kotlin {
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commonMain.dependencies {
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implementation(project(":domain"))
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implementation(project(":data"))
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implementation(libs.kotlinInject.runtimeKmp)
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implementation(libs.navigation.compose)
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implementation(libs.jetbrains.lifecycle.viewmodel)
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implementation(libs.jetbrains.lifecycle.runtime)
@@ -162,17 +157,6 @@ compose.desktop {
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dependencies {
164159

165-
// This is the same as repeating:
166-
// add(target, libs.kotlinInject.compilerKsp)
167-
// where `target` is "kspDesktop", "kspAndroid", "kspIosX64" "kspIosArm64" or "kspIosSimulatorArm64"
168-
val kotlinTargets: Sequence<KotlinTarget> = kotlin.targets.asSequence()
169-
kotlinTargets.filter {
170-
// Don't add KSP for common target, only final platforms
171-
it.platformType != KotlinPlatformType.common
172-
}.forEach {
173-
add("ksp${it.targetName.capitalizeFirstCharacter()}", libs.kotlinInject.compilerKsp)
174-
}
175-
176160
androidRuntimeClasspath(libs.jetbrains.compose.ui.tooling)
177161
}
178162

@@ -246,6 +230,6 @@ rootProject.file("iosApp/Configuration/Version.xcconfig").writeText(
246230
""".trimIndent() + "\n"
247231
)
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249-
tasks.withType(KspAATask::class.java).configureEach {
233+
tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompilationTask<*>>().configureEach {
250234
dependsOn(versionInfoProvider)
251235
}

‎composeApp/src/androidMain/kotlin/org/neotech/app/abysner/di/PlatformComponent.android.kt‎

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This file was deleted.

‎composeApp/src/commonMain/kotlin/org/neotech/app/abysner/di/AppComponent.kt‎

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@@ -1,6 +1,6 @@
11
/*
22
* Abysner - Dive planner
3-
* Copyright (C) 2024 Neotech
3+
* Copyright (C) 2024-2026 Neotech
44
*
55
* Abysner is free software: you can redistribute it and/or modify
66
* it under the terms of the GNU Affero General Public License version 3,
@@ -12,9 +12,9 @@
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1313
package org.neotech.app.abysner.di
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15-
import me.tatarka.inject.annotations.Component
16-
import me.tatarka.inject.annotations.Provides
17-
import me.tatarka.inject.annotations.Scope
15+
import dev.zacsweers.metro.DependencyGraph
16+
import dev.zacsweers.metro.Provides
17+
import dev.zacsweers.metro.SingleIn
1818
import org.neotech.app.abysner.data.PersistenceRepositoryImpl
1919
import org.neotech.app.abysner.data.diveplanning.PlanningRepositoryImpl
2020
import org.neotech.app.abysner.data.PlatformFileDataSource
@@ -24,30 +24,28 @@ import org.neotech.app.abysner.domain.persistence.PersistenceRepository
2424
import org.neotech.app.abysner.domain.settings.SettingsRepository
2525
import org.neotech.app.abysner.presentation.MainNavController
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27-
@Scope
28-
annotation class AppScope
27+
abstract class AppScope
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30-
@AppScope
31-
@Component
32-
abstract class AppComponent(@Component val platformComponent: PlatformComponent) {
29+
@SingleIn(AppScope::class)
30+
@DependencyGraph
31+
abstract class AppComponent {
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3433
abstract val mainNavController: MainNavController
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36-
@AppScope
35+
@SingleIn(AppScope::class)
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@Provides
3837
fun providesPlanningRepository(planningRepository: PlanningRepositoryImpl): PlanningRepository = planningRepository
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40-
@AppScope
39+
@SingleIn(AppScope::class)
4140
@Provides
4241
fun providesSettingsRepository(settingsRepository: SettingsRepositoryImpl): SettingsRepository = settingsRepository
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44-
@AppScope
43+
@SingleIn(AppScope::class)
4544
@Provides
4645
fun providesPersistenceRepository(persistenceRepository: PersistenceRepositoryImpl): PersistenceRepository = persistenceRepository
4746

48-
}
49-
50-
abstract class PlatformComponent {
51-
52-
abstract val providesPlatformFileDataSource: PlatformFileDataSource
47+
@DependencyGraph.Factory
48+
fun interface Factory {
49+
fun create(@Provides platformFileDataSource: PlatformFileDataSource): AppComponent
50+
}
5351
}

‎composeApp/src/commonMain/kotlin/org/neotech/app/abysner/presentation/MainNavController.kt‎

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@@ -12,28 +12,26 @@
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1313
package org.neotech.app.abysner.presentation
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15+
import androidx.compose.foundation.layout.Box
1516
import androidx.compose.runtime.Composable
1617
import androidx.compose.runtime.CompositionLocalProvider
1718
import androidx.compose.runtime.collectAsState
1819
import androidx.compose.runtime.getValue
1920
import androidx.lifecycle.viewmodel.compose.viewModel
2021
import androidx.navigation.compose.rememberNavController
21-
import me.tatarka.inject.annotations.Inject
22-
import androidx.compose.ui.tooling.preview.Preview
23-
import org.neotech.app.abysner.di.AppScope
24-
import org.neotech.app.abysner.presentation.screens.about.AboutScreen
25-
import org.neotech.app.abysner.presentation.screens.planner.PlannerScreen
22+
import dev.zacsweers.metro.Inject
23+
import org.neotech.app.abysner.presentation.component.BitmapRenderRoot
2624
import org.neotech.app.abysner.presentation.screens.DiveConfigurationScreen
2725
import org.neotech.app.abysner.presentation.screens.SettingsScreen
26+
import org.neotech.app.abysner.presentation.screens.about.AboutScreen
27+
import org.neotech.app.abysner.presentation.screens.planner.PlannerScreen
2828
import org.neotech.app.abysner.presentation.screens.terms_and_conditions.TermsAndConditionsScreen
2929
import org.neotech.app.abysner.presentation.theme.LocalThemeMode
3030
import org.neotech.app.abysner.presentation.utilities.DestinationDefinition
3131
import org.neotech.app.abysner.presentation.utilities.NavHost
3232
import org.neotech.app.abysner.presentation.utilities.fadeComposable
3333
import org.neotech.app.abysner.presentation.utilities.rootComposable
3434
import org.neotech.app.abysner.presentation.utilities.slideComposable
35-
import androidx.compose.foundation.layout.Box
36-
import org.neotech.app.abysner.presentation.component.BitmapRenderRoot
3735

3836
enum class Destinations(override val destinationName: String) : DestinationDefinition {
3937
PLANNER("planner"),
@@ -44,25 +42,41 @@ enum class Destinations(override val destinationName: String) : DestinationDefin
4442
TERMS_AND_CONDITIONS_INITIAL("terms-and-conditions-initial")
4543
}
4644

47-
typealias MainNavController = @Composable () -> Unit
45+
// Metro supports @Inject on top-level functions, but the generated types are not resolved by the
46+
// IDE, causing "Unresolved reference" errors. This wrapper class avoids those IDE errors.
47+
// See: https://zacsweers.github.io/metro/latest/installation/#ide-support
48+
@Inject
49+
class MainNavController(
50+
private val viewModelCreator: () -> MainNavControllerViewModel,
51+
private val plannerScreen: PlannerScreen,
52+
private val diveConfigurationScreen: DiveConfigurationScreen,
53+
private val settingsScreen: SettingsScreen,
54+
private val termsAndConditionsScreen: TermsAndConditionsScreen,
55+
private val aboutScreen: AboutScreen,
56+
) {
57+
@Composable
58+
operator fun invoke() {
59+
MainNavController(
60+
viewModel = viewModel { viewModelCreator() },
61+
plannerScreen = plannerScreen,
62+
diveConfigurationScreen = diveConfigurationScreen,
63+
settingsScreen = settingsScreen,
64+
termsAndConditionsScreen = termsAndConditionsScreen,
65+
aboutScreen = aboutScreen,
66+
)
67+
}
68+
}
4869

4970
@Composable
50-
@Preview
51-
@AppScope
52-
@Inject
5371
fun MainNavController(
54-
viewModelCreator: () -> MainNavControllerViewModel,
72+
viewModel: MainNavControllerViewModel,
5573
plannerScreen: PlannerScreen,
5674
diveConfigurationScreen: DiveConfigurationScreen,
5775
settingsScreen: SettingsScreen,
5876
termsAndConditionsScreen: TermsAndConditionsScreen,
59-
aboutScreen: AboutScreen
77+
aboutScreen: AboutScreen,
6078
) {
6179

62-
val viewModel = viewModel {
63-
viewModelCreator()
64-
}
65-
6680
val startDestination = when (viewModel.settings.value.termsAndConditionsAccepted) {
6781
false -> Destinations.TERMS_AND_CONDITIONS_INITIAL
6882
true -> Destinations.PLANNER

‎composeApp/src/commonMain/kotlin/org/neotech/app/abysner/presentation/MainNavControllerViewModel.kt‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -18,7 +18,7 @@ import kotlinx.coroutines.flow.SharingStarted
1818
import kotlinx.coroutines.flow.StateFlow
1919
import kotlinx.coroutines.flow.stateIn
2020
import kotlinx.coroutines.runBlocking
21-
import me.tatarka.inject.annotations.Inject
21+
import dev.zacsweers.metro.Inject
2222
import org.neotech.app.abysner.domain.settings.SettingsRepository
2323
import org.neotech.app.abysner.domain.settings.model.SettingsModel
2424

‎composeApp/src/commonMain/kotlin/org/neotech/app/abysner/presentation/screens/DiveConfigurationScreen.kt‎

Lines changed: 21 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -33,15 +33,14 @@ import androidx.compose.runtime.getValue
3333
import androidx.compose.ui.Modifier
3434
import androidx.compose.ui.platform.LocalInspectionMode
3535
import androidx.compose.ui.text.buildAnnotatedString
36+
import androidx.compose.ui.tooling.preview.Preview
3637
import androidx.compose.ui.unit.dp
3738
import androidx.navigation.NavHostController
3839
import androidx.navigation.compose.currentBackStackEntryAsState
3940
import androidx.navigation.compose.rememberNavController
41+
import dev.zacsweers.metro.Inject
4042
import kotlinx.collections.immutable.persistentListOf
4143
import kotlinx.collections.immutable.toImmutableList
42-
import me.tatarka.inject.annotations.Assisted
43-
import me.tatarka.inject.annotations.Inject
44-
import androidx.compose.ui.tooling.preview.Preview
4544
import org.neotech.app.abysner.domain.core.model.Configuration
4645
import org.neotech.app.abysner.domain.core.model.Salinity
4746
import org.neotech.app.abysner.domain.core.model.UnitSystem
@@ -67,16 +66,32 @@ import org.neotech.app.abysner.presentation.utilities.volumePerMinuteUnitLabel
6766
import kotlin.math.abs
6867
import kotlin.math.roundToInt
6968

70-
typealias DiveConfigurationScreen = @Composable (navController: NavHostController) -> Unit
7169

72-
@OptIn(ExperimentalMaterial3Api::class)
70+
// Metro supports @Inject on top-level functions, but the generated types are not resolved by the
71+
// IDE, causing "Unresolved reference" errors. This wrapper class avoids those IDE errors.
72+
// See: https://zacsweers.github.io/metro/latest/installation/#ide-support
7373
@Inject
74+
class DiveConfigurationScreen(
75+
private val planningRepository: PlanningRepository,
76+
private val settingsRepository: SettingsRepository,
77+
) {
78+
@Composable
79+
operator fun invoke(navController: NavHostController) {
80+
DiveConfigurationScreen(
81+
navController = navController,
82+
planningRepository = planningRepository,
83+
settingsRepository = settingsRepository,
84+
)
85+
}
86+
}
87+
7488
@Composable
7589
fun DiveConfigurationScreen(
90+
navController: NavHostController,
7691
planningRepository: PlanningRepository,
7792
settingsRepository: SettingsRepository,
78-
@Assisted navController: NavHostController = rememberNavController()
7993
) {
94+
// TODO should be adding a ViewModel to this screen
8095
val configuration by planningRepository.configuration.collectAsState()
8196
val settings by settingsRepository.settings.collectAsState()
8297
DiveConfigurationScreen(

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