Replace Dagger-Android with Hilt and remove Kapt (#4423)

Hilt is an annotation processor built on top of Dagger which allows to
remove all the Android dependency injection boilerplate code (currently
around 900 lines) by writing it for us.

Hilt can use KSP instead of Kapt so Kapt can be completely removed from
the project. Kapt is slow, deprecated and has a few compatibility
issues. Removing Kapt will improve build times since no Java stubs have
to be generated for Kotlin classes anymore (Note that KSP also processes
annotations in Java classes so it can completely replace Kapt).

- Remove all modules related to manual dependency injection
configuration.
- Rename `AppModule` to `StorageModule` since it now only contains
configuration to retrieve the DataBase and SharedPreferences.
- Annotate all entry points (Activities, Fragments, BroadcastReceivers
and Services) with `@AndroidEntryPoint`.
- Annotate all injected ViewModels with `@HiltViewModel` and replace the
custom ViewModel Factory with the default one (which integrates with the
one generated by Hilt).
- Add a public field to allow overriding the default
ViewModelProvider.Factory in `BaseActivity` in tests.
- Annotate tested Activities with `@OptionalInject` since Activity tests
currently rely on the Activities not being injected automatically.
- Annotate injected `Context` arguments with `@ApplicationContext`. Hilt
provides the `Context` binding automatically but requires to specify if
the Application or Activity Context is wanted.
- Add WorkManager Hilt integration so all Workers are injected by Hilt
automatically using `HiltWorkerFactory`.
- Lazily initialize WorkManager in `TuskyApplication`.
- Remove Kapt and Kapt workarounds.
- ~~Remove toolchain configuration for Java 21. Toolchains force the
Java bytecode to match the JDK version used to build the project, and
apparently Hilt doesn't run inside the toolchain so cannot process the
source code if the JDK version of the toolchain is higher than the JDK
used to run Gradle. [And configuring a toolchain for an older Java
version causes other
issues](https://jakewharton.com/gradle-toolchains-are-rarely-a-good-idea/).
**Removing toolchains configuration doesn't prevent the project from
being built using JDK 21** or more recent versions but allows to build
the project using older JDKs as well.~~
Added a fix to allow Hilt to properly use the JDK toolchain.
- ~~Set the Java and Kotlin bytecode target to Java 17. The standard
bytecode target for Android projects is usually Java 8 or 11 (any higher
version doesn't provide any benefit but may cause compatibility issues).
However, since the app currently uses a library built against Java 17
bytecode (`networkresult-calladapter`), it needs to target at least Java
17 bytecode as well.~~
- Update the Dagger 2 URL in the licenses screen. Hilt is part of Dagger
2 so the label wasn't changed.

app/build.gradle

@@ -1,8 +1,8 @@
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.google.ksp)
+    alias(libs.plugins.hilt.android)
     alias(libs.plugins.kotlin.android)
-    alias(libs.plugins.kotlin.kapt)
     alias(libs.plugins.kotlin.parcelize)
 }
 
@@ -81,6 +81,7 @@ android {
         resValues true
         viewBinding true
     }
+
     testOptions {
         unitTests {
             returnDefaultValues = true
@@ -156,8 +157,10 @@ dependencies {
     implementation libs.bundles.glide
     ksp libs.glide.compiler
 
-    implementation libs.bundles.dagger
-    kapt libs.bundles.dagger.processors
+    implementation libs.hilt.android
+    ksp libs.hilt.compiler
+    implementation libs.androidx.hilt.work
+    ksp libs.androidx.hilt.compiler
 
     implementation libs.sparkbutton
 
@@ -189,20 +192,3 @@ dependencies {
     androidTestImplementation libs.androidx.room.testing
     androidTestImplementation libs.androidx.test.junit
 }
-
-// Work around warnings of:
-// WARNING: Illegal reflective access by org.jetbrains.kotlin.kapt3.util.ModuleManipulationUtilsKt (file:/C:/Users/Andi/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-annotation-processing-gradle/1.8.22/28dab7e0ee9ce62c03bf97de3543c911dc653700/kotlin-annotation-processing-gradle-1.8.22.jar) to constructor com.sun.tools.javac.util.Context()
-// See https://youtrack.jetbrains.com/issue/KT-30589/Kapt-An-illegal-reflective-access-operation-has-occurred
-tasks.withType(org.jetbrains.kotlin.gradle.internal.KaptWithoutKotlincTask).configureEach {
-    kaptProcessJvmArgs.addAll([
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED",
-        "--add-opens", "jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED"])
-}

app/src/main/java/com/keylesspalace/tusky/AboutActivity.kt

@@ -17,15 +17,16 @@ import androidx.annotation.StringRes
 import androidx.lifecycle.lifecycleScope
 import com.keylesspalace.tusky.components.instanceinfo.InstanceInfoRepository
 import com.keylesspalace.tusky.databinding.ActivityAboutBinding
-import com.keylesspalace.tusky.di.Injectable
 import com.keylesspalace.tusky.util.NoUnderlineURLSpan
 import com.keylesspalace.tusky.util.hide
 import com.keylesspalace.tusky.util.show
 import com.keylesspalace.tusky.util.startActivityWithSlideInAnimation
+import dagger.hilt.android.AndroidEntryPoint
 import javax.inject.Inject
 import kotlinx.coroutines.launch
 
-class AboutActivity : BottomSheetActivity(), Injectable {
+@AndroidEntryPoint
+class AboutActivity : BottomSheetActivity() {
     @Inject
     lateinit var instanceInfoRepository: InstanceInfoRepository
 

app/src/main/java/com/keylesspalace/tusky/AccountsInListFragment.kt

@@ -31,8 +31,6 @@ import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.ListAdapter
 import com.keylesspalace.tusky.databinding.FragmentAccountsInListBinding
 import com.keylesspalace.tusky.databinding.ItemFollowRequestBinding
-import com.keylesspalace.tusky.di.Injectable
-import com.keylesspalace.tusky.di.ViewModelFactory
 import com.keylesspalace.tusky.entity.TimelineAccount
 import com.keylesspalace.tusky.settings.PrefKeys
 import com.keylesspalace.tusky.util.BindingHolder
@@ -45,17 +43,15 @@ import com.keylesspalace.tusky.util.unsafeLazy
 import com.keylesspalace.tusky.util.viewBinding
 import com.keylesspalace.tusky.viewmodel.AccountsInListViewModel
 import com.keylesspalace.tusky.viewmodel.State
-import javax.inject.Inject
+import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.launch
 
 private typealias AccountInfo = Pair<TimelineAccount, Boolean>
 
-class AccountsInListFragment : DialogFragment(), Injectable {
+@AndroidEntryPoint
+class AccountsInListFragment : DialogFragment() {
 
-    @Inject
-    lateinit var viewModelFactory: ViewModelFactory
-
-    private val viewModel: AccountsInListViewModel by viewModels { viewModelFactory }
+    private val viewModel: AccountsInListViewModel by viewModels()
     private val binding by viewBinding(FragmentAccountsInListBinding::bind)
 
     private lateinit var listId: String

app/src/main/java/com/keylesspalace/tusky/BaseActivity.java

@@ -33,6 +33,7 @@
 import androidx.annotation.StringRes;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.preference.PreferenceManager;
 
 import com.google.android.material.color.MaterialColors;
@@ -41,7 +42,6 @@
 import com.keylesspalace.tusky.components.login.LoginActivity;
 import com.keylesspalace.tusky.db.entity.AccountEntity;
 import com.keylesspalace.tusky.db.AccountManager;
-import com.keylesspalace.tusky.di.Injectable;
 import com.keylesspalace.tusky.interfaces.AccountSelectionListener;
 import com.keylesspalace.tusky.settings.AppTheme;
 import com.keylesspalace.tusky.settings.PrefKeys;
@@ -55,7 +55,10 @@
 
 import static com.keylesspalace.tusky.settings.PrefKeys.APP_THEME;
 
-public abstract class BaseActivity extends AppCompatActivity implements Injectable {
+/**
+ * All activities inheriting from BaseActivity must be annotated with @AndroidEntryPoint
+ */
+public abstract class BaseActivity extends AppCompatActivity {
 
     public static final String OPEN_WITH_SLIDE_IN = "OPEN_WITH_SLIDE_IN";
 
@@ -65,6 +68,12 @@ public abstract class BaseActivity extends AppCompatActivity implements Injectab
     @NonNull
     public AccountManager accountManager;
 
+    /**
+     * Allows overriding the default ViewModelProvider.Factory for testing purposes.
+     */
+    @Nullable
+    public ViewModelProvider.Factory viewModelProviderFactory = null;
+
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -152,6 +161,13 @@ protected void attachBaseContext(Context newBase) {
         super.attachBaseContext(fontScaleContext);
     }
 
+    @NonNull
+    @Override
+    public ViewModelProvider.Factory getDefaultViewModelProviderFactory() {
+        final ViewModelProvider.Factory factory = viewModelProviderFactory;
+        return (factory != null) ? factory : super.getDefaultViewModelProviderFactory();
+    }
+
     protected boolean requiresLogin() {
         return true;
     }

app/src/main/java/com/keylesspalace/tusky/EditProfileActivity.kt

@@ -43,8 +43,6 @@ import com.google.android.material.snackbar.Snackbar
 import com.keylesspalace.tusky.adapter.AccountFieldEditAdapter
 import com.keylesspalace.tusky.components.instanceinfo.InstanceInfoRepository
 import com.keylesspalace.tusky.databinding.ActivityEditProfileBinding
-import com.keylesspalace.tusky.di.Injectable
-import com.keylesspalace.tusky.di.ViewModelFactory
 import com.keylesspalace.tusky.util.Error
 import com.keylesspalace.tusky.util.Loading
 import com.keylesspalace.tusky.util.Success
@@ -57,22 +55,20 @@ import com.mikepenz.iconics.IconicsDrawable
 import com.mikepenz.iconics.typeface.library.googlematerial.GoogleMaterial
 import com.mikepenz.iconics.utils.colorInt
 import com.mikepenz.iconics.utils.sizeDp
-import javax.inject.Inject
+import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.launch
 
-class EditProfileActivity : BaseActivity(), Injectable {
+@AndroidEntryPoint
+class EditProfileActivity : BaseActivity() {
 
     companion object {
         const val AVATAR_SIZE = 400
         const val HEADER_WIDTH = 1500
         const val HEADER_HEIGHT = 500
     }
 
-    @Inject
-    lateinit var viewModelFactory: ViewModelFactory
-
-    private val viewModel: EditProfileViewModel by viewModels { viewModelFactory }
+    private val viewModel: EditProfileViewModel by viewModels()
 
     private val binding by viewBinding(ActivityEditProfileBinding::inflate)
 

app/src/main/java/com/keylesspalace/tusky/LicenseActivity.kt

@@ -21,13 +21,15 @@ import android.widget.TextView
 import androidx.annotation.RawRes
 import androidx.lifecycle.lifecycleScope
 import com.keylesspalace.tusky.databinding.ActivityLicenseBinding
+import dagger.hilt.android.AndroidEntryPoint
 import java.io.IOException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import okio.buffer
 import okio.source
 
+@AndroidEntryPoint
 class LicenseActivity : BaseActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {

app/src/main/java/com/keylesspalace/tusky/ListsActivity.kt

@@ -37,8 +37,6 @@ import com.google.android.material.snackbar.Snackbar
 import com.keylesspalace.tusky.databinding.ActivityListsBinding
 import com.keylesspalace.tusky.databinding.DialogListBinding
 import com.keylesspalace.tusky.databinding.ItemListBinding
-import com.keylesspalace.tusky.di.Injectable
-import com.keylesspalace.tusky.di.ViewModelFactory
 import com.keylesspalace.tusky.entity.MastoList
 import com.keylesspalace.tusky.util.BindingHolder
 import com.keylesspalace.tusky.util.hide
@@ -53,22 +51,15 @@ import com.keylesspalace.tusky.viewmodel.ListsViewModel.LoadingState.ERROR_OTHER
 import com.keylesspalace.tusky.viewmodel.ListsViewModel.LoadingState.INITIAL
 import com.keylesspalace.tusky.viewmodel.ListsViewModel.LoadingState.LOADED
 import com.keylesspalace.tusky.viewmodel.ListsViewModel.LoadingState.LOADING
-import dagger.android.DispatchingAndroidInjector
-import dagger.android.HasAndroidInjector
-import javax.inject.Inject
+import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.launch
 
 // TODO use the ListSelectionFragment (and/or its adapter or binding) here; but keep the LoadingState from here (?)
 
-class ListsActivity : BaseActivity(), Injectable, HasAndroidInjector {
+@AndroidEntryPoint
+class ListsActivity : BaseActivity() {
 
-    @Inject
-    lateinit var viewModelFactory: ViewModelFactory
-
-    @Inject
-    lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
-
-    private val viewModel: ListsViewModel by viewModels { viewModelFactory }
+    private val viewModel: ListsViewModel by viewModels()
 
     private val binding by viewBinding(ActivityListsBinding::inflate)
 
@@ -287,8 +278,6 @@ class ListsActivity : BaseActivity(), Injectable, HasAndroidInjector {
         }
     }
 
-    override fun androidInjector() = dispatchingAndroidInjector
-
     companion object {
         fun newIntent(context: Context) = Intent(context, ListsActivity::class.java)
     }

app/src/main/java/com/keylesspalace/tusky/MainActivity.kt

@@ -142,17 +142,17 @@ import com.mikepenz.materialdrawer.util.addItems
 import com.mikepenz.materialdrawer.util.addItemsAtPosition
 import com.mikepenz.materialdrawer.util.updateBadge
 import com.mikepenz.materialdrawer.widget.AccountHeaderView
-import dagger.android.DispatchingAndroidInjector
-import dagger.android.HasAndroidInjector
+import dagger.hilt.android.AndroidEntryPoint
+import dagger.hilt.android.migration.OptionalInject
 import de.c1710.filemojicompat_ui.helpers.EMOJI_PREFERENCE
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 
-class MainActivity : BottomSheetActivity(), ActionButtonActivity, HasAndroidInjector, MenuProvider {
-    @Inject
-    lateinit var androidInjector: DispatchingAndroidInjector<Any>
+@OptionalInject
+@AndroidEntryPoint
+class MainActivity : BottomSheetActivity(), ActionButtonActivity, MenuProvider {
 
     @Inject
     lateinit var eventHub: EventHub
@@ -1215,8 +1215,6 @@ class MainActivity : BottomSheetActivity(), ActionButtonActivity, HasAndroidInje
 
     override fun getActionButton() = binding.composeButton
 
-    override fun androidInjector() = androidInjector
-
     companion object {
         const val OPEN_WITH_EXPLODE_ANIMATION = "explode"
 

app/src/main/java/com/keylesspalace/tusky/SplashActivity.kt

@@ -21,11 +21,12 @@ import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import com.keylesspalace.tusky.components.login.LoginActivity
 import com.keylesspalace.tusky.db.AccountManager
-import com.keylesspalace.tusky.di.Injectable
+import dagger.hilt.android.AndroidEntryPoint
 import javax.inject.Inject
 
 @SuppressLint("CustomSplashScreen")
-class SplashActivity : AppCompatActivity(), Injectable {
+@AndroidEntryPoint
+class SplashActivity : AppCompatActivity() {
 
     @Inject
     lateinit var accountManager: AccountManager

app/src/main/java/com/keylesspalace/tusky/StatusListActivity.kt

@@ -37,15 +37,12 @@ import com.keylesspalace.tusky.entity.FilterV1
 import com.keylesspalace.tusky.util.isHttpNotFound
 import com.keylesspalace.tusky.util.startActivityWithSlideInAnimation
 import com.keylesspalace.tusky.util.viewBinding
-import dagger.android.DispatchingAndroidInjector
-import dagger.android.HasAndroidInjector
+import dagger.hilt.android.AndroidEntryPoint
 import javax.inject.Inject
 import kotlinx.coroutines.launch
 
-class StatusListActivity : BottomSheetActivity(), HasAndroidInjector {
-
-    @Inject
-    lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
+@AndroidEntryPoint
+class StatusListActivity : BottomSheetActivity() {
 
     @Inject
     lateinit var eventHub: EventHub
@@ -399,8 +396,6 @@ class StatusListActivity : BottomSheetActivity(), HasAndroidInjector {
         return true
     }
 
-    override fun androidInjector() = dispatchingAndroidInjector
-
     companion object {
 
         private const val EXTRA_KIND = "kind"

app/src/main/java/com/keylesspalace/tusky/TabPreferenceActivity.kt

@@ -39,30 +39,26 @@ import com.keylesspalace.tusky.appstore.EventHub
 import com.keylesspalace.tusky.appstore.MainTabsChangedEvent
 import com.keylesspalace.tusky.components.account.list.ListSelectionFragment
 import com.keylesspalace.tusky.databinding.ActivityTabPreferenceBinding
-import com.keylesspalace.tusky.di.Injectable
 import com.keylesspalace.tusky.entity.MastoList
 import com.keylesspalace.tusky.network.MastodonApi
 import com.keylesspalace.tusky.util.unsafeLazy
 import com.keylesspalace.tusky.util.viewBinding
 import com.keylesspalace.tusky.util.visible
-import dagger.android.DispatchingAndroidInjector
-import dagger.android.HasAndroidInjector
+import dagger.hilt.android.AndroidEntryPoint
 import java.util.regex.Pattern
 import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 
-class TabPreferenceActivity : BaseActivity(), Injectable, HasAndroidInjector, ItemInteractionListener, ListSelectionFragment.ListSelectionListener {
+@AndroidEntryPoint
+class TabPreferenceActivity : BaseActivity(), ItemInteractionListener, ListSelectionFragment.ListSelectionListener {
 
     @Inject
     lateinit var mastodonApi: MastodonApi
 
     @Inject
     lateinit var eventHub: EventHub
 
-    @Inject
-    lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any>
-
     private val binding by viewBinding(ActivityTabPreferenceBinding::inflate)
 
     private lateinit var currentTabs: MutableList<TabData>
@@ -368,8 +364,6 @@ class TabPreferenceActivity : BaseActivity(), Injectable, HasAndroidInjector, It
         }
     }
 
-    override fun androidInjector() = dispatchingAndroidInjector
-
     companion object {
         private const val MIN_TAB_COUNT = 2
     }