refactor: Use AppTheme enum exclusively (#311)

Previous code treated the app theme as a mix of strings and enums.
Convert to exclusively use the `AppTheme` enum to improve type safety.

app/src/main/java/app/pachli/BaseActivity.kt

@@ -37,15 +37,13 @@ import app.pachli.adapter.AccountSelectionAdapter
 import app.pachli.core.accounts.AccountManager
 import app.pachli.core.database.model.AccountEntity
 import app.pachli.core.navigation.LoginActivityIntent
+import app.pachli.core.preferences.AppTheme
 import app.pachli.core.preferences.PrefKeys
-import app.pachli.core.preferences.PrefKeys.APP_THEME
 import app.pachli.core.preferences.SharedPreferencesRepository
 import app.pachli.interfaces.AccountSelectionListener
 import app.pachli.interfaces.PermissionRequester
-import app.pachli.util.APP_THEME_DEFAULT
 import app.pachli.util.EmbeddedFontFamily
 import app.pachli.util.EmbeddedFontFamily.Companion.from
-import app.pachli.util.THEME_BLACK
 import com.google.android.material.color.MaterialColors
 import com.google.android.material.snackbar.Snackbar
 import dagger.hilt.EntryPoint
@@ -84,9 +82,9 @@ abstract class BaseActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
 
         // Set the theme from preferences
-        val theme = sharedPreferencesRepository.getString(APP_THEME, APP_THEME_DEFAULT)
+        val theme = AppTheme.from(sharedPreferencesRepository)
         Timber.d("activeTheme: %s", theme)
-        if (theme == THEME_BLACK) {
+        if (theme == AppTheme.BLACK) {
             setTheme(R.style.Theme_Pachli_Black)
         }
 

app/src/main/java/app/pachli/PachliApplication.kt

@@ -24,12 +24,11 @@ import androidx.work.ExistingPeriodicWorkPolicy
 import androidx.work.PeriodicWorkRequestBuilder
 import androidx.work.WorkManager
 import app.pachli.components.notifications.createWorkerNotificationChannel
+import app.pachli.core.preferences.AppTheme
 import app.pachli.core.preferences.NEW_INSTALL_SCHEMA_VERSION
 import app.pachli.core.preferences.PrefKeys
-import app.pachli.core.preferences.PrefKeys.APP_THEME
 import app.pachli.core.preferences.SCHEMA_VERSION
 import app.pachli.core.preferences.SharedPreferencesRepository
-import app.pachli.util.APP_THEME_DEFAULT
 import app.pachli.util.LocaleManager
 import app.pachli.util.setAppNightMode
 import app.pachli.worker.PruneCacheWorker
@@ -88,7 +87,7 @@ class PachliApplication : Application() {
         EmojiPackHelper.init(this, DefaultEmojiPackList.get(this), allowPackImports = false)
 
         // init night mode
-        val theme = sharedPreferencesRepository.getString(APP_THEME, APP_THEME_DEFAULT)
+        val theme = AppTheme.from(sharedPreferencesRepository)
         setAppNightMode(theme)
 
         localeManager.setLocale()

app/src/main/java/app/pachli/components/compose/ComposeActivity.kt

@@ -81,14 +81,12 @@ import app.pachli.core.navigation.ComposeActivityIntent.ComposeOptions.InitialCu
 import app.pachli.core.network.model.Attachment
 import app.pachli.core.network.model.Emoji
 import app.pachli.core.network.model.Status
+import app.pachli.core.preferences.AppTheme
 import app.pachli.core.preferences.PrefKeys
-import app.pachli.core.preferences.PrefKeys.APP_THEME
 import app.pachli.core.preferences.SharedPreferencesRepository
 import app.pachli.databinding.ActivityComposeBinding
-import app.pachli.util.APP_THEME_DEFAULT
 import app.pachli.util.MentionSpan
 import app.pachli.util.PickMediaFiles
-import app.pachli.util.THEME_BLACK
 import app.pachli.util.getInitialLanguages
 import app.pachli.util.getLocaleList
 import app.pachli.util.getMediaSize
@@ -205,8 +203,8 @@ class ComposeActivity :
 
         activeAccount = accountManager.activeAccount ?: return
 
-        val theme = sharedPreferencesRepository.getString(APP_THEME, APP_THEME_DEFAULT)
+        val theme = AppTheme.from(sharedPreferencesRepository)
-        if (theme == THEME_BLACK) {
+        if (theme == AppTheme.BLACK) {
             setTheme(R.style.AppDialogActivityBlackTheme)
         }
         setContentView(binding.root)

app/src/main/java/app/pachli/components/preference/PreferencesActivity.kt

@@ -30,11 +30,10 @@ import app.pachli.appstore.EventHub
 import app.pachli.core.navigation.MainActivityIntent
 import app.pachli.core.navigation.PreferencesActivityIntent
 import app.pachli.core.navigation.PreferencesActivityIntent.PreferenceScreen
+import app.pachli.core.preferences.AppTheme
 import app.pachli.core.preferences.PrefKeys
 import app.pachli.core.preferences.PrefKeys.APP_THEME
-import app.pachli.core.preferences.getNonNullString
 import app.pachli.databinding.ActivityPreferencesBinding
-import app.pachli.util.APP_THEME_DEFAULT
 import app.pachli.util.setAppNightMode
 import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.flow.filterNotNull
@@ -102,7 +101,7 @@ class PreferencesActivity :
             sharedPreferencesRepository.changes.filterNotNull().collect { key ->
                 when (key) {
                     APP_THEME -> {
-                        val theme = sharedPreferencesRepository.getNonNullString(APP_THEME, APP_THEME_DEFAULT)
+                        val theme = AppTheme.from(sharedPreferencesRepository)
                         Timber.d("activeTheme: %s", theme)
                         setAppNightMode(theme)
 

app/src/main/java/app/pachli/components/preference/PreferencesFragment.kt

@@ -23,6 +23,7 @@ import app.pachli.R
 import app.pachli.core.accounts.AccountManager
 import app.pachli.core.network.model.Notification
 import app.pachli.core.preferences.AppTheme
+import app.pachli.core.preferences.AppTheme.Companion.APP_THEME_DEFAULT
 import app.pachli.core.preferences.PrefKeys
 import app.pachli.settings.emojiPreference
 import app.pachli.settings.listPreference
@@ -32,7 +33,6 @@ import app.pachli.settings.preferenceCategory
 import app.pachli.settings.sliderPreference
 import app.pachli.settings.switchPreference
 import app.pachli.updatecheck.UpdateNotificationFrequency
-import app.pachli.util.APP_THEME_DEFAULT
 import app.pachli.util.LocaleManager
 import app.pachli.util.deserialize
 import app.pachli.util.makeIcon
@@ -60,7 +60,7 @@ class PreferencesFragment : PreferenceFragmentCompat() {
         makePreferenceScreen {
             preferenceCategory(R.string.pref_title_appearance_settings) {
                 listPreference {
-                    setDefaultValue(APP_THEME_DEFAULT)
+                    setDefaultValue(APP_THEME_DEFAULT.value)
                     setEntries(R.array.app_theme_names)
                     entryValues = AppTheme.stringValues()
                     key = PrefKeys.APP_THEME

app/src/main/java/app/pachli/util/ThemeUtils.kt

@@ -24,6 +24,7 @@ import android.graphics.drawable.Drawable
 import androidx.annotation.AttrRes
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.core.content.res.use
+import app.pachli.core.preferences.AppTheme
 import com.google.android.material.color.MaterialColors
 
 /**
@@ -31,13 +32,6 @@ import com.google.android.material.color.MaterialColors
  * the ability to do so is not supported in resource files.
  */
 
-const val THEME_NIGHT = "night"
-const val THEME_DAY = "day"
-const val THEME_BLACK = "black"
-const val THEME_AUTO = "auto"
-const val THEME_SYSTEM = "auto_system"
-const val APP_THEME_DEFAULT = THEME_SYSTEM
-
 fun getDimension(context: Context, @AttrRes attribute: Int): Int {
     return context.obtainStyledAttributes(intArrayOf(attribute)).use { array ->
         array.getDimensionPixelSize(0, -1)
@@ -51,18 +45,17 @@ fun setDrawableTint(context: Context, drawable: Drawable, @AttrRes attribute: In
     )
 }
 
-fun setAppNightMode(flavor: String?) {
+fun setAppNightMode(flavor: AppTheme) {
     when (flavor) {
-        THEME_NIGHT, THEME_BLACK -> AppCompatDelegate.setDefaultNightMode(
+        AppTheme.NIGHT, AppTheme.BLACK -> AppCompatDelegate.setDefaultNightMode(
             AppCompatDelegate.MODE_NIGHT_YES,
         )
-        THEME_DAY -> AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
+        AppTheme.DAY -> AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
-        THEME_AUTO -> AppCompatDelegate.setDefaultNightMode(
+        AppTheme.AUTO -> AppCompatDelegate.setDefaultNightMode(
             AppCompatDelegate.MODE_NIGHT_AUTO_TIME,
         )
-        THEME_SYSTEM -> AppCompatDelegate.setDefaultNightMode(
+        AppTheme.AUTO_SYSTEM -> AppCompatDelegate.setDefaultNightMode(
             AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM,
         )
-        else -> AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
     }
 }

app/src/main/res/values/string-arrays.xml

@@ -1,6 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
+    <!-- Modifications to this list or order must be kept in sync with
+         SettingsConstants.AppTheme -->
     <string-array name="app_theme_names">
         <item>@string/app_them_dark</item>
         <item>@string/app_theme_light</item>

core/preferences/src/main/kotlin/app/pachli/core/preferences/SettingsConstants.kt

@@ -1,5 +1,11 @@
 package app.pachli.core.preferences
 
+/**
+ * Possible themes.
+ *
+ * The order of the values is important, and must be kept in sync with
+ * R.array.app_theme_names.
+ */
 enum class AppTheme(val value: String) {
     NIGHT("night"),
     DAY("day"),
@@ -9,7 +15,16 @@ enum class AppTheme(val value: String) {
     ;
 
     companion object {
-        fun stringValues() = values().map { it.value }.toTypedArray()
+        val APP_THEME_DEFAULT = AUTO_SYSTEM
+
+        fun stringValues() = entries.map { it.value }.toTypedArray()
+
+        fun from(sharedPreferencesRepository: SharedPreferencesRepository): AppTheme {
+            val pref = sharedPreferencesRepository.getString(PrefKeys.APP_THEME, null)
+                ?: return APP_THEME_DEFAULT
+
+            return enumValueOf(pref.uppercase())
+        }
     }
 }