refactor: extract AnkiDroidApp.instance to :common:android as AnkiDroidApplication

Adds a top-level `appContext: Context` accessor in :common:android, set
during AnkiDroidApp.onCreate() via AnkiDroidApplication.setApplicationInstance.
Shared and feature-module code can now reach the Application context without
depending on :AnkiDroid's AnkiDroidApp subclass.

Author: criticalAY

AnkiDroid/src/main/java/com/ichi2/anki/AnkiDroidApp.kt

@@ -36,6 +36,8 @@ import anki.collection.OpChanges
 import com.ichi2.anki.AnkiDroidApp.Companion.sharedPreferencesTestingOverride
 import com.ichi2.anki.analytics.UsageAnalytics
 import com.ichi2.anki.browser.SharedPreferencesLastDeckIdRepository
+import com.ichi2.anki.common.android.AnkiDroidApplication
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.annotations.LegacyNotifications
 import com.ichi2.anki.common.annotations.NeedsTest
 import com.ichi2.anki.common.coroutines.applicationScope
@@ -141,6 +143,7 @@ open class AnkiDroidApp :
             }
         }
         instance = this
+        AnkiDroidApplication.setApplicationInstance(this)
 
         // Get preferences
         val preferences = this.sharedPrefs()
@@ -467,6 +470,9 @@ open class AnkiDroidApp :
                 isAccessible = true
                 set(field, null)
             }
+            // Mirror reality: when AnkiDroidApp.onCreate doesn't run (the bmgr-restore
+            // scenario), appContext is also uninitialized.
+            AnkiDroidApplication.clearForTesting()
         }
 
         @VisibleForTesting(otherwise = VisibleForTesting.NONE)
@@ -477,6 +483,10 @@ open class AnkiDroidApp :
                 isAccessible = true
                 set(field, value)
             }
+            // Production code (AnkiDroidApp.onCreate) sets appContext
+            // right after AnkiDroidApp.instance. Mirror that in tests so callers using the
+            // common-side accessor see the same mock.
+            AnkiDroidApplication.setApplicationInstance(value)
         }
 
         /** Load the libraries to allow access to Anki-Android-Backend */

AnkiDroid/src/main/java/com/ichi2/anki/CardBrowser.kt

@@ -676,7 +676,7 @@ open class CardBrowser :
     /**
      * Implementation of `by viewModels()` for use in [onCreate]
      *
-     * @see showedActivityFailedScreen - we may not have AnkiDroidApp.instance and therefore can't
+     * @see showedActivityFailedScreen - we may not have appContext and therefore can't
      * create the ViewModel
      *
      * @param fragmented True if `noteEditorFrame` is non-null (x-large displays)

AnkiDroid/src/main/java/com/ichi2/anki/CardTemplateEditor.kt

@@ -63,6 +63,7 @@ import com.ichi2.anki.CollectionManager.withCol
 import com.ichi2.anki.android.input.ShortcutGroup
 import com.ichi2.anki.android.input.shortcut
 import com.ichi2.anki.cardviewer.SingleCardSide
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.annotations.NeedsTest
 import com.ichi2.anki.common.utils.android.showThemedToast
 import com.ichi2.anki.common.utils.annotation.KotlinCleanup
@@ -1277,7 +1278,7 @@ open class CardTemplateEditor : AnkiActivity(R.layout.activity_card_template_edi
             }
 
         private fun launchCardBrowserAppearance(currentTemplate: BackendCardTemplate) {
-            val context = AnkiDroidApp.instance.baseContext
+            val context = appContext
             val browserAppearanceIntent = CardTemplateBrowserAppearanceEditor.getIntentFromTemplate(context, currentTemplate)
             onCardBrowserAppearanceActivityResult.launch(browserAppearanceIntent)
         }

AnkiDroid/src/main/java/com/ichi2/anki/CardTemplateNotetype.kt

@@ -22,6 +22,7 @@ import android.os.Parcel
 import android.os.Parcelable
 import androidx.core.os.bundleOf
 import com.ichi2.anki.CollectionManager.withCol
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.annotations.NeedsTest
 import com.ichi2.anki.compat.CompatHelper.Companion.compat
 import com.ichi2.anki.compat.CompatHelper.Companion.getSerializableCompat
@@ -53,9 +54,10 @@ class CardTemplateNotetype(
     var templateChanges = ArrayList<TemplateChange>()
         private set
 
+    // TODO: cleanup applicationContext is not necessary, this is an Application
     fun toBundle(): Bundle =
         bundleOf(
-            INTENT_MODEL_FILENAME to saveTempNoteType(AnkiDroidApp.instance.applicationContext, notetype),
+            INTENT_MODEL_FILENAME to saveTempNoteType(appContext, notetype),
             "mTemplateChanges" to templateChanges,
         )
 
@@ -406,7 +408,7 @@ class CardTemplateNotetype(
         /** Clear any temp note type files saved into internal cache directory  */
         fun clearTempNoteTypeFiles(): Int {
             var deleteCount = 0
-            for (c in AnkiDroidApp.instance.cacheDir.listFiles() ?: arrayOf()) {
+            for (c in appContext.cacheDir.listFiles() ?: arrayOf()) {
                 val absolutePath = c.absolutePath
                 if (absolutePath.contains("editedTemplate") && absolutePath.endsWith("json")) {
                     if (!c.delete()) {

AnkiDroid/src/main/java/com/ichi2/anki/CollectionHelper.kt

@@ -288,7 +288,7 @@ object CollectionHelper {
      *
      * @return the absolute path to the AnkiDroid directory.
      */
-    // This uses a lambda as we typically depends on the `lateinit` AnkiDroidApp.instance
+    // This uses a lambda as we typically depends on the `lateinit` appContext
     // If we remove all Android references, we get a significant unit test speedup
     @VisibleForTesting(otherwise = VisibleForTesting.NONE)
     internal fun getCurrentAnkiDroidDirectoryOptionalContext(

AnkiDroid/src/main/java/com/ichi2/anki/CollectionManager.kt

@@ -31,6 +31,7 @@ import com.ichi2.anki.CollectionManager.withCol
 import com.ichi2.anki.CollectionManager.withOpenColOrNull
 import com.ichi2.anki.CollectionManager.withQueue
 import com.ichi2.anki.backend.createDatabaseUsingRustBackend
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.utils.android.isRobolectric
 import com.ichi2.anki.libanki.Collection
 import com.ichi2.anki.libanki.CollectionFiles
@@ -288,8 +289,8 @@ object CollectionManager {
     }
 
     fun getCollectionDirectory() =
-        // Allow execution if AnkiDroidApp.instance is not initialized
-        CollectionHelper.getCurrentAnkiDroidDirectoryOptionalContext(AnkiDroidApp.sharedPrefs()) { AnkiDroidApp.instance }
+        // Allow execution if appContext is not initialized
+        CollectionHelper.getCurrentAnkiDroidDirectoryOptionalContext(AnkiDroidApp.sharedPrefs()) { appContext }
 
     /** Ensures the AnkiDroid directory is created, then returns the path to the
      * folder and the name of the collection file inside it. */

AnkiDroid/src/main/java/com/ichi2/anki/DayRolloverHandler.kt

@@ -35,6 +35,7 @@ import anki.collection.OpChanges
 import anki.collection.opChanges
 import com.ichi2.anki.CollectionManager.withOpenColOrNull
 import com.ichi2.anki.android.AnkiBroadcastReceiver
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.coroutines.applicationScope
 import com.ichi2.anki.common.crashreporting.CrashReportService
 import com.ichi2.anki.common.exception.ManuallyReportedException
@@ -110,7 +111,7 @@ object DayRolloverHandler : AnkiBroadcastReceiver() {
 
         Timber.i("day cutoff changed %d -> %d", lastCutoff, currentCutoff)
         // Re-arm the wall-clock alarm whenever the cutoff changes
-        DayRolloverAlarm.scheduleNext(AnkiDroidApp.instance)
+        DayRolloverAlarm.scheduleNext(appContext)
         // we do not want to send a "study queues changes" message initially
         if (lastCutoff != null) {
             handleDayRollover()
@@ -126,7 +127,7 @@ object DayRolloverHandler : AnkiBroadcastReceiver() {
 
         Timber.i("day rollover: updating widgets")
         try {
-            WidgetStatus.updateInBackground(AnkiDroidApp.instance)
+            WidgetStatus.updateInBackground(appContext)
         } catch (e: Exception) {
             Timber.w(e, "failed to update widgets")
         }

AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt

@@ -102,6 +102,7 @@ import com.ichi2.anki.android.back.exitViaDoubleTapBackCallback
 import com.ichi2.anki.android.input.ShortcutGroup
 import com.ichi2.anki.android.input.shortcut
 import com.ichi2.anki.android.view.locationInWindow
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.annotations.NeedsTest
 import com.ichi2.anki.common.crashreporting.CrashReportService
 import com.ichi2.anki.common.destinations.navigate
@@ -989,7 +990,7 @@ open class DeckPicker :
      * @see DeckPickerViewModel.handleStartup
      */
     private fun handleStartup() {
-        val context = AnkiDroidApp.instance
+        val context = appContext
 
         val environment: AnkiDroidEnvironment =
             object : AnkiDroidEnvironment {

AnkiDroid/src/main/java/com/ichi2/anki/JavaScriptTTS.kt

@@ -20,6 +20,7 @@ import android.os.Bundle
 import android.speech.tts.TextToSpeech
 import android.speech.tts.TextToSpeech.OnInitListener
 import androidx.annotation.IntDef
+import com.ichi2.anki.common.android.appContext
 
 /**
  * Since it is assumed that only advanced users will use the JavaScript api,
@@ -136,7 +137,7 @@ class JavaScriptTTS internal constructor() : OnInitListener {
     }
 
     init {
-        val context = AnkiDroidApp.instance.applicationContext
+        val context = appContext
         tts = TextToSpeech(context, this)
     }
 }

AnkiDroid/src/main/java/com/ichi2/anki/NoteEditorFragment.kt

@@ -89,6 +89,7 @@ import com.ichi2.anki.OnContextAndLongClickListener.Companion.setOnContextAndLon
 import com.ichi2.anki.android.input.ShortcutGroup
 import com.ichi2.anki.android.input.ShortcutGroupProvider
 import com.ichi2.anki.android.input.shortcut
+import com.ichi2.anki.common.android.appContext
 import com.ichi2.anki.common.annotations.NeedsTest
 import com.ichi2.anki.common.crashreporting.CrashReportService
 import com.ichi2.anki.common.utils.HashUtil
@@ -130,7 +131,6 @@ import com.ichi2.anki.multimedia.MultimediaResult
 import com.ichi2.anki.multimedia.MultimediaResultContract
 import com.ichi2.anki.multimedia.MultimediaUtils.createImageFile
 import com.ichi2.anki.multimedia.MultimediaViewModel
-import com.ichi2.anki.multimediacard.IMultimediaEditableNote
 import com.ichi2.anki.multimediacard.impl.MultimediaEditableNote
 import com.ichi2.anki.noteeditor.CustomToolbarButton
 import com.ichi2.anki.noteeditor.FieldState
@@ -2730,7 +2730,7 @@ class NoteEditorFragment :
         fun addNoteArgs(): Bundle = Bundle().apply { putInt(EXTRA_CALLER, NoteEditorCaller.DECKPICKER.value) }
 
         fun shouldReplaceNewlines(): Boolean =
-            AnkiDroidApp.instance
+            appContext
                 .sharedPrefs()
                 .getBoolean(PREF_NOTE_EDITOR_NEWLINE_REPLACE, true)
 
@@ -2743,7 +2743,7 @@ class NoteEditorFragment :
         }
 
         private fun shouldHideToolbar(): Boolean =
-            !AnkiDroidApp.instance
+            !appContext
                 .sharedPrefs()
                 .getBoolean(PREF_NOTE_EDITOR_SHOW_TOOLBAR, true)
     }