refactor: add SingleFragmentActivity class

AnkiDroid/src/main/AndroidManifest.xml

@@ -345,6 +345,10 @@
             android:label="@string/preview_title"
             android:exported="false"
             />
+        <activity
+            android:name="com.ichi2.anki.SingleFragmentActivity"
+            android:exported="false"
+            />
         <activity
             android:name="com.ichi2.anki.CardTemplatePreviewer"
             android:label="@string/preview_title"

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

@@ -0,0 +1,66 @@
+/*
+ *  Copyright (c) 2023 Brayan Oliveira <[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or modify it under
+ *  the terms of the GNU General Public License as published by the Free Software
+ *  Foundation; either version 3 of the License, or (at your option) any later
+ *  version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ *  PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with
+ *  this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.ichi2.anki
+
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentContainerView
+import androidx.fragment.app.commit
+import com.ichi2.themes.setTransparentStatusBar
+import com.ichi2.utils.getInstanceFromClassName
+import kotlin.reflect.KClass
+import kotlin.reflect.jvm.jvmName
+
+/**
+ * Activity aimed to host a fragment on the entire screen.
+ * For that, it uses [R.layout.single_fragment_activity], which has only a [FragmentContainerView]
+ *
+ * Useful to avoid creating a Activity for every new screen
+ * while being able to reuse the fragment on other places.
+ *
+ * [getIntent] can be used as an easy way to build a [SingleFragmentActivity]
+ */
+class SingleFragmentActivity : AnkiActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        if (showedActivityFailedScreen(savedInstanceState)) {
+            return
+        }
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.single_fragment_activity)
+        setTransparentStatusBar()
+
+        val fragmentClassName = requireNotNull(intent.getStringExtra(FRAGMENT_NAME_EXTRA)) { "'fragmentName' should be provided" }
+        val fragment = getInstanceFromClassName<Fragment>(fragmentClassName).apply {
+            arguments = intent.getBundleExtra(FRAGMENT_ARGS_EXTRA)
+        }
+        supportFragmentManager.commit {
+            replace(R.id.fragment_container, fragment)
+        }
+    }
+    companion object {
+        private const val FRAGMENT_NAME_EXTRA = "fragmentName"
+        private const val FRAGMENT_ARGS_EXTRA = "fragmentArgs"
+
+        fun getIntent(context: Context, fragmentClass: KClass<out Fragment>, arguments: Bundle? = null): Intent {
+            return Intent(context, SingleFragmentActivity::class.java).apply {
+                putExtra(FRAGMENT_NAME_EXTRA, fragmentClass.jvmName)
+                putExtra(FRAGMENT_ARGS_EXTRA, arguments)
+            }
+        }
+    }
+}

AnkiDroid/src/main/res/layout/single_fragment_activity.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:id="@+id/root_layout"
+    tools:context=".SingleFragmentActivity">
+
+    <androidx.fragment.app.FragmentContainerView
+        android:id="@+id/fragment_container"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"/>
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

AnkiDroid/src/test/java/com/ichi2/anki/ActivityStartupUnderBackupTest.kt

@@ -53,6 +53,7 @@ class ActivityStartupUnderBackupTest : RobolectricTest() {
         notYetHandled(IntentHandler::class.java.simpleName, "Not working (or implemented) - inherits from Activity")
         notYetHandled(Preferences::class.java.simpleName, "Not working (or implemented) - inherits from AppCompatPreferenceActivity")
         notYetHandled(FilteredDeckOptions::class.java.simpleName, "Not working (or implemented) - inherits from AppCompatPreferenceActivity")
+        notYetHandled(SingleFragmentActivity::class.java.simpleName, "Implemented, but the test fails because the activity throws if a specific intent extra isn't set")
     }
 
     /**

AnkiDroid/src/test/java/com/ichi2/testutils/ActivityList.kt

@@ -74,7 +74,8 @@ object ActivityList {
             get(IntroductionActivity::class.java),
             get(ManageNotetypes::class.java),
             get(ManageSpaceActivity::class.java),
-            get(PermissionsActivity::class.java)
+            get(PermissionsActivity::class.java),
+            get(SingleFragmentActivity::class.java)
         )
     }