Option to open reader in a separated task

app/src/main/kotlin/org/koitharu/kotatsu/core/nav/AppRouter.kt

@@ -165,7 +165,11 @@ class AppRouter private constructor(
 	}
 
 	fun openReader(intent: ReaderIntent, anchor: View? = null) {
-		startActivity(intent.intent, anchor?.let { view -> scaleUpActivityOptionsOf(view) })
+		val activityIntent = intent.intent
+		if (settings.isReaderMultiTaskEnabled && activityIntent.data != null) {
+			activityIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_DOCUMENT)
+		}
+		startActivity(activityIntent, anchor?.let { view -> scaleUpActivityOptionsOf(view) })
 	}
 
 	fun openAlternatives(manga: Manga) {
@@ -779,7 +783,7 @@ class AppRouter private constructor(
 			else -> true
 		}
 
-		private fun shortMangaUrl(mangaId: Long) = Uri.Builder()
+		fun shortMangaUrl(mangaId: Long) = Uri.Builder()
 			.scheme("kotatsu")
 			.path("manga")
 			.appendQueryParameter("id", mangaId.toString())

app/src/main/kotlin/org/koitharu/kotatsu/core/nav/ReaderIntent.kt

@@ -21,10 +21,12 @@ value class ReaderIntent private constructor(
 
 		fun manga(manga: Manga) = apply {
 			intent.putExtra(AppRouter.KEY_MANGA, ParcelableManga(manga))
+			intent.setData(AppRouter.shortMangaUrl(manga.id))
 		}
 
 		fun mangaId(mangaId: Long) = apply {
 			intent.putExtra(AppRouter.KEY_ID, mangaId)
+			intent.setData(AppRouter.shortMangaUrl(mangaId))
 		}
 
 		fun incognito() = apply {

app/src/main/kotlin/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -225,6 +225,9 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		get() = prefs.getBoolean(KEY_INCOGNITO_MODE, false)
 		set(value) = prefs.edit { putBoolean(KEY_INCOGNITO_MODE, value) }
 
+	val isReaderMultiTaskEnabled: Boolean
+		get() = prefs.getBoolean(KEY_READER_MULTITASK, false)
+
 	var isChaptersReverse: Boolean
 		get() = prefs.getBoolean(KEY_REVERSE_CHAPTERS, false)
 		set(value) = prefs.edit { putBoolean(KEY_REVERSE_CHAPTERS, value) }
@@ -688,6 +691,7 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		const val KEY_DOH = "doh"
 		const val KEY_EXIT_CONFIRM = "exit_confirm"
 		const val KEY_INCOGNITO_MODE = "incognito"
+		const val KEY_READER_MULTITASK = "reader_multitask"
 		const val KEY_SYNC = "sync"
 		const val KEY_SYNC_SETTINGS = "sync_settings"
 		const val KEY_READER_BAR = "reader_bar"

app/src/main/res/values/strings.xml

@@ -847,4 +847,6 @@
 	<string name="collapse_long_description">Collapse long description</string>
 	<string name="creating_backup">Creating backup</string>
 	<string name="share_backup">Share backup</string>
+	<string name="reader_multitask">Open reader in a separate task</string>
+	<string name="reader_multitask_summary">Allows you to keep multiple readers with different manga open at the same time</string>
 </resources>

app/src/main/res/xml/pref_reader.xml

@@ -119,6 +119,12 @@
 		android:summary="@string/keep_screen_on_summary"
 		android:title="@string/keep_screen_on" />
 
+	<SwitchPreferenceCompat
+		android:defaultValue="false"
+		android:key="reader_multitask"
+		android:summary="@string/reader_multitask_summary"
+		android:title="@string/reader_multitask" />
+
 	<SwitchPreferenceCompat
 		android:defaultValue="true"
 		android:key="reader_bar"