Fix MangaDetailsPresenter sharing

app/build.gradle

@@ -16,7 +16,7 @@ android {
 		minSdkVersion 21
 		targetSdkVersion 29
 		versionCode gitCommits
-		versionName '0.5-b1'
+		versionName '0.5-b2'
 
 		kapt {
 			arguments {

app/src/main/java/org/koitharu/kotatsu/ui/browser/BrowserActivity.kt

@@ -29,7 +29,7 @@ class BrowserActivity : BaseActivity(), BrowserCallback {
 		webView.webViewClient = BrowserClient(this)
 		val url = intent?.dataString
 		if (url.isNullOrEmpty()) {
-			finish()
+			finishAfterTransition()
 		} else {
 			webView.loadUrl(url)
 		}
@@ -43,7 +43,7 @@ class BrowserActivity : BaseActivity(), BrowserCallback {
 	override fun onOptionsItemSelected(item: MenuItem): Boolean = when (item.itemId) {
 		android.R.id.home -> {
 			webView.stopLoading()
-			finish()
+			finishAfterTransition()
 			true
 		}
 		R.id.action_browser -> {

app/src/main/java/org/koitharu/kotatsu/ui/common/BaseActivity.kt

@@ -1,12 +1,10 @@
 package org.koitharu.kotatsu.ui.common
 
-import android.view.KeyEvent
 import android.view.MenuItem
 import android.view.View
 import androidx.appcompat.widget.Toolbar
 import moxy.MvpAppCompatActivity
 import org.koin.core.KoinComponent
-import org.koitharu.kotatsu.BuildConfig
 import org.koitharu.kotatsu.R
 
 abstract class BaseActivity : MvpAppCompatActivity(), KoinComponent {
@@ -29,13 +27,4 @@ abstract class BaseActivity : MvpAppCompatActivity(), KoinComponent {
 		onBackPressed()
 		true
 	} else super.onOptionsItemSelected(item)
-
-	override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
-		//TODO remove. Just for testing
-		if (BuildConfig.DEBUG && keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
-			recreate()
-			return true
-		}
-		return super.onKeyDown(keyCode, event)
-	}
 }

app/src/main/java/org/koitharu/kotatsu/ui/common/SharedPresenterHolder.kt

@@ -0,0 +1,25 @@
+package org.koitharu.kotatsu.ui.common
+
+import android.util.ArrayMap
+import moxy.MvpPresenter
+import java.lang.ref.WeakReference
+
+abstract class SharedPresenterHolder<T : MvpPresenter<*>> {
+
+	private val cache = ArrayMap<Int, WeakReference<T>>(3)
+
+	fun getInstance(key: Int): T {
+		var instance = cache[key]?.get()
+		if (instance == null) {
+			instance = onCreatePresenter(key)
+			cache[key] = WeakReference(instance)
+		}
+		return instance
+	}
+
+	fun clear(key: Int) {
+		cache.remove(key)
+	}
+
+	protected abstract fun onCreatePresenter(key: Int): T
+}

app/src/main/java/org/koitharu/kotatsu/ui/details/ChaptersFragment.kt

@@ -25,7 +25,9 @@ class ChaptersFragment : BaseFragment(R.layout.fragment_chapters), MangaDetailsV
 	OnRecyclerItemClickListener<MangaChapter>, ActionMode.Callback {
 
 	@Suppress("unused")
-	private val presenter by moxyPresenter(factory = MangaDetailsPresenter.Companion::getInstance)
+	private val presenter by moxyPresenter {
+		MangaDetailsPresenter.getInstance(activity.hashCode())
+	}
 
 	private var manga: Manga? = null
 

app/src/main/java/org/koitharu/kotatsu/ui/details/MangaDetailsActivity.kt

@@ -37,7 +37,9 @@ import org.koitharu.kotatsu.utils.ext.getThemeColor
 class MangaDetailsActivity : BaseActivity(), MangaDetailsView,
 	TabLayoutMediator.TabConfigurationStrategy {
 
-	private val presenter by moxyPresenter(factory = MangaDetailsPresenter.Companion::getInstance)
+	private val presenter by moxyPresenter {
+		MangaDetailsPresenter.getInstance(hashCode())
+	}
 
 	private var manga: Manga? = null
 
@@ -52,7 +54,7 @@ class MangaDetailsActivity : BaseActivity(), MangaDetailsView,
 				presenter.loadDetails(it, true)
 			} ?: intent?.getLongExtra(EXTRA_MANGA_ID, 0)?.takeUnless { it == 0L }?.let {
 				presenter.findMangaById(it)
-			} ?: finish()
+			} ?: finishAfterTransition()
 		}
 	}
 
@@ -73,13 +75,13 @@ class MangaDetailsActivity : BaseActivity(), MangaDetailsView,
 			this, getString(R.string._s_deleted_from_local_storage, manga.title),
 			Toast.LENGTH_SHORT
 		).show()
-		finish()
+		finishAfterTransition()
 	}
 
 	override fun onError(e: Throwable) {
 		if (manga == null) {
 			Toast.makeText(this, e.getDisplayMessage(resources), Toast.LENGTH_LONG).show()
-			finish()
+			finishAfterTransition()
 		} else {
 			Snackbar.make(pager, e.getDisplayMessage(resources), Snackbar.LENGTH_LONG).show()
 		}

app/src/main/java/org/koitharu/kotatsu/ui/details/MangaDetailsFragment.kt

@@ -29,7 +29,9 @@ class MangaDetailsFragment : BaseFragment(R.layout.fragment_details), MangaDetai
 	View.OnLongClickListener {
 
 	@Suppress("unused")
-	private val presenter by moxyPresenter(factory = MangaDetailsPresenter.Companion::getInstance)
+	private val presenter by moxyPresenter {
+		MangaDetailsPresenter.getInstance(activity.hashCode())
+	}
 
 	private var manga: Manga? = null
 	private var history: MangaHistory? = null

app/src/main/java/org/koitharu/kotatsu/ui/details/MangaDetailsPresenter.kt

@@ -1,5 +1,6 @@
 package org.koitharu.kotatsu.ui.details
 
+import android.util.Log
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.*
@@ -21,13 +22,13 @@ import org.koitharu.kotatsu.domain.history.HistoryRepository
 import org.koitharu.kotatsu.domain.history.OnHistoryChangeListener
 import org.koitharu.kotatsu.domain.tracking.TrackingRepository
 import org.koitharu.kotatsu.ui.common.BasePresenter
+import org.koitharu.kotatsu.ui.common.SharedPresenterHolder
 import org.koitharu.kotatsu.utils.ext.safe
 import java.io.IOException
 
 @InjectViewState
-class MangaDetailsPresenter private constructor() : BasePresenter<MangaDetailsView>(),
+class MangaDetailsPresenter private constructor(private val key: Int) :
-	OnHistoryChangeListener,
+	BasePresenter<MangaDetailsView>(), OnHistoryChangeListener, OnFavouritesChangeListener {
-	OnFavouritesChangeListener {
 
 	private lateinit var historyRepository: HistoryRepository
 	private lateinit var favouritesRepository: FavouritesRepository
@@ -55,7 +56,7 @@ class MangaDetailsPresenter private constructor() : BasePresenter<MangaDetailsVi
 				} ?: throw MangaNotFoundException("Cannot find manga by id")
 				viewState.onMangaUpdated(manga)
 				loadDetails(manga, true)
-			} catch (_: CancellationException){
+			} catch (_: CancellationException) {
 			} catch (e: Throwable) {
 				if (BuildConfig.DEBUG) {
 					e.printStackTrace()
@@ -83,7 +84,7 @@ class MangaDetailsPresenter private constructor() : BasePresenter<MangaDetailsVi
 				viewState.onMangaUpdated(data)
 				this@MangaDetailsPresenter.manga = data
 				viewState.onNewChaptersChanged(trackingRepository.getNewChaptersCount(manga.id))
-			} catch (_: CancellationException){
+			} catch (_: CancellationException) {
 			} catch (e: Throwable) {
 				if (BuildConfig.DEBUG) {
 					e.printStackTrace()
@@ -198,18 +199,12 @@ class MangaDetailsPresenter private constructor() : BasePresenter<MangaDetailsVi
 	override fun onDestroy() {
 		HistoryRepository.unsubscribe(this)
 		FavouritesRepository.unsubscribe(this)
-		instance = null
+		clear(key)
 		super.onDestroy()
 	}
 
-	companion object {
+	companion object Holder : SharedPresenterHolder<MangaDetailsPresenter>() {
 
-		private var instance: MangaDetailsPresenter? = null
+		override fun onCreatePresenter(key: Int) = MangaDetailsPresenter(key)
-
-		fun getInstance(): MangaDetailsPresenter = instance ?: synchronized(this) {
-			MangaDetailsPresenter().also {
-				instance = it
-			}
-		}
 	}
 }

app/src/main/java/org/koitharu/kotatsu/ui/details/RelatedMangaFragment.kt

@@ -10,7 +10,9 @@ import org.koitharu.kotatsu.ui.list.MangaListFragment
 
 class RelatedMangaFragment : MangaListFragment<Unit>(), MangaDetailsView {
 
-	private val presenter by moxyPresenter(factory = MangaDetailsPresenter.Companion::getInstance)
+	private val presenter by moxyPresenter {
+		MangaDetailsPresenter.getInstance(activity.hashCode())
+	}
 
 	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
 		super.onViewCreated(view, savedInstanceState)

app/src/main/java/org/koitharu/kotatsu/ui/list/local/LocalListPresenter.kt

@@ -38,11 +38,11 @@ class LocalListPresenter : BasePresenter<MangaListView<File>>() {
 	}
 
 	fun loadList(offset: Int) {
-		if (offset != 0) {
-			viewState.onListAppended(emptyList())
-			return
-		}
 		presenterScope.launch {
+			if (offset != 0) {
+				viewState.onListAppended(emptyList())
+				return@launch
+			}
 			viewState.onLoadingStateChanged(true)
 			try {
 				val list = withContext(Dispatchers.IO) {

app/src/main/java/org/koitharu/kotatsu/ui/reader/ReaderActivity.kt

@@ -75,7 +75,7 @@ class ReaderActivity : BaseFullscreenActivity(), ReaderView, ChaptersDialog.OnCh
 			?: intent.getParcelableExtra<ReaderState>(EXTRA_STATE)
 					?: let {
 				Toast.makeText(this, R.string.error_occurred, Toast.LENGTH_SHORT).show()
-				finish()
+				finishAfterTransition()
 				return
 			}
 

app/src/main/java/org/koitharu/kotatsu/ui/search/SearchActivity.kt

@@ -19,7 +19,7 @@ class SearchActivity : BaseActivity(), SearchView.OnQueryTextListener {
 		super.onCreate(savedInstanceState)
 		setContentView(R.layout.activity_search)
 		source = intent.getParcelableExtra(EXTRA_SOURCE) ?: run {
-			finish()
+			finishAfterTransition()
 			return
 		}
 		val query = intent.getStringExtra(EXTRA_QUERY)

app/src/main/java/org/koitharu/kotatsu/ui/search/global/GlobalSearchActivity.kt

@@ -14,7 +14,7 @@ class GlobalSearchActivity : BaseActivity() {
 		val query = intent.getStringExtra(EXTRA_QUERY)
 
 		if (query == null) {
-			finish()
+			finishAfterTransition()
 			return
 		}
 

app/src/main/java/org/koitharu/kotatsu/ui/widget/shelf/ShelfConfigActivity.kt

@@ -48,7 +48,7 @@ class ShelfConfigActivity : BaseActivity(), FavouriteCategoriesView,
 			AppWidgetManager.INVALID_APPWIDGET_ID
 		) ?: AppWidgetManager.INVALID_APPWIDGET_ID
 		if (appWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {
-			finish()
+			finishAfterTransition()
 			return
 		}
 		config = AppWidgetConfig.getInstance(this, appWidgetId)