Recycle view holders in library. Format fixes

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryCategoryAdapter.kt

@@ -85,10 +85,9 @@ class LibraryCategoryAdapter(val fragment: LibraryCategoryFragment) :
      */
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): LibraryHolder {
         //depending on preferences, display a list or display a grid
-        if(parent.id == R.id.library_list) {
+        if (parent.id == R.id.library_list) {
             val view = parent.inflate(R.layout.item_library_list)
             return LibraryListHolder(view, this, fragment)
-
         } else {
             val view = parent.inflate(R.layout.item_catalogue_grid).apply {
                 card.layoutParams = FrameLayout.LayoutParams(MATCH_PARENT, coverHeight)

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryCategoryFragment.kt

@@ -2,6 +2,7 @@ package eu.kanade.tachiyomi.ui.library
 
 import android.content.res.Configuration
 import android.os.Bundle
+import android.support.v7.widget.GridLayoutManager
 import android.support.v7.widget.LinearLayoutManager
 import android.support.v7.widget.RecyclerView
 import android.view.LayoutInflater
@@ -91,8 +92,6 @@ class LibraryCategoryFragment : BaseFragment(), FlexibleViewHolder.OnListItemCli
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedState: Bundle?): View? {
         return inflater.inflate(R.layout.fragment_library_category, container, false)
-
-
     }
 
     override fun onViewCreated(view: View, savedState: Bundle?) {
@@ -100,14 +99,16 @@ class LibraryCategoryFragment : BaseFragment(), FlexibleViewHolder.OnListItemCli
 
         //set up grid
         recycler.setHasFixedSize(true)
+        (recycler.layoutManager as GridLayoutManager).recycleChildrenOnDetach = true
+        recycler.recycledViewPool = libraryFragment.pool
         recycler.adapter = adapter
 
         //set up list
         library_list.setHasFixedSize(true)
-        library_list.adapter = adapter
         library_list.layoutManager = LinearLayoutManager(activity)
-
+        library_list.recycledViewPool = libraryFragment.pool
-
+        (library_list.layoutManager as LinearLayoutManager).recycleChildrenOnDetach = true
+        library_list.adapter = adapter
 
         if (libraryFragment.actionMode != null) {
             setSelectionMode(FlexibleAdapter.MODE_MULTI)
@@ -119,19 +120,19 @@ class LibraryCategoryFragment : BaseFragment(), FlexibleViewHolder.OnListItemCli
                 // Set again the adapter to recalculate the covers height
                 .subscribe { recycler.adapter = adapter }
 
-        searchSubscription = libraryPresenter.searchSubject?.subscribe { text ->
+        searchSubscription = libraryPresenter.searchSubject.subscribe { text ->
             adapter.searchText = text
             adapter.updateDataSet()
         }
 
-        toggleViewSubscription = preferences.libraryAsList().asObservable().subscribe {onViewModeChange(it)}
+        toggleViewSubscription = preferences.libraryAsList().asObservable()
+                .subscribe { onViewModeChange(it) }
 
-        if(libraryPresenter.displayAsList != displayAsList) {
+        if (libraryPresenter.displayAsList != displayAsList) {
             library_switcher.showNext()
             displayAsList = libraryPresenter.displayAsList
         }
 
-
         library_switcher.inAnimation = AnimationUtils.loadAnimation(activity, android.R.anim.fade_in)
         library_switcher.outAnimation = AnimationUtils.loadAnimation(activity, android.R.anim.fade_out)
 
@@ -176,11 +177,8 @@ class LibraryCategoryFragment : BaseFragment(), FlexibleViewHolder.OnListItemCli
 
     override fun onResume() {
         super.onResume()
-
-
         libraryMangaSubscription = libraryPresenter.libraryMangaSubject
-                ?.subscribe { onNextLibraryManga(it) }
+                .subscribe { onNextLibraryManga(it) }
-
     }
 
     override fun onPause() {
@@ -310,7 +308,7 @@ class LibraryCategoryFragment : BaseFragment(), FlexibleViewHolder.OnListItemCli
 
     fun onViewModeChange(isList: Boolean) {
         //do nothing if the display does not need to change
-        if(isList == displayAsList) return
+        if (isList == displayAsList) return
 
         //else change view and display mode
         library_switcher.showNext()

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryFragment.kt

@@ -6,6 +6,7 @@ import android.os.Bundle
 import android.support.design.widget.TabLayout
 import android.support.v4.view.ViewPager
 import android.support.v7.view.ActionMode
+import android.support.v7.widget.RecyclerView
 import android.support.v7.widget.SearchView
 import android.view.*
 import com.afollestad.materialdialogs.MaterialDialog
@@ -86,6 +87,11 @@ class LibraryFragment : BaseRxFragment<LibraryPresenter>(), ActionMode.Callback
      */
     var isFilterUnread = false
 
+    /**
+     * A pool to share view holders between all the registered categories (fragments).
+     */
+    val pool = RecyclerView.RecycledViewPool()
+
     companion object {
         /**
          * Key to change the cover of a manga in [onActivityResult].
@@ -138,7 +144,7 @@ class LibraryFragment : BaseRxFragment<LibraryPresenter>(), ActionMode.Callback
         if (savedState != null) {
             activeCategory = savedState.getInt(CATEGORY_KEY)
             query = savedState.getString(QUERY_KEY)
-            presenter.searchSubject?.onNext(query)
+            presenter.searchSubject.onNext(query)
         } else {
             activeCategory = presenter.preferences.lastUsedCategory().getOrDefault()
         }
@@ -311,7 +317,7 @@ class LibraryFragment : BaseRxFragment<LibraryPresenter>(), ActionMode.Callback
         view_pager.post { if (isAdded) tabs.setScrollPosition(view_pager.currentItem, 0f, true) }
 
         // Send the manga map to child fragments after the adapter is updated.
-        presenter.libraryMangaSubject?.onNext(LibraryMangaEvent(mangaMap))
+        presenter.libraryMangaSubject.onNext(LibraryMangaEvent(mangaMap))
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryPresenter.kt

@@ -39,12 +39,12 @@ class LibraryPresenter : BasePresenter<LibraryFragment>() {
     /**
      * Search query of the library.
      */
-    val searchSubject: BehaviorSubject<String>? = BehaviorSubject.create<String>()
+    val searchSubject: BehaviorSubject<String> = BehaviorSubject.create<String>()
 
     /**
      * Subject to notify the library's viewpager for updates.
      */
-    val libraryMangaSubject: BehaviorSubject<LibraryMangaEvent>? = BehaviorSubject.create<LibraryMangaEvent>()
+    val libraryMangaSubject: BehaviorSubject<LibraryMangaEvent> = BehaviorSubject.create<LibraryMangaEvent>()
 
     /**
      * Database.
@@ -95,9 +95,7 @@ class LibraryPresenter : BasePresenter<LibraryFragment>() {
             start(GET_LIBRARY)
         }
 
-
+        add(preferences.libraryAsList().asObservable().subscribe { setDisplayMode(it) })
-        add(preferences.libraryAsList().asObservable().subscribe{setDisplayMode(it)})
-
     }
 
     /**