Give view pager unique ids, avoiding subtle bugs

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

@@ -138,8 +138,8 @@ class LibraryController(
         super.onViewCreated(view)
 
         adapter = LibraryAdapter(this)
-        view_pager.adapter = adapter
-        view_pager.pageSelections().skip(1).subscribeUntilDestroy {
+        library_pager.adapter = adapter
+        library_pager.pageSelections().skip(1).subscribeUntilDestroy {
             preferences.lastUsedCategory().set(it)
             activeCategory = it
         }
@@ -158,7 +158,7 @@ class LibraryController(
     override fun onChangeStarted(handler: ControllerChangeHandler, type: ControllerChangeType) {
         super.onChangeStarted(handler, type)
         if (type.isEnter) {
-            activity?.tabs?.setupWithViewPager(view_pager)
+            activity?.tabs?.setupWithViewPager(library_pager)
             presenter.subscribeLibrary()
         }
     }
@@ -232,7 +232,7 @@ class LibraryController(
 
         // Get the current active category.
         val activeCat = if (adapter.categories.isNotEmpty())
-            view_pager.currentItem
+            library_pager.currentItem
         else
             activeCategory
 
@@ -240,14 +240,14 @@ class LibraryController(
         adapter.categories = categories
 
         // Restore active category.
-        view_pager.setCurrentItem(activeCat, false)
+        library_pager.setCurrentItem(activeCat, false)
 
         tabsVisibilityRelay.call(categories.size > 1)
 
         // Delay the scroll position to allow the view to be properly measured.
         view.post {
             if (isAttached) {
-                activity?.tabs?.setScrollPosition(view_pager.currentItem, 0f, true)
+                activity?.tabs?.setScrollPosition(library_pager.currentItem, 0f, true)
             }
         }
 
@@ -292,11 +292,11 @@ class LibraryController(
     private fun reattachAdapter() {
         val adapter = adapter ?: return
 
-        val position = view_pager.currentItem
+        val position = library_pager.currentItem
 
         adapter.recycle = false
-        view_pager.adapter = adapter
-        view_pager.currentItem = position
+        library_pager.adapter = adapter
+        library_pager.currentItem = position
         adapter.recycle = true
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaController.kt

@@ -87,11 +87,11 @@ class MangaController : RxController, TabbedController {
         requestPermissionsSafe(arrayOf(WRITE_EXTERNAL_STORAGE), 301)
 
         adapter = MangaDetailAdapter()
-        view_pager.offscreenPageLimit = 3
-        view_pager.adapter = adapter
+        manga_pager.offscreenPageLimit = 3
+        manga_pager.adapter = adapter
 
         if (!fromCatalogue)
-            view_pager.currentItem = CHAPTERS_CONTROLLER
+            manga_pager.currentItem = CHAPTERS_CONTROLLER
     }
 
     override fun onDestroyView(view: View) {
@@ -102,7 +102,7 @@ class MangaController : RxController, TabbedController {
     override fun onChangeStarted(handler: ControllerChangeHandler, type: ControllerChangeType) {
         super.onChangeStarted(handler, type)
         if (type.isEnter) {
-            activity?.tabs?.setupWithViewPager(view_pager)
+            activity?.tabs?.setupWithViewPager(manga_pager)
             trackingIconSubscription = trackingIconRelay.subscribe { setTrackingIconInternal(it) }
         }
     }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerReader.kt

@@ -118,7 +118,7 @@ abstract class PagerReader : BaseReader() {
         this.pager = pager.apply {
             setLayoutParams(ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT))
             setOffscreenPageLimit(1)
-            setId(R.id.view_pager)
+            setId(R.id.reader_pager)
             setOnChapterBoundariesOutListener(object : OnChapterBoundariesOutListener {
                 override fun onFirstPageOutEvent() {
                     readerActivity.requestPreviousChapter()

app/src/main/res/layout/library_controller.xml

@@ -8,7 +8,7 @@
     <android.support.v4.view.ViewPager
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:id="@+id/view_pager"/>
+        android:id="@+id/library_pager"/>
 
     <eu.kanade.tachiyomi.widget.EmptyView
         android:id="@+id/empty_view"

app/src/main/res/layout/manga_controller.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <android.support.v4.view.ViewPager
     xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/view_pager"
+    android:id="@+id/manga_pager"
     android:layout_width="match_parent"
     android:layout_height="match_parent" />

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

@@ -3,4 +3,6 @@
 
     <item name="catalogue_filter_sort_group" type="id"/>
     <item name="catalogue_filter_sort_item" type="id"/>
+
+    <item name="reader_pager" type="id"/>
 </resources>