Fix multi-select phantom anchor bug in manga chapters and library (#4201)

* Fix phantom anchor bug in manga chapters list when multi-selecting

* Fix phantom bug when long pressing selected items not at top of stack

* Fix phantom anchor bug in library page

(cherry picked from commit 496a476c13396f3063388e0d7e8f5ab2c3663858)

# Conflicts:
#	app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryCategoryView.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaController.kt

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

@@ -35,6 +35,7 @@ import reactivecircus.flowbinding.swiperefreshlayout.refreshes
 import rx.android.schedulers.AndroidSchedulers
 import rx.subscriptions.CompositeSubscription
 import uy.kohesive.injekt.injectLazy
+import java.util.ArrayDeque
 import java.util.concurrent.TimeUnit
 
 /**
@@ -81,7 +82,7 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
      */
     private var subscriptions = CompositeSubscription()
 
-    private var lastClickPosition = -1
+    private var lastClickPositionStack = ArrayDeque(listOf(-1))
 
     // EXH -->
     private var initialLoadHandle: LoadingHandle? = null
@@ -294,7 +295,11 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
             }
             is LibrarySelectionEvent.Unselected -> {
                 findAndToggleSelection(event.manga)
-                if (adapter.indexOf(event.manga) != -1) lastClickPosition = -1
+
+                with(adapter.indexOf(event.manga)) {
+                    if (this != -1) lastClickPositionStack.remove(this)
+                }
+
                 if (controller.selectedMangas.isEmpty()) {
                     adapter.mode = SelectableAdapter.Mode.SINGLE
                     // SY -->
@@ -305,7 +310,9 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
             is LibrarySelectionEvent.Cleared -> {
                 adapter.mode = SelectableAdapter.Mode.SINGLE
                 adapter.clearSelection()
-                lastClickPosition = -1
+
+                lastClickPositionStack.clear()
+                lastClickPositionStack.push(-1)
                 // SY -->
                 adapter.isLongPressDragEnabled = adapter.canDrag()
                 // SY <--
@@ -336,7 +343,11 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
         // If the action mode is created and the position is valid, toggle the selection.
         val item = adapter.getItem(position) ?: return false
         return if (adapter.mode == SelectableAdapter.Mode.MULTI) {
-            lastClickPosition = position
+            if (adapter.isSelected(position)) {
+                lastClickPositionStack.remove(position)
+            } else {
+                lastClickPositionStack.push(position)
+            }
             toggleSelection(position)
             true
         } else {
@@ -352,6 +363,7 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
      */
     override fun onItemLongClick(position: Int) {
         controller.createActionModeIfNeeded()
+        val lastClickPosition = lastClickPositionStack.peek()!!
         // SY -->
         adapter.isLongPressDragEnabled = adapter.canDrag()
         // SY <--
@@ -365,7 +377,10 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
                     setSelection(i)
             else -> setSelection(position)
         }
-        lastClickPosition = position
+        if (lastClickPosition != position) {
+            lastClickPositionStack.remove(position)
+            lastClickPositionStack.push(position)
+        }
     }
 
     // SY -->

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

@@ -119,6 +119,7 @@ import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
 import uy.kohesive.injekt.injectLazy
 import java.io.IOException
+import java.util.ArrayDeque
 import kotlin.math.min
 
 class MangaController :
@@ -216,7 +217,7 @@ class MangaController :
 
     private val isLocalSource by lazy { presenter.source.id == LocalSource.ID }
 
-    private var lastClickPosition = -1
+    private var lastClickPositionStack = ArrayDeque(listOf(-1))
 
     private var isRefreshingInfo = false
     private var isRefreshingChapters = false
@@ -1138,7 +1139,12 @@ class MangaController :
         val adapter = chaptersAdapter ?: return false
         val item = adapter.getItem(position) ?: return false
         return if (actionMode != null && adapter.mode == SelectableAdapter.Mode.MULTI) {
-            lastClickPosition = position
+            if (adapter.isSelected(position)) {
+                lastClickPositionStack.remove(position) // possible that it's not there, but no harm
+            } else {
+                lastClickPositionStack.push(position)
+            }
+
             toggleSelection(position)
             true
         } else {
@@ -1149,6 +1155,7 @@ class MangaController :
 
     override fun onItemLongClick(position: Int) {
         createActionModeIfNeeded()
+        val lastClickPosition = lastClickPositionStack.peek()!!
         when {
             lastClickPosition == -1 -> setSelection(position)
             lastClickPosition > position ->
@@ -1159,7 +1166,10 @@ class MangaController :
                     setSelection(i)
             else -> setSelection(position)
         }
-        lastClickPosition = position
+        if (lastClickPosition != position) {
+            lastClickPositionStack.remove(position) // move to top if already exists
+            lastClickPositionStack.push(position)
+        }
         chaptersAdapter?.notifyDataSetChanged()
     }
 
@@ -1208,7 +1218,8 @@ class MangaController :
     }
 
     private fun destroyActionModeIfNeeded() {
-        lastClickPosition = -1
+        lastClickPositionStack.clear()
+        lastClickPositionStack.push(-1)
         actionMode?.finish()
     }