Invalidate span cache to prevent infinite layout loops

dpadrecyclerview/src/androidTest/kotlin/com/rubensousa/dpadrecyclerview/test/tests/AbstractTestAdapter.kt

@@ -140,6 +140,6 @@ abstract class AbstractTestAdapter<VH : RecyclerView.ViewHolder>(
 
     override fun getItemCount(): Int = items.size
 
-    protected fun getItem(position: Int) = items[position]
+    fun getItem(position: Int) = items[position]
 
 }

dpadrecyclerview/src/androidTest/kotlin/com/rubensousa/dpadrecyclerview/test/tests/mutation/GridAdapterMutationTest.kt

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 Rúben Sousa
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rubensousa.dpadrecyclerview.test.tests.mutation
+
+import androidx.recyclerview.widget.RecyclerView
+import com.google.common.truth.Truth.assertThat
+import com.rubensousa.dpadrecyclerview.ChildAlignment
+import com.rubensousa.dpadrecyclerview.DpadSpanSizeLookup
+import com.rubensousa.dpadrecyclerview.ParentAlignment
+import com.rubensousa.dpadrecyclerview.test.TestAdapterConfiguration
+import com.rubensousa.dpadrecyclerview.test.TestLayoutConfiguration
+import com.rubensousa.dpadrecyclerview.test.helpers.assertFocusAndSelection
+import com.rubensousa.dpadrecyclerview.test.helpers.assertItemAtPosition
+import com.rubensousa.dpadrecyclerview.test.helpers.getRelativeItemViewBounds
+import com.rubensousa.dpadrecyclerview.test.helpers.onRecyclerView
+import com.rubensousa.dpadrecyclerview.test.tests.AbstractTestAdapter
+import com.rubensousa.dpadrecyclerview.test.tests.DpadRecyclerViewTest
+import com.rubensousa.dpadrecyclerview.testing.KeyEvents
+import com.rubensousa.dpadrecyclerview.testing.rules.DisableIdleTimeoutRule
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+
+class GridAdapterMutationTest : DpadRecyclerViewTest() {
+
+    @get:Rule
+    val idleTimeoutRule = DisableIdleTimeoutRule()
+
+    override fun getDefaultLayoutConfiguration(): TestLayoutConfiguration {
+        return TestLayoutConfiguration(
+            spans = 4,
+            orientation = RecyclerView.VERTICAL,
+            parentAlignment = ParentAlignment(
+                edge = ParentAlignment.Edge.MIN_MAX,
+                fraction = 0.5f
+            ),
+            childAlignment = ChildAlignment(
+                fraction = 0.5f
+            )
+        )
+    }
+
+    override fun getDefaultAdapterConfiguration(): TestAdapterConfiguration {
+        return super.getDefaultAdapterConfiguration().copy(
+            numberOfItems = 40
+        )
+    }
+
+    @Before
+    fun setup() {
+        launchFragment()
+    }
+
+    @Test
+    fun testGridRemovalWithSpanLookupDoesNotCrash() {
+        onRecyclerView("Change span size") { recyclerView ->
+            recyclerView.setSpanSizeLookup(object : DpadSpanSizeLookup() {
+                override fun getSpanSize(position: Int): Int {
+                    val adapter = recyclerView.adapter as AbstractTestAdapter<*>
+                    val item = adapter.getItem(position)
+                    return if (item % 9 == 0) {
+                        recyclerView.getSpanCount()
+                    } else {
+                        1
+                    }
+                }
+            })
+        }
+        KeyEvents.pressDown()
+        val oldViewBounds = getRelativeItemViewBounds(position = 1)
+        mutateAdapter { adapter ->
+            adapter.removeAt(3)
+            adapter.removeAt(13)
+        }
+        assertFocusAndSelection(1)
+        assertItemAtPosition(position = 1, item = 1)
+
+        val newViewBounds = getRelativeItemViewBounds(position = 1)
+        assertThat(newViewBounds).isEqualTo(oldViewBounds)
+    }
+
+}

dpadrecyclerview/src/main/java/com/rubensousa/dpadrecyclerview/layoutmanager/PivotLayoutManager.kt

@@ -258,24 +258,24 @@ class PivotLayoutManager(properties: Properties) : RecyclerView.LayoutManager()
     }
 
     override fun onItemsAdded(recyclerView: RecyclerView, positionStart: Int, itemCount: Int) {
-        configuration.spanSizeLookup.invalidateCache()
+        layoutInfo.invalidateSpanCache()
         pivotLayout.onItemsAdded(positionStart, itemCount)
         pivotSelector.onItemsAdded(positionStart, itemCount)
     }
 
     override fun onItemsChanged(recyclerView: RecyclerView) {
-        configuration.spanSizeLookup.invalidateCache()
+        layoutInfo.invalidateSpanCache()
         pivotSelector.onItemsChanged()
     }
 
     override fun onItemsRemoved(recyclerView: RecyclerView, positionStart: Int, itemCount: Int) {
-        configuration.spanSizeLookup.invalidateCache()
+        layoutInfo.invalidateSpanCache()
         pivotLayout.onItemsRemoved(positionStart, itemCount)
         pivotSelector.onItemsRemoved(positionStart, itemCount)
     }
 
     override fun onItemsMoved(recyclerView: RecyclerView, from: Int, to: Int, itemCount: Int) {
-        configuration.spanSizeLookup.invalidateCache()
+        layoutInfo.invalidateSpanCache()
         pivotLayout.onItemsMoved(from, to, itemCount)
         pivotSelector.onItemsMoved(from, to, itemCount)
     }

dpadrecyclerview/src/main/java/com/rubensousa/dpadrecyclerview/layoutmanager/layout/LayoutInfo.kt

@@ -134,6 +134,10 @@ internal class LayoutInfo(
         return getStartSpanIndex(position) + configuration.spanSizeLookup.getSpanSize(position) - 1
     }
 
+    fun invalidateSpanCache() {
+        configuration.spanSizeLookup.invalidateCache()
+    }
+
     fun getSpanGroupIndex(position: Int): Int {
         return configuration.spanSizeLookup.getCachedSpanGroupIndex(
             position,

dpadrecyclerview/src/main/java/com/rubensousa/dpadrecyclerview/layoutmanager/layout/grid/GridLayoutEngineer.kt

@@ -589,6 +589,7 @@ internal class GridLayoutEngineer(
             )
             return layoutInfo.getStartSpanIndex(position)
         }
+        layoutInfo.invalidateSpanCache()
         return layoutInfo.getStartSpanIndex(adapterPosition)
     }
 
@@ -608,6 +609,7 @@ internal class GridLayoutEngineer(
             )
             return layoutInfo.getSpanSize(position)
         }
+        layoutInfo.invalidateSpanCache()
         return layoutInfo.getSpanSize(adapterPosition)
     }