Add autocomplete suggestions for previously checked list items

app/src/main/java/com/philkes/notallyx/presentation/view/note/listitem/ListManager.kt

@@ -37,6 +37,8 @@ data class ListState(
     val cursorPos: Int? = null,
 )
 
+data class CheckedItemSuggestion(val id: Int, val body: String)
+
 /**
  * Should be used for all changes to the items list. Notifies the [RecyclerView.Adapter] and pushes
  * according changes to the [ChangeHistory]
@@ -401,6 +403,74 @@ class ListManager(
         return if (fromCheckedList) itemsChecked!![position] else items[position]
     }
 
+    internal fun getCheckedItemSuggestions(
+        query: CharSequence,
+        currentItemId: Int,
+    ): List<CheckedItemSuggestion> {
+        val checkedItems =
+            items.filter { it.checked } +
+                (itemsChecked?.toMutableList()?.filter { it.checked } ?: emptyList())
+        return checkedItems
+            .asSequence()
+            .filter { it.id != currentItemId && it.body.isNotBlank() }
+            .filter { matchesCheckedItem(query.toString(), it.body) }
+            .map { CheckedItemSuggestion(it.id, it.body.trim()) }
+            .distinctBy { it.body.lowercase() }
+            .take(MAX_AUTOCOMPLETE_SUGGESTIONS)
+            .toList()
+    }
+
+    internal fun completeWithCheckedItem(currentItemId: Int, checkedItemId: Int) {
+        val stateBefore = getState()
+        val stateAfter = createAutocompleteState(stateBefore, currentItemId, checkedItemId) ?: return
+        changeHistory.push(ListBatchChange(stateBefore, stateAfter, this))
+        setState(stateAfter)
+        onItemSizeChanged?.invoke(stateAfter.items.size + (stateAfter.checkedItems?.size ?: 0))
+    }
+
+    private fun createAutocompleteState(
+        stateBefore: ListState,
+        currentItemId: Int,
+        checkedItemId: Int,
+    ): ListState? {
+        val itemsAfter = stateBefore.items.cloneList()
+        val checkedItemsAfter = stateBefore.checkedItems?.cloneList()
+        val currentItem = itemsAfter.find { it.id == currentItemId } ?: return null
+        val sourceItems =
+            if (itemsAfter.any { it.id == checkedItemId && it.checked }) {
+                itemsAfter
+            } else {
+                checkedItemsAfter ?: return null
+            }
+        val checkedItem = sourceItems.find { it.id == checkedItemId && it.checked } ?: return null
+
+        currentItem.body = checkedItem.body.trim()
+        currentItem.check(false, checkChildren = false)
+
+        sourceItems.removeFromParent(checkedItem)
+        sourceItems.remove(checkedItem)
+        checkedItem.children.forEach { it.isChild = false }
+        checkedItem.children.clear()
+
+        val currentPosition = itemsAfter.indexOfFirst { it.id == currentItem.id }
+        if (currentPosition == -1) return null
+
+        val orderedIds =
+            (stateBefore.items + (stateBefore.checkedItems ?: emptyList()))
+                .sortedBy { it.order }
+                .map { it.id }
+                .filterNot { it == checkedItem.id }
+        val finalItems = itemsAfter + (checkedItemsAfter ?: emptyList())
+        orderedIds.forEachIndexed { order, id -> finalItems.find { it.id == id }?.order = order }
+
+        return ListState(
+            itemsAfter,
+            checkedItemsAfter,
+            focusedItemPos = currentPosition,
+            cursorPos = currentItem.body.length,
+        )
+    }
+
     private fun RecyclerView.getFocusedPositionAndCursor(): Pair<Int?, Int?> {
         return focusedChild?.let { view ->
             val position = getChildAdapterPosition(view)
@@ -579,5 +649,15 @@ class ListManager(
 
     companion object {
         private const val TAG = "ListManager"
+        private const val MAX_AUTOCOMPLETE_SUGGESTIONS = 2
     }
 }
+
+internal fun matchesCheckedItem(query: String, candidate: String): Boolean {
+    val normalizedQuery = query.trim()
+    val normalizedCandidate = candidate.trim()
+    return normalizedQuery.length >= MIN_AUTOCOMPLETE_QUERY_LENGTH &&
+        normalizedCandidate.startsWith(normalizedQuery, ignoreCase = true)
+}
+
+private const val MIN_AUTOCOMPLETE_QUERY_LENGTH = 2

app/src/main/java/com/philkes/notallyx/presentation/view/note/listitem/adapter/ListItemVH.kt

@@ -6,11 +6,13 @@ import android.view.MotionEvent
 import android.view.View.GONE
 import android.view.ViewGroup
 import android.view.inputmethod.InputMethodManager
+import android.widget.ArrayAdapter
 import android.widget.CompoundButton.OnCheckedChangeListener
 import android.widget.EditText
 import android.widget.TextView.INVISIBLE
 import android.widget.TextView.VISIBLE
 import androidx.annotation.ColorInt
+import androidx.appcompat.widget.ListPopupWindow
 import androidx.recyclerview.widget.ItemTouchHelper
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.RecyclerView.NO_POSITION
@@ -28,6 +30,7 @@ import com.philkes.notallyx.presentation.setControlsContrastColorForAllViews
 import com.philkes.notallyx.presentation.setOnNextAction
 import com.philkes.notallyx.presentation.setTextSizeSp
 import com.philkes.notallyx.presentation.view.misc.EditTextAutoClearFocus
+import com.philkes.notallyx.presentation.view.note.listitem.CheckedItemSuggestion
 import com.philkes.notallyx.presentation.view.note.listitem.ListManager
 import com.philkes.notallyx.presentation.view.note.listitem.firstBodyOrEmptyString
 import com.philkes.notallyx.presentation.viewmodel.preference.ListItemSort
@@ -46,6 +49,9 @@ class ListItemVH(
 ) : RecyclerView.ViewHolder(binding.root) {
 
     private var dragHandleInitialY: Float = 0f
+    private val suggestionPopup = ListPopupWindow(binding.root.context)
+    private var suggestions: List<CheckedItemSuggestion> = emptyList()
+    private var boundItemId: Int = NO_POSITION
 
     init {
         val body = textSize.editBodySize
@@ -57,14 +63,29 @@ class ListItemVH(
                     listManager,
                     this@ListItemVH::getAdapterPosition,
                 ) { text, start, count ->
-                    if (count > 1) {
-                        checkListPasted(text, start, count, this)
-                    } else {
-                        false
+                    val listPasteHandled =
+                        if (count > 1) {
+                            checkListPasted(text, start, count, this)
+                        } else {
+                            false
+                        }
+                    if (!listPasteHandled) {
+                        updateSuggestions(text)
                     }
+                    listPasteHandled
                 }
         }
 
+        suggestionPopup.apply {
+            anchorView = binding.EditText
+            isModal = false
+            setOnItemClickListener { _, _, position, _ ->
+                val suggestion = suggestions[position]
+                suggestionPopup.dismiss()
+                listManager.completeWithCheckedItem(boundItemId, suggestion.id)
+            }
+        }
+
         binding.DragHandle.setOnTouchListener { _, event ->
             when (event.actionMasked) {
                 MotionEvent.ACTION_DOWN -> dragHandleInitialY = event.y
@@ -95,6 +116,8 @@ class ListItemVH(
         autoSort: ListItemSort,
         viewMode: NoteViewMode,
     ) {
+        suggestionPopup.dismiss()
+        boundItemId = item.id
         updateEditText(item, position, viewMode)
 
         updateCheckBox(item, position)
@@ -164,6 +187,7 @@ class ListItemVH(
             if (viewMode == NoteViewMode.EDIT) {
                 setOnFocusChangeListener { _, hasFocus ->
                     binding.Delete.visibility = if (hasFocus) VISIBLE else INVISIBLE
+                    if (!hasFocus) suggestionPopup.dismiss()
                 }
                 binding.Content.descendantFocusability = ViewGroup.FOCUS_BEFORE_DESCENDANTS
             } else {
@@ -288,4 +312,25 @@ class ListItemVH(
     }
 
     fun getSelection() = with(binding.EditText) { Pair(selectionStart, selectionEnd) }
+
+    private fun updateSuggestions(text: CharSequence) {
+        if (!binding.EditText.hasFocus() || boundItemId == NO_POSITION || text.isBlank()) {
+            suggestionPopup.dismiss()
+            return
+        }
+        suggestions = listManager.getCheckedItemSuggestions(text, boundItemId)
+        if (suggestions.isEmpty()) {
+            suggestionPopup.dismiss()
+            return
+        }
+        suggestionPopup.setAdapter(
+            ArrayAdapter(
+                binding.root.context,
+                android.R.layout.simple_list_item_1,
+                suggestions.map { it.body },
+            )
+        )
+        suggestionPopup.width = binding.EditText.width
+        suggestionPopup.show()
+    }
 }

app/src/test/kotlin/com/philkes/notallyx/presentation/view/note/listitem/CheckedItemAutocompleteTest.kt

@@ -0,0 +1,35 @@
+package com.philkes.notallyx.presentation.view.note.listitem
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+
+class CheckedItemAutocompleteTest {
+
+    @Test
+    fun `matches candidate beginning case insensitively`() {
+        assertThat(matchesCheckedItem("lat", "Latte intero")).isTrue()
+        assertThat(matchesCheckedItem("LATTE I", "latte intero")).isTrue()
+    }
+
+    @Test
+    fun `does not match letters found after candidate beginning`() {
+        assertThat(matchesCheckedItem("latte", "Comprare latte")).isFalse()
+    }
+
+    @Test
+    fun `does not suggest blank text`() {
+        assertThat(matchesCheckedItem("  ", "Latte intero")).isFalse()
+    }
+
+    @Test
+    fun `matches text equal to candidate case insensitively`() {
+        assertThat(matchesCheckedItem("Latte", "Latte")).isTrue()
+        assertThat(matchesCheckedItem("LATTE", "latte")).isTrue()
+    }
+
+    @Test
+    fun `requires at least two typed letters`() {
+        assertThat(matchesCheckedItem("l", "Latte intero")).isFalse()
+        assertThat(matchesCheckedItem("la", "Latte intero")).isTrue()
+    }
+}

app/src/test/kotlin/com/philkes/notallyx/recyclerview/listmanager/ListManagerCheckedTest.kt

@@ -500,6 +500,106 @@ class ListManagerCheckedTest : ListManagerTestBase() {
         items.assertChecked(false, false, false, false, false, false)
     }
 
+    @Test
+    fun `autocomplete applies delete and uncheck atomically without auto-sort`() {
+        setSorting(ListItemSort.NO_AUTO_SORT)
+        listManager.changeChecked(1, true)
+        changeHistory.reset()
+
+        listManager.completeWithCheckedItem(currentItemId = 0, checkedItemId = 1)
+
+        items.assertOrder("B", "C", "D", "E", "F")
+        "B".assertIsNotChecked()
+        changeHistory.undo()
+        items.assertOrder("A", "B", "C", "D", "E", "F")
+        "B".assertIsChecked()
+    }
+
+    @Test
+    fun `autocomplete applies delete and uncheck atomically with auto-sort`() {
+        setSorting(ListItemSort.AUTO_SORT_BY_CHECKED)
+        listManager.changeChecked(1, true)
+        changeHistory.reset()
+
+        listManager.completeWithCheckedItem(currentItemId = 0, checkedItemId = 1)
+
+        itemsChecked!!.assertSize(0)
+        items.assertOrder("B", "C", "D", "E", "F")
+        "B".assertIsNotChecked()
+        changeHistory.undo()
+        items.assertOrder("A", "C", "D", "E", "F")
+        itemsChecked!!.assertOrder("B")
+        "B".assertIsChecked()
+    }
+
+    @Test
+    fun `autocomplete replaces parent text and removes its checked child`() {
+        setSorting(ListItemSort.NO_AUTO_SORT)
+        listManager.changeIsChild(1, true)
+        listManager.changeIsChild(2, true)
+        listManager.changeChecked(1, true)
+        changeHistory.reset()
+
+        listManager.completeWithCheckedItem(currentItemId = 0, checkedItemId = 1)
+
+        items.assertOrder("B", "C", "D", "E", "F")
+        items.assertSize(5)
+        "B".assertChildren("C")
+        "B".assertIsNotChecked()
+        changeHistory.undo()
+        items.assertOrder("A", "B", "C", "D", "E", "F")
+        "A".assertChildren("B", "C")
+        "B".assertIsChecked()
+    }
+
+    @Test
+    fun `autocomplete replaces parent text and removes its checked child with auto-sort`() {
+        setSorting(ListItemSort.AUTO_SORT_BY_CHECKED)
+        listManager.changeIsChild(1, true)
+        listManager.changeIsChild(2, true)
+        listManager.changeChecked(1, true)
+
+        listManager.completeWithCheckedItem(currentItemId = 0, checkedItemId = 1)
+
+        items.assertOrder("B", "C", "D", "E", "F")
+        itemsChecked!!.assertSize(0)
+        "B".assertChildren("C")
+        "B".assertIsNotChecked()
+    }
+
+    @Test
+    fun `autocomplete keeps current children and promotes selected parent children`() {
+        setSorting(ListItemSort.NO_AUTO_SORT)
+        listManager.changeIsChild(1, true)
+        listManager.changeIsChild(3, true)
+        listManager.changeChecked(2, true)
+
+        listManager.completeWithCheckedItem(currentItemId = 0, checkedItemId = 2)
+
+        items.assertOrder("C", "B", "D", "E", "F")
+        "C".assertChildren("B")
+        "D".assertIsParent()
+        "C".assertIsNotChecked()
+        "B".assertIsNotChecked()
+        "D".assertIsChecked()
+    }
+
+    @Test
+    fun `autocomplete promotes children from auto-sorted parent`() {
+        setSorting(ListItemSort.AUTO_SORT_BY_CHECKED)
+        listManager.changeIsChild(1, true)
+        listManager.changeIsChild(3, true)
+        listManager.changeChecked(2, true)
+
+        listManager.completeWithCheckedItem(currentItemId = 0, checkedItemId = 2)
+
+        items.assertOrder("C", "B", "E", "F")
+        itemsChecked!!.assertOrder("D")
+        "C".assertChildren("B")
+        "D".assertIsParent()
+        "C".assertIsNotChecked()
+    }
+
     // endregion
 
 }