From 171a9d61a0ce4fff88db8e16d03c3bac3f35f264 Mon Sep 17 00:00:00 2001
From: nobe4 <nobe4@users.noreply.github.com>
Date: Thu, 10 Oct 2024 01:59:04 +0200
Subject: [PATCH] feat(list): implement GlobalIndex helper (#574)

* feat(list): implement GlobalIndex helper

This commit introduces a new `filteredItem` field called `index` which
stores the index of the filtered item in the unfiltered list. This
allows to get at runtime the unfiltered list index for the selected (and
possibly filtered) item.

This is the only solution I found to use `SetItem` with a filtered
list.

The name `GlobalIndex` might not be ideal, I'm happy to change it to
something else. (`UnfilteredIndex`?)

Fixes: #550

* docs(list): improve Index() documentation
---
 list/list.go | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/list/list.go b/list/list.go
index 00d27a0..9ee1643 100644
--- a/list/list.go
+++ b/list/list.go
@@ -53,6 +53,7 @@ type ItemDelegate interface {
 }
 
 type filteredItem struct {
+	index   int   // index in the unfiltered list
 	item    Item  // item matched
 	matches []int // rune indices of matched items
 }
@@ -484,12 +485,26 @@ func (m Model) MatchesForItem(index int) []int {
 	return m.filteredItems[index].matches
 }
 
-// Index returns the index of the currently selected item as it appears in the
-// entire slice of items.
+// Index returns the index of the currently selected item as it is stored in the
+// filtered list of items.
+// Using this value with SetItem() might be incorrect, consider using
+// GlobalIndex() instead.
 func (m Model) Index() int {
 	return m.Paginator.Page*m.Paginator.PerPage + m.cursor
 }
 
+// GlobalIndex returns the index of the currently selected item as it is stored
+// in the unfiltered list of items. This value can be used with SetItem().
+func (m Model) GlobalIndex() int {
+	index := m.Index()
+
+	if m.filteredItems == nil || index >= len(m.filteredItems) {
+		return index
+	}
+
+	return m.filteredItems[index].index
+}
+
 // Cursor returns the index of the cursor on the current page.
 func (m Model) Cursor() int {
 	return m.cursor
@@ -1256,6 +1271,7 @@ func filterItems(m Model) tea.Cmd {
 		filterMatches := []filteredItem{}
 		for _, r := range m.Filter(m.FilterInput.Value(), targets) {
 			filterMatches = append(filterMatches, filteredItem{
+				index:   r.Index,
 				item:    items[r.Index],
 				matches: r.MatchedIndexes,
 			})