Add in-file search (find bar)

- pool: SearchTask + FindSubstring (case-insensitive substring scan with
  query generation for stale-result dropping)
- editor: FindState on EditorState; find bar handlers (ToggleFind/FindNext/
  FindPrev/FindClose); worker-pool scan of the in-memory content; edit-aware
  offset remapping (shift after, drop overlapping); next/prev with
  wrap-around, selection + scroll to match; main-owned find_bar input
  forwarded via FindQueryChan (browser search_bar precedent)
- ui: find-bar layout below the margin-free top bar; search icon on the top
  bar right; new search/close/chevron_up/chevron_down icons
- logic: findQueryChan, TypeSearch result handling, findReset on open
- frame: FindQuery field (main syncs the widget text like Query)
- tests: pool scan tests, find-state unit tests (remap, nav, gen gate,
  focus), e2e find bar + navigation + edit-survival on real files
- docs: spec/architecture/development_plan updated (search implemented,
  channel/task tables)

cmd/pad/main.go

@@ -101,6 +101,11 @@ func run(w *app.Window) error {
 	var searchEditor widget.Editor
 	renderer.RegisterGioEditor("search_bar", &searchEditor)
 
+	// The find bar's (in-file search) widget.Editor is main-owned the same
+	// way; its text is forwarded via FindQueryChan (editor.findSetQuery).
+	var findEditor widget.Editor
+	renderer.RegisterGioEditor("find_bar", &findEditor)
+
 	// Clipboard plumbing (architecture.md §6.3): the logic goroutine only
 	// REQUESTS clipboard operations through channels (copy/cut write, paste
 	// read); the main goroutine executes the Gio ops during a frame and
@@ -209,6 +214,8 @@ func run(w *app.Window) error {
 			// The logic goroutine handles filtering and triggers a new frame.
 			newQuery := searchEditor.Text()
 			sendQuery := newQuery != frame.Query
+			newFind := findEditor.Text()
+			sendFind := newFind != frame.FindQuery
 			events := renderer.CheckGestures(e.Source, gtx.Metric)
 			// Keep frames flowing while a long press is pending: a stationary
 			// finger generates no pointer events, so without this the window
@@ -305,6 +312,9 @@ func run(w *app.Window) error {
 			if sendQuery {
 				logic.SearchQueryChan() <- newQuery
 			}
+			if sendFind {
+				logic.FindQueryChan() <- newFind
+			}
 			logic.LayoutChan() <- ui.LayoutFeedback{
 				GlyphLayout:     glyphLayout,
 				WindowText:      frame.WindowText,

doc/architecture.md

@@ -110,6 +110,7 @@ Sole owner of `*State`. `Run()` selects on:
 | `configChan` | main | `ConfigUpdate` (pixels or scale) | store scale/pixels; recompute layout |
 | `inputChan` | main | `[]ui.InputEvent` | run each `Handler(evt.Data)` on the owner |
 | `searchQueryChan` | main | `string` | store `Browser.Query`, re-filter, new frame |
+| `findQueryChan` | main | `string` | in-file search: store `Editor.Find.Query`, dispatch `Search` task, new frame |
 | `openFileChan` | main (tap) | `string` path | open file in editor (chunked buffer + async index) |
 | `layoutChan` | main | `ui.GlyphLayout` | store on editor state; derive `LastLineY` for scroll clamping |
 | `retryChan` | logic | `string` filename | autosave retry |
@@ -131,7 +132,12 @@ has a real implementation (`io/pool/real`, rooted at `/`) and a mock
 (`io/pool/mock`) for tests.
 
 Task types in active use: `StatFile`, `ReadFile`, `BuildLineIndex`,
-`WriteFile` (editor); `BuildIndex`, `LoadPages` (browser). Dormant/dead task
+`WriteFile`, `Search` (editor); `BuildIndex`, `LoadPages` (browser). The
+`Search` task runs a case-insensitive substring scan over a full-content
+snapshot (`FindSubstring`) and returns the match byte ranges plus the query
+generation that dispatched it; the logic drops results whose generation no
+longer matches (`EditorState.applySearchResult`), so a superseded scan can
+never clobber newer results. Dormant/dead task
 types — `ReadChunk` (no-op for fully-loaded in-range files), `ReadDir`,
 `StatDir`, `ReadCache`, `WriteCache`, `Invalidate`, `SaveState`, `SaveUndo` —
 are candidates for removal in a cleanup round.
@@ -139,7 +145,7 @@ are candidates for removal in a cleanup round.
 ## 3. Channel topology summary
 
 - **main → logic:** `InputChan`, `ConfigChan`, `LayoutChan`, `SearchQueryChan`,
-  `OpenFileChan`.
+  `FindQueryChan`, `OpenFileChan`.
 - **timer → logic:** `autosaveChan` (token only).
 - **logic → logic:** `retryChan` (self-piped).
 - **logic → frameReceiver:** `FrameChan` (the only outbound state carrier).

doc/development_plan.md

@@ -720,7 +720,8 @@ that kills `widget.Editor`.
 ## 8. Non-goals (v1)
 
 - File-system watcher / live browser refresh (re-scan on return to browser).
-- Tabs, split view, search-in-file, syntax highlighting, diff/merge.
+- Tabs, split view, syntax highlighting, diff/merge. (Search-in-file was
+  later implemented; see spec §2.2.)
 - Desktop/other platforms (Android-first; window `390×844` dp).
 - Rewriting on `widget.Editor` (v1 plan) — kept only as fallback (§12).
 

doc/spec.md

@@ -75,6 +75,17 @@ elsewhere.
   selection is highlighted in the editor and pushed to the IME. (Shift state
   is tracked by the app, since Gio's Android bridge drops modifier keys —
   architecture.md §2.1.)
+- **In-file search:** a find icon on the top bar (right side) opens a find
+  bar directly below it, with a text input, an "N / M" counter, next/prev
+  navigation, and a close button. The query is a plain substring,
+  case-insensitive, no regex; each change is scanned over the entire
+  in-memory content by a worker (`Search` task), so typing never blocks the
+  UI and stale scans are dropped by generation. Next/prev select and scroll
+  to the surrounding matches (wrapping around); the first discovery selects
+  and scrolls to the first match. Edits do not invalidate the result set:
+  match offsets before the edit are unchanged, matches after it shift by the
+  length delta, and matches overlapping the edited range are dropped
+  (finding text an edit creates requires re-typing the query).
 - **Autosave:** every edit restarts a 1 s debounce; on expiry the full content
   is written to disk by a worker. At most one write per file is in flight at
   any time; saves requested during a write are deferred and re-issued with
@@ -174,7 +185,7 @@ recorded here so future rounds don't mistake doc text for behavior:
 | Syncthing conflict handling | **not implemented** | No `.sync-conflict-*` file detection or merging. |
 | File-system watcher | **not implemented** | Browser does not live-refresh; it re-scans on navigation. |
 | Alphabetical index sidebar | **not implemented** | `AlphaIndex` element exists but is unused. |
-| In-file search, tabs, split view | **not implemented** | — |
+| Tabs, split view | **not implemented** | In-file search IS implemented (spec §2.2); only tabs/split remain deferred. |
 | Files > 50 MB | **not supported** | `TooLarge` state instead. |
 | Desktop / other platforms | **not supported** | Android-first. |
 

internal/editor/frame.go

@@ -28,6 +28,11 @@ type Frame struct {
 	FontScale        float32 // user font-size setting the logic bookkeeping used
 	FocusedElementID string
 	Query            string
+	// FindQuery: the in-file search query the logic goroutine has processed
+	// (mirrors EditorState.Find.Query). Main compares it against the
+	// "find_bar" widget's text and forwards changes via FindQueryChan — the
+	// same contract as Query/searchQueryChan.
+	FindQuery string
 	// WindowStartByte / WindowStartLine / EditSeq: the editor window this
 	// frame's elements describe. The main goroutine forwards them with the
 	// shaped glyph layout (LayoutFeedback) so the logic goroutine can apply
@@ -48,6 +53,7 @@ func (l *Logic) frameOf(elems []ui.Element) Frame {
 		FontScale:        l.state.fontScale,
 		FocusedElementID: l.state.FocusedElementID,
 		Query:            l.state.Browser.Query,
+		FindQuery:        l.state.Editor.Find.Query,
 		WindowStartByte:  l.state.Editor.IMEWindowStartByte,
 		WindowStartLine:  l.state.WindowStartLine,
 		WindowText:       l.state.Editor.IMEWindowText,

internal/editor/logic.go

@@ -69,6 +69,7 @@ type Logic struct {
 	layoutChan      chan ui.LayoutFeedback
 	resultChan      chan ResultEvent
 	searchQueryChan chan string
+	findQueryChan   chan string // in-file search text (main-owned "find_bar")
 	openFileChan    chan string
 	retryChan       chan string   // auto-save retries
 	autosaveChan    chan struct{} // auto-save debounce ticks (timer -> owner)
@@ -127,6 +128,7 @@ func NewLogic(mfs pool.FileSystem, path string, openfunc func(string)) *Logic {
 		layoutChan:      make(chan ui.LayoutFeedback),
 		resultChan:      make(chan ResultEvent),
 		searchQueryChan: make(chan string),
+		findQueryChan:   make(chan string),
 		openFileChan:    make(chan string),
 		retryChan:       make(chan string, 1), // Buffered channel
 		autosaveChan:    make(chan struct{}),
@@ -173,6 +175,13 @@ func (l *Logic) SearchQueryChan() chan<- string {
 	return l.searchQueryChan
 }
 
+// FindQueryChan returns the in-file search query channel. The main goroutine
+// forwards the "find_bar" widget's text here when it changes (see
+// search.go).
+func (l *Logic) FindQueryChan() chan<- string {
+	return l.findQueryChan
+}
+
 // ClipboardSetChan returns the channel the logic goroutine uses to request a
 // system clipboard write; the main goroutine executes the Gio clipboard op.
 func (l *Logic) ClipboardSetChan() <-chan string {
@@ -247,7 +256,13 @@ func (l *Logic) Run() {
 				}
 			}
 			l.emitFrame()
+		case q := <-l.findQueryChan:
+			l.state.Editor.findSetQuery(q)
+			l.emitFrame()
 		case path := <-l.openFileChan:
+			// Discard find results for the previous file; the query is kept
+			// (see EditorState.findReset) and re-scanned against the new file.
+			TheState.Editor.findReset()
 			// Create chunked buffer for virtual scrolling
 			chunkSize := DefaultChunkSize
 			cb := NewChunkedBuffer(path, chunkSize, l.mockFS, "")
@@ -579,11 +594,14 @@ func (l *Logic) handleWorkerResult(res pool.Result) {
 				}
 			})
 		}
+	} else if res.TaskType == pool.TypeSearch {
+		if res.Success {
+			l.state.Editor.applySearchResult(res)
+		}
 	}
 	l.emitFrame()
 }
 
-
 // State returns the current state.
 func (l *Logic) State() *State {
 	return l.state

internal/editor/search.go

@@ -0,0 +1,288 @@
+package editor
+
+// In-file search (find bar).
+//
+// Model:
+//   - FindState is logic-owned (EditorState.Find); only the logic goroutine
+//     mutates it.
+//   - The find bar's text field is a MAIN-owned widget.Editor registered as
+//     "find_bar" (the browser search bar "search_bar" is the precedent,
+//     architecture.md §1): its text reaches the logic only through
+//     Logic.findQueryChan. The find icon, counter, and prev/next/close
+//     buttons are plain elements whose taps run the handlers below on the
+//     logic goroutine.
+//   - A query is scanned by a pool SearchTask over a snapshot of the
+//     FULL in-memory content (in-range files are fully loaded, so the
+//     snapshot is exact and unsaved edits are searchable). Results carry a
+//     generation; only the latest generation is applied, so typing fast
+//     simply supersedes older scans.
+//   - Edits do NOT invalidate search: matches outside the edited range are
+//     shifted by the length delta, matches overlapping it are dropped
+//     (findEdit). The count is therefore "as of the last scan, adjusted for
+//     edits" — re-typing the query re-scans.
+
+import (
+	"sort"
+
+	"pad/internal/io/pool"
+	"pad/internal/ui"
+)
+
+// FindState holds the in-file search state for the open file.
+type FindState struct {
+	Visible  bool     // the find bar is shown
+	Query    string   // the query the logic last processed
+	Matches  [][2]int // ascending, non-overlapping byte ranges
+	Cur      int      // index into Matches; -1 when none is selected
+	Gen      uint64   // generation of the newest dispatched scan
+	Scanning bool     // a scan for Gen is in flight
+}
+
+// ToggleFind opens the find bar (or closes it when open). It is the tap
+// handler of the find icon in the editor top bar.
+func ToggleFind(data any) {
+	e := &TheState.Editor
+	if e.Find.Visible {
+		e.findClose()
+	} else {
+		e.findShow()
+	}
+}
+
+// FindNext / FindPrev move to the next/previous match, wrap around, select
+// it, and scroll it into view. They are the tap handlers of the find bar's
+// chevron buttons.
+func FindNext(data any) { findStep(1) }
+
+func FindPrev(data any) { findStep(-1) }
+
+// FindClose is the tap handler of the find bar's close button.
+func FindClose(data any) { TheState.Editor.findClose() }
+
+// findShow opens the find bar. The text input is main-owned, so logic takes
+// key focus off the editor (FocusedElementID) and, if a previous query has
+// no live matches (they are cleared on close and on file open), re-scans it.
+func (e *EditorState) findShow() {
+	e.Find.Visible = true
+	if e.Filename != "" {
+		TheState.FocusedElementID = "find_bar"
+	}
+	if e.Find.Query != "" && len(e.Find.Matches) == 0 && !e.Find.Scanning {
+		e.findDispatchScan()
+	}
+}
+
+// findClose hides the find bar. The query is kept so re-opening shows it
+// (the main-owned widget keeps its text); matches are dropped — the next
+// show re-scans, so they are never stale.
+func (e *EditorState) findClose() {
+	e.Find.Visible = false
+	e.Find.Matches = nil
+	e.Find.Cur = -1
+	e.Find.Scanning = false
+	if TheState.FocusedElementID == "find_bar" {
+		TheState.FocusedElementID = "editor_text"
+	}
+}
+
+// findReset discards all find state for the open file (file open, page
+// change). The query is kept: the main-owned widget still shows it, and
+// keeping it lets the next show() re-scan the NEW file with the old query
+// (and a frame with a changed FindQuery re-sends it, re-scanning live).
+func (e *EditorState) findReset() {
+	// Monotonic generation bump (do not zero the counter): a stale
+	// in-flight scan carrying a HIGH generation must never equal a fresh
+	// one, or its result would pass the gen gate in applySearchResult.
+	e.Find = FindState{Query: e.Find.Query, Gen: e.Find.Gen + 1}
+}
+
+// findSetQuery processes a query forwarded from the main-owned "find_bar"
+// widget. An empty query clears the results; otherwise a fresh scan of the
+// full in-memory content is dispatched on the worker pool.
+func (e *EditorState) findSetQuery(q string) {
+	f := &e.Find
+	f.Query = q
+	f.Matches = nil
+	f.Cur = -1
+	if q == "" || e.TooLarge {
+		f.Scanning = false
+		return
+	}
+	e.findDispatchScan()
+}
+
+// findDispatchScan snapshots the full content and dispatches a SearchTask.
+// Must be called on the logic goroutine.
+func (e *EditorState) findDispatchScan() {
+	f := &e.Find
+	f.Gen++
+	f.Scanning = true
+	if TheLogic == nil || TheLogic.workerPool == nil { // unit tests
+		return
+	}
+	text := e.Buffer
+	if cb := e.ChunkedBuffer; cb != nil {
+		if full, err := cb.FullContent(); err == nil {
+			text = full
+		}
+	}
+	TheLogic.workerPool.Dispatch(pool.NewSearchTask(text, f.Query, f.Gen))
+}
+
+// applySearchResult applies a completed SearchTask result. Stale generations
+// (a newer query superseded this scan) are dropped. Must be called on the
+// logic goroutine.
+func (e *EditorState) applySearchResult(res pool.Result) {
+	f := &e.Find
+	var sd pool.SearchData
+	switch v := res.Data.(type) {
+	case pool.SearchData:
+		sd = v
+	case *pool.SearchData:
+		sd = *v
+	default:
+		return
+	}
+	if sd.Gen != f.Gen || !f.Visible {
+		return
+	}
+	f.Scanning = false
+	wasEmpty := len(f.Matches) == 0
+	prevStart := -1
+	if f.Cur >= 0 && f.Cur < len(f.Matches) {
+		prevStart = f.Matches[f.Cur][0]
+	}
+	f.Matches = sd.Matches
+	f.Cur = -1
+	if len(f.Matches) > 0 {
+		// Keep the previously current match when it survived the
+		// re-scan; otherwise select the first one.
+		if prevStart >= 0 {
+			if i := sort.Search(len(f.Matches), func(i int) bool {
+				return f.Matches[i][0] >= prevStart
+			}); i < len(f.Matches) && f.Matches[i][0] == prevStart {
+				f.Cur = i
+			}
+		}
+		if f.Cur < 0 {
+			f.Cur = 0
+		}
+		// The first discovery of matches (matches went 0 -> N) selects and
+		// scrolls the view to the current match; while the user keeps
+		// typing, results update in place and the view moves only on
+		// explicit next/prev.
+		if wasEmpty {
+			SetSelection(f.Matches[f.Cur][0], f.Matches[f.Cur][1])
+			scrollToFindMatch(f.Matches[f.Cur][0])
+		}
+	}
+}
+
+// findStep selects the next (dir>0) or previous (dir<0) match, wrapping
+// around. With no current match yet, "next" goes to the first match at or
+// after the current selection start/caret (wrapping to the first) and
+// "prev" to the last match ending before the selection end (wrapping to the
+// last).
+func findStep(dir int) {
+	e := &TheState.Editor
+	f := &e.Find
+	n := len(f.Matches)
+	if n == 0 {
+		return
+	}
+	idx := -1
+	if f.Cur >= 0 {
+		idx = (f.Cur + dir + n) % n
+	} else {
+		ref := e.CursorPosition
+		if selActive() {
+			if dir > 0 {
+				ref = e.SelectionStart
+			} else {
+				ref = e.SelectionEnd
+			}
+		}
+		if dir > 0 {
+			for i, m := range f.Matches {
+				if m[0] >= ref {
+					idx = i
+					break
+				}
+			}
+			if idx < 0 {
+				idx = 0 // wrap to the first
+			}
+		} else {
+			for i := n - 1; i >= 0; i-- {
+				if f.Matches[i][1] < ref {
+					idx = i
+					break
+				}
+			}
+			if idx < 0 {
+				idx = n - 1 // wrap to the last
+			}
+		}
+	}
+	m := f.Matches[idx]
+	f.Cur = idx
+	SetSelection(m[0], m[1])
+	scrollToFindMatch(m[0])
+}
+
+// scrollToFindMatch scrolls so the visual line containing absByte sits at
+// the top of the editor viewport (clamped to [0, MaxScroll]).
+func scrollToFindMatch(absByte int) {
+	cb := TheState.Editor.ChunkedBuffer
+	if cb == nil || cb.LineIndex == nil {
+		return
+	}
+	li := cb.LineIndex.FindLogicalLineForByteOffset(absByte)
+	vl := int64(li)
+	if w := cb.WrapIndex; w != nil {
+		vl += int64(w.VisualsBefore(li))
+	}
+	lh := float64(EffectiveLineHeight())
+	target := ui.Dp(float64(vl) * lh)
+	if target < 0 {
+		target = 0
+	}
+	if target > TheState.MaxScroll {
+		target = TheState.MaxScroll
+	}
+	TheState.ScrollOffset = target
+}
+
+// findEdit reports a length-changing edit to the find state: the byte range
+// [start, end) of the pre-edit content was replaced by newLen bytes. Matches
+// entirely before it are unchanged, matches entirely after it shift by
+// newLen-(end-start), and matches overlapping it are dropped (their text no
+// longer matches the query — finding text an edit creates requires a
+// re-scan, which happens when the query is re-typed).
+func (e *EditorState) findEdit(start, end, newLen int) {
+	f := &e.Find
+	if len(f.Matches) == 0 {
+		return
+	}
+	delta := newLen - (end - start)
+	out := make([][2]int, 0, len(f.Matches))
+	cur := -1
+	for i, m := range f.Matches {
+		s, mEnd := m[0], m[1]
+		var kept [2]int
+		switch {
+		case mEnd <= start:
+			kept = m
+		case s >= end:
+			kept = [2]int{s + delta, mEnd + delta}
+		default:
+			continue // overlaps the edited range: drop
+		}
+		if i == f.Cur {
+			cur = len(out)
+		}
+		out = append(out, kept)
+	}
+	f.Matches = out
+	f.Cur = cur
+}

internal/editor/search_test.go

@@ -0,0 +1,195 @@
+package editor
+
+import (
+	"testing"
+
+	"pad/internal/io/pool"
+)
+
+// findTestState builds a small state: 10 lines of "aa\n" (30 bytes) with a
+// find query "a" whose matches were scanned before the test's edits.
+func findTestState() {
+	// NewLogic (used by other tests in this package) leaves the global
+	// TheLogic pointing at a STOPPED logic; the find code must not dispatch
+	// through it (findDispatchScan guards on nil).
+	TheLogic = nil
+	TheState = NewState()
+	TheState.Editor.Filename = "t.txt"
+	content := "aa\naa\naa\naa\naa\naa\naa\naa\naa\naa\n"
+	TheState.Editor.Buffer = content
+	TheState.Editor.ChunkedBuffer = nil
+	e := &TheState.Editor
+	e.Find = FindState{Visible: true, Query: "a", Cur: -1}
+	// Every byte except newlines matches "a".
+	for i := 0; i < len(content); i++ {
+		if content[i] != '\n' {
+			e.Find.Matches = append(e.Find.Matches, [2]int{i, i + 1})
+		}
+	}
+}
+
+func TestFindEdit_ShiftAfter(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	// Insert 4 bytes at offset 20: matches at/after 20 shift by 4; the
+	// current match (pick one after the edit) keeps its identity.
+	before := e.Find.Matches[len(e.Find.Matches)-1]
+	e.Find.Cur = len(e.Find.Matches) - 1
+	e.findEdit(20, 20, 4)
+	if got := e.Find.Matches[len(e.Find.Matches)-1]; got != [2]int{before[0] + 4, before[1] + 4} {
+		t.Fatalf("last match %v, want %v shifted by 4", got, [2]int{before[0] + 4, before[1] + 4})
+	}
+	if e.Find.Cur != len(e.Find.Matches)-1 {
+		t.Fatalf("cur %d", e.Find.Cur)
+	}
+	// A match before the edit is untouched.
+	if e.Find.Matches[0] != [2]int{0, 1} {
+		t.Fatalf("first match %v", e.Find.Matches[0])
+	}
+}
+
+func TestFindEdit_DropOverlapping(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	e.Find.Cur = 2 // byte 2
+	// Replace [2,4) with nothing: matches 2 and 3 (bytes 2,3) overlap and
+	// are dropped; later matches shift left by 2; the current match is
+	// dropped, so Cur resets to -1.
+	e.findEdit(2, 4, 0)
+	for _, m := range e.Find.Matches {
+		if m[0] == 2 && m[1] == 4 {
+			t.Fatalf("stale match %v survived an edit inside it", m)
+		}
+	}
+	if e.Find.Cur != -1 {
+		t.Fatalf("cur %d, want -1 (current match was edited away)", e.Find.Cur)
+	}
+	// The match that was at byte 4 is now at byte 2.
+	if e.Find.Matches[0][0] != 0 || e.Find.Matches[1][0] != 1 || e.Find.Matches[2][0] != 2 {
+		t.Fatalf("matches after delete: %v", e.Find.Matches[:5])
+	}
+}
+
+func TestFindStep_NextPrevWrap(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	// No current match yet: next from caret 0 -> the match AT 0 (index 0).
+	e.CursorPosition = 0
+	findStep(1)
+	if e.Find.Cur != 0 {
+		t.Fatalf("cur %d, want 0", e.Find.Cur)
+	}
+	if e.SelectionStart != 0 || e.SelectionEnd != 1 {
+		t.Fatalf("selection [%d,%d), want [0,1)", e.SelectionStart, e.SelectionEnd)
+	}
+	// next -> 1, prev -> 0.
+	findStep(1)
+	findStep(-1)
+	if e.Find.Cur != 0 {
+		t.Fatalf("cur %d, want 0", e.Find.Cur)
+	}
+	// prev from 0 wraps to the LAST match.
+	findStep(-1)
+	if e.Find.Cur != len(e.Find.Matches)-1 {
+		t.Fatalf("cur %d, want last (wrapped)", e.Find.Cur)
+	}
+	// next from last wraps to the FIRST.
+	findStep(1)
+	if e.Find.Cur != 0 {
+		t.Fatalf("cur %d, want 0 (wrapped)", e.Find.Cur)
+	}
+}
+
+func TestFindStep_NoMatches(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	e.Find.Matches = nil
+	e.CursorPosition = 5
+	findStep(1)
+	if e.Find.Cur != -1 {
+		t.Fatalf("cur %d, want -1 with no matches", e.Find.Cur)
+	}
+}
+
+func TestApplySearchResult_GenGate(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	e.Find.Gen = 3
+	// Stale generation: dropped, state untouched.
+	stale := e.Find.Matches
+	e.applySearchResult(pool.Result{TaskType: pool.TypeSearch, Success: true, Data: pool.SearchData{Gen: 2, Matches: [][2]int{}}})
+	if len(e.Find.Matches) != len(stale) {
+		t.Fatalf("stale result was applied: %d matches", len(e.Find.Matches))
+	}
+	// Current generation: applied; the surviving previous current match
+	// keeps its position.
+	e.Find.Cur = 1
+	e.applySearchResult(pool.Result{TaskType: pool.TypeSearch, Success: true, Data: pool.SearchData{Gen: 3, Matches: stale}})
+	if e.Find.Cur != 1 {
+		t.Fatalf("cur %d, want 1 (kept)", e.Find.Cur)
+	}
+}
+
+func TestApplySearchResult_FirstDiscoveryScrolls(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	// No ChunkedBuffer/LineIndex in this unit state: scrollToFindMatch is a
+	// no-op, so this only pins that first discovery selects match 0.
+	e.Find.Matches = nil
+	e.Find.Cur = -1
+	e.Find.Scanning = true
+	e.Find.Gen = 1
+	e.applySearchResult(pool.Result{TaskType: pool.TypeSearch, Success: true, Data: pool.SearchData{
+		Gen: 1, Matches: [][2]int{{10, 11}, {20, 21}},
+	}})
+	if e.Find.Scanning {
+		t.Fatal("scanning flag not cleared")
+	}
+	if e.Find.Cur != 0 {
+		t.Fatalf("cur %d, want 0 (first discovery)", e.Find.Cur)
+	}
+}
+
+func TestFindShowClose_FocusTransitions(t *testing.T) {
+	findTestState()
+	TheState.FocusedElementID = "editor_text"
+	TheState.Editor.Find.Visible = false
+	TheState.Editor.findShow()
+	if !TheState.Editor.Find.Visible {
+		t.Fatal("find bar not shown")
+	}
+	if TheState.FocusedElementID != "find_bar" {
+		t.Fatalf("focus %q, want find_bar", TheState.FocusedElementID)
+	}
+	TheState.Editor.findClose()
+	if TheState.Editor.Find.Visible {
+		t.Fatal("find bar still visible")
+	}
+	if TheState.FocusedElementID != "editor_text" {
+		t.Fatalf("focus %q, want editor_text", TheState.FocusedElementID)
+	}
+	// The query survives close/reopen.
+	q := TheState.Editor.Find.Query
+	TheState.Editor.findShow()
+	if TheState.Editor.Find.Query != q {
+		t.Fatal("query lost across close/reopen")
+	}
+}
+
+func TestFindReset_SupersedesInflight(t *testing.T) {
+	findTestState()
+	e := &TheState.Editor
+	e.Find.Gen = 5
+	e.findReset()
+	if e.Find.Visible || len(e.Find.Matches) != 0 {
+		t.Fatal("findReset did not clear state")
+	}
+	if e.Find.Gen != 6 {
+		t.Fatalf("gen %d, want 6 (in-flight scan must be superseded)", e.Find.Gen)
+	}
+	// The in-flight (gen 5) result must now be dropped.
+	e.applySearchResult(pool.Result{TaskType: pool.TypeSearch, Success: true, Data: pool.SearchData{Gen: 5, Matches: [][2]int{{0, 1}}}})
+	if len(e.Find.Matches) != 0 {
+		t.Fatal("superseded result was applied")
+	}
+}

internal/editor/state.go

@@ -125,7 +125,9 @@ type EditorState struct {
 	SelDragPressY  float64
 	SelDragAnchorX float64
 	SelDragAnchorY float64
-	Filename       string
+	// Find is the in-file search state (find bar); see search.go.
+	Find     FindState
+	Filename string
 	// TooLarge is set when an opened file exceeds MaxEditableFileSize. The
 	// editor shows a "too large to edit" notice instead of content (the
 	// browser can still list the file).
@@ -376,6 +378,7 @@ func GoToBrowser(data any) {
 	if TheLogic != nil {
 		TheLogic.FlushAll()
 	}
+	TheState.Editor.findClose()
 	TheState.page = BrowserPage
 }
 
@@ -638,6 +641,7 @@ func deleteRange(start, end int) {
 		str := TheState.Editor.Buffer
 		TheState.Editor.Buffer = str[:start] + str[end:]
 	}
+	TheState.Editor.findEdit(start, end, 0)
 }
 
 // --- Touch selection (v1) ---------------------------------------------------
@@ -1630,6 +1634,7 @@ func HandleDelete() {
 		if w := utf8AdvanceWidth(seg); w > 0 {
 			buf.Delete(pos, w)
 			buf.UpdateLineIndexAfterDelete(pos, pos+w)
+			e.findEdit(pos, pos+w, 0)
 			markDirty()
 		}
 		return
@@ -1643,7 +1648,9 @@ func HandleDelete() {
 	if pos+4 < end {
 		end = pos + 4
 	}
-	TheState.Editor.Buffer = str[:pos] + str[pos+utf8AdvanceWidth(str[pos:end]):]
+	w := utf8AdvanceWidth(str[pos:end])
+	TheState.Editor.Buffer = str[:pos] + str[pos+w:]
+	e.findEdit(pos, pos+w, 0)
 	markDirty()
 }
 
@@ -1668,6 +1675,7 @@ func HandleInsert(s string) {
 		str := e.Buffer
 		e.Buffer = str[:pos] + s + str[pos:]
 	}
+	e.findEdit(pos, pos, len(s))
 	e.CursorPosition = pos + len(s)
 	markDirty()
 }
@@ -1697,6 +1705,7 @@ func HandleBackspace() {
 		buf.Delete(pos-w, w)
 		buf.UpdateLineIndexAfterDelete(pos-w, pos)
 		TheState.Editor.CursorPosition = pos - w
+		e.findEdit(pos-w, pos, 0)
 		markDirty()
 		return
 	}
@@ -1709,6 +1718,7 @@ func HandleBackspace() {
 	w := utf8BackspaceWidth(str[segStart:pos])
 	TheState.Editor.Buffer = str[:pos-w] + str[pos:]
 	TheState.Editor.CursorPosition = pos - w
+	e.findEdit(pos-w, pos, 0)
 	markDirty()
 }
 
@@ -1807,6 +1817,7 @@ func HandleReplaceRange(startRune, endRune int, text string) {
 		TheState.Editor.Buffer = s[:absStart] + text + s[absStart:]
 		newCursor = absStart + len(text)
 	}
+	TheState.Editor.findEdit(absStart, absEnd, len(text))
 	TheState.Editor.CursorPosition = newCursor
 	// A commit consumed any selection it overlapped (see the union above).
 	ClearSelection()
@@ -1846,6 +1857,54 @@ func markDirty() {
 }
 
 // EditorLayout computes the element tree for the editor page.
+// buildFindBar lays out the in-file search bar: [input][counter][prev][next]
+// [close], full screen width, directly below the margin-free top bar (the
+// bars merge, so this one does too; inner content keeps the margin). The
+// input is a MAIN-owned GioEditor registered as "find_bar" (the browser
+// "search_bar" precedent, architecture.md §1); the counter and buttons are
+// logic-owned elements whose taps run the handlers in search.go.
+func buildFindBar(screenWidth ui.Dp) ui.Element {
+	margin := ui.Dp(10)
+	gap := ui.Dp(8)
+	h := ui.Dp(40)
+	topY := ui.Dp(32) // top bar height (see EditorLayout)
+
+	// Right-hand button column: prev, next, close.
+	iconW := ui.IconSize
+	closeX := screenWidth - margin - iconW
+	nextX := closeX - gap - iconW
+	prevX := nextX - gap - iconW
+	counterW := ui.Dp(96)
+	inputX := margin
+	inputW := prevX - gap - counterW - margin
+
+	f := TheState.Editor.Find
+	counter := "0"
+	switch {
+	case f.Scanning:
+		counter = "…"
+	case f.Query != "" && len(f.Matches) == 0:
+		counter = "No matches"
+	case f.Cur >= 0:
+		counter = fmt.Sprintf("%d / %d", f.Cur+1, len(f.Matches))
+	}
+
+	return ui.NewContainer(
+		ui.Region{X: 0, Y: topY, W: screenWidth, H: h},
+		ui.Color{R: 230, G: 230, B: 230, A: 255},
+		[]ui.Element{
+			ui.NewGioEditor("find_bar", ui.Region{X: inputX, Y: ui.Dp(6), W: inputW, H: ui.Dp(28)}),
+			ui.NewLabel(counter, 12, ui.Region{X: inputX + inputW + gap, Y: ui.Dp(8), W: counterW, H: ui.Dp(20)}, ui.AlignEnd, "", nil),
+			ui.NewIcon("chevron_up", ui.Region{X: prevX, Y: ui.Dp(8), W: iconW, H: iconW}, 0,
+				[]ui.Interaction{{Gesture: ui.Tap, Handler: FindPrev}}),
+			ui.NewIcon("chevron_down", ui.Region{X: nextX, Y: ui.Dp(8), W: iconW, H: iconW}, 0,
+				[]ui.Interaction{{Gesture: ui.Tap, Handler: FindNext}}),
+			ui.NewIcon("close", ui.Region{X: closeX, Y: ui.Dp(8), W: iconW, H: iconW}, 0,
+				[]ui.Interaction{{Gesture: ui.Tap, Handler: FindClose}}),
+		},
+	)
+}
+
 func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
 	margin := ui.Dp(10)
 
@@ -1870,7 +1929,9 @@ func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
 		[]ui.Element{
 			ui.NewIcon("back", ui.Region{X: margin, Y: ui.Dp(4), W: ui.IconSize, H: ui.IconSize}, 0,
 				[]ui.Interaction{{Gesture: ui.Tap, Handler: GoToBrowser}}),
-			ui.NewLabel(filename, 14, ui.Region{X: ui.Dp(32) + margin, Y: ui.Dp(6), W: statusBarW - ui.Dp(32) - margin, H: ui.Dp(20)}, ui.AlignStart, "", nil),
+			ui.NewLabel(filename, 14, ui.Region{X: ui.Dp(32) + margin, Y: ui.Dp(6), W: statusBarW - ui.Dp(32) - margin - ui.IconSize - ui.Dp(8), H: ui.Dp(20)}, ui.AlignStart, "", nil),
+			ui.NewIcon("search", ui.Region{X: screenWidth - margin - ui.IconSize, Y: ui.Dp(4), W: ui.IconSize, H: ui.IconSize}, 0,
+				[]ui.Interaction{{Gesture: ui.Tap, Handler: ToggleFind}}),
 		},
 	)
 
@@ -1919,6 +1980,13 @@ func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
 		},
 	)
 
+	// --- Find bar (in-file search): full width, directly below the top bar,
+	// while open (see search.go / buildFindBar). ---
+	var findBar ui.Element
+	if TheState.Editor.Find.Visible {
+		findBar = buildFindBar(screenWidth)
+	}
+
 	// --- Editor text area ---
 	editorY := statusBarRegion.Y + statusBarRegion.H
 	editorH := bottomBarRegion.Y - editorY
@@ -2137,6 +2205,15 @@ func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
 			{Gesture: ui.SelDrag, Handler: HandleSelDragEvt},
 		},
 	)
+	// While the find bar is open, key focus belongs to the main-owned
+	// "find_bar" widget.Editor: the editor stops its per-frame IME sync, and
+	// regaining "editor_text" focus re-issues key.FocusCmd on close (see
+	// TextField.Draw's focus dedup).
+	if TheState.Editor.Find.Visible {
+		TheState.FocusedElementID = "find_bar"
+	} else if TheState.FocusedElementID == "find_bar" {
+		TheState.FocusedElementID = "editor_text"
+	}
 	// Set Focused so TextField.Draw() issues key.FocusCmd, which is required
 	// for Gio to deliver key events to this element. ShowIMESeq carries the
 	// keyboard-raise pulse (see TextField.ShowIMESeq).
@@ -2146,6 +2223,9 @@ func EditorLayout(screenWidth, screenHeight ui.Dp, wordWrap bool) []ui.Element {
 	editorElem.CaretDrag = TheState.Editor.CaretDrag
 
 	elems := []ui.Element{statusBar, editorElem, bottomBar}
+	if findBar != nil {
+		elems = append(elems, findBar)
+	}
 	// The selection menu is added last so it draws on top of the editor.
 	// Re-anchor it to the selection's live screen position every frame so it
 	// follows the text while scrolling (it used to stay where it was first

internal/io/pool/search_test.go

@@ -0,0 +1,107 @@
+package pool
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestFindSubstring_Basic(t *testing.T) {
+	text := "hello world hello"
+	got := FindSubstring(text, "hello")
+	want := [][2]int{{0, 5}, {12, 17}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestFindSubstring_CaseInsensitive(t *testing.T) {
+	got := FindSubstring("Hello HELLo hellO", "hEllO")
+	want := [][2]int{{0, 5}, {6, 11}, {12, 17}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestFindSubstring_NonASCIIFold(t *testing.T) {
+	// Only the ASCII-foldable "STRASSE" matches "strasse" (lower-cased to
+	// "strasse"); "Straße" lower-cases to "straße", which does not contain it.
+	// Byte offset 8: "ß" is two UTF-8 bytes, so "Straße" is 7 bytes.
+	got := FindSubstring("Straße STRASSE", "strasse")
+	want := [][2]int{{8, 15}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+	// And a query containing a multibyte rune still folds its ASCII parts.
+	got = FindSubstring("Straße", "STRA")
+	want = [][2]int{{0, 4}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestFindSubstring_NoMatch(t *testing.T) {
+	if got := FindSubstring("abc", "xyz"); got != nil {
+		t.Fatalf("got %v, want nil", got)
+	}
+}
+
+func TestFindSubstring_EmptyQuery(t *testing.T) {
+	if got := FindSubstring("abc", ""); got != nil {
+		t.Fatalf("got %v, want nil for empty query", got)
+	}
+}
+
+func TestFindSubstring_OverlappingConsumed(t *testing.T) {
+	// "aa" in "aaa": one match; the match consumes its range.
+	got := FindSubstring("aaa", "aa")
+	want := [][2]int{{0, 2}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+	// "...abaaba": matches at 3 and 6, not at 4.
+	got = FindSubstring("abaaba", "aba")
+	want = [][2]int{{0, 3}, {3, 6}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestFindSubstring_Multibyte(t *testing.T) {
+	// Offsets are BYTE offsets. "é" is 2 bytes.
+	text := "éxéx" // bytes: 0-1 é, 2 x, 3-4 é, 5 x
+	got := FindSubstring(text, "xé")
+	want := [][2]int{{2, 5}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestFindSubstring_WholeText(t *testing.T) {
+	got := FindSubstring("abc", "ABC")
+	want := [][2]int{{0, 3}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestSearchTask_Execute(t *testing.T) {
+	task := NewSearchTask("one two One TWO", "two", 7)
+	res := task.Execute()
+	if !res.Success {
+		t.Fatalf("unexpected error: %v", res.Error)
+	}
+	if res.TaskType != TypeSearch {
+		t.Fatalf("type %v", res.TaskType)
+	}
+	sd, ok := res.Data.(SearchData)
+	if !ok {
+		t.Fatalf("data type %T", res.Data)
+	}
+	if sd.Gen != 7 {
+		t.Fatalf("gen %d", sd.Gen)
+	}
+	want := [][2]int{{4, 7}, {12, 15}}
+	if !reflect.DeepEqual(sd.Matches, want) {
+		t.Fatalf("matches %v, want %v", sd.Matches, want)
+	}
+}

internal/io/pool/task.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -71,6 +72,8 @@ const (
 	// State persistence types
 	TypeSaveState
 	TypeSaveUndo
+	// In-file search (scans an in-memory content snapshot on a worker)
+	TypeSearch
 )
 
 func (t TaskType) String() string {
@@ -105,6 +108,8 @@ func (t TaskType) String() string {
 		return "save_state"
 	case TypeSaveUndo:
 		return "save_undo"
+	case TypeSearch:
+		return "search"
 	default:
 		return "unknown"
 	}
@@ -502,6 +507,94 @@ func (t *ReadFileTask) Context() context.Context { return t.ctx }
 func (t *ReadFileTask) Timeout() time.Duration { return 5 * time.Second }
 func (t *ReadFileTask) Cancel()              { if t.cancel != nil { t.cancel() } }
 
+// SearchData is the payload of a completed SearchTask: the byte ranges
+// [start, end) of every match of Query in the scanned Text, ascending and
+// non-overlapping. Gen is the query generation the scan was dispatched for,
+// so the caller can drop stale results.
+type SearchData struct {
+	Gen     uint64
+	Matches [][2]int
+}
+
+// SearchTask scans an in-memory content snapshot for a plain, case-
+// insensitive substring. The caller snapshots the content (the editor's
+// in-range files are fully resident) so the scan never races edits or chunk
+// state; a superseding query gets a higher Gen and its result is dropped by
+// the caller. Matching is plain substring (no regex), case-insensitive via
+// unicode lower-casing of both sides, matching the browser's name filter.
+type SearchTask struct {
+	taskID string
+	Text   string
+	Query  string
+	Gen    uint64
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+// NewSearchTask creates a new SearchTask.
+func NewSearchTask(text, query string, gen uint64) *SearchTask {
+	ctx, cancel := context.WithCancel(context.Background())
+	return &SearchTask{
+		taskID: fmt.Sprintf("search-%d", taskIDCounter.Add(1)),
+		Text:   text,
+		Query:  query,
+		Gen:    gen,
+		ctx:    ctx,
+		cancel: cancel,
+	}
+}
+
+func (t *SearchTask) Execute() Result {
+	matches := FindSubstring(t.Text, t.Query)
+	return Result{TaskID: t.taskID, TaskType: TypeSearch, Success: true, Data: SearchData{Gen: t.Gen, Matches: matches}}
+}
+
+// FindSubstring returns the byte ranges [start, end) of every occurrence of
+// query in text, case-insensitively. Occurrences are ascending and non-
+// overlapping (a match consumes its range, so "aa" finds one match in
+// "aaa"). An empty query matches nothing.
+func FindSubstring(text, query string) [][2]int {
+	if query == "" {
+		return nil
+	}
+	q := toLowerFold(query)
+	t := toLowerFold(text)
+	var matches [][2]int
+	from := 0
+	for {
+		i := indexOf(t[from:], q)
+		if i < 0 {
+			return matches
+		}
+		abs := from + i
+		matches = append(matches, [2]int{abs, abs + len(q)})
+		from = abs + len(q)
+	}
+}
+
+// toLowerFold lower-cases s without allocating when s is already
+// lower-case ASCII (the common case for both query and content).
+func toLowerFold(s string) string {
+	for i := 0; i < len(s); i++ {
+		if b := s[i]; b >= 'A' && b <= 'Z' {
+			return strings.ToLower(s)
+		}
+	}
+	return s
+}
+
+// indexOf is strings.Index but kept local so the scan above reads as one
+// unit; it is the standard library's two-way search.
+func indexOf(s, sub string) int { return strings.Index(s, sub) }
+
+func (t *SearchTask) Priority() Priority          { return MediumPriority }
+func (t *SearchTask) TaskType() TaskType          { return TypeSearch }
+func (t *SearchTask) TaskID() string              { return t.taskID }
+func (t *SearchTask) DirPath() string             { return "" }
+func (t *SearchTask) Context() context.Context    { return t.ctx }
+func (t *SearchTask) Timeout() time.Duration      { return 10 * time.Second }
+func (t *SearchTask) Cancel()                     { if t.cancel != nil { t.cancel() } }
+
 // WriteFileTask writes content to a file.
 type WriteFileTask struct {
 	taskID  string

internal/test/e2e/find_test.go

@@ -0,0 +1,216 @@
+package e2e_test
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"pad/internal/editor"
+	"pad/internal/test/e2e"
+	"pad/internal/ui"
+)
+
+// findContent is the file the in-file search e2e tests open. "needle"
+// occurs 3 times, at byte offsets 0, 25, and 50.
+const findContent = "needle at start\n" +
+	"some filler line here\n" +
+	"needle in the middle\n" +
+	"another filler line\n" +
+	"needle at the end"
+
+// frameHasFindBar reports whether the latest frame carries the find bar
+// (the "find_bar" GioEditor inside the find-bar container).
+func frameHasFindBar(h *e2e.Harness) bool {
+	for _, el := range e2e.GetLastFrame(h) {
+		c, ok := el.(ui.Container)
+		if !ok {
+			continue
+		}
+		for _, ch := range c.Children {
+			if ge, ok := ch.(ui.GioEditor); ok && ge.ID() == "find_bar" {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// waitForFindMatches polls the logic state until the find scan has produced
+// n matches (the scan runs on the worker pool and the result lands on the
+// logic goroutine asynchronously).
+func waitForFindMatches(t *testing.T, h *e2e.Harness, n int) {
+	t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		v, err := h.Inspect(func(st *editor.State) any {
+			return len(st.Editor.Find.Matches)
+		})
+		if err != nil {
+			t.Fatalf("Inspect: %v", err)
+		}
+		if v.(int) == n {
+			return
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	t.Fatalf("timed out waiting for %d find matches", n)
+}
+
+func TestRealFile_FindBarAndNavigation(t *testing.T) {
+	h, _ := realFileHarness(t, "find.txt", findContent)
+	defer h.Cleanup()
+
+	h.SendConfig(780, 1688)
+	if _, err := h.WaitForFrame(5 * time.Second); err != nil {
+		t.Fatalf("wait for frame: %v", err)
+	}
+	if ok, _ := h.FileLoaded(); !ok {
+		t.Fatal("file not loaded")
+	}
+
+	// Open the find bar via the top-bar icon handler.
+	h.SendInput([]ui.InputEvent{{Handler: editor.ToggleFind, Data: ui.Point{}}})
+	if _, err := h.WaitForFrameCount(h.FrameCount()+1, 5*time.Second); err != nil {
+		t.Fatalf("wait for find-bar frame: %v", err)
+	}
+	if !frameHasFindBar(h) {
+		t.Fatal("find bar not in frame after ToggleFind")
+	}
+	focus, _ := h.Inspect(func(st *editor.State) any { return st.FocusedElementID })
+	if focus.(string) != "find_bar" {
+		t.Fatalf("focus %q, want find_bar", focus)
+	}
+
+	// Type the query through the same channel main uses.
+	h.Logic().FindQueryChan() <- "NEEDLE" // case-insensitive
+	waitForFindMatches(t, h, 3)
+
+	// The first discovery already selects the first match (Cur=0).
+	sel, _ := h.Inspect(func(st *editor.State) any {
+		return [2]int{st.Editor.SelectionStart, st.Editor.SelectionEnd}
+	})
+	if sel.([2]int) != [2]int{0, 6} {
+		t.Fatalf("selection after first discovery %v, want [0,6)", sel)
+	}
+	if got := findContent[:6]; got != "needle" {
+		t.Fatalf("test content drift: %q", got)
+	}
+
+	// Next -> the second match (byte 38); the selection text must be a
+	// match, whatever the offset.
+	h.SendInput([]ui.InputEvent{{Handler: editor.FindNext, Data: ui.Point{}}})
+	sel, _ = h.Inspect(func(st *editor.State) any {
+		return [2]int{st.Editor.SelectionStart, st.Editor.SelectionEnd}
+	})
+	if want := strings.Index(findContent[6:], "needle") + 6; sel.([2]int) != [2]int{want, want + 6} {
+		t.Fatalf("selection %v, want [%d,%d)", sel, want, want+6)
+	}
+
+	// Next -> the third; next again wraps to the FIRST.
+	h.SendInput([]ui.InputEvent{{Handler: editor.FindNext, Data: ui.Point{}}})
+	h.SendInput([]ui.InputEvent{{Handler: editor.FindNext, Data: ui.Point{}}})
+	sel, _ = h.Inspect(func(st *editor.State) any {
+		return [2]int{st.Editor.SelectionStart, st.Editor.SelectionEnd}
+	})
+	if sel.([2]int) != [2]int{0, 6} {
+		t.Fatalf("selection %v, want [0,6) (wrapped to first)", sel)
+	}
+
+	// Prev from the first wraps to the LAST.
+	h.SendInput([]ui.InputEvent{{Handler: editor.FindPrev, Data: ui.Point{}}})
+	nMatches, _ := h.Inspect(func(st *editor.State) any { return len(st.Editor.Find.Matches) })
+	last := nMatches.(int) - 1
+	cur, _ := h.Inspect(func(st *editor.State) any { return st.Editor.Find.Cur })
+	if cur.(int) != last {
+		t.Fatalf("cur %d, want last (wrapped)", cur)
+	}
+
+	// A query with no hits reports zero matches.
+	h.Logic().FindQueryChan() <- "no-such-text"
+	waitForFindMatches(t, h, 0)
+
+	// Close the find bar: it leaves the frame and focus returns to the
+	// editor.
+	h.SendInput([]ui.InputEvent{{Handler: editor.FindClose, Data: ui.Point{}}})
+	if _, err := h.WaitForFrameCount(h.FrameCount()+1, 5*time.Second); err != nil {
+		t.Fatalf("wait for close frame: %v", err)
+	}
+	if frameHasFindBar(h) {
+		t.Fatal("find bar still in frame after close")
+	}
+	focus, _ = h.Inspect(func(st *editor.State) any { return st.FocusedElementID })
+	if focus.(string) != "editor_text" {
+		t.Fatalf("focus %q, want editor_text after close", focus)
+	}
+}
+
+func TestRealFile_FindMatchesSurviveEdits(t *testing.T) {
+	h, _ := realFileHarness(t, "find_edit.txt", findContent)
+	defer h.Cleanup()
+
+	h.SendConfig(780, 1688)
+	if ok, _ := h.FileLoaded(); !ok {
+		t.Fatal("file not loaded")
+	}
+
+	h.SendInput([]ui.InputEvent{{Handler: editor.ToggleFind, Data: ui.Point{}}})
+	h.Logic().FindQueryChan() <- "needle"
+	waitForFindMatches(t, h, 3)
+
+	// Insert 5 bytes at the start: ALL matches shift by 5, none is dropped
+	// (the edit is outside every match), and no re-scan happens. Clear the
+	// first-discovery selection first: HandleInsert REPLACES an active
+	// selection, which would eat match 0.
+	if err := h.WithState(func(st *editor.State) {
+		editor.ClearSelection()
+		st.Editor.CursorPosition = 0
+	}); err != nil {
+		t.Fatalf("WithState: %v", err)
+	}
+	h.SendInput([]ui.InputEvent{{Handler: func(data any) { editor.HandleInsert(data.(string)) }, Data: "12345"}})
+	m, _ := h.Inspect(func(st *editor.State) any {
+		return st.Editor.Find.Matches
+	})
+	got := m.([][2]int)
+	want := [][2]int{}
+	for _, mm := range initialNeedleMatches(t) {
+		want = append(want, [2]int{mm[0] + 5, mm[1] + 5})
+	}
+	if len(got) != len(want) {
+		t.Fatalf("matches %v, want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("match[%d] = %v, want %v (shifted by the insert)", i, got[i], want[i])
+		}
+	}
+
+	// An edit INSIDE the first (now shifted) match drops only that match.
+	// Match 0 is now at [5,11); put the caret in its middle and insert.
+	if err := h.WithState(func(st *editor.State) { st.Editor.CursorPosition = 7 }); err != nil {
+		t.Fatalf("WithState: %v", err)
+	}
+	h.SendInput([]ui.InputEvent{{Handler: func(data any) { editor.HandleInsert(data.(string)) }, Data: "X"}})
+	waitForFindMatches(t, h, 2)
+	m, _ = h.Inspect(func(st *editor.State) any { return st.Editor.Find.Matches })
+	got = m.([][2]int)
+	// The surviving matches (at 43 and 84 after the +5 shift) sit after the
+	// edit at byte 7, so they shift by 1 more.
+	if got[0] != [2]int{44, 50} || got[1] != [2]int{85, 91} {
+		t.Fatalf("surviving matches %v, want [44,50) and [85,91)", got)
+	}
+}
+
+// initialNeedleMatches computes the expected byte ranges of "needle" in
+// findContent (the pre-edit ground truth).
+func initialNeedleMatches(t *testing.T) [][2]int {
+	t.Helper()
+	var out [][2]int
+	for i := 0; i+len("needle") <= len(findContent); i++ {
+		if strings.EqualFold(findContent[i:i+len("needle")], "needle") {
+			out = append(out, [2]int{i, i + len("needle")})
+			i += len("needle")
+		}
+	}
+	return out
+}

internal/ui/icons/chevron_down.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <polyline points="6 9 12 15 18 9"/>
+</svg>

internal/ui/icons/chevron_up.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <polyline points="6 15 12 9 18 15"/>
+</svg>

internal/ui/icons/close.svg

@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <line x1="6" y1="6" x2="18" y2="18"/>
+  <line x1="18" y1="6" x2="6" y2="18"/>
+</svg>

internal/ui/icons/icons.go

@@ -6,7 +6,7 @@ import (
 	"embed"
 )
 
-//go:embed back.svg copy.svg cut.svg paste.svg
+//go:embed back.svg chevron_down.svg chevron_up.svg close.svg copy.svg cut.svg paste.svg search.svg
 var svgFS embed.FS
 
 // backSVG contains the back icon SVG source.
@@ -15,6 +15,25 @@ var backSVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width
 </svg>
 `
 
+// chevron_downSVG contains the chevron_down icon SVG source.
+var chevron_downSVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <polyline points="6 9 12 15 18 9"/>
+</svg>
+`
+
+// chevron_upSVG contains the chevron_up icon SVG source.
+var chevron_upSVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <polyline points="6 15 12 9 18 15"/>
+</svg>
+`
+
+// closeSVG contains the close icon SVG source.
+var closeSVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <line x1="6" y1="6" x2="18" y2="18"/>
+  <line x1="18" y1="6" x2="6" y2="18"/>
+</svg>
+`
+
 // copySVG contains the copy icon SVG source.
 var copySVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">
   <rect x="7" y="7" width="12" height="14" rx="1" fill="none" stroke="currentColor" stroke-width="1.5"/>
@@ -40,3 +59,10 @@ var pasteSVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" widt
   <line x1="8" y1="14" x2="16" y2="14" stroke="currentColor" stroke-width="1.5" stroke-linecap="round"/>
 </svg>
 `
+
+// searchSVG contains the search icon SVG source.
+var searchSVG = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <circle cx="11" cy="11" r="7"/>
+  <line x1="16.5" y1="16.5" x2="21" y2="21"/>
+</svg>
+`

internal/ui/icons/search.svg

@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+  <circle cx="11" cy="11" r="7"/>
+  <line x1="16.5" y1="16.5" x2="21" y2="21"/>
+</svg>

internal/ui/render.go

@@ -203,7 +203,7 @@ func (r *Renderer) GioEditor(id string) (*widget.Editor, bool) {
 
 // loadIcons loads PNG icons from the embedded filesystem.
 func (r *Renderer) loadIcons() {
-	for _, name := range []string{"back", "cut", "copy", "paste"} {
+	for _, name := range []string{"back", "cut", "copy", "paste", "search", "close", "chevron_up", "chevron_down"} {
 		data, err := iconFS.ReadFile("icons/" + name + ".png")
 		if err != nil {
 			continue