Preview filter while browsing an open dropdown; Esc closes only the list

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

SPECS.md

@@ -67,7 +67,7 @@ Notes:
 
 ### 4.2 v0.2 (done, M8)
 
-- **Library view:** movies (top) and series (below) with the details of the selected item on the right; Tab switches between the two lists. Filters (all, missing, downloaded, monitored, unmonitored), a file-property filter (`F`: quality 2160p/1080p/720p/SD, codec x265/x264/AV1, HDR/DV/SDR, audio format Atmos/TrueHD/DTS:X/DTS-HD/DTS/DD+/DD/AAC/FLAC/Opus, audio language; changes apply live to the list behind the dialog and Esc restores the previous filter) and a text filter apply to both lists. Movie properties come from the movie list; series properties are read per series from `GET /episodefile?seriesId=` only while a property filter is active, cached while a series' file count and size stay the same, and a series matches when any of its files does. `t` toggles monitoring, `s` starts an automatic search, `i`/Enter opens the release search (movies) or the drill-down (series).
+- **Library view:** movies (top) and series (below) with the details of the selected item on the right; Tab switches between the two lists. Filters (all, missing, downloaded, monitored, unmonitored), a file-property filter (`F`: quality 2160p/1080p/720p/SD, codec x265/x264/AV1, HDR/DV/SDR, audio format Atmos/TrueHD/DTS:X/DTS-HD/DTS/DD+/DD/AAC/FLAC/Opus, audio language; changes apply live to the list behind the dialog, including while moving through an open dropdown, and Esc restores the previous filter) and a text filter apply to both lists. Movie properties come from the movie list; series properties are read per series from `GET /episodefile?seriesId=` only while a property filter is active, cached while a series' file count and size stay the same, and a series matches when any of its files does. `t` toggles monitoring, `s` starts an automatic search, `i`/Enter opens the release search (movies) or the drill-down (series).
 - **Series drill-down:** seasons and episodes, toggle monitoring per season/episode, trigger season/episode search and release search.
 
 ### 4.3 Later / ideas

internal/ui/form.go

@@ -11,16 +11,39 @@ import (
 //     (and move between the buttons),
 //
 // Enter or Space still opens a dropdown list. While a list is open it gets all keys.
-func arrowNavigation(f *tview.Form) {
+//
+// With hooks, the highlighted entry of an open list is reported while the user
+// moves through it, before anything is selected.
+//
+// cancel is called on Esc, except when Esc only closes an open dropdown list
+// (tview would otherwise treat that as cancelling the whole form).
+func arrowNavigation(f *tview.Form, cancel func(), hooks *browseHooks) {
+	var b browser
+	var closingList bool
+	f.SetCancelFunc(func() {
+		if closingList {
+			closingList = false
+			return
+		}
+		if cancel != nil {
+			cancel()
+		}
+	})
 	f.SetInputCapture(func(ev *tcell.EventKey) *tcell.EventKey {
+		closingList = false
 		item, button := f.GetFocusedItemIndex()
 		if item < 0 && button < 0 {
 			return ev
 		}
 		dd, _ := focusedDropDown(f, item)
 		if dd != nil && dd.IsOpen() {
+			closingList = ev.Key() == tcell.KeyEscape
+			if hooks != nil {
+				b.track(dd, ev, hooks)
+			}
 			return ev
 		}
+		b.dd = nil
 		total := f.GetFormItemCount() + f.GetButtonCount()
 		pos := item
 		if button >= 0 {
@@ -90,3 +113,50 @@ func bindSearchNow(box *tview.Checkbox, searchable func() bool, blocked func())
 		box.SetChecked(false)
 	}
 }
+
+// browseHooks lets a form follow the highlight of an open dropdown list.
+type browseHooks struct {
+	browse func(dd *tview.DropDown, index int) // the highlight moved to entry index
+	abort  func()                              // the list was closed without selecting
+}
+
+// browser mirrors the highlight of an open dropdown list, which tview does
+// not expose: it starts at the current option and follows the navigation keys.
+type browser struct {
+	dd    *tview.DropDown
+	idx   int
+	known bool // false after keys that move the highlight in ways we do not track
+}
+
+func (b *browser) track(dd *tview.DropDown, ev *tcell.EventKey, h *browseHooks) {
+	n := dd.GetOptionCount()
+	if b.dd != dd {
+		cur, _ := dd.GetCurrentOption()
+		b.dd, b.idx, b.known = dd, max(cur, 0), true
+	}
+	move := func(to int) {
+		b.idx = to
+		if b.known && h.browse != nil {
+			h.browse(dd, b.idx)
+		}
+	}
+	switch ev.Key() {
+	case tcell.KeyDown:
+		move((b.idx + 1) % n)
+	case tcell.KeyUp:
+		move((b.idx - 1 + n) % n)
+	case tcell.KeyHome:
+		move(0)
+	case tcell.KeyEnd:
+		move(n - 1)
+	case tcell.KeyEscape:
+		b.dd = nil
+		if h.abort != nil {
+			h.abort()
+		}
+	case tcell.KeyEnter:
+		b.dd = nil // the selection is reported by the dropdown itself
+	default:
+		b.known = false // paging, typed prefixes
+	}
+}

internal/ui/form_test.go

@@ -1,6 +1,7 @@
 package ui
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/gdamore/tcell/v2"
@@ -12,7 +13,7 @@ func TestArrowNavigation(t *testing.T) {
 		AddDropDown("A", []string{"x", "y", "z"}, 0, nil).
 		AddCheckbox("B", true, nil).
 		AddButton("Add", nil).AddButton("Cancel", nil)
-	arrowNavigation(f)
+	arrowNavigation(f, nil, nil)
 	var focus func(p tview.Primitive)
 	focus = func(p tview.Primitive) { p.Focus(focus) }
 	f.Focus(focus)
@@ -56,7 +57,7 @@ func TestSearchNowFollowsMonitored(t *testing.T) {
 		AddCheckbox("M", true, nil).
 		AddCheckbox("S", true, nil).
 		AddButton("Add", nil)
-	arrowNavigation(f)
+	arrowNavigation(f, nil, nil)
 	var focus func(p tview.Primitive)
 	focus = func(p tview.Primitive) { p.Focus(focus) }
 	f.Focus(focus)
@@ -108,3 +109,53 @@ func TestSearchNowFollowsMonitored(t *testing.T) {
 		t.Error("Search now should return to its previous choice")
 	}
 }
+
+func TestBrowseOpenDropDown(t *testing.T) {
+	f := tview.NewForm().AddDropDown("D", []string{"any", "a", "b", "c"}, 0, nil)
+	var seen []int
+	aborted, cancelled := 0, 0
+	arrowNavigation(f, func() { cancelled++ }, &browseHooks{
+		browse: func(_ *tview.DropDown, i int) { seen = append(seen, i) },
+		abort:  func() { aborted++ },
+	})
+	var focus func(p tview.Primitive)
+	focus = func(p tview.Primitive) { p.Focus(focus) }
+	f.Focus(focus)
+	send := func(k tcell.Key) { f.InputHandler()(tcell.NewEventKey(k, 0, 0), focus) }
+	dd := f.GetFormItem(0).(*tview.DropDown)
+
+	send(tcell.KeyEnter) // open
+	if !dd.IsOpen() {
+		t.Fatal("dropdown did not open")
+	}
+	send(tcell.KeyDown)
+	send(tcell.KeyDown)
+	send(tcell.KeyUp)
+	send(tcell.KeyUp)
+	send(tcell.KeyUp) // wraps to the last entry
+	if want := []int{1, 2, 1, 0, 3}; !reflect.DeepEqual(seen, want) {
+		t.Fatalf("browse saw %v, want %v", seen, want)
+	}
+	send(tcell.KeyEnter) // select what the highlight is on
+	if i, _ := dd.GetCurrentOption(); i != 3 {
+		t.Errorf("selected option %d, want 3: the mirrored highlight drifted from the real list", i)
+	}
+
+	seen = nil
+	send(tcell.KeyEnter)
+	send(tcell.KeyDown) // wraps to 0
+	send(tcell.KeyEscape)
+	if cancelled != 0 {
+		t.Error("Esc on an open list must only close the list")
+	}
+	send(tcell.KeyEscape) // list closed: now Esc cancels the form
+	if cancelled != 1 {
+		t.Errorf("cancelled=%d, want 1", cancelled)
+	}
+	if aborted != 1 || !reflect.DeepEqual(seen, []int{0}) {
+		t.Errorf("aborted=%d seen=%v", aborted, seen)
+	}
+	if i, _ := dd.GetCurrentOption(); i != 3 {
+		t.Errorf("Esc must keep the committed option, got %d", i)
+	}
+}

internal/ui/help.go

@@ -24,7 +24,8 @@ const helpText = `[yellow]Global[-]
                          filters apply to both lists
   F                      filter by file properties: quality, codec (x265, x264, AV1),
                          HDR / DV / SDR, audio (Atmos, TrueHD, DTS, DD+ ...), language.
-                         Changes apply live behind the dialog; Esc undoes them.
+                         Changes apply live behind the dialog, also while you move through an
+                         open list; Esc undoes them.
                          Series are read on demand.
   /                      text filter (Enter or Esc returns to the list)
   t                      toggle monitored

internal/ui/libfilter.go

@@ -131,14 +131,20 @@ func (a *App) openAttrFilter(cur attrFilter, languages []string, set func(attrFi
 		AddDropDown(lAudio, withAny(audioOptions), indexOf(audioOptions, cur.audio), nil).
 		AddDropDown(lLang, withAny(languages), indexOf(languages, cur.lang), nil)
 
-	pick := func(label string, options []string) string {
+	// filterWith reads the dialog; the entry at index in dropdown over (if
-		i := selected(form, label)
+	// any) stands in for that dropdown's committed choice.
-		if i <= 0 {
+	filterWith := func(over *tview.DropDown, index int) attrFilter {
-			return ""
+		pick := func(label string, options []string) string {
+			dd := form.GetFormItemByLabel(label).(*tview.DropDown)
+			i, _ := dd.GetCurrentOption()
+			if dd == over {
+				i = index
+			}
+			if i <= 0 {
+				return ""
+			}
+			return options[i-1]
 		}
-		return options[i-1]
-	}
-	current := func() attrFilter {
 		return attrFilter{
 			res:   pick(lRes, resOptions),
 			codec: pick(lCodec, codecOptions),
@@ -147,6 +153,7 @@ func (a *App) openAttrFilter(cur attrFilter, languages []string, set func(attrFi
 			lang:  pick(lLang, languages),
 		}
 	}
+	current := func() attrFilter { return filterWith(nil, 0) }
 	for _, label := range []string{lRes, lCodec, lHDR, lAudio, lLang} {
 		form.GetFormItemByLabel(label).(*tview.DropDown).SetSelectedFunc(func(string, int) { set(current()) })
 	}
@@ -161,8 +168,10 @@ func (a *App) openAttrFilter(cur attrFilter, languages []string, set func(attrFi
 		set(attrFilter{})
 	})
 	form.AddButton("Cancel", cancel)
-	form.SetCancelFunc(cancel)
+	arrowNavigation(form, cancel, &browseHooks{
-	arrowNavigation(form)
+		browse: func(dd *tview.DropDown, index int) { set(filterWith(dd, index)) },
+		abort:  func() { set(current()) }, // list closed without choosing: back to the committed value
+	})
 	form.SetBorder(true).SetTitle(" Filter by properties ")
 	a.openSidePanel(form, 40, 17, "↑↓ move · ←→ change (applies live) · Enter apply · Esc cancel")
 }

internal/ui/search.go

@@ -343,8 +343,7 @@ func (v *searchView) add(i int) {
 		v.doAdd(r, choice)
 	})
 	form.AddButton("Cancel", v.app.closeModal)
-	form.SetCancelFunc(v.app.closeModal)
+	arrowNavigation(form, v.app.closeModal, nil)
-	arrowNavigation(form)
 	form.SetBorder(true).SetTitle(" Add " + tview.Escape(r.title()) + " ")
 
 	v.app.openModal(form, 60, height)