simplify SearchEntry and extract a debouncer util func

ui/browsing/albumspage.go

@@ -26,7 +26,7 @@ type AlbumsPage struct {
 	lm         *backend.LibraryManager
 	grid       *widgets.GridView
 	searchGrid *widgets.GridView
-	searcher   *widgets.Searcher
+	searcher   *widgets.SearchEntry
 	searchText string
 	titleDisp  *widget.RichText
 	sortOrder  *selectWidget
@@ -74,7 +74,7 @@ func NewAlbumsPage(cfg *backend.AlbumsPageConfig, contr *controller.Controller,
 	iter := lm.AlbumsIter(backend.AlbumSortOrder(a.sortOrder.Selected))
 	a.grid = widgets.NewGridView(widgets.NewGridViewAlbumIterator(iter), im)
 	contr.ConnectAlbumGridActions(a.grid)
-	a.searcher = widgets.NewSearcher()
+	a.searcher = widgets.NewSearchEntry()
 	a.searcher.OnSearched = a.OnSearched
 	a.createContainer(false)
 
@@ -82,7 +82,7 @@ func NewAlbumsPage(cfg *backend.AlbumsPageConfig, contr *controller.Controller,
 }
 
 func (a *AlbumsPage) createContainer(searchgrid bool) {
-	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher.Entry, layout.NewSpacer())
+	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher, layout.NewSpacer())
 	sortVbox := container.NewVBox(layout.NewSpacer(), a.sortOrder, layout.NewSpacer())
 	g := a.grid
 	if searchgrid {
@@ -115,7 +115,7 @@ func restoreAlbumsPage(saved *savedAlbumsPage) *AlbumsPage {
 	a.sortOrder.Selected = saved.sortOrder
 	a.sortOrder.OnChanged = a.onSortOrderChanged
 	a.grid = widgets.NewGridViewFromState(saved.gridState)
-	a.searcher = widgets.NewSearcher()
+	a.searcher = widgets.NewSearchEntry()
 	a.searcher.OnSearched = a.OnSearched
 	a.searcher.Entry.Text = saved.searchText
 	a.searchText = saved.searchText
@@ -147,7 +147,7 @@ func (a *AlbumsPage) Route() controller.Route {
 var _ Searchable = (*AlbumsPage)(nil)
 
 func (a *AlbumsPage) SearchWidget() fyne.Focusable {
-	return a.searcher.Entry
+	return a.searcher
 }
 
 func (a *AlbumsPage) Reload() {

ui/browsing/artistsgenrespage.go

@@ -33,7 +33,7 @@ type ArtistsGenresPage struct {
 
 	titleDisp *widget.RichText
 	container *fyne.Container
-	searcher  *widgets.Searcher
+	searcher  *widgets.SearchEntry
 }
 
 func NewArtistsGenresPage(isGenresPage bool, contr *controller.Controller, sm *backend.ServerManager) *ArtistsGenresPage {
@@ -63,7 +63,7 @@ func newArtistsGenresPage(isGenresPage bool, contr *controller.Controller, sm *b
 			a.contr.NavigateTo(controller.ArtistRoute(id))
 		}
 	}
-	a.searcher = widgets.NewSearcher()
+	a.searcher = widgets.NewSearchEntry()
 	a.searcher.OnSearched = a.onSearched
 	a.searcher.Entry.Text = searchText
 	a.buildContainer()
@@ -111,7 +111,7 @@ func (a *ArtistsGenresPage) onSearched(query string) {
 var _ Searchable = (*ArtistsGenresPage)(nil)
 
 func (a *ArtistsGenresPage) SearchWidget() fyne.Focusable {
-	return a.searcher.Entry
+	return a.searcher
 }
 
 func (a *ArtistsGenresPage) Route() controller.Route {
@@ -175,7 +175,7 @@ func (a *ArtistsGenresPage) buildGenresListModel(genres []*subsonic.Genre) []wid
 }
 
 func (a *ArtistsGenresPage) buildContainer() {
-	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher.Entry, layout.NewSpacer())
+	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher, layout.NewSpacer())
 	a.container = container.New(&layouts.MaxPadLayout{PadLeft: 15, PadRight: 15, PadTop: 5, PadBottom: 15},
 		container.NewBorder(
 			container.New(&layouts.MaxPadLayout{PadLeft: -5},

ui/browsing/favoritespage.go

@@ -38,7 +38,7 @@ type FavoritesPage struct {
 	searchGrid    *widgets.GridView
 	artistListCtr *fyne.Container
 	tracklistCtr  *fyne.Container
-	searcher      *widgets.Searcher
+	searcher      *widgets.SearchEntry
 	titleDisp     *widget.RichText
 	toggleBtns    *widgets.ToggleButtonGroup
 	container     *fyne.Container
@@ -78,13 +78,13 @@ func (a *FavoritesPage) createHeader(activeBtnIdx int, searchText string) {
 		widget.NewButtonWithIcon("", myTheme.AlbumIcon, a.onShowFavoriteAlbums),
 		widget.NewButtonWithIcon("", myTheme.ArtistIcon, a.onShowFavoriteArtists),
 		widget.NewButtonWithIcon("", myTheme.TracksIcon, a.onShowFavoriteSongs))
-	a.searcher = widgets.NewSearcher()
+	a.searcher = widgets.NewSearchEntry()
 	a.searcher.OnSearched = a.OnSearched
 	a.searcher.Entry.Text = searchText
 }
 
 func (a *FavoritesPage) createContainer(initialView fyne.CanvasObject) {
-	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher.Entry, layout.NewSpacer())
+	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher, layout.NewSpacer())
 	a.container = container.NewBorder(
 		container.NewHBox(util.NewHSpace(9), a.titleDisp, container.NewCenter(a.toggleBtns), layout.NewSpacer(), searchVbox, util.NewHSpace(15)),
 		nil, nil, nil, initialView)
@@ -182,7 +182,7 @@ func (a *FavoritesPage) Save() SavedPage {
 var _ Searchable = (*FavoritesPage)(nil)
 
 func (a *FavoritesPage) SearchWidget() fyne.Focusable {
-	return a.searcher.Entry
+	return a.searcher
 }
 
 func (a *FavoritesPage) OnSearched(query string) {

ui/browsing/genrepage.go

@@ -27,7 +27,7 @@ type GenrePage struct {
 	lm         *backend.LibraryManager
 	grid       *widgets.GridView
 	searchGrid *widgets.GridView
-	searcher   *widgets.Searcher
+	searcher   *widgets.SearchEntry
 	searchText string
 	titleDisp  *widget.RichText
 	playRandom *widget.Button
@@ -55,7 +55,7 @@ func NewGenrePage(genre string, contr *controller.Controller, pm *backend.Playba
 	iter := g.lm.GenreIter(g.genre)
 	g.grid = widgets.NewGridView(widgets.NewGridViewAlbumIterator(iter), g.im)
 	g.contr.ConnectAlbumGridActions(g.grid)
-	g.searcher = widgets.NewSearcher()
+	g.searcher = widgets.NewSearchEntry()
 	g.searcher.OnSearched = g.OnSearched
 	g.createContainer(false)
 
@@ -63,7 +63,7 @@ func NewGenrePage(genre string, contr *controller.Controller, pm *backend.Playba
 }
 
 func (g *GenrePage) createContainer(searchGrid bool) {
-	searchVbox := container.NewVBox(layout.NewSpacer(), g.searcher.Entry, layout.NewSpacer())
+	searchVbox := container.NewVBox(layout.NewSpacer(), g.searcher, layout.NewSpacer())
 	gr := g.grid
 	if searchGrid {
 		gr = g.searchGrid
@@ -94,7 +94,7 @@ func restoreGenrePage(saved *savedGenrePage) *GenrePage {
 	}
 	g.playRandom = widget.NewButtonWithIcon(" Play random", myTheme.ShuffleIcon, g.playRandomSongs)
 	g.grid = widgets.NewGridViewFromState(saved.gridState)
-	g.searcher = widgets.NewSearcher()
+	g.searcher = widgets.NewSearchEntry()
 	g.searcher.OnSearched = g.OnSearched
 	g.searcher.Entry.Text = saved.searchText
 	g.searchText = saved.searchText
@@ -142,7 +142,7 @@ func (g *GenrePage) Save() SavedPage {
 var _ Searchable = (*AlbumsPage)(nil)
 
 func (g *GenrePage) SearchWidget() fyne.Focusable {
-	return g.searcher.Entry
+	return g.searcher
 }
 
 func (g *GenrePage) OnSearched(query string) {

ui/browsing/playlistspage.go

@@ -32,7 +32,7 @@ type PlaylistsPage struct {
 	searchedPlaylists []*subsonic.Playlist
 
 	viewToggle *widgets.ToggleButtonGroup
-	searcher   *widgets.Searcher
+	searcher   *widgets.SearchEntry
 	titleDisp  *widget.RichText
 	container  *fyne.Container
 	listView   *PlaylistList
@@ -56,7 +56,7 @@ func newPlaylistsPage(contr *controller.Controller, cfg *backend.PlaylistsPageCo
 	}
 	a.ExtendBaseWidget(a)
 	a.titleDisp.Segments[0].(*widget.TextSegment).Style.SizeName = theme.SizeNameHeadingText
-	a.searcher = widgets.NewSearcher()
+	a.searcher = widgets.NewSearchEntry()
 	a.searcher.OnSearched = a.onSearched
 	a.searcher.Entry.Text = searchText
 	a.viewToggle = widgets.NewToggleButtonGroup(0,
@@ -199,7 +199,7 @@ func (a *PlaylistsPage) refreshView(playlists []*subsonic.Playlist) {
 var _ Searchable = (*PlaylistsPage)(nil)
 
 func (a *PlaylistsPage) SearchWidget() fyne.Focusable {
-	return a.searcher.Entry
+	return a.searcher
 }
 
 func (a *PlaylistsPage) Route() controller.Route {
@@ -233,7 +233,7 @@ func (s *savedPlaylistsPage) Restore() Page {
 }
 
 func (a *PlaylistsPage) buildContainer(initialView fyne.CanvasObject) {
-	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher.Entry, layout.NewSpacer())
+	searchVbox := container.NewVBox(layout.NewSpacer(), a.searcher, layout.NewSpacer())
 	a.container = container.New(&layouts.MaxPadLayout{PadLeft: 15, PadRight: 15, PadTop: 5, PadBottom: 15},
 		container.NewBorder(
 			container.NewHBox(a.titleDisp, container.NewCenter(a.viewToggle), layout.NewSpacer(), searchVbox),

ui/browsing/trackspage.go

@@ -24,7 +24,7 @@ type TracksPage struct {
 	nowPlayingID string
 
 	title           *widget.RichText
-	searcher        *widgets.Searcher
+	searcher        *widgets.SearchEntry
 	tracklist       *widgets.Tracklist
 	loader          widgets.TracklistLoader
 	searchTracklist *widgets.Tracklist
@@ -58,7 +58,7 @@ func NewTracksPage(contr *controller.Controller, conf *backend.TracksPageConfig,
 	t.title = widget.NewRichTextWithText("All Tracks")
 	t.title.Segments[0].(*widget.TextSegment).Style.SizeName = widget.RichTextStyleHeading.SizeName
 	t.playRandom = widget.NewButtonWithIcon("Play random", theme.ShuffleIcon, t.playRandomSongs)
-	t.searcher = widgets.NewSearcher()
+	t.searcher = widgets.NewSearchEntry()
 	t.searcher.OnSearched = t.OnSearched
 	t.createContainer()
 	t.Reload()
@@ -67,7 +67,7 @@ func NewTracksPage(contr *controller.Controller, conf *backend.TracksPageConfig,
 
 func (t *TracksPage) createContainer() {
 	playRandomVbox := container.NewVBox(layout.NewSpacer(), t.playRandom, layout.NewSpacer())
-	searchVbox := container.NewVBox(layout.NewSpacer(), t.searcher.Entry, layout.NewSpacer())
+	searchVbox := container.NewVBox(layout.NewSpacer(), t.searcher, layout.NewSpacer())
 	topRow := container.NewHBox(t.title, playRandomVbox, layout.NewSpacer(), searchVbox)
 	t.container = container.New(&layouts.MaxPadLayout{PadLeft: 15, PadRight: 15, PadTop: 5, PadBottom: 15},
 		container.NewBorder(topRow, nil, nil, nil, t.tracklist))
@@ -100,7 +100,7 @@ func (t *TracksPage) OnSongChange(track *subsonic.Child, lastScrobbledIfAny *sub
 var _ Searchable = (*TracksPage)(nil)
 
 func (t *TracksPage) SearchWidget() fyne.Focusable {
-	return t.searcher.Entry
+	return t.searcher
 }
 
 func (t *TracksPage) OnSearched(query string) {

ui/util/util.go

@@ -6,6 +6,8 @@ import (
 	"math"
 	"strconv"
 	"strings"
+	"sync"
+	"time"
 
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/layout"
@@ -60,6 +62,22 @@ func ImageAspect(im image.Image) float32 {
 	return float32(b.Max.X-b.Min.X) / float32(b.Max.Y-b.Min.Y)
 }
 
+// Debouncer returns a function that will call callOnDone when
+// it has not been invoked since the last dur interval.
+func NewDebouncer(dur time.Duration, callOnDone func()) func() {
+	var mu sync.Mutex
+	var timer *time.Timer
+	return func() {
+		mu.Lock()
+		defer mu.Unlock()
+
+		if timer != nil {
+			timer.Stop()
+		}
+		timer = time.AfterFunc(dur, callOnDone)
+	}
+}
+
 func RichTextSegsFromHTMLString(s string) []widget.RichTextSegment {
 	tokr := html.NewTokenizer(strings.NewReader(s))
 	var segs []widget.RichTextSegment

ui/widgets/searchentry.go

@@ -1,76 +1,21 @@
 package widgets
 
 import (
-	"sync"
 	"time"
 
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/theme"
 	"fyne.io/fyne/v2/widget"
+	"github.com/dweymouth/supersonic/ui/util"
 )
 
-// Searcher is a search entry widget that will issue a search command
+// SearchEntry is a search entry widget that will issue a search command
 // (aka call OnSearched) when a short span of time has elapsed since
 // the user typed into the widget.
-type Searcher struct {
-	Entry      *SearchEntry
-	OnSearched func(string)
-
-	searchGoroutine   bool
-	pendingSearch     bool
-	pendingSearchLock sync.Mutex
-}
-
-func NewSearcher() *Searcher {
-	s := &Searcher{
-		Entry: NewSearchEntry(),
-	}
-	s.Entry.OnChanged = s.onSearchTextChanged
-	return s
-}
-
-func (s *Searcher) onSearchTextChanged(text string) {
-	if text == "" {
-		s.sendSearch("")
-		return
-	}
-	s.pendingSearchLock.Lock()
-	defer s.pendingSearchLock.Unlock()
-	s.pendingSearch = true
-	if !s.searchGoroutine {
-		go s.waitAndSearch()
-		s.searchGoroutine = true
-	}
-}
-
-func (s *Searcher) waitAndSearch() {
-	t := time.NewTicker(200 * time.Millisecond)
-	var getReadyToSearch bool
-	var done bool
-	for !done {
-		<-t.C
-		s.pendingSearchLock.Lock()
-		if s.pendingSearch {
-			getReadyToSearch = true
-			s.pendingSearch = false
-		} else if getReadyToSearch {
-			s.sendSearch(s.Entry.Text)
-			t.Stop()
-			s.searchGoroutine = false
-			done = true
-		}
-		s.pendingSearchLock.Unlock()
-	}
-}
-
-func (s *Searcher) sendSearch(text string) {
-	if s.OnSearched != nil {
-		s.OnSearched(text)
-	}
-}
-
 type SearchEntry struct {
 	widget.Entry
+
+	OnSearched func(string)
 }
 
 func NewSearchEntry() *SearchEntry {
@@ -80,6 +25,10 @@ func NewSearchEntry() *SearchEntry {
 	sf.ActionItem = NewClearTextButton(func() {
 		sf.SetText("")
 	})
+	debounceFunc := util.NewDebouncer(200*time.Millisecond, func() {
+		sf.sendSearch(sf.Entry.Text)
+	})
+	sf.Entry.OnChanged = func(_ string) { debounceFunc() }
 	return sf
 }
 
@@ -104,6 +53,12 @@ type clearTextButton struct {
 	OnTapped func()
 }
 
+func (s *SearchEntry) sendSearch(text string) {
+	if s.OnSearched != nil {
+		s.OnSearched(text)
+	}
+}
+
 func NewClearTextButton(onTapped func()) *clearTextButton {
 	c := &clearTextButton{OnTapped: onTapped}
 	c.ExtendBaseWidget(c)