refactoring package organization

ui/browsing/browsingpane.go

@@ -0,0 +1,172 @@
+package browsing
+
+import (
+	"image/color"
+	"supersonic/backend"
+	"supersonic/ui/widgets"
+	"sync"
+	"time"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/layout"
+	"fyne.io/fyne/v2/theme"
+	"fyne.io/fyne/v2/widget"
+	"github.com/dweymouth/go-subsonic"
+)
+
+type Page interface {
+	fyne.CanvasObject
+
+	Route() Route
+}
+
+type Searchable interface {
+	OnSearched(string)
+}
+
+type CanPlayAlbum interface {
+	SetPlayAlbumCallback(func(albumID string, startingTrack int))
+}
+
+type CanShowNowPlaying interface {
+	OnSongChange(song *subsonic.Child)
+}
+
+type BrowsingPane struct {
+	widget.BaseWidget
+
+	app *backend.App
+
+	curPage Page
+
+	forward    *widget.Button
+	back       *widget.Button
+	history    []Page
+	historyIdx int
+
+	searchBar         *widgets.SearchEntry
+	pendingSearchLock sync.Mutex
+	pendingSearch     bool
+	searchGoroutine   bool
+
+	pageContainer *fyne.Container
+	container     *fyne.Container
+}
+
+func NewBrowsingPane(app *backend.App) *BrowsingPane {
+	b := &BrowsingPane{app: app}
+	b.ExtendBaseWidget(b)
+	b.searchBar = widgets.NewSearchEntry()
+	b.searchBar.OnTextChanged = b.onSearchTextChanged
+	b.back = widget.NewButtonWithIcon("", theme.NavigateBackIcon(), b.GoBack)
+	b.forward = widget.NewButtonWithIcon("", theme.NavigateNextIcon(), b.GoForward)
+	b.app.PlaybackManager.OnSongChange(b.onSongChange)
+	b.pageContainer = container.NewMax(
+		canvas.NewRectangle(color.RGBA{R: 24, G: 24, B: 24, A: 255}),
+		layout.NewSpacer())
+	b.container = container.NewBorder(
+		container.NewHBox(b.back, b.forward, b.searchBar),
+		nil, nil, nil, b.pageContainer)
+	return b
+}
+
+func (b *BrowsingPane) SetPage(p Page) {
+	if b.doSetPage(p) {
+		b.addPageToHistory(p)
+	}
+}
+
+func (b *BrowsingPane) doSetPage(p Page) bool {
+	if b.curPage != nil && b.curPage.Route() == p.Route() {
+		return false
+	}
+	b.curPage = p
+	if pa, ok := p.(CanPlayAlbum); ok {
+		pa.SetPlayAlbumCallback(func(albumID string, firstTrack int) {
+			_ = b.app.PlaybackManager.PlayAlbum(albumID, firstTrack)
+		})
+	}
+	if np, ok := p.(CanShowNowPlaying); ok {
+		np.OnSongChange(b.app.PlaybackManager.NowPlaying())
+	}
+	_, s := p.(Searchable)
+	b.searchBar.Hidden = !s
+	b.pageContainer.Objects[1] = p
+	b.Refresh()
+	return true
+}
+
+func (b *BrowsingPane) onSongChange(song *subsonic.Child) {
+	if b.curPage == nil {
+		return
+	}
+	if p, ok := b.curPage.(CanShowNowPlaying); ok {
+		p.OnSongChange(song)
+	}
+}
+
+func (b *BrowsingPane) addPageToHistory(p Page) {
+	b.history = b.history[:b.historyIdx]
+	b.history = append(b.history, p)
+	b.historyIdx++
+}
+
+func (b *BrowsingPane) GoBack() {
+	if b.historyIdx > 1 {
+		b.historyIdx -= 1
+		b.doSetPage(b.history[b.historyIdx-1])
+	}
+}
+
+func (b *BrowsingPane) GoForward() {
+	if b.historyIdx < len(b.history) {
+		b.historyIdx++
+		b.doSetPage(b.history[b.historyIdx-1])
+	}
+}
+
+func (b *BrowsingPane) onSearchTextChanged(text string) {
+	if text == "" {
+		b.sendSearch("")
+		return
+	}
+	b.pendingSearchLock.Lock()
+	defer b.pendingSearchLock.Unlock()
+	b.pendingSearch = true
+	if !b.searchGoroutine {
+		go b.waitAndSearch()
+		b.searchGoroutine = true
+	}
+}
+
+func (b *BrowsingPane) waitAndSearch() {
+	t := time.NewTicker(200 * time.Millisecond)
+	var getReadyToSearch bool
+	var done bool
+	for !done {
+		<-t.C
+		b.pendingSearchLock.Lock()
+		if b.pendingSearch {
+			getReadyToSearch = true
+			b.pendingSearch = false
+		} else if getReadyToSearch {
+			b.sendSearch(b.searchBar.Text)
+			t.Stop()
+			b.searchGoroutine = false
+			done = true
+		}
+		b.pendingSearchLock.Unlock()
+	}
+}
+
+func (b *BrowsingPane) sendSearch(query string) {
+	if s, ok := b.curPage.(Searchable); ok {
+		s.OnSearched(query)
+	}
+}
+
+func (b *BrowsingPane) CreateRenderer() fyne.WidgetRenderer {
+	return widget.NewSimpleRenderer(b.container)
+}