feat: Add Share option for artists, albums, and tracks

This feature is only available on the Subsonic media provider. Using a
Jellyfin server will make Supersonic hide the "Share" option.

* Artists: Option available in grid view and in Artist view.
* Albums: Option available in grid view and in Album view.
* Tracks: Option available in tracklist, when a single track is selected.

ui/browsing/artistpage.go

@@ -237,7 +237,9 @@ func (a *ArtistPage) showTopTracks() {
 		}
 		tl.Options = widgets.TracklistOptions{AutoNumber: true}
 		_, canRate := a.mp.(mediaprovider.SupportsRating)
+		_, canShare := a.mp.(mediaprovider.SupportsSharing)
 		tl.Options.DisableRating = !canRate
+		tl.Options.HideSharing = !canShare
 		tl.SetVisibleColumns(a.cfg.TracklistColumns)
 		tl.SetSorting(a.trackSort)
 		tl.OnVisibleColumnsChanged = func(cols []string) {
@@ -292,6 +294,7 @@ type ArtistPageHeader struct {
 	favoriteBtn    *widgets.FavoriteButton
 	playBtn        *widget.Button
 	playRadioBtn   *widget.Button
+	menuBtn        *widget.Button
 	container      *fyne.Container
 }
 
@@ -318,6 +321,25 @@ func NewArtistPageHeader(page *ArtistPage) *ArtistPageHeader {
 		go a.artistPage.contr.PlayArtistDiscography(a.artistID, false /*shuffle*/)
 	})
 	a.playRadioBtn = widget.NewButtonWithIcon("Play Artist Radio", myTheme.ShuffleIcon, a.artistPage.playArtistRadio)
+
+	_, canShare := a.artistPage.mp.(mediaprovider.SupportsSharing)
+	if canShare {
+		var pop *widget.PopUpMenu
+		a.menuBtn = widget.NewButtonWithIcon("", theme.MoreHorizontalIcon(), nil)
+		a.menuBtn.OnTapped = func() {
+			if pop == nil {
+				share := fyne.NewMenuItem("Share...", func() {
+					a.artistPage.contr.CreateShareURL(a.artistID)
+				})
+				share.Icon = myTheme.ShareIcon
+				menu := fyne.NewMenu("", share)
+				pop = widget.NewPopUpMenu(menu, fyne.CurrentApp().Driver().CanvasForObject(a))
+			}
+			pos := fyne.CurrentApp().Driver().AbsolutePositionForObject(a.menuBtn)
+			pop.ShowAtPosition(fyne.NewPos(pos.X, pos.Y+a.menuBtn.Size().Height))
+		}
+	}
+
 	a.biographyDisp.Wrapping = fyne.TextWrapWord
 	a.biographyDisp.Truncation = fyne.TextTruncateEllipsis
 	a.ExtendBaseWidget(a)
@@ -407,12 +429,17 @@ func (a *ArtistPageHeader) toggleFavorited() {
 }
 
 func (a *ArtistPageHeader) createContainer() {
+	btnContainer := container.NewHBox(util.NewHSpace(2), a.favoriteBtn, a.playBtn, a.playRadioBtn)
+	if a.menuBtn != nil {
+		btnContainer.Add(a.menuBtn)
+	}
+
 	a.container = util.AddHeaderBackground(
 		container.NewBorder(nil, nil, a.artistImage, nil,
 			container.NewVBox(
 				container.New(&layouts.VboxCustomPadding{ExtraPad: -10},
 					a.titleDisp, a.biographyDisp, a.similarArtists),
-				container.NewHBox(util.NewHSpace(2), a.favoriteBtn, a.playBtn, a.playRadioBtn)),
+				btnContainer),
 		))
 }