Handle local tracks in playlist

- Show error on deletion, as we currently do not have a Uri we can pass to the
  Spotify API to delete local files in playlists
- Mark local files in `ListView`

fixes #1213

src/ui/listview.rs

@@ -220,6 +220,7 @@ impl<I: ListItem + Clone> View for ListView<I> {
                 let item = &content[i];
                 let currently_playing =
                     item.is_playing(&self.queue) && self.queue.get_current_index() == Some(i);
+                let is_local = item.track().map(|t| t.is_local).unwrap_or_default();
 
                 let style = if self.selected == i {
                     if currently_playing {
@@ -227,6 +228,11 @@ impl<I: ListItem + Clone> View for ListView<I> {
                             *printer.theme.palette.custom("playing_selected").unwrap(),
                             ColorType::Palette(PaletteColor::Highlight),
                         )
+                    } else if is_local {
+                        ColorStyle::new(
+                            ColorType::Palette(PaletteColor::Secondary),
+                            ColorType::Palette(PaletteColor::Highlight),
+                        )
                     } else {
                         ColorStyle::highlight()
                     }
@@ -235,6 +241,8 @@ impl<I: ListItem + Clone> View for ListView<I> {
                         ColorType::Color(*printer.theme.palette.custom("playing").unwrap()),
                         ColorType::Color(*printer.theme.palette.custom("playing_bg").unwrap()),
                     )
+                } else if is_local {
+                    ColorStyle::secondary()
                 } else {
                     ColorStyle::primary()
                 };

src/ui/playlist.rs

@@ -80,13 +80,16 @@ impl ViewExt for PlaylistView {
     fn on_command(&mut self, s: &mut Cursive, cmd: &Command) -> Result<CommandResult, String> {
         if let Command::Delete = cmd {
             let pos = self.list.get_selected_index();
-            if self
+
+            return if self
                 .playlist
                 .delete_track(pos, self.spotify.clone(), &self.library)
             {
                 self.list.remove(pos);
-            }
-            return Ok(CommandResult::Consumed(None));
+                Ok(CommandResult::Consumed(None))
+            } else {
+                Err("Could not delete track.".to_string())
+            };
         }
 
         if let Command::Sort(key, direction) = cmd {