main screen: Add button to start random playback

backend/src/player.rs

@@ -110,18 +110,18 @@ impl Player {
             result
                 .mpris
                 .connect_play_pause(clone!(@weak result => move || {
-                    result.play_pause();
+                    result.play_pause().unwrap();
                 }));
 
             result.mpris.connect_play(clone!(@weak result => move || {
                 if !result.is_playing() {
-                    result.play_pause();
+                    result.play_pause().unwrap();
                 }
             }));
 
             result.mpris.connect_pause(clone!(@weak result => move || {
                 if result.is_playing() {
-                    result.play_pause();
+                    result.play_pause().unwrap();
                 }
             }));
 
@@ -223,7 +223,7 @@ impl Player {
         Ok(())
     }
 
-    pub fn play_pause(&self) {
+    pub fn play_pause(&self) -> Result<()> {
         if self.is_playing() {
             self.player.pause();
             self.playing.set(false);
@@ -235,6 +235,10 @@ impl Player {
             #[cfg(target_os = "linux")]
             self.mpris.set_playback_status(PlaybackStatus::Paused);
         } else {
+            if self.current_track.get().is_none() {
+                self.next()?;
+            }
+
             self.player.play();
             self.playing.set(true);
 
@@ -245,6 +249,8 @@ impl Player {
             #[cfg(target_os = "linux")]
             self.mpris.set_playback_status(PlaybackStatus::Playing);
         }
+
+        Ok(())
     }
 
     pub fn seek(&self, ms: u64) {
@@ -287,23 +293,30 @@ impl Player {
     }
 
     pub fn next(&self) -> Result<()> {
-        let mut current_track = self.current_track.get().ok_or_else(|| {
-            Error::Other(String::from(
-                "Player tried to access non existant current track.",
-            ))
-        })?;
+        let current_track = self.current_track.get();
+        let cb = self.generate_next_track_cb.borrow();
 
-        if current_track + 1 < self.playlist.borrow().len() {
-            current_track += 1;
-        } else if let Some(cb) = &*self.generate_next_track_cb.borrow() {
+        if let Some(current_track) = current_track {
+            if current_track + 1 >= self.playlist.borrow().len() {
+                if let Some(cb) = &*cb {
+                    let new_track = cb();
+                    self.add_item(new_track)?;
+                } else {
+                    return Err(Error::Other(String::from("No existing next track.")));
+                }
+            }
+
+            self.set_track(current_track + 1)?;
+
+            Ok(())
+        } else if let Some(cb) = &*cb {
             let new_track = cb();
             self.add_item(new_track)?;
-            current_track += 1;
-        } else {
-            return Err(Error::Other(String::from("No existing next track.")));
-        }
 
-        self.set_track(current_track)
+            Ok(())
+        } else {
+            Err(Error::Other(String::from("No existing next track.")))
+        }
     }
 
     pub fn set_track(&self, current_track: usize) -> Result<()> {

musicus/res/ui/main_screen.ui

@@ -7,7 +7,7 @@
     <child>
       <object class="AdwHeaderBar">
         <property name="title-widget">
-          <object class="GtkLabel"/>
+          <object class="GtkLabel" />
         </property>
       </object>
     </child>
@@ -17,6 +17,18 @@
         <property name="title" translatable="yes">Welcome to Musicus!</property>
         <property name="description" translatable="yes">Get startet by selecting something from the sidebar or adding new things to your library using the button in the top left corner.</property>
         <property name="vexpand">true</property>
+        <child>
+          <object class="GtkRevealer" id="play_button_revealer">
+            <property name="reveal-child">true</property>
+            <property name="transition-type">crossfade</property>
+            <child>
+              <object class="GtkButton" id="play_button">
+                <property name="halign">center</property>
+                <property name="label" translatable="yes">Play something</property>
+              </object>
+            </child>
+          </object>
+        </child>
       </object>
     </child>
   </object>
@@ -40,7 +52,7 @@
                       <object class="GtkLabel">
                         <property name="label">Musicus</property>
                         <style>
-                          <class name="title"/>
+                          <class name="title" />
                         </style>
                       </object>
                     </property>
@@ -104,7 +116,7 @@
                         <property name="child">
                           <object class="GtkScrolledWindow" id="scroll">
                             <child>
-                              <placeholder/>
+                              <placeholder />
                             </child>
                           </object>
                         </property>

musicus/src/screens/main.rs

@@ -32,6 +32,8 @@ impl Screen<(), ()> for MainScreen {
 
         get_widget!(builder, gtk::Box, widget);
         get_widget!(builder, adw::Leaflet, leaflet);
+        get_widget!(builder, gtk::Revealer, play_button_revealer);
+        get_widget!(builder, gtk::Button, play_button);
         get_widget!(builder, gtk::Button, add_button);
         get_widget!(builder, gtk::SearchEntry, search_entry);
         get_widget!(builder, gtk::Stack, stack);
@@ -126,6 +128,14 @@ impl Screen<(), ()> for MainScreen {
                 search.is_empty() || title.contains(&search)
             }));
 
+        this.handle.backend.pl().add_playlist_cb(clone!(@weak play_button_revealer => move |new_playlist| {
+                play_button_revealer.set_reveal_child(new_playlist.is_empty());
+        }));
+
+        play_button.connect_clicked(clone!(@weak this => move |_| {
+            this.handle.backend.pl().play_pause().unwrap();
+        }));
+
         this.navigator.set_back_cb(clone!(@weak this =>  move || {
             this.leaflet.set_visible_child_name("sidebar");
         }));

musicus/src/screens/player.rs

@@ -163,7 +163,7 @@ impl Screen<(), ()> for PlayerScreen {
 
         this.play_button
             .connect_clicked(clone!(@weak this =>  move |_| {
-                this.handle.backend.pl().play_pause();
+                this.handle.backend.pl().play_pause().unwrap();
             }));
 
         this.next_button

musicus/src/widgets/player_bar.rs

@@ -47,7 +47,7 @@ impl PlayerBar {
 
         play_button.connect_clicked(clone!(@strong player => move |_| {
             if let Some(player) = &*player.borrow() {
-                player.play_pause();
+                player.play_pause().unwrap();
             }
         }));