Add clear queue button (#795)

Author: Oowoosh0

src/Application.vala

@@ -10,6 +10,7 @@ public class Music.Application : Gtk.Application {
     public const string ACTION_PREVIOUS = "action-previous";
     public const string ACTION_SHUFFLE = "action-shuffle";
     public const string ACTION_FIND = "action-find";
+    public const string ACTION_CLEAR_QUEUE = "action-clear-queue";
     public const string ACTION_QUIT = "action-quit";
 
     private const ActionEntry[] ACTION_ENTRIES = {
@@ -18,6 +19,7 @@ public class Music.Application : Gtk.Application {
         { ACTION_PREVIOUS, action_previous },
         { ACTION_SHUFFLE, action_shuffle },
         { ACTION_FIND, action_find },
+        { ACTION_CLEAR_QUEUE, action_clear_queue },
         { ACTION_QUIT, quit }
     };
 
@@ -190,6 +192,10 @@ public class Music.Application : Gtk.Application {
         ((MainWindow)active_window).start_search ();
     }
 
+    private void action_clear_queue () {
+        playback_manager.clear_queue ();
+    }
+
     private void on_bus_acquired (DBusConnection connection, string name) {
         try {
             connection.register_object ("/org/mpris/MediaPlayer2", new MprisRoot ());

src/MainWindow.vala

@@ -73,8 +73,28 @@ public class Music.MainWindow : Gtk.ApplicationWindow {
 
         add_button_label.mnemonic_widget = add_button;
 
+        var clear_button_label = new Gtk.Label (_("Clear Queue"));
+
+        var clear_button_box = new Gtk.Box (HORIZONTAL, 0);
+        clear_button_box.append (new Gtk.Image.from_icon_name ("edit-clear-all-symbolic"));
+        clear_button_box.append (clear_button_label);
+
+        var clear_button = new Gtk.Button () {
+            child = clear_button_box,
+            action_name = Application.ACTION_PREFIX + Application.ACTION_CLEAR_QUEUE
+        };
+        clear_button.add_css_class (Granite.STYLE_CLASS_FLAT);
+
+        clear_button_label.mnemonic_widget = clear_button;
+
+        var clear_queue_action = GLib.Application.get_default ().lookup_action (Application.ACTION_CLEAR_QUEUE);
+        playback_manager.bind_property (
+            "has-items", clear_queue_action, "enabled", DEFAULT | SYNC_CREATE
+        );
+
         var queue_action_bar = new Gtk.ActionBar ();
         queue_action_bar.pack_start (add_button);
+        queue_action_bar.pack_end (clear_button);
 
         var queue = new Adw.ToolbarView () {
             bottom_bar_style = RAISED,

src/PlaybackManager.vala

@@ -145,6 +145,12 @@ public class Music.PlaybackManager : Object {
         }
     }
 
+    public void clear_queue () {
+        playbin.set_state (Gst.State.NULL);
+        current_audio = null;
+        queue_liststore.remove_all ();
+    }
+
     private void update_metadata (Gst.PbUtils.DiscovererInfo info, Error? err) {
         string uri = info.get_uri ();
         switch (info.get_result ()) {