add new widgets; rewrite workspace indicator

lua/widgets/bar/volume.lua

@@ -0,0 +1,26 @@
+local wp <const> = lgi.require("AstalWp").get_default()
+
+local endpoint = wp:get_audio():get_default_speaker()
+
+return Widget.Box({
+  class_name = 'volume-slider',
+  children = {
+    Widget.Button({
+      child = Widget.Icon({
+        icon = bind(endpoint, "volume-icon"),
+      }),
+      on_clicked = function()
+        endpoint:set_mute(not endpoint:get_mute())
+      end
+    }),
+    Widget.Slider({
+      class_name = 'volume-slider',
+      hexpand = true,
+      draw_value = false,
+      value = bind(endpoint, 'volume'),
+      on_value_changed = function(self)
+        endpoint:set_volume(self.value)
+      end
+    })
+  }
+})