PopoverManager: animate popover

meson.build

@@ -24,6 +24,7 @@ i18n = import('i18n')
 gnome = import('gnome')
 pkg = import('pkgconfig')
 
+adw_dep = dependency('libadwaita-1')
 glib_dep = dependency('glib-2.0', version: '>=2.32')
 gio_dep = dependency('gio-2.0')
 gio_unix_dep = dependency('gio-unix-2.0')

src/Services/PopoverManager.vala

@@ -20,6 +20,8 @@
 public class Wingpanel.Services.PopoverManager : Object {
     public bool indicator_open { get; private set; default = false; }
 
+    private Adw.TimedAnimation fade;
+    private Adw.TimedAnimation scale;
     private Gtk.Popover popover;
 
     private Wingpanel.Widgets.IndicatorEntry? _current_indicator = null;
@@ -54,30 +56,91 @@ public class Wingpanel.Services.PopoverManager : Object {
             }
 
             if (_current_indicator != null) {
-                popover.child = _current_indicator.indicator_widget;
-                _current_indicator.display_widget.has_tooltip = false;
-                popover.set_parent (_current_indicator);
-                popover.popup ();
-                _current_indicator.set_state_flags (CHECKED, true);
-                _current_indicator.base_indicator.opened ();
+                set_revealed (true);
             } else {
-                ((Widgets.IndicatorEntry)popover.parent).display_widget.has_tooltip = true;
-                popover.popdown ();
+                set_revealed (false);
             }
         }
     }
 
     construct {
         popover = new Gtk.Popover () {
+            halign = CENTER,
             has_arrow = false,
             position = BOTTOM
         };
         popover.add_css_class ("indicator");
 
+        fade = new Adw.TimedAnimation (
+            popover, 0, 1,
+            Granite.TRANSITION_DURATION_OPEN,
+            new Adw.PropertyAnimationTarget (popover, "opacity")
+        ) {
+            easing = EASE_IN_OUT_QUAD
+        };
+
+        var scale_target = new Adw.CallbackAnimationTarget ((val) => {
+            var popover_height = popover.get_height ();
+            var popover_width = popover.get_width ();
+
+            popover.size_allocate (
+                (int) (popover_width * val), (int) (popover_height * val), -1
+            );
+
+            _current_indicator.indicator_widget.allocate (
+                //FIXME: what sorcery is this?
+                int.max (0, popover_width - 14), int.max (0, popover_height - 20), -1,
+                new Gsk.Transform ()
+                    .scale ((float) val, (float) val)
+            );
+        });
+
+        scale = new Adw.TimedAnimation (
+            popover, 0, 1,
+            Granite.TRANSITION_DURATION_OPEN,
+            scale_target
+        ) {
+            easing = EASE_IN_OUT_QUAD
+        };
+
         popover.closed.connect (() => {
             _current_indicator.set_state_flags (NORMAL, true);
             current_indicator = null;
             popover.unparent ();
         });
     }
+
+    private void set_revealed (bool revealed) {
+        fade.skip ();
+        scale.skip ();
+
+        // Avoid a stutter at the beginning
+        popover.opacity = 0;
+
+        fade.reverse = !revealed;
+
+        if (revealed) {
+            _current_indicator.display_widget.has_tooltip = false;
+            _current_indicator.set_state_flags (CHECKED, true);
+            _current_indicator.base_indicator.opened ();
+
+            popover.set_parent (_current_indicator);
+            popover.child = _current_indicator.indicator_widget;
+            popover.present ();
+            popover.popup ();
+
+            fade.duration = Granite.TRANSITION_DURATION_OPEN;
+            scale.duration = Granite.TRANSITION_DURATION_OPEN;
+            scale.easing = EASE_OUT_ELASTIC;
+        } else {
+            ((Widgets.IndicatorEntry)popover.parent).display_widget.has_tooltip = true;
+
+            fade.duration = Granite.TRANSITION_DURATION_CLOSE;
+            scale.duration = Granite.TRANSITION_DURATION_CLOSE;
+            scale.easing = EASE_IN_OUT_QUAD;
+        }
+
+        fade.play ();
+        scale.play ();
+    }
 }

src/meson.build

@@ -12,6 +12,7 @@ wingpanel_files = files(
 
 wingpanel_deps = [
     libwingpanel_dep,
+    adw_dep,
     granite_dep,
     gdk_wl_dep,
     posix_dep,