Introduce PropertyAnimator

Author: lenemter

lib/PropertyAnimator.vala

@@ -0,0 +1,65 @@
+/*
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ * SPDX-FileCopyrightText: 2025 elementary, Inc. (https://elementary.io)
+ */
+
+public class Gala.PropertyAnimator : Object {
+    public struct AnimatableProperty {
+        string property;
+        Type value_type;
+        Value? from_value;
+        Value target_value;
+    }
+
+    public delegate void OnStopped (Clutter.Actor actor);
+
+    private Clutter.Actor actor;
+    private OnStopped on_stopped;
+
+    public PropertyAnimator (
+        Clutter.Actor actor,
+        uint duration,
+        Clutter.AnimationMode animation_mode,
+        AnimatableProperty[] properties,
+        OnStopped on_stopped
+    ) {
+        this.actor = actor;
+        this.on_stopped = on_stopped;
+
+        ref ();
+
+        if (!Meta.Prefs.get_gnome_animations ()) {
+            call_on_stopped ();
+            return;
+        }
+
+        for (var i = 0; i < properties.length; i++) {
+            var property = properties[i];
+
+            Value actor_current_property = {};
+            actor.get_property (property.property, ref actor_current_property);
+
+            var transition = new Clutter.PropertyTransition (property.property) {
+                progress_mode = animation_mode,
+                remove_on_complete = true,
+                duration = duration,
+                interval = new Clutter.Interval.with_values (
+                    property.value_type,
+                    property.from_value ?? actor_current_property,
+                    property.target_value
+                )
+            };
+
+            if (i == 0) {
+                transition.stopped.connect (call_on_stopped);
+            }
+
+            actor.add_transition (property.property, transition);
+        }
+    }
+
+    private void call_on_stopped () {
+        on_stopped (actor);
+        unref ();
+    }
+}

lib/meson.build

@@ -19,6 +19,7 @@ gala_lib_sources = files(
     'Drawing/Utilities.vala',
     'Image.vala',
     'Plugin.vala',
+    'PropertyAnimator.vala',
     'RoundedCornersEffect.vala',
     'ShadowEffect.vala',
     'Text.vala',