Add base gnome extensions

gnome/.local/share/extensions/blur-my-shell@aunetx/conveniences/effects_manager.js

@@ -0,0 +1,89 @@
+import { ColorEffect } from '../effects/color_effect.js';
+import { NoiseEffect } from '../effects/noise_effect.js';
+
+
+/// An object to manage effects (by not destroying them all the time)
+export const EffectsManager = class EffectsManager {
+    constructor(connections) {
+        this.connections = connections;
+        this.used = [];
+        this.color_effects = [];
+        this.noise_effects = [];
+    }
+
+    connect_to_destroy(effect) {
+        effect.old_actor = effect.get_actor();
+        if (effect.old_actor)
+            effect.old_actor_id = effect.old_actor.connect('destroy', _ => {
+                this.remove(effect);
+            });
+
+        this.connections.connect(effect, 'notify::actor', _ => {
+            let actor = effect.get_actor();
+
+            if (effect.old_actor && actor != effect.old_actor)
+                effect.old_actor.disconnect(effect.old_actor_id);
+
+            if (actor) {
+                effect.old_actor_id = actor.connect('destroy', _ => {
+                    this.remove(effect);
+                });
+            }
+        });
+    }
+
+    new_color_effect(params, settings) {
+        let effect;
+        if (this.color_effects.length > 0) {
+            effect = this.color_effects.splice(0, 1)[0];
+            effect.set(params);
+        } else
+            effect = new ColorEffect(params, settings);
+
+        this.used.push(effect);
+        this.connect_to_destroy(effect);
+        return effect;
+    }
+
+    new_noise_effect(params, settings) {
+        let effect;
+        if (this.noise_effects.length > 0) {
+            effect = this.noise_effects.splice(0, 1)[0];
+            effect.set(params);
+        } else
+            effect = new NoiseEffect(params, settings);
+
+        this.used.push(effect);
+        this.connect_to_destroy(effect);
+        return effect;
+    }
+
+    remove(effect) {
+        effect.get_actor()?.remove_effect(effect);
+        if (effect.old_actor)
+            effect.old_actor.disconnect(effect.old_actor_id);
+        delete effect.old_actor;
+        delete effect.old_actor_id;
+
+        let index = this.used.indexOf(effect);
+        if (index >= 0) {
+            this.used.splice(index, 1);
+
+            if (effect instanceof ColorEffect)
+                this.color_effects.push(effect);
+            else if (effect instanceof NoiseEffect)
+                this.noise_effects.push(effect);
+        }
+    }
+
+    destroy_all() {
+        this.used.forEach(effect => { this.remove(effect); });
+        [
+            this.used,
+            this.color_effects,
+            this.noise_effects
+        ].forEach(array => {
+            array.splice(0, array.length);
+        });
+    }
+};