Add onChange handler

src/ig-template/features/settings/BooleanSetting.ts

@@ -17,6 +17,6 @@ export class BooleanSetting extends Setting {
     }
 
     public toggle(): void {
-        this.value = !this.value;
+        this.set(!this.value);
     }
 }

src/ig-template/features/settings/Setting.ts

@@ -3,6 +3,7 @@ import {Requirement} from "@/ig-template/tools/requirements/Requirement";
 import {NoRequirement} from "@/ig-template/tools/requirements/NoRequirement";
 import {SettingOption} from "@/ig-template/features/settings/SettingOption";
 import {SettingsValue} from "@/ig-template/features/settings/SettingsValueType";
+import { ISimpleEvent, SimpleEventDispatcher } from "strongly-typed-events";
 
 
 export abstract class Setting {
@@ -14,6 +15,8 @@ export abstract class Setting {
 
     requirement: Requirement;
 
+    protected _onChange = new SimpleEventDispatcher<[SettingsValue, SettingsValue]>();
+
     protected constructor(id: SettingId, displayName: string, options: SettingOption[], defaultValue: SettingsValue, requirement: Requirement = new NoRequirement()) {
         this.id = id;
         this.displayName = displayName;
@@ -25,12 +28,21 @@ export abstract class Setting {
         this.requirement = requirement;
     }
 
+    /**
+     * Emitted whenever the setting is changed.
+     */
+    public get onChange(): ISimpleEvent<[SettingsValue, SettingsValue]> {
+        return this._onChange.asEvent();
+    }
+
     set(value: SettingsValue): void {
         if (!this.canAccess) {
             return;
         }
         if (this.validValue(value)) {
+            const prevValue = this.value;
             this.value = value;
+            this._onChange.dispatch([prevValue, value]);
         } else {
             console.warn(`${value} is not a valid value for setting ${this.id}. It could be that the option is not yet unlocked.`);
         }

tests/unit/ig-template/features/settings/Settings.spec.ts

@@ -18,7 +18,7 @@ describe('Settings', () => {
                 new SettingOption("Option 2", 2),
                 new SettingOption("Option 3", 3),
             ], 2)
-        )
+        );
     });
 
     test('adding same setting multiple times', () => {
@@ -62,6 +62,21 @@ describe('Settings', () => {
         }).not.toThrow()
     });
 
+    test('test change event', () => {
+        expect.assertions(4);
+
+        const setting = settings.getSetting(id);
+        setting?.onChange.subscribe(([prevValue, value]) => {
+            expect(prevValue).toBe(2);
+            expect(value).toBe(3);
+        });
+
+        settings.setSetting(id, 3);
+
+        expect(setting).toBeDefined();
+        expect(setting?.value).toBe(3);
+    });
+
     test('save empty', () => {
         // Arrange
         const expectedSaveData: SettingsSaveData = {