feat(esl-event-listener): add ability to ESLWheelTarget to ignore inc…

…ome wheel events by predicate

src/modules/esl-event-listener/core/targets/wheel.target.ts

@@ -9,6 +9,7 @@ import {ESLEventListener} from '../listener';
 import {ESLWheelEvent} from './wheel.target.event';
 
 import type {ESLWheelEventInfo} from './wheel.target.event';
+import type {Predicate} from '../../../esl-utils/misc/functions';
 import type {ESLDomElementTarget} from '../../../esl-utils/abstract/dom-target';
 import type {ElementScrollOffset} from '../../../esl-utils/dom/scroll';
 
@@ -24,6 +25,8 @@ export interface ESLWheelTargetSetting {
   distance?: number;
   /** The maximum duration of the wheel events to consider it inertial */
   timeout?: number;
+  /** Predicate to ignore wheel events */
+  ignore?: Predicate<WheelEvent>;
 }
 
 /**
@@ -33,7 +36,8 @@ export class ESLWheelTarget extends SyntheticEventTarget {
   protected static defaultConfig: Required<ESLWheelTargetSetting> = {
     skipOnScroll: true,
     distance: 400,
-    timeout: 100
+    timeout: 100,
+    ignore: () => false
   };
 
   protected readonly config: Required<ESLWheelTargetSetting>;
@@ -70,6 +74,7 @@ export class ESLWheelTarget extends SyntheticEventTarget {
   /** Handles wheel events */
   @bind
   protected _onWheel(event: WheelEvent): void {
+    if (this.config.ignore(event)) return;
     if (this.config.skipOnScroll) {
       const offsets = getParentScrollOffsets(event.target as Element, this.target);
       this.scrollData = this.scrollData.concat(offsets);

src/modules/esl-event-listener/test/targets/wheel.test.ts

@@ -59,6 +59,32 @@ describe('ESLWheelTarget', () => {
     });
   });
 
+  describe('ESLWheelTarget instance ignore predicate support', () => {
+    const $el = document.createElement('div');
+    const target = ESLWheelTarget.for($el, {
+      distance: 50,
+      timeout: 10,
+      ignore: (e) => e.deltaX === 0
+    });
+    const listener = jest.fn();
+
+    beforeAll(() => target.addEventListener('longwheel', listener));
+    afterAll(() => target.removeEventListener('longwheel', listener));
+    beforeEach(() => listener.mockReset());
+
+    test('ESLWheelTarget ignores vertical scroll when predicate filter deltaX amount', () => {
+      $el.dispatchEvent(Object.assign(new Event('wheel'), {deltaX: 0, deltaY: 100}));
+      jest.advanceTimersByTime(100);
+      expect(listener).not.toHaveBeenCalled();
+    });
+
+    test('ESLWheelTarget ignores horizontal scroll when predicate filter deltaX amount', () => {
+      $el.dispatchEvent(Object.assign(new Event('wheel'), {deltaX: 100, deltaY: 0}));
+      jest.advanceTimersByTime(100);
+      expect(listener).toHaveBeenCalled();
+    });
+  });
+
   describe('ESLWheelTarget ignores "short" scroll events', () => {
     const $el = document.createElement('div');
     const target = ESLWheelTarget.for($el, {timeout: 50, distance: 101});