// (C) Copyright 2015 Moodle Pty Ltd. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. import { AfterViewInit, Directive, ElementRef, Input, OnDestroy } from '@angular/core'; import { CoreSwipeNavigationItemsManager } from '@classes/items-management/swipe-navigation-items-manager'; import { Gesture } from '@ionic/angular'; import { CoreScreen } from '@services/screen'; import { GestureController } from '@singletons'; const ACTIVATION_THRESHOLD = 150; const SWIPE_FRICTION = 0.6; /** * Directive to enable content navigation with swipe. * * Example usage: * * */ @Directive({ selector: 'ion-content[core-swipe-navigation]', }) export class CoreSwipeNavigationDirective implements AfterViewInit, OnDestroy { // eslint-disable-next-line @angular-eslint/no-input-rename @Input('core-swipe-navigation') manager?: CoreSwipeNavigationItemsManager; protected element: HTMLElement; protected swipeGesture?: Gesture; constructor(el: ElementRef) { this.element = el.nativeElement; } get enabled(): boolean { return CoreScreen.isMobile && !!this.manager; } /** * @inheritdoc */ ngAfterViewInit(): void { const style = this.element.style; this.swipeGesture = GestureController.create({ el: this.element, gestureName: 'swipe', threshold: 10, gesturePriority: 10, canStart: () => this.enabled, onStart: () => { style.transition = ''; }, onMove: (ev) => { style.transform = `translateX(${ev.deltaX * SWIPE_FRICTION }px)`; }, onEnd: (ev) => { style.transition = '.5s ease-out'; if (ev.deltaX > ACTIVATION_THRESHOLD) { this.manager?.hasNextItem().then((hasNext) => { if (hasNext) { this.preventClickOnElement(); style.transform = 'translateX(100%) !important'; this.swipeRight(); } else { style.transform = ''; } return; }); return; } if (ev.deltaX < -ACTIVATION_THRESHOLD) { this.manager?.hasPreviousItem().then((hasPrevious) => { if (hasPrevious) { this.preventClickOnElement(); style.transform = 'translateX(-100%) !important'; this.swipeLeft(); } else { style.transform = ''; } return; }); return; } style.transform = ''; }, }); this.swipeGesture.enable(); } /** * Swipe to previous item. */ swipeLeft(): void { if (!this.enabled) { return; } this.manager?.navigateToPreviousItem(); } /** * Swipe to next item. */ swipeRight(): void { if (!this.enabled) { return; } this.manager?.navigateToNextItem(); } /** * Prevent click event by capturing the click before happening. */ protected preventClickOnElement(): void { this.element.addEventListener( 'click', (ev: Event) => { ev.preventDefault(); ev.stopPropagation(); return false; }, true, // Register event on the capture phase. ); } /** * @inheritdoc */ ngOnDestroy(): void { this.swipeGesture?.destroy(); } }