OverlayStack.ts

/*
Copyright 2023 Adobe. All rights reserved.
This file is licensed to you 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 REPRESENTATIONS
OF ANY KIND, either express or implied. See the License for the specific language
governing permissions and limitations under the License.
*/

import { Overlay } from './Overlay.js';

const supportsPopover = 'showPopover' in document.createElement('div');

class OverlayStack {
    private get document(): Document {
        return this.root.ownerDocument /* c8 ignore next */ || document;
    }

    private pointerdownPath?: EventTarget[];

    private lastOverlay?: Overlay;

    private root: HTMLElement = document.body;

    stack: Overlay[] = [];

    constructor() {
        this.bindEvents();
    }

    bindEvents(): void {
        this.document.addEventListener('pointerdown', this.handlePointerdown);
        this.document.addEventListener('pointerup', this.handlePointerup);
        this.document.addEventListener('keydown', this.handleKeydown);
    }

    private closeOverlay(overlay: Overlay): void {
        const overlayIndex = this.stack.indexOf(overlay);
        if (overlayIndex > -1) {
            this.stack.splice(overlayIndex, 1);
        }
        overlay.open = false;
    }

    /**
     * Cach the `pointerdownTarget` for later testing
     *
     * @param event {ClickEvent}
     */
    handlePointerdown = (event: Event): void => {
        this.pointerdownPath = event.composedPath();
        this.lastOverlay = this.stack[this.stack.length - 1];
    };

    /**
     * Close all overlays that are not ancestors of this click event
     *
     * @param event {ClickEvent}
     */
    handlePointerup = (): void => {
        // Test against the composed path in `pointerdown` in case the visitor moved their
        // pointer during the course of the interaction.
        // Ensure that this value is cleared even if the work in this method goes undone.
        const composedPath = this.pointerdownPath;
        this.pointerdownPath = undefined;
        if (!this.stack.length) return;
        if (!composedPath?.length) return;
        const lastOverlay = this.lastOverlay;
        this.lastOverlay = undefined;

        const lastIndex = this.stack.length - 1;
        const nonAncestorOverlays = this.stack.filter((overlay, i) => {
            const inStack = composedPath.find(
                (el) =>
                    // The Overlay is in the stack
                    el === overlay ||
                    // The Overlay trigger is in the stack and the Overlay is a "hint"
                    (el === overlay?.triggerElement &&
                        'hint' === overlay?.type) ||
                    // The last Overlay in the stack is not the last Overlay at `pointerdown` time and has a
                    // `triggerInteraction` of "longpress", meaning it was opened by this poitner interaction
                    (i === lastIndex &&
                        overlay !== lastOverlay &&
                        overlay.triggerInteraction === 'longpress')
            );
            return (
                !inStack &&
                !overlay.shouldPreventClose() &&
                overlay.type !== 'manual' &&
                // Don't close if this overlay is modal and not on top of the overlay stack.
                !(overlay.type === 'modal' && lastOverlay !== overlay)
            );
        }) as Overlay[];
        nonAncestorOverlays.reverse();
        nonAncestorOverlays.forEach((overlay) => {
            this.closeOverlay(overlay);
            let parentToClose = overlay.parentOverlayToForceClose;
            while (parentToClose) {
                this.closeOverlay(parentToClose);
                parentToClose = parentToClose.parentOverlayToForceClose;
            }
        });
    };

    handleBeforetoggle = (event: Event): void => {
        const { target, newState: open } = event as Event & {
            newState: string;
        };
        if (open === 'open') return;
        this.closeOverlay(target as Overlay);
    };

    private handleKeydown = (event: KeyboardEvent): void => {
        if (event.code !== 'Escape') return;
        if (!this.stack.length) return;
        const last = this.stack[this.stack.length - 1];
        if (last?.type === 'page') {
            event.preventDefault();
            return;
        }
        if (supportsPopover) return;
        if (last?.type === 'manual') {
            // Manual Overlays should not close on "light dismiss".
            return;
        }

        if (!last) return;
        this.closeOverlay(last);
    };

    /**
     * Get an array of Overlays that all share the same trigger element.
     *
     * @param triggerElement {HTMLELement}
     * @returns {Overlay[]}
     */
    overlaysByTriggerElement(triggerElement: HTMLElement): Overlay[] {
        return this.stack.filter(
            (overlay) => overlay.triggerElement === triggerElement
        );
    }

    /**
     * When overlays are added manage the open state of exisiting overlays appropriately:
     * - 'modal': should close other non-'modal' and non-'manual' overlays
     * - 'page': should close other non-'modal' and non-'manual' overlays
     * - 'auto': should close other 'auto' overlays and other 'hint' overlays, but not 'manual' overlays
     * - 'manual': shouldn't close other overlays
     * - 'hint': shouldn't close other overlays and give way to all other overlays on a trigger
     */
    add(overlay: Overlay): void {
        if (this.stack.includes(overlay)) {
            const overlayIndex = this.stack.indexOf(overlay);
            if (overlayIndex > -1) {
                this.stack.splice(overlayIndex, 1);
                this.stack.push(overlay);
            }
            return;
        }
        if (
            overlay.type === 'auto' ||
            overlay.type === 'modal' ||
            overlay.type === 'page'
        ) {
            // manage closing open overlays
            const queryPathEventName = 'sp-overlay-query-path';
            const queryPathEvent = new Event(queryPathEventName, {
                composed: true,
                bubbles: true,
            });
            overlay.addEventListener(
                queryPathEventName,
                (event: Event) => {
                    const path = event.composedPath();
                    this.stack.forEach((overlayEl) => {
                        const inPath = path.find((el) => el === overlayEl);
                        if (
                            !inPath &&
                            overlayEl.type !== 'manual' &&
                            overlayEl.type !== 'modal'
                        ) {
                            this.closeOverlay(overlayEl);
                        }
                    });
                },
                { once: true }
            );
            overlay.dispatchEvent(queryPathEvent);
        } else if (overlay.type === 'hint') {
            const hasPrevious = this.stack.some((overlayEl) => {
                return (
                    overlayEl.type !== 'manual' &&
                    overlayEl.triggerElement &&
                    overlayEl.triggerElement === overlay.triggerElement
                );
            });
            if (hasPrevious) {
                overlay.open = false;
                return;
            }
            this.stack.forEach((overlayEl) => {
                if (overlayEl.type === 'hint') {
                    this.closeOverlay(overlayEl);
                }
            });
        }
        requestAnimationFrame(() => {
            this.stack.push(overlay);
            overlay.addEventListener('beforetoggle', this.handleBeforetoggle, {
                once: true,
            });
        });
    }

    remove(overlay: Overlay): void {
        this.closeOverlay(overlay);
    }
}

export const overlayStack = new OverlayStack();