| // Copyright (C) 2019 The Android Open Source Project |
| // |
| // 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 m from 'mithril'; |
| import {defer} from '../base/deferred'; |
| import {scheduleFullRedraw} from './raf'; |
| import {Icon} from './icon'; |
| |
| // This module deals with modal dialogs. Unlike most components, here we want to |
| // render the DOM elements outside of the corresponding vdom tree. For instance |
| // we might want to instantiate a modal dialog all the way down from a nested |
| // Mithril sub-component, but we want the result dom element to be nested under |
| // the root <body>. |
| |
| // Usage: |
| // Full-screen modal use cases (the most common case) |
| // -------------------------------------------------- |
| // - app.ts calls maybeRenderFullscreenModalDialog() when rendering the |
| // top-level vdom, if a modal dialog is created via showModal() |
| // - The user (any TS code anywhere) calls showModal() |
| // - showModal() takes either: |
| // - A static set of mithril vnodes (for cases when the contents of the modal |
| // dialog is static and never changes) |
| // - A function, invoked on each render pass, that returns mithril vnodes upon |
| // each invocation. |
| // - See examples in widgets_page.ts for both. |
| // |
| // Nested modal use-cases |
| // ---------------------- |
| // A modal dialog can be created in a "positioned" layer (e.g., any div that has |
| // position:relative|absolute), so it's modal but only within the scope of that |
| // layer. |
| // In this case, just ust the Modal class as a standard mithril component. |
| // showModal()/closeModal() are irrelevant in this case. |
| |
| export interface ModalAttrs { |
| title: string; |
| buttons?: ModalButton[]; |
| vAlign?: 'MIDDLE' /* default */ | 'TOP'; |
| |
| // Used to disambiguate between different modal dialogs that might overlap |
| // due to different client showing modal dialogs at the same time. This needs |
| // to match the key passed to closeModal() (if non-undefined). If the key is |
| // not provided, showModal will make up a random key in the showModal() call. |
| key?: string; |
| |
| // A callback that is called when the dialog is closed, whether by pressing |
| // any buttons or hitting ESC or clicking outside of the modal. |
| onClose?: () => void; |
| |
| // The content/body of the modal dialog. This can be either: |
| // 1. A static set of children, for simple dialogs which content never change. |
| // 2. A factory method that returns a m() vnode for dyamic content. |
| content?: m.Children | (() => m.Children); |
| } |
| |
| export interface ModalButton { |
| text: string; |
| primary?: boolean; |
| id?: string; |
| action?: () => void; |
| } |
| |
| // Usually users don't need to care about this class, as this is instantiated |
| // by showModal. The only case when users should depend on this is when they |
| // want to nest a modal dialog in a <div> they control (i.e. when the modal |
| // is scoped to a mithril component, not fullscreen). |
| export class Modal implements m.ClassComponent<ModalAttrs> { |
| onbeforeremove(vnode: m.VnodeDOM<ModalAttrs>) { |
| const removePromise = defer<void>(); |
| vnode.dom.addEventListener('animationend', () => removePromise.resolve()); |
| vnode.dom.classList.add('modal-fadeout'); |
| |
| // Retuning `removePromise` will cause Mithril to defer the actual component |
| // removal until the fade-out animation is done. onremove() will be invoked |
| // after this. |
| return removePromise; |
| } |
| |
| onremove(vnode: m.VnodeDOM<ModalAttrs>) { |
| if (vnode.attrs.onClose !== undefined) { |
| // The onClose here is the promise wrapper created by showModal(), which |
| // in turn will: (1) call the user's original attrs.onClose; (2) resolve |
| // the promise returned by showModal(). |
| vnode.attrs.onClose(); |
| scheduleFullRedraw(); |
| } |
| } |
| |
| oncreate(vnode: m.VnodeDOM<ModalAttrs>) { |
| if (vnode.dom instanceof HTMLElement) { |
| // Focus the newly created dialog, so that we react to Escape keydown |
| // even if the user has not clicked yet on any element. |
| // If there is a primary button, focus that, so Enter does the default |
| // action. If not just focus the whole dialog. |
| const primaryBtn = vnode.dom.querySelector('.modal-btn-primary'); |
| if (primaryBtn) { |
| (primaryBtn as HTMLElement).focus(); |
| } else { |
| vnode.dom.focus(); |
| } |
| // If the modal dialog is instantiated in a tall scrollable container, |
| // make sure to scroll it into the view. |
| vnode.dom.scrollIntoView({block: 'center'}); |
| } |
| } |
| |
| view(vnode: m.Vnode<ModalAttrs>) { |
| const attrs = vnode.attrs; |
| |
| const buttons: m.Children = []; |
| for (const button of attrs.buttons || []) { |
| buttons.push( |
| m( |
| 'button.modal-btn', |
| { |
| class: button.primary ? 'modal-btn-primary' : '', |
| id: button.id, |
| onclick: () => { |
| closeModal(attrs.key); |
| if (button.action !== undefined) button.action(); |
| }, |
| }, |
| button.text, |
| ), |
| ); |
| } |
| |
| const aria = '[aria-labelledby=mm-title][aria-model][role=dialog]'; |
| const align = attrs.vAlign === 'TOP' ? '.modal-dialog-valign-top' : ''; |
| return m( |
| '.modal-backdrop', |
| { |
| onclick: this.onBackdropClick.bind(this, attrs), |
| onkeyup: this.onBackdropKeyupdown.bind(this, attrs), |
| onkeydown: this.onBackdropKeyupdown.bind(this, attrs), |
| tabIndex: 0, |
| }, |
| m( |
| `.modal-dialog${align}${aria}`, |
| m( |
| 'header', |
| m('h2', {id: 'mm-title'}, attrs.title), |
| m( |
| 'button[aria-label=Close Modal]', |
| {onclick: () => closeModal(attrs.key)}, |
| m(Icon, {icon: 'close'}), |
| ), |
| ), |
| m('main', vnode.children), |
| buttons.length > 0 ? m('footer', buttons) : null, |
| ), |
| ); |
| } |
| |
| onBackdropClick(attrs: ModalAttrs, e: MouseEvent) { |
| e.stopPropagation(); |
| // Only react when clicking on the backdrop. Don't close if the user clicks |
| // on the dialog itself. |
| const t = e.target; |
| if (t instanceof Element && t.classList.contains('modal-backdrop')) { |
| closeModal(attrs.key); |
| } |
| } |
| |
| onBackdropKeyupdown(attrs: ModalAttrs, e: KeyboardEvent) { |
| e.stopPropagation(); |
| if (e.key === 'Escape' && e.type !== 'keyup') { |
| closeModal(attrs.key); |
| } |
| } |
| } |
| |
| // Set by showModal(). |
| let currentModal: ModalAttrs | undefined = undefined; |
| let generationCounter = 0; |
| |
| // This should be called only by app.ts and nothing else. |
| // This generates the modal dialog at the root of the DOM, so it can overlay |
| // on top of everything else. |
| export function maybeRenderFullscreenModalDialog() { |
| // We use the generation counter as key to distinguish between: (1) two render |
| // passes for the same dialog vs (2) rendering a new dialog that has been |
| // created invoking showModal() while another modal dialog was already being |
| // shown. |
| if (currentModal === undefined) return []; |
| let children: m.Children; |
| if (currentModal.content === undefined) { |
| children = null; |
| } else if (typeof currentModal.content === 'function') { |
| children = currentModal.content(); |
| } else { |
| children = currentModal.content; |
| } |
| return [m(Modal, currentModal, children)]; |
| } |
| |
| // Shows a full-screen modal dialog. |
| export async function showModal(userAttrs: ModalAttrs): Promise<void> { |
| const returnedClosePromise = defer<void>(); |
| const userOnClose = userAttrs.onClose ?? (() => {}); |
| |
| // If the user doesn't specify a key (to match the closeModal), generate a |
| // random key to distinguish two showModal({key:undefined}) calls. |
| const key = userAttrs.key ?? `${++generationCounter}`; |
| const attrs: ModalAttrs = { |
| ...userAttrs, |
| key, |
| onClose: () => { |
| userOnClose(); |
| returnedClosePromise.resolve(); |
| }, |
| }; |
| currentModal = attrs; |
| scheduleFullRedraw(); |
| return returnedClosePromise; |
| } |
| |
| // Technically we don't need to redraw the whole app, but it's the more |
| // pragmatic option. This is exposed to keep the plugin code more clear, so it's |
| // evident why a redraw is requested. |
| export function redrawModal() { |
| if (currentModal !== undefined) { |
| scheduleFullRedraw(); |
| } |
| } |
| |
| // Closes the full-screen modal dialog (if any). |
| // `key` is optional: if provided it will close the modal dialog only if the key |
| // matches. This is to avoid accidentally closing another dialog that popped |
| // in the meanwhile. If undefined, it closes whatever modal dialog is currently |
| // open (if any). |
| export function closeModal(key?: string) { |
| if ( |
| currentModal === undefined || |
| (key !== undefined && currentModal.key !== key) |
| ) { |
| // Somebody else closed the modal dialog already, or opened a new one with |
| // a different key. |
| return; |
| } |
| currentModal = undefined; |
| scheduleFullRedraw(); |
| } |
| |
| export function getCurrentModalKey(): string | undefined { |
| return currentModal?.key; |
| } |