ui/src/frontend/modal.ts - third_party/perfetto - Git at Google

 // 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.


 // 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>.
 //
 // This is achieved by splitting:
 // 1. ModalContainer: it's the placeholder (e.g., the thing that should be added
 //    under <body>) where the DOM elements will be rendered into. This is NOT
 //    a mithril component itself.
 // 2. Modal: is the Mithril component with the actual VDOM->DOM handling.
 //    This can be used directly in the cases where the modal DOM should be
 //    placed presicely where the corresponding Mithril VDOM is.
 //    In turn this is split into Modal and ModalImpl, to deal with fade-out, see
 //    comments around onbeforeremove.

 // Usage (in the case of DOM not matching VDOM):
 // - Create a ModalContainer instance somewhere (e.g. a singleton for the case
 //   of the full-screen modal dialog).
 // - In the view() method of the component that should host the DOM elements
 //   (e.g. in the root pages.ts) do the following:
 //   view() {
 //     return m('main',
 //        m('h2', ...)
 //        m(modalContainerInstance.mithrilComponent);
 //   }
 //
 // - In the view() method of the nested component that wants to show the modal
 //   dialog do the following:
 //   view() {
 //     if (shouldShowModalDialog) {
 //       modalContainerInstance.update({title: 'Foo', content, buttons: ...});
 //     }
 //     return m('.nested-widget',
 //       m('div', ...));
 //   }
 //
 // For one-show use-cases it's still possible to just use:
 // showModal({title: 'Foo', content, buttons: ...});

 import m from 'mithril';

 import {defer} from '../base/deferred';
 import {assertExists, assertTrue} from '../base/logging';
 import {raf} from '../core/raf_scheduler';

 export interface ModalDefinition {
   title: string;
   content: m.Children|(() => m.Children);
   vAlign?: 'MIDDLE' /* default */ | 'TOP';
   buttons?: Button[];
   close?: boolean;
   onClose?: () => void;
 }

 export interface Button {
   text: string;
   primary?: boolean;
   id?: string;
   action?: () => void;
 }

 // The component that handles the actual modal dialog. Note that this uses
 // position: absolute, so the modal dialog will be relative to the surrounding
 // DOM.
 // We need to split this into two components (Modal and ModalImpl) so that we
 // can handle the fade-out animation via onbeforeremove. The problem here is
 // that onbeforeremove is emitted only when the *parent* component removes the
 // children from the vdom hierarchy. So we need a parent/child in our control to
 // trigger this.
 export class Modal implements m.ClassComponent<ModalDefinition> {
   private requestClose = false;

   close() {
     // The next view pass will kick-off the modalFadeOut CSS animation by
     // appending the .modal-hidden CSS class.
     this.requestClose = true;
     raf.scheduleFullRedraw();
   }

   view(vnode: m.Vnode<ModalDefinition>) {
     if (this.requestClose || vnode.attrs.close) {
       return null;
     }

     return m(ModalImpl, {...vnode.attrs, parent: this} as ModalImplAttrs);
   }
 }

 interface ModalImplAttrs extends ModalDefinition {
   parent: Modal;
 }

 // The component that handles the actual modal dialog. Note that this uses
 // position: absolute, so the modal dialog will be relative to the surrounding
 // DOM.
 class ModalImpl implements m.ClassComponent<ModalImplAttrs> {
   private parent ?: Modal;
   private onClose?: () => void;

   view({attrs}: m.Vnode<ModalImplAttrs>) {
     this.onClose = attrs.onClose;
     this.parent = attrs.parent;

     const buttons: Array<m.Vnode<Button>> = [];
     for (const button of attrs.buttons || []) {
       buttons.push(m('button.modal-btn', {
         class: button.primary ? 'modal-btn-primary' : '',
         id: button.id,
         onclick: () => {
           attrs.parent.close();
           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.onclick.bind(this),
           onkeyup: this.onkeyupdown.bind(this),
           onkeydown: this.onkeyupdown.bind(this),
           // onanimationend: this.onanimationend.bind(this),
           tabIndex: 0,
         },
         m(
             `.modal-dialog${align}${aria}`,
             m(
                 'header',
                 m('h2', {id: 'mm-title'}, attrs.title),
                 m(
                     'button[aria-label=Close Modal]',
                     {onclick: () => attrs.parent.close()},
                     m.trust('&#x2715'),
                     ),
                 ),
             m('main', this.renderContent(attrs.content)),
             m('footer', buttons),
             ));
   }

   private renderContent(content: m.Children|(() => m.Children)): m.Children {
     if (typeof content === 'function') {
       return content();
     } else {
       return content;
     }
   }

   oncreate(vnode: m.VnodeDOM<ModalImplAttrs>) {
     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'});
     }
   }


   onbeforeremove(vnode: m.VnodeDOM<ModalImplAttrs>) {
     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.
     return removePromise;
   }

   onremove() {
     if (this.onClose !== undefined) {
       this.onClose();
       raf.scheduleFullRedraw();
     }
   }

   onclick(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')) {
       assertExists(this.parent).close();
     }
   }

   onkeyupdown(e: KeyboardEvent) {
     e.stopPropagation();
     if (e.key === 'Escape' && e.type !== 'keyup') {
       assertExists(this.parent).close();
     }
   }
 }


 // This is deliberately NOT a Mithril component. We want to manage the lifetime
 // independently (outside of Mithril), so we can render from outside the current
 // vdom sub-tree. ModalContainer instances should be singletons / globals.
 export class ModalContainer {
   private attrs?: ModalDefinition;
   private generation = 1; // Start with a generation > `closeGeneration`.
   private closeGeneration = 0;

   // This is the mithril component that is exposed to the embedder (e.g. see
   // pages.ts). The caller is supposed to hyperscript this while building the
   // vdom tree that should host the modal dialog.
   readonly mithrilComponent = {
     container: this,
     view:
         function() {
           const thiz = this.container;
           const attrs = thiz.attrs;
           if (attrs === undefined) {
             return null;
           }
           return [m(Modal, {
             ...attrs,
             onClose: () => {
               // Remember the fact that the dialog was dismissed, in case the
               // whole ModalContainer gets instantiated from a different page
               // (which would cause the Modal to be destroyed and recreated).
               thiz.closeGeneration = thiz.generation;
               if (thiz.attrs?.onClose !== undefined) {
                 thiz.attrs.onClose();
                 raf.scheduleFullRedraw();
               }
             },
             close: thiz.closeGeneration === thiz.generation ? true :
                                                               attrs.close,
             key: thiz.generation,
           })];
         },
   };

   // This should be called to show a new modal dialog. The modal dialog will
   // be shown the next time something calls render() in a Mithril draw pass.
   // This enforces the creation of a new dialog.
   createNew(attrs: ModalDefinition) {
     this.generation++;
     this.updateVdom(attrs);
   }

   // Updates the current dialog or creates a new one if not existing. If a
   // dialog exists already, this will update the DOM of the existing dialog.
   // This should be called in at view() time by a nested Mithril component which
   // wants to display a modal dialog (but wants it to render outside).
   updateVdom(attrs: ModalDefinition) {
     this.attrs = attrs;
   }

   close() {
     this.closeGeneration = this.generation;
     raf.scheduleFullRedraw();
   }
 }

 // This is the default instance used for full-screen modal dialogs.
 // page.ts calls `m(fullscreenModalContainer.mithrilComponent)` in its view().
 export const fullscreenModalContainer = new ModalContainer();


 export async function showModal(attrs: ModalDefinition): Promise<void> {
   // When using showModal, the caller cannot pass an onClose promise. It should
   // use the returned promised instead. onClose is only for clients using the
   // Mithril component directly.
   assertTrue(attrs.onClose === undefined);
   const promise = defer<void>();
   fullscreenModalContainer.createNew({
     ...attrs,
     onClose: () => promise.resolve(),
   });
   raf.scheduleFullRedraw();
   return promise;
 }
	// 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.


	// 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>.
	//
	// This is achieved by splitting:
	// 1. ModalContainer: it's the placeholder (e.g., the thing that should be added
	// under <body>) where the DOM elements will be rendered into. This is NOT
	// a mithril component itself.
	// 2. Modal: is the Mithril component with the actual VDOM->DOM handling.
	// This can be used directly in the cases where the modal DOM should be
	// placed presicely where the corresponding Mithril VDOM is.
	// In turn this is split into Modal and ModalImpl, to deal with fade-out, see
	// comments around onbeforeremove.

	// Usage (in the case of DOM not matching VDOM):
	// - Create a ModalContainer instance somewhere (e.g. a singleton for the case
	// of the full-screen modal dialog).
	// - In the view() method of the component that should host the DOM elements
	// (e.g. in the root pages.ts) do the following:
	// view() {
	// return m('main',
	// m('h2', ...)
	// m(modalContainerInstance.mithrilComponent);
	// }
	//
	// - In the view() method of the nested component that wants to show the modal
	// dialog do the following:
	// view() {
	// if (shouldShowModalDialog) {
	// modalContainerInstance.update({title: 'Foo', content, buttons: ...});
	// }
	// return m('.nested-widget',
	// m('div', ...));
	// }
	//
	// For one-show use-cases it's still possible to just use:
	// showModal({title: 'Foo', content, buttons: ...});

	import m from 'mithril';

	import {defer} from '../base/deferred';
	import {assertExists, assertTrue} from '../base/logging';
	import {raf} from '../core/raf_scheduler';

	export interface ModalDefinition {
	title: string;
	content: m.Children\|(() => m.Children);
	vAlign?: 'MIDDLE' /* default */ \| 'TOP';
	buttons?: Button[];
	close?: boolean;
	onClose?: () => void;
	}

	export interface Button {
	text: string;
	primary?: boolean;
	id?: string;
	action?: () => void;
	}

	// The component that handles the actual modal dialog. Note that this uses
	// position: absolute, so the modal dialog will be relative to the surrounding
	// DOM.
	// We need to split this into two components (Modal and ModalImpl) so that we
	// can handle the fade-out animation via onbeforeremove. The problem here is
	// that onbeforeremove is emitted only when the parent component removes the
	// children from the vdom hierarchy. So we need a parent/child in our control to
	// trigger this.
	export class Modal implements m.ClassComponent<ModalDefinition> {
	private requestClose = false;

	close() {
	// The next view pass will kick-off the modalFadeOut CSS animation by
	// appending the .modal-hidden CSS class.
	this.requestClose = true;
	raf.scheduleFullRedraw();
	}

	view(vnode: m.Vnode<ModalDefinition>) {
	if (this.requestClose \|\| vnode.attrs.close) {
	return null;
	}

	return m(ModalImpl, {...vnode.attrs, parent: this} as ModalImplAttrs);
	}
	}

	interface ModalImplAttrs extends ModalDefinition {
	parent: Modal;
	}

	// The component that handles the actual modal dialog. Note that this uses
	// position: absolute, so the modal dialog will be relative to the surrounding
	// DOM.
	class ModalImpl implements m.ClassComponent<ModalImplAttrs> {
	private parent ?: Modal;
	private onClose?: () => void;

	view({attrs}: m.Vnode<ModalImplAttrs>) {
	this.onClose = attrs.onClose;
	this.parent = attrs.parent;

	const buttons: Array<m.Vnode<Button>> = [];
	for (const button of attrs.buttons \|\| []) {
	buttons.push(m('button.modal-btn', {
	class: button.primary ? 'modal-btn-primary' : '',
	id: button.id,
	onclick: () => {
	attrs.parent.close();
	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.onclick.bind(this),
	onkeyup: this.onkeyupdown.bind(this),
	onkeydown: this.onkeyupdown.bind(this),
	// onanimationend: this.onanimationend.bind(this),
	tabIndex: 0,
	},
	m(
	`.modal-dialog${align}${aria}`,
	m(
	'header',
	m('h2', {id: 'mm-title'}, attrs.title),
	m(
	'button[aria-label=Close Modal]',
	{onclick: () => attrs.parent.close()},
	m.trust('&#x2715'),
	),
	),
	m('main', this.renderContent(attrs.content)),
	m('footer', buttons),
	));
	}

	private renderContent(content: m.Children\|(() => m.Children)): m.Children {
	if (typeof content === 'function') {
	return content();
	} else {
	return content;
	}
	}

	oncreate(vnode: m.VnodeDOM<ModalImplAttrs>) {
	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'});
	}
	}


	onbeforeremove(vnode: m.VnodeDOM<ModalImplAttrs>) {
	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.
	return removePromise;
	}

	onremove() {
	if (this.onClose !== undefined) {
	this.onClose();
	raf.scheduleFullRedraw();
	}
	}

	onclick(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')) {
	assertExists(this.parent).close();
	}
	}

	onkeyupdown(e: KeyboardEvent) {
	e.stopPropagation();
	if (e.key === 'Escape' && e.type !== 'keyup') {
	assertExists(this.parent).close();
	}
	}
	}


	// This is deliberately NOT a Mithril component. We want to manage the lifetime
	// independently (outside of Mithril), so we can render from outside the current
	// vdom sub-tree. ModalContainer instances should be singletons / globals.
	export class ModalContainer {
	private attrs?: ModalDefinition;
	private generation = 1; // Start with a generation > `closeGeneration`.
	private closeGeneration = 0;

	// This is the mithril component that is exposed to the embedder (e.g. see
	// pages.ts). The caller is supposed to hyperscript this while building the
	// vdom tree that should host the modal dialog.
	readonly mithrilComponent = {
	container: this,
	view:
	function() {
	const thiz = this.container;
	const attrs = thiz.attrs;
	if (attrs === undefined) {
	return null;
	}
	return [m(Modal, {
	...attrs,
	onClose: () => {
	// Remember the fact that the dialog was dismissed, in case the
	// whole ModalContainer gets instantiated from a different page
	// (which would cause the Modal to be destroyed and recreated).
	thiz.closeGeneration = thiz.generation;
	if (thiz.attrs?.onClose !== undefined) {
	thiz.attrs.onClose();
	raf.scheduleFullRedraw();
	}
	},
	close: thiz.closeGeneration === thiz.generation ? true :
	attrs.close,
	key: thiz.generation,
	})];
	},
	};

	// This should be called to show a new modal dialog. The modal dialog will
	// be shown the next time something calls render() in a Mithril draw pass.
	// This enforces the creation of a new dialog.
	createNew(attrs: ModalDefinition) {
	this.generation++;
	this.updateVdom(attrs);
	}

	// Updates the current dialog or creates a new one if not existing. If a
	// dialog exists already, this will update the DOM of the existing dialog.
	// This should be called in at view() time by a nested Mithril component which
	// wants to display a modal dialog (but wants it to render outside).
	updateVdom(attrs: ModalDefinition) {
	this.attrs = attrs;
	}

	close() {
	this.closeGeneration = this.generation;
	raf.scheduleFullRedraw();
	}
	}

	// This is the default instance used for full-screen modal dialogs.
	// page.ts calls `m(fullscreenModalContainer.mithrilComponent)` in its view().
	export const fullscreenModalContainer = new ModalContainer();


	export async function showModal(attrs: ModalDefinition): Promise<void> {
	// When using showModal, the caller cannot pass an onClose promise. It should
	// use the returned promised instead. onClose is only for clients using the
	// Mithril component directly.
	assertTrue(attrs.onClose === undefined);
	const promise = defer<void>();
	fullscreenModalContainer.createNew({
	...attrs,
	onClose: () => promise.resolve(),
	});
	raf.scheduleFullRedraw();
	return promise;
	}