92 |
93 |
94 |
108 |
109 |
110 |
111 |
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/test/shadow.js:
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1 | /**
2 | * @license
3 | * Copyright 2016 Google Inc. All rights reserved.
4 | *
5 | * Licensed under the Apache License, Version 2.0 (the "License");
6 | * you may not use this file except in compliance with the License.
7 | * You may obtain a copy of the License at
8 | *
9 | * http://www.apache.org/licenses/LICENSE-2.0
10 | *
11 | * Unless required by applicable law or agreed to in writing, software
12 | * distributed under the License is distributed on an "AS IS" BASIS,
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 | * See the License for the specific language governing permissions and
15 | * limitations under the License.
16 | */
17 | (function() {
18 | var assert = chai.assert;
19 | var fixtureLoader = new Fixture();
20 | /* eslint-disable require-jsdoc */
21 |
22 | function emptyBlockingElements() {
23 | while (document.$blockingElements.pop()) {
24 | // keep popping!
25 | }
26 | }
27 |
28 | describe('ShadowDom v1', function() {
29 | if (!Element.prototype.attachShadow) {
30 | console.log('ShadowDOM v1 is not supported by the browser.');
31 | return;
32 | }
33 |
34 | var container;
35 |
36 | beforeEach(function(done) {
37 | container = fixtureLoader.load(`
38 |
39 |
40 |
41 |
42 |
`);
43 | var template = document.createElement('template');
44 | template.innerHTML = ``;
45 | container.attachShadow({
46 | mode: 'open',
47 | }).appendChild(template.content);
48 | // Needed by ShadowDOM polyfill.
49 | setTimeout(function() {
50 | done();
51 | });
52 | });
53 |
54 | afterEach(function() {
55 | emptyBlockingElements();
56 | fixtureLoader.destroy();
57 | });
58 |
59 | it('update elements in shadow dom', function() {
60 | var shadowBtn = container.shadowRoot.querySelector('button');
61 |
62 | // Distributed element as a blocking element.
63 | document.$blockingElements.push(container.children[0]);
64 | assert.equal(document.$blockingElements.top, container.children[0]);
65 | assert.isTrue(shadowBtn.inert, 'button in shadow dom inert');
66 | assert.isNotOk(container.children[0].inert, '1st child active');
67 | assert.isTrue(container.children[1].inert, '2nd child inert');
68 | assert.isTrue(container.children[2].inert, '3rd child inert');
69 |
70 | // Button in shadow dom as a blocking element, its siblings should be inert
71 | document.$blockingElements.push(shadowBtn);
72 | assert.isTrue(document.$blockingElements.has(container.children[0]),
73 | '1st child is a blocking element');
74 | assert.equal(document.$blockingElements.top, shadowBtn);
75 | assert.isNotOk(shadowBtn.inert, 'button in shadow dom active');
76 | assert.isTrue(shadowBtn.nextElementSibling.inert, 'button sibling (slot) inert');
77 | assert.isNotOk(container.children[0].inert, '1st child inert restored');
78 | assert.isNotOk(container.children[1].inert, '2nd child inert restored');
79 | assert.isNotOk(container.children[2].inert, '3rd child inert restored');
80 | });
81 |
82 | it('push() adds only elements contained in document', function() {
83 | assert.equal(document.$blockingElements.top, null);
84 | // We remove the container, then we try to add one of its shadowRoot children.
85 | container.parentNode.removeChild(container);
86 | assert.throws(function() {
87 | document.$blockingElements.push(container.shadowRoot.firstElementChild);
88 | }, 'Non-connected element cannot be a blocking element');
89 | assert.equal(document.$blockingElements.top, null, 'element is not a blocking element');
90 | });
91 |
92 | it('mutation to shadow root should inert siblings', function(done) {
93 | // Make the first shadow root child blocking.
94 | var shadowA = container.shadowRoot.querySelector('button');
95 | document.$blockingElements.push(shadowA);
96 | // Add a new shadow child (a sibling of the first one).
97 | var shadowB = document.createElement('input');
98 | container.shadowRoot.appendChild(shadowB);
99 | // Mutation observer should notice the new child and inert it.
100 | setTimeout(function() {
101 | assert.isTrue(shadowB.inert, 'new shadow child inert');
102 | done();
103 | });
104 | });
105 | });
106 | })();
107 |
--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | [](https://travis-ci.org/PolymerLabs/blocking-elements)
2 | [](https://www.npmjs.com/package/blocking-elements)
3 |
4 | # Blocking Elements stack API
5 |
6 | Implementation of proposal https://github.com/whatwg/html/issues/897
7 |
8 | > The polyfill chooses a non-colliding name (`document.$blockingElements` instead of `document.blockingElements`) as the proposal is still work in progress and hasn't yet reached consensus on the semantics and functionality (see [this discussion](https://github.com/PolymerLabs/blocking-elements/pull/1#issuecomment-235102344) for more details).
9 |
10 | `document.$blockingElements` manages a stack of elements that inert the interaction outside them.
11 |
12 | - the stack can be updated with the methods `push(elem), remove(elem), pop()`
13 | - the top element (`document.$blockingElements.top`) and its subtree is the interactive part of the document
14 | - `has(elem)` returns if the element is a blocking element
15 |
16 | This polyfill will:
17 |
18 | - search for the path of the element to block up to `document.body`
19 | - set `inert` to all the siblings of each parent, skipping the parents and the element's distributed content (if any)
20 |
21 | Use this polyfill together with the [wicg-inert](https://github.com/WICG/inert) polyfill to disable interactions on the rest of the document. See the [demo page](https://github.com/PolymerLabs/blocking-elements/blob/master/demo/index.html) as an example.
22 |
23 | ## Why not listening to events that trigger focus change?
24 |
25 | Another approach could be to listen for events that trigger focus change (e.g. `focus, blur, keydown`) and prevent those if focus moves out of the blocking element.
26 |
27 | Wrapping the focus requires to find all the focusable nodes within the top blocking element, eventually sort by tabindex, in order to find first and last focusable node.
28 |
29 | This approach doesn't allow the focus to move outside the window (e.g. to the browser's url bar, dev console if opened, etc.), and is less robust when used with assistive technology (e.g. android talkback allows to move focus with swipe on screen, Apple Voiceover allows to move focus with special keyboard combinations).
30 |
31 | ## Install & use
32 |
33 | Blocking Elements relies on the [`inert` attribute](https://github.com/WICG/inert) and uses [`Set` objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set), so make sure to include their polyfills as needed.
34 |
35 | ```bash
36 | npm install --save babel-polyfill
37 | npm install --save wicg-inert
38 | npm install --save blocking-elements
39 | ```
40 |
41 | ```html
42 |
43 |
44 |
45 |
46 |
47 |
48 |
49 |
50 |
51 |
52 |
53 |
61 | ```
62 |
63 | ## Files
64 |
65 | Two scripts are included:
66 |
67 | 1. `/dist/blocking-elements.min.js`: minified and transpiled to ES5.
68 |
69 | 2. `/dist/blocking-elements.js`: un-minified ES2017.
70 |
71 | If your toolchain supports Node-style module resolution (e.g. TypeScript's `--moduleResolution=node`), then the main `blocking-elements` bare module specifier resolves to this file. TypeScript declarations are also included for this module:
72 |
73 | ```ts
74 | import {DocumentWithBlockingElements} from 'blocking-elements';
75 |
76 | const blockingElements =
77 | (document as DocumentWithBlockingElements).$blockingElements;
78 |
79 | blockingElements.push(...);
80 | blockingElements.remove(...);
81 | ```
82 |
83 |
84 | ## Local development
85 |
86 | Install the dependencies with `npm install` and serve the resources.
87 |
88 | Run the tests locally by navigating to http://localhost:8080/test/
89 |
90 | ## Performance
91 |
92 | Performance is dependent on the `inert` polyfill performance. Chrome recently landed [the `inert` attribute implementation](https://codereview.chromium.org/2088453002/) behind a flag.
93 |
94 | Let's compare the how long it takes to toggle the deepest `x-trap-focus` inside nested `x-b` of the demo page ()
95 |
96 | .
97 |
98 | `document.$blockingElements` with native inert is **~15x faster** than polyfilled inert 🎉 🎉 🎉
99 |
100 | | with polyfilled inert (M58) | with native inert (M60) |
101 | |----------|--------|
102 | |  |  |
103 | |  |  |
104 | |  |  |
105 | |  |  |
106 |
--------------------------------------------------------------------------------
/test/basic.js:
--------------------------------------------------------------------------------
1 | /**
2 | * @license
3 | * Copyright 2016 Google Inc. All rights reserved.
4 | *
5 | * Licensed under the Apache License, Version 2.0 (the "License");
6 | * you may not use this file except in compliance with the License.
7 | * You may obtain a copy of the License at
8 | *
9 | * http://www.apache.org/licenses/LICENSE-2.0
10 | *
11 | * Unless required by applicable law or agreed to in writing, software
12 | * distributed under the License is distributed on an "AS IS" BASIS,
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 | * See the License for the specific language governing permissions and
15 | * limitations under the License.
16 | */
17 | (function() {
18 | var assert = chai.assert;
19 | var fixtureLoader = new Fixture();
20 | /* eslint-disable require-jsdoc */
21 |
22 | function emptyBlockingElements() {
23 | while (document.$blockingElements.pop()) {
24 | // keep popping!
25 | }
26 | }
27 |
28 | describe('basic', function() {
29 | var container;
30 |
31 | beforeEach(function() {
32 | assert.equal(document.$blockingElements.top, null);
33 | container = fixtureLoader.load(`
34 |
35 |
36 |
37 |
38 |
`);
39 | });
40 |
41 | afterEach(function() {
42 | emptyBlockingElements();
43 | fixtureLoader.destroy();
44 | });
45 |
46 | it('document.$blockingElements is defined', function() {
47 | assert.isOk(document.$blockingElements);
48 | });
49 |
50 | it('push() adds an element to the stack, remove() removes it', function() {
51 | var child = container.children[0];
52 | document.$blockingElements.push(child);
53 | assert.equal(document.$blockingElements.top, child);
54 |
55 | document.$blockingElements.remove(child);
56 | assert.equal(document.$blockingElements.top, null);
57 | });
58 |
59 | it('push() can be used to make an already blocking element the top blocking element',
60 | function() {
61 | document.$blockingElements.push(container.children[0]);
62 | assert.equal(document.$blockingElements.top, container.children[0],
63 | 'child0 is top blocking element');
64 | // Add another element.
65 | document.$blockingElements.push(container.children[1]);
66 | assert.equal(document.$blockingElements.top, container.children[1],
67 | 'child1 is top blocking element');
68 | // Push again first element.
69 | document.$blockingElements.push(container.children[0]);
70 | assert.equal(document.$blockingElements.top, container.children[0],
71 | 'child0 brought to top');
72 | });
73 |
74 | it('push() adds only elements contained in document', function() {
75 | assert.throws(function() {
76 | document.$blockingElements.push(document.createElement('div'));
77 | }, 'Non-connected element cannot be a blocking element');
78 | assert.equal(document.$blockingElements.top, null, 'element is not a blocking element');
79 | });
80 |
81 | it('pop() removes the top blocking element from stack and returns it', function() {
82 | document.$blockingElements.push(container.children[0]);
83 | document.$blockingElements.push(container.children[1]);
84 | assert.isTrue(document.$blockingElements.has(container.children[0]),
85 | '1st child is a blocking element');
86 | assert.equal(document.$blockingElements.top, container.children[1],
87 | '2nd child is top blocking element');
88 | assert.equal(document.$blockingElements.pop(), container.children[1],
89 | '2nd child removed');
90 | assert.equal(document.$blockingElements.top, container.children[0],
91 | '1sd child is top blocking element');
92 | });
93 |
94 | it('preserve already inert elements', function() {
95 | var child = container.children[0];
96 | // Make children[1] inert
97 | container.children[1].inert = true;
98 | // Push and remove children[0], see if inert is preserved.
99 | document.$blockingElements.push(child);
100 | assert.equal(document.$blockingElements.top, child);
101 | document.$blockingElements.remove(child);
102 | assert.equal(document.$blockingElements.top, null);
103 | assert.isTrue(container.children[1].inert, 'inert preserved');
104 | });
105 |
106 | it('multiple push() update elements inertness', function() {
107 | document.$blockingElements.push(container.children[0]);
108 | assert.equal(document.$blockingElements.top, container.children[0]);
109 | assert.isNotOk(container.children[0].inert, '1st child active');
110 | assert.isTrue(container.children[1].inert, '2nd child inert');
111 | assert.isTrue(container.children[2].inert, '3rd child inert');
112 |
113 | document.$blockingElements.push(container.children[1]);
114 | assert.isTrue(document.$blockingElements.has(container.children[0]),
115 | '1st child is a blocking element');
116 | assert.equal(document.$blockingElements.top, container.children[1],
117 | '2nd child is top blocking element');
118 | assert.isTrue(container.children[0].inert, '1st child inert');
119 | assert.isNotOk(container.children[1].inert, '2nd child active');
120 | assert.isTrue(container.children[2].inert, '3rd child inert');
121 | });
122 |
123 | it('remove() handles elements not in the dom anymore', function() {
124 | var child = container.children[0];
125 | document.$blockingElements.push(child);
126 | assert.equal(document.$blockingElements.top, child);
127 | container.removeChild(child);
128 | document.$blockingElements.remove(child);
129 | assert.equal(document.$blockingElements.top, null);
130 | assert.isNotOk(container.inert, 'container active');
131 | // Remaining children should be active.
132 | for (var i = 0; i < container.children.length; i++) {
133 | assert.isNotOk(container.children[i].inert, 'sibling active');
134 | }
135 | });
136 |
137 | it('destructor resets the document inertness', function() {
138 | document.$blockingElements.push(container.children[0]);
139 | // Destroy and then construct again.
140 | document.$blockingElements.destructor();
141 | document.$blockingElements = new document.$blockingElements.constructor();
142 | assert.isNotOk(container.inert, 'container active');
143 | // Remaining children should be active.
144 | for (var i = 0; i < container.children.length; i++) {
145 | assert.isNotOk(container.children[i].inert, 'sibling active');
146 | }
147 | });
148 | });
149 |
150 | describe('nested', function() {
151 | var container;
152 | var inner;
153 |
154 | beforeEach(function() {
155 | assert.equal(document.$blockingElements.top, null);
156 | container = fixtureLoader.load(`
157 |
`);
204 | });
205 |
206 | afterEach(function() {
207 | emptyBlockingElements();
208 | fixtureLoader.destroy();
209 | });
210 |
211 | it('should inert new siblings', function(done) {
212 | document.$blockingElements.push(container);
213 | var input = document.createElement('input');
214 | container.parentNode.appendChild(input);
215 | // Wait for mutation observer to see the change.
216 | setTimeout(function() {
217 | assert.isTrue(input.inert, 'inerted');
218 | done();
219 | });
220 | });
221 |
222 | it('should inert new parent siblings', function(done) {
223 | document.$blockingElements.push(container);
224 | var input = document.createElement('input');
225 | document.body.appendChild(input);
226 | // Wait for mutation observer to see the change.
227 | setTimeout(function() {
228 | assert.isTrue(input.inert, 'inerted');
229 | document.body.removeChild(input);
230 | done();
231 | });
232 | });
233 |
234 | it('should restore inertness of removed siblings', function(done) {
235 | document.$blockingElements.push(container.children[0]);
236 | var child1 = container.children[1];
237 | assert.isTrue(child1.inert, 'inerted');
238 | container.removeChild(child1);
239 | // Wait for mutation observer to see the change.
240 | setTimeout(function() {
241 | assert.isFalse(child1.inert, 'inert restored');
242 | done();
243 | });
244 | });
245 |
246 | it('should remove top if it was removed', function(done) {
247 | document.$blockingElements.push(container);
248 | container.parentNode.removeChild(container);
249 | // Wait for mutation observer to see the change.
250 | setTimeout(function() {
251 | assert.equal(document.$blockingElements.top, null);
252 | done();
253 | });
254 | });
255 | });
256 | })();
257 |
--------------------------------------------------------------------------------
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/src/blocking-elements.ts:
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1 | /**
2 | * @license
3 | * Copyright 2016 Google Inc. All rights reserved.
4 | *
5 | * Licensed under the Apache License, Version 2.0 (the "License");
6 | * you may not use this file except in compliance with the License.
7 | * You may obtain a copy of the License at
8 | *
9 | * http://www.apache.org/licenses/LICENSE-2.0
10 | *
11 | * Unless required by applicable law or agreed to in writing, software
12 | * distributed under the License is distributed on an "AS IS" BASIS,
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 | * See the License for the specific language governing permissions and
15 | * limitations under the License.
16 | */
17 |
18 | /**
19 | * `BlockingElements` manages a stack of elements that inert the interaction
20 | * outside them. The top element is the interactive part of the document.
21 | * The stack can be updated with the methods `push, remove, pop`.
22 | */
23 | export interface BlockingElements {
24 | /**
25 | * Call this whenever this object is about to become obsolete. This empties
26 | * the blocking elements
27 | */
28 | destructor(): void;
29 |
30 | /**
31 | * The top blocking element.
32 | */
33 | top: HTMLElement|null;
34 |
35 | /**
36 | * Adds the element to the blocking elements.
37 | */
38 | push(element: HTMLElement): void;
39 |
40 | /**
41 | * Removes the element from the blocking elements. Returns true if the
42 | * element was removed.
43 | */
44 | remove(element: HTMLElement): boolean;
45 |
46 | /**
47 | * Remove the top blocking element and returns it.
48 | */
49 | pop(): HTMLElement|null;
50 |
51 | /**
52 | * Returns if the element is a blocking element.
53 | */
54 | has(element: HTMLElement): boolean;
55 | }
56 |
57 | export interface DocumentWithBlockingElements extends Document {
58 | $blockingElements: BlockingElements;
59 | }
60 |
61 | (() => {
62 | /* Symbols for private properties */
63 | const _blockingElements = Symbol();
64 | const _alreadyInertElements = Symbol();
65 | const _topElParents = Symbol();
66 | const _siblingsToRestore = Symbol();
67 | const _parentMO = Symbol();
68 |
69 | /* Symbols for private static methods */
70 | const _topChanged = Symbol();
71 | const _swapInertedSibling = Symbol();
72 | const _inertSiblings = Symbol();
73 | const _restoreInertedSiblings = Symbol();
74 | const _getParents = Symbol();
75 | const _getDistributedChildren = Symbol();
76 | const _isInertable = Symbol();
77 | const _handleMutations = Symbol();
78 |
79 | interface Inertable extends HTMLElement {
80 | inert?: boolean;
81 | }
82 |
83 | interface InternalState {
84 | [_siblingsToRestore]: Set;
85 | [_parentMO]: MutationObserver;
86 | }
87 | interface HasInternalState extends Inertable, InternalState {}
88 | interface MaybeHasInternalState extends Inertable, Partial {}
89 |
90 | /**
91 | * ShadyDOM shady roots look a lot like real ShadowRoots. The __shady property
92 | * gives them away, though.
93 | */
94 | interface MaybeShadyRoot extends Element {
95 | __shady: unknown;
96 | host: Element;
97 | }
98 |
99 | class BlockingElementsImpl implements BlockingElements {
100 | /**
101 | * The blocking elements.
102 | */
103 | private[_blockingElements]: MaybeHasInternalState[] = [];
104 |
105 | /**
106 | * Used to keep track of the parents of the top element, from the element
107 | * itself up to body. When top changes, the old top might have been removed
108 | * from the document, so we need to memoize the inerted parents' siblings
109 | * in order to restore their inerteness when top changes.
110 | */
111 | private[_topElParents]: HasInternalState[] = [];
112 |
113 | /**
114 | * Elements that are already inert before the first blocking element is
115 | * pushed.
116 | */
117 | private[_alreadyInertElements] = new Set();
118 |
119 | destructor(): void {
120 | // Restore original inertness.
121 | this[_restoreInertedSiblings](this[_topElParents]);
122 | // Note we don't want to make these properties nullable on the class,
123 | // since then we'd need non-null casts in many places. Calling a method on
124 | // a BlockingElements instance after calling destructor will result in an
125 | // exception.
126 | const nullable = this as unknown as {
127 | [_blockingElements]: null;
128 | [_topElParents]: null;
129 | [_alreadyInertElements]: null;
130 | };
131 | nullable[_blockingElements] = null;
132 | nullable[_topElParents] = null;
133 | nullable[_alreadyInertElements] = null;
134 | }
135 |
136 | get top(): HTMLElement|null {
137 | const elems = this[_blockingElements];
138 | return elems[elems.length - 1] || null;
139 | }
140 |
141 | push(element: HTMLElement): void {
142 | if (!element || element === this.top) {
143 | return;
144 | }
145 | // Remove it from the stack, we'll bring it to the top.
146 | this.remove(element);
147 | this[_topChanged](element);
148 | this[_blockingElements].push(element);
149 | }
150 |
151 | remove(element: HTMLElement): boolean {
152 | const i = this[_blockingElements].indexOf(element);
153 | if (i === -1) {
154 | return false;
155 | }
156 | this[_blockingElements].splice(i, 1);
157 | // Top changed only if the removed element was the top element.
158 | if (i === this[_blockingElements].length) {
159 | this[_topChanged](this.top);
160 | }
161 | return true;
162 | }
163 |
164 | pop(): HTMLElement|null {
165 | const top = this.top;
166 | top && this.remove(top);
167 | return top;
168 | }
169 |
170 | has(element: HTMLElement): boolean {
171 | return this[_blockingElements].indexOf(element) !== -1;
172 | }
173 |
174 | /**
175 | * Sets `inert` to all document elements except the new top element, its
176 | * parents, and its distributed content.
177 | */
178 | private[_topChanged](newTop: MaybeHasInternalState|null): void {
179 | const toKeepInert = this[_alreadyInertElements];
180 | const oldParents = this[_topElParents];
181 | // No new top, reset old top if any.
182 | if (!newTop) {
183 | this[_restoreInertedSiblings](oldParents);
184 | toKeepInert.clear();
185 | this[_topElParents] = [];
186 | return;
187 | }
188 |
189 | const newParents = this[_getParents](newTop);
190 | // New top is not contained in the main document!
191 | if (newParents[newParents.length - 1].parentNode !== document.body) {
192 | throw Error('Non-connected element cannot be a blocking element');
193 | }
194 | // Cast here because we know we'll call _inertSiblings on newParents
195 | // below.
196 | this[_topElParents] = newParents as Array;
197 |
198 | const toSkip = this[_getDistributedChildren](newTop);
199 |
200 | // No previous top element.
201 | if (!oldParents.length) {
202 | this[_inertSiblings](newParents, toSkip, toKeepInert);
203 | return;
204 | }
205 |
206 | let i = oldParents.length - 1;
207 | let j = newParents.length - 1;
208 | // Find common parent. Index 0 is the element itself (so stop before it).
209 | while (i > 0 && j > 0 && oldParents[i] === newParents[j]) {
210 | i--;
211 | j--;
212 | }
213 | // If up the parents tree there are 2 elements that are siblings, swap
214 | // the inerted sibling.
215 | if (oldParents[i] !== newParents[j]) {
216 | this[_swapInertedSibling](oldParents[i], newParents[j]);
217 | }
218 | // Restore old parents siblings inertness.
219 | i > 0 && this[_restoreInertedSiblings](oldParents.slice(0, i));
220 | // Make new parents siblings inert.
221 | j > 0 && this[_inertSiblings](newParents.slice(0, j), toSkip, null);
222 | }
223 |
224 | /**
225 | * Swaps inertness between two sibling elements.
226 | * Sets the property `inert` over the attribute since the inert spec
227 | * doesn't specify if it should be reflected.
228 | * https://html.spec.whatwg.org/multipage/interaction.html#inert
229 | */
230 | private[_swapInertedSibling](
231 | oldInert: HasInternalState, newInert: MaybeHasInternalState): void {
232 | const siblingsToRestore = oldInert[_siblingsToRestore];
233 | // oldInert is not contained in siblings to restore, so we have to check
234 | // if it's inertable and if already inert.
235 | if (this[_isInertable](oldInert) && !oldInert.inert) {
236 | oldInert.inert = true;
237 | siblingsToRestore.add(oldInert);
238 | }
239 | // If newInert was already between the siblings to restore, it means it is
240 | // inertable and must be restored.
241 | if (siblingsToRestore.has(newInert)) {
242 | newInert.inert = false;
243 | siblingsToRestore.delete(newInert);
244 | }
245 | newInert[_parentMO] = oldInert[_parentMO];
246 | newInert[_siblingsToRestore] = siblingsToRestore;
247 | (oldInert as MaybeHasInternalState)[_parentMO] = undefined;
248 | (oldInert as MaybeHasInternalState)[_siblingsToRestore] = undefined;
249 | }
250 |
251 | /**
252 | * Restores original inertness to the siblings of the elements.
253 | * Sets the property `inert` over the attribute since the inert spec
254 | * doesn't specify if it should be reflected.
255 | * https://html.spec.whatwg.org/multipage/interaction.html#inert
256 | */
257 | private[_restoreInertedSiblings](elements: HasInternalState[]) {
258 | for (const element of elements) {
259 | const mo = element[_parentMO];
260 | mo.disconnect();
261 | (element as MaybeHasInternalState)[_parentMO] = undefined;
262 | const siblings = element[_siblingsToRestore];
263 | for (const sibling of siblings) {
264 | sibling.inert = false;
265 | }
266 | (element as MaybeHasInternalState)[_siblingsToRestore] = undefined;
267 | }
268 | }
269 |
270 | /**
271 | * Inerts the siblings of the elements except the elements to skip. Stores
272 | * the inerted siblings into the element's symbol `_siblingsToRestore`.
273 | * Pass `toKeepInert` to collect the already inert elements.
274 | * Sets the property `inert` over the attribute since the inert spec
275 | * doesn't specify if it should be reflected.
276 | * https://html.spec.whatwg.org/multipage/interaction.html#inert
277 | */
278 | private[_inertSiblings](
279 | elements: MaybeHasInternalState[], toSkip: Set|null,
280 | toKeepInert: Set|null) {
281 | for (const element of elements) {
282 | // Assume element is not a Document, so it must have a parentNode.
283 | const parent = element.parentNode!;
284 | const children = parent.children;
285 | const inertedSiblings = new Set();
286 | for (let j = 0; j < children.length; j++) {
287 | const sibling = children[j] as MaybeHasInternalState;
288 | // Skip the input element, if not inertable or to be skipped.
289 | if (sibling === element || !this[_isInertable](sibling) ||
290 | (toSkip && toSkip.has(sibling))) {
291 | continue;
292 | }
293 | // Should be collected since already inerted.
294 | if (toKeepInert && sibling.inert) {
295 | toKeepInert.add(sibling);
296 | } else {
297 | sibling.inert = true;
298 | inertedSiblings.add(sibling);
299 | }
300 | }
301 | // Store the siblings that were inerted.
302 | element[_siblingsToRestore] = inertedSiblings;
303 | // Observe only immediate children mutations on the parent.
304 | const mo = new MutationObserver(this[_handleMutations].bind(this));
305 | element[_parentMO] = mo;
306 | let parentToObserve = parent;
307 | // If we're using the ShadyDOM polyfill, then our parent could be a
308 | // shady root, which is an object that acts like a ShadowRoot, but isn't
309 | // actually a node in the real DOM. Observe the real DOM parent instead.
310 | const maybeShadyRoot = parentToObserve as MaybeShadyRoot;
311 | if (maybeShadyRoot.__shady && maybeShadyRoot.host) {
312 | parentToObserve = maybeShadyRoot.host;
313 | }
314 | mo.observe(parentToObserve, {
315 | childList: true,
316 | });
317 | }
318 | }
319 |
320 | /**
321 | * Handles newly added/removed nodes by toggling their inertness.
322 | * It also checks if the current top Blocking Element has been removed,
323 | * notifying and removing it.
324 | */
325 | private[_handleMutations](mutations: MutationRecord[]): void {
326 | const parents = this[_topElParents];
327 | const toKeepInert = this[_alreadyInertElements];
328 | for (const mutation of mutations) {
329 | // If the target is a shadowRoot, get its host as we skip shadowRoots when
330 | // computing _topElParents.
331 | const target = (mutation.target as ShadowRoot).host || mutation.target;
332 | const idx = target === document.body ?
333 | parents.length :
334 | parents.indexOf(target as HasInternalState);
335 | const inertedChild = parents[idx - 1];
336 | const inertedSiblings = inertedChild[_siblingsToRestore];
337 |
338 | // To restore.
339 | for (let i = 0; i < mutation.removedNodes.length; i++) {
340 | const sibling = mutation.removedNodes[i] as MaybeHasInternalState;
341 | if (sibling === inertedChild) {
342 | console.info('Detected removal of the top Blocking Element.');
343 | this.pop();
344 | return;
345 | }
346 | if (inertedSiblings.has(sibling)) {
347 | sibling.inert = false;
348 | inertedSiblings.delete(sibling);
349 | }
350 | }
351 |
352 | // To inert.
353 | for (let i = 0; i < mutation.addedNodes.length; i++) {
354 | const sibling = mutation.addedNodes[i] as MaybeHasInternalState;
355 | if (!this[_isInertable](sibling)) {
356 | continue;
357 | }
358 | if (toKeepInert && sibling.inert) {
359 | toKeepInert.add(sibling);
360 | } else {
361 | sibling.inert = true;
362 | inertedSiblings.add(sibling);
363 | }
364 | }
365 | }
366 | }
367 |
368 | /**
369 | * Returns if the element is inertable.
370 | */
371 | private[_isInertable](element: HTMLElement): boolean {
372 | return false === /^(style|template|script)$/.test(element.localName);
373 | }
374 |
375 | /**
376 | * Returns the list of newParents of an element, starting from element
377 | * (included) up to `document.body` (excluded).
378 | */
379 | private[_getParents](element: HTMLElement): Array {
380 | const parents = [];
381 | let current: HTMLElement|null|undefined = element;
382 | // Stop to body.
383 | while (current && current !== document.body) {
384 | // Skip shadow roots.
385 | if (current.nodeType === Node.ELEMENT_NODE) {
386 | parents.push(current);
387 | }
388 | // ShadowDom v1
389 | if (current.assignedSlot) {
390 | // Collect slots from deepest slot to top.
391 | while (current = current.assignedSlot) {
392 | parents.push(current);
393 | }
394 | // Continue the search on the top slot.
395 | current = parents.pop();
396 | continue;
397 | }
398 | current = current.parentNode as HTMLElement ||
399 | (current as Node as ShadowRoot).host;
400 | }
401 | return parents;
402 | }
403 |
404 | /**
405 | * Returns the distributed children of the element's shadow root.
406 | * Returns null if the element doesn't have a shadow root.
407 | */
408 | private[_getDistributedChildren](element: HTMLElement):
409 | Set|null {
410 | const shadowRoot = element.shadowRoot;
411 | if (!shadowRoot) {
412 | return null;
413 | }
414 | const result = new Set();
415 | let i;
416 | let j;
417 | let nodes;
418 | const slots = shadowRoot.querySelectorAll('slot');
419 | if (slots.length && slots[0].assignedNodes) {
420 | for (i = 0; i < slots.length; i++) {
421 | nodes = slots[i].assignedNodes({
422 | flatten: true,
423 | });
424 | for (j = 0; j < nodes.length; j++) {
425 | if (nodes[j].nodeType === Node.ELEMENT_NODE) {
426 | result.add(nodes[j] as HTMLElement);
427 | }
428 | }
429 | }
430 | // No need to search for .
431 | }
432 | return result;
433 | }
434 | }
435 |
436 | (document as DocumentWithBlockingElements).$blockingElements =
437 | new BlockingElementsImpl();
438 | })();
439 |
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