Files
squoosh/src/client/lazy-app/util/index.ts
2021-05-24 16:26:05 +01:00

452 lines
13 KiB
TypeScript

/**
* Copyright 2020 Google Inc. All Rights Reserved.
* 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 * as WebCodecs from '../util/web-codecs';
/**
* Compare two objects, returning a boolean indicating if
* they have the same properties and strictly equal values.
*/
export function shallowEqual(one: any, two: any) {
for (const i in one) if (one[i] !== two[i]) return false;
for (const i in two) if (!(i in one)) return false;
return true;
}
/** Replace the contents of a canvas with the given data */
export function drawDataToCanvas(canvas: HTMLCanvasElement, data: ImageData) {
const ctx = canvas.getContext('2d');
if (!ctx) throw Error('Canvas not initialized');
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.putImageData(data, 0, 0);
}
/**
* Encode some image data in a given format using the browser's encoders
*
* @param {ImageData} data
* @param {string} type A mime type, eg image/jpeg.
* @param {number} [quality] Between 0-1.
*/
export async function canvasEncode(
data: ImageData,
type: string,
quality?: number,
): Promise<Blob> {
const canvas = document.createElement('canvas');
canvas.width = data.width;
canvas.height = data.height;
const ctx = canvas.getContext('2d');
if (!ctx) throw Error('Canvas not initialized');
ctx.putImageData(data, 0, 0);
let blob: Blob | null;
if ('toBlob' in canvas) {
blob = await new Promise<Blob | null>((r) =>
canvas.toBlob(r, type, quality),
);
} else {
// Welcome to Edge.
// TypeScript thinks `canvas` is 'never', so it needs casting.
const dataUrl = (canvas as HTMLCanvasElement).toDataURL(type, quality);
const result = /data:([^;]+);base64,(.*)$/.exec(dataUrl);
if (!result) throw Error('Data URL reading failed');
const outputType = result[1];
const binaryStr = atob(result[2]);
const data = new Uint8Array(binaryStr.length);
for (let i = 0; i < data.length; i += 1) {
data[i] = binaryStr.charCodeAt(i);
}
blob = new Blob([data], { type: outputType });
}
if (!blob) throw Error('Encoding failed');
return blob;
}
async function decodeImage(url: string): Promise<HTMLImageElement> {
const img = new Image();
img.decoding = 'async';
img.src = url;
const loaded = new Promise<void>((resolve, reject) => {
img.onload = () => resolve();
img.onerror = () => reject(Error('Image loading error'));
});
if (img.decode) {
// Nice off-thread way supported in Safari/Chrome.
// Safari throws on decode if the source is SVG.
// https://bugs.webkit.org/show_bug.cgi?id=188347
await img.decode().catch(() => null);
}
// Always await loaded, as we may have bailed due to the Safari bug above.
await loaded;
return img;
}
/** Caches results from canDecodeImageType */
const canDecodeCache = new Map<string, Promise<boolean>>();
/**
* Tests whether the browser supports a particular image mime type.
*
* @param type Mimetype
* @example await canDecodeImageType('image/avif')
*/
export function canDecodeImageType(type: string): Promise<boolean> {
if (!canDecodeCache.has(type)) {
const resultPromise = (async () => {
const picture = document.createElement('picture');
const img = document.createElement('img');
const source = document.createElement('source');
source.srcset = 'data:,x';
source.type = type;
picture.append(source, img);
// Wait a single microtick just for the `img.currentSrc` to get populated.
await 0;
// At this point `img.currentSrc` will contain "data:,x" if format is supported and ""
// otherwise.
return !!img.currentSrc;
})();
canDecodeCache.set(type, resultPromise);
}
return canDecodeCache.get(type)!;
}
export function blobToArrayBuffer(blob: Blob): Promise<ArrayBuffer> {
return new Response(blob).arrayBuffer();
}
export function blobToText(blob: Blob): Promise<string> {
return new Response(blob).text();
}
const magicNumberMapInput = [
[/^%PDF-/, 'application/pdf'],
[/^GIF87a/, 'image/gif'],
[/^GIF89a/, 'image/gif'],
[/^\x89PNG\x0D\x0A\x1A\x0A/, 'image/png'],
[/^\xFF\xD8\xFF/, 'image/jpeg'],
[/^BM/, 'image/bmp'],
[/^I I/, 'image/tiff'],
[/^II*/, 'image/tiff'],
[/^MM\x00*/, 'image/tiff'],
[/^RIFF....WEBPVP8[LX ]/, 'image/webp'],
[/^\xF4\xFF\x6F/, 'image/webp2'],
[/^\x00\x00\x00 ftypavif\x00\x00\x00\x00/, 'image/avif'],
[/^\xff\x0a/, 'image/jxl'],
[/^\x00\x00\x00\x0cJXL \x0d\x0a\x87\x0a/, 'image/jxl'],
] as const;
export type ImageMimeTypes = typeof magicNumberMapInput[number][1];
const magicNumberToMimeType = new Map<RegExp, ImageMimeTypes>(
magicNumberMapInput,
);
export async function sniffMimeType(blob: Blob): Promise<ImageMimeTypes | ''> {
const firstChunk = await blobToArrayBuffer(blob.slice(0, 16));
const firstChunkString = Array.from(new Uint8Array(firstChunk))
.map((v) => String.fromCodePoint(v))
.join('');
for (const [detector, mimeType] of magicNumberToMimeType) {
if (detector.test(firstChunkString)) {
return mimeType;
}
}
return '';
}
export async function blobToImg(blob: Blob): Promise<HTMLImageElement> {
const url = URL.createObjectURL(blob);
try {
return await decodeImage(url);
} finally {
URL.revokeObjectURL(url);
}
}
interface DrawableToImageDataOptions {
width?: number;
height?: number;
sx?: number;
sy?: number;
sw?: number;
sh?: number;
}
function getWidth(
drawable: ImageBitmap | HTMLImageElement | VideoFrame,
): number {
if ('displayWidth' in drawable) {
return drawable.displayWidth;
}
return drawable.width;
}
function getHeight(
drawable: ImageBitmap | HTMLImageElement | VideoFrame,
): number {
if ('displayHeight' in drawable) {
return drawable.displayHeight;
}
return drawable.height;
}
export function drawableToImageData(
drawable: ImageBitmap | HTMLImageElement | VideoFrame,
opts: DrawableToImageDataOptions = {},
): ImageData {
const {
width = getWidth(drawable),
height = getHeight(drawable),
sx = 0,
sy = 0,
sw = getWidth(drawable),
sh = getHeight(drawable),
} = opts;
// Make canvas same size as image
const canvas = document.createElement('canvas');
canvas.width = width;
canvas.height = height;
// Draw image onto canvas
const ctx = canvas.getContext('2d');
if (!ctx) throw new Error('Could not create canvas context');
ctx.drawImage(drawable, sx, sy, sw, sh, 0, 0, width, height);
return ctx.getImageData(0, 0, width, height);
}
export async function builtinDecode(
signal: AbortSignal,
blob: Blob,
mimeType: string,
): Promise<ImageData> {
// If WebCodecs are supported, use that.
if (await WebCodecs.isTypeSupported(mimeType)) {
if (signal.aborted) return Promise.reject('Aborted');
try {
return await WebCodecs.decode(blob, mimeType);
} catch (e) {}
}
assertSignal(signal);
// Prefer createImageBitmap as it's the off-thread option for Firefox.
const drawable = await abortable(
signal,
'createImageBitmap' in self ? createImageBitmap(blob) : blobToImg(blob),
);
return drawableToImageData(drawable);
}
export type BuiltinResizeMethod = 'pixelated' | 'low' | 'medium' | 'high';
export function builtinResize(
data: ImageData,
sx: number,
sy: number,
sw: number,
sh: number,
dw: number,
dh: number,
method: BuiltinResizeMethod,
): ImageData {
const canvasSource = document.createElement('canvas');
canvasSource.width = data.width;
canvasSource.height = data.height;
drawDataToCanvas(canvasSource, data);
const canvasDest = document.createElement('canvas');
canvasDest.width = dw;
canvasDest.height = dh;
const ctx = canvasDest.getContext('2d');
if (!ctx) throw new Error('Could not create canvas context');
if (method === 'pixelated') {
ctx.imageSmoothingEnabled = false;
} else {
ctx.imageSmoothingQuality = method;
}
ctx.drawImage(canvasSource, sx, sy, sw, sh, 0, 0, dw, dh);
return ctx.getImageData(0, 0, dw, dh);
}
/**
* @param field An HTMLInputElement, but the casting is done here to tidy up onChange.
* @param defaultVal Value to return if 'field' doesn't exist.
*/
export function inputFieldValueAsNumber(
field: any,
defaultVal: number = 0,
): number {
if (!field) return defaultVal;
return Number(inputFieldValue(field));
}
/**
* @param field An HTMLInputElement, but the casting is done here to tidy up onChange.
* @param defaultVal Value to return if 'field' doesn't exist.
*/
export function inputFieldCheckedAsNumber(
field: any,
defaultVal: number = 0,
): number {
if (!field) return defaultVal;
return Number(inputFieldChecked(field));
}
/**
* @param field An HTMLInputElement, but the casting is done here to tidy up onChange.
* @param defaultVal Value to return if 'field' doesn't exist.
*/
export function inputFieldChecked(
field: any,
defaultVal: boolean = false,
): boolean {
if (!field) return defaultVal;
return (field as HTMLInputElement).checked;
}
/**
* @param field An HTMLInputElement, but the casting is done here to tidy up onChange.
* @param defaultVal Value to return if 'field' doesn't exist.
*/
export function inputFieldValue(field: any, defaultVal: string = ''): string {
if (!field) return defaultVal;
return (field as HTMLInputElement).value;
}
/**
* Creates a promise that resolves when the user types the konami code.
*/
export function konami(): Promise<void> {
return new Promise((resolve) => {
// Keycodes for: ↑ ↑ ↓ ↓ ← → ← → B A
const expectedPattern = '38384040373937396665';
let rollingPattern = '';
const listener = (event: KeyboardEvent) => {
rollingPattern += event.keyCode;
rollingPattern = rollingPattern.slice(-expectedPattern.length);
if (rollingPattern === expectedPattern) {
window.removeEventListener('keydown', listener);
resolve();
}
};
window.addEventListener('keydown', listener);
});
}
interface TransitionOptions {
from?: number;
to?: number;
duration?: number;
easing?: string;
}
export async function transitionHeight(
el: HTMLElement,
opts: TransitionOptions,
): Promise<void> {
const {
from = el.getBoundingClientRect().height,
to = el.getBoundingClientRect().height,
duration = 1000,
easing = 'ease-in-out',
} = opts;
if (from === to || duration === 0) {
el.style.height = to + 'px';
return;
}
el.style.height = from + 'px';
// Force a style calc so the browser picks up the start value.
getComputedStyle(el).transform;
el.style.transition = `height ${duration}ms ${easing}`;
el.style.height = to + 'px';
return new Promise<void>((resolve) => {
const listener = (event: Event) => {
if (event.target !== el) return;
el.style.transition = '';
el.removeEventListener('transitionend', listener);
el.removeEventListener('transitioncancel', listener);
resolve();
};
el.addEventListener('transitionend', listener);
el.addEventListener('transitioncancel', listener);
});
}
/**
* Simple event listener that prevents the default.
*/
export function preventDefault(event: Event) {
event.preventDefault();
}
/**
* Throw an abort error if a signal is aborted.
*/
export function assertSignal(signal: AbortSignal) {
if (signal.aborted) throw new DOMException('AbortError', 'AbortError');
}
/**
* Take a signal and promise, and returns a promise that rejects with an AbortError if the abort is
* signalled, otherwise resolves with the promise.
*/
export async function abortable<T>(
signal: AbortSignal,
promise: Promise<T>,
): Promise<T> {
assertSignal(signal);
return Promise.race([
promise,
new Promise<T>((_, reject) => {
signal.addEventListener('abort', () =>
reject(new DOMException('AbortError', 'AbortError')),
);
}),
]);
}
/**
* Test whether <canvas> can encode to a particular type.
*/
export async function canvasEncodeTest(mimeType: string): Promise<boolean> {
try {
const blob = await canvasEncode(new ImageData(1, 1), mimeType);
// According to the spec, the blob should be null if the format isn't supported…
if (!blob) return false;
// …but Safari & Firefox fall back to PNG, so we need to check the mime type.
return blob.type === mimeType;
} catch (err) {
return false;
}
}