signal-desktop/ts/util/avatarDataToBytes.ts
2022-08-31 12:57:21 -07:00

122 lines
3.5 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import type { AvatarColorType } from '../types/Colors';
import { AvatarColorMap } from '../types/Colors';
import type { AvatarDataType } from '../types/Avatar';
import { canvasToBytes } from './canvasToBytes';
import { getFittedFontSize } from './avatarTextSizeCalculator';
const CANVAS_SIZE = 1024;
function getAvatarColor(color: AvatarColorType): { bg: string; fg: string } {
return AvatarColorMap.get(color) || { bg: 'black', fg: 'white' };
}
function setCanvasBackground(
bg: string,
context: CanvasRenderingContext2D,
canvas: HTMLCanvasElement
): void {
context.fillStyle = bg;
context.fillRect(0, 0, canvas.width, canvas.height);
}
async function drawImage(
src: string,
context: CanvasRenderingContext2D,
canvas: HTMLCanvasElement
): Promise<void> {
const image = new Image();
image.src = src;
await image.decode();
// eslint-disable-next-line no-param-reassign
canvas.width = image.width;
// eslint-disable-next-line no-param-reassign
canvas.height = image.height;
context.drawImage(image, 0, 0);
}
async function getFont(text: string): Promise<string> {
const font = new window.FontFace(
'Inter',
'url("fonts/inter-v3.19/Inter-Regular.woff2")'
);
await font.load();
const measurerCanvas = document.createElement('canvas');
measurerCanvas.width = CANVAS_SIZE;
measurerCanvas.height = CANVAS_SIZE;
const measurerContext = measurerCanvas.getContext('2d');
if (!measurerContext) {
throw new Error('getFont: could not get canvas rendering context');
}
const fontSize = getFittedFontSize(CANVAS_SIZE, text, candidateFontSize => {
const candidateFont = `${candidateFontSize}px Inter`;
measurerContext.font = candidateFont;
const {
actualBoundingBoxLeft,
actualBoundingBoxRight,
actualBoundingBoxAscent,
actualBoundingBoxDescent,
} = measurerContext.measureText(text);
const width =
Math.abs(actualBoundingBoxLeft) + Math.abs(actualBoundingBoxRight);
const height =
Math.abs(actualBoundingBoxAscent) + Math.abs(actualBoundingBoxDescent);
return { height, width };
});
return `${fontSize}px Inter`;
}
export async function avatarDataToBytes(
avatarData: AvatarDataType
): Promise<Uint8Array> {
const canvas = document.createElement('canvas');
canvas.width = CANVAS_SIZE;
canvas.height = CANVAS_SIZE;
const context = canvas.getContext('2d');
if (!context) {
throw new Error(
'avatarDataToBytes: could not get canvas rendering context'
);
}
const { color, icon, imagePath, text } = avatarData;
if (imagePath) {
await drawImage(
window.Signal?.Migrations
? window.Signal.Migrations.getAbsoluteAvatarPath(imagePath)
: imagePath,
context,
canvas
);
} else if (color && text) {
const { bg, fg } = getAvatarColor(color);
const textToWrite = text.toLocaleUpperCase();
setCanvasBackground(bg, context, canvas);
context.fillStyle = fg;
const font = await getFont(textToWrite);
context.font = font;
context.textBaseline = 'middle';
context.textAlign = 'center';
context.fillText(textToWrite, CANVAS_SIZE / 2, CANVAS_SIZE / 2 + 30);
} else if (color && icon) {
const iconPath = `images/avatars/avatar_${icon}.svg`;
await drawImage(iconPath, context, canvas);
context.globalCompositeOperation = 'destination-over';
const { bg } = getAvatarColor(color);
setCanvasBackground(bg, context, canvas);
}
return canvasToBytes(canvas);
}