Files
web-dslr/src/camera.js
2023-08-04 17:59:42 +02:00

132 lines
3.6 KiB
JavaScript

/*
* Copyright 2021 Google LLC
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/** @typedef {import('./libapi.mjs.d.ts').Context} Context */
// To avoid errors for users who use SSR or Hybrid rendering (e.g. Nuxt.js), we need to check if we're in the browser.
let initModule;
async function initializeModule() {
if (typeof window !== "undefined") {
const module = await import("../build/libapi.mjs");
initModule = module.default;
return initModule;
} else {
console.warn("web-gphoto2 is only available in the browser");
return null;
}
}
export function rethrowIfCritical(err) {
// If it's precisely Error, it's a custom error; anything else - SyntaxError,
// WebAssembly.RuntimeError, TypeError, etc. - is treated as critical here.
if (err.constructor !== Error) {
throw err;
}
}
const INTERFACE_CLASS = 6; // PTP
const INTERFACE_SUBCLASS = 1; // MTP
class Camera {
constructor() {
/** @type {Promise<unknown>} */
this.queue = Promise.resolve();
this.Module = null;
this.context = null;
this.ModulePromise = null;
}
async showCameraPicker() {
// @ts-ignore
await navigator.usb.requestDevice({
filters: [
{
classCode: INTERFACE_CLASS,
subclassCode: INTERFACE_SUBCLASS,
},
],
});
}
async connect() {
if (!this.ModulePromise) {
this.ModulePromise = initializeModule().then((initModule) => {
if (initModule) {
return initModule();
} else {
return null;
}
});
}
this.Module = await this.ModulePromise;
this.context = await new this.Module.Context();
}
/** Schedules an exclusive async operation on the global context.
* @template T
* @param {(ctx: Context) => Promise<T>} op
* @returns {Promise<T>}
*/
async schedule(op) {
let res = this.queue.then(() => op(this.context));
this.queue = res.catch(rethrowIfCritical);
return res;
}
async disconnect() {
if (!this.context.isDeleted()) {
this.context.delete();
}
}
async getConfig() {
return this.schedule((context) => context.configToJS());
}
async getSupportedOps() {
if (this.context) {
return await this.context.supportedOps();
}
throw new Error("You need to connect to the camera first");
}
async setConfigValue(name, value) {
const uiTimeout = new Promise((resolve) => setTimeout(resolve, 800));
const setResult = this.schedule((context) =>
context.setConfigValue(name, value)
);
// wait for both the config set operation and the timeout to complete
return Promise.all([setResult, uiTimeout]);
}
async capturePreviewAsBlob() {
return this.schedule((context) => context.capturePreviewAsBlob());
}
async captureImageAsFile() {
return this.schedule((context) => context.captureImageAsFile());
}
async consumeEvents() {
return this.schedule((context) => context.consumeEvents());
}
}
export default Camera;