Files
web-dslr/src/camera.js
2023-08-05 15:19:17 +02:00

106 lines
2.8 KiB
JavaScript

/*
* Copyright 2023 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
*/
import initModule from "../build/libapi.mjs";
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
let ModulePromise = null;
class Camera {
constructor() {
this.queue = Promise.resolve();
this.Module = null;
this.context = null;
}
async showCameraPicker() {
// @ts-ignore
await navigator.usb.requestDevice({
filters: [
{
classCode: INTERFACE_CLASS,
subclassCode: INTERFACE_SUBCLASS,
},
],
});
}
async connect() {
if (!ModulePromise) {
ModulePromise = initModule()
}
this.Module = await ModulePromise;
this.context = await new this.Module.Context();
}
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)
);
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 { Camera };