Files
web-dslr/ui.js
Ingvar Stepanyan 51864cc154 Rename constants
2021-07-20 13:30:55 +00:00

435 lines
11 KiB
JavaScript

import { h, render, Component, createRef, Fragment } from 'preact';
import initModule from './libapi.mjs';
/** @typedef {InstanceType<import('./libapi.mjs').Module['Context']>} Context */
/** @typedef {import('./libapi.mjs').Config} Config */
let isDebug = new URLSearchParams(location.search).has('debug');
if (isDebug) {
// @ts-ignore
await import('preact/debug');
}
/** This function should be called once user has selected the camera and other operations can begin. */
let prepareContext;
/** Schedules an exclusive async operation on the global context. */
const scheduleOp = (() => {
let queue = (async () => {
await new Promise(resolve => {
prepareContext = resolve;
});
let { Context } = await initModule();
let ctx = await new Context();
addEventListener('beforeunload', e => {
ctx.delete();
});
return ctx;
})();
/**
* @template T
* @param {(ctx: Context) => Promise<T>} op
* @returns {Promise<T>}
*/
return function scheduleOp(op) {
let caughtRes = queue.then(async ctx => {
let resultPromise = op(ctx);
try {
await resultPromise;
} catch {}
return {
ctx,
resultPromise
};
});
// Queue should ignore result values as well as errors from singular ops.
queue = caughtRes.then(res => res.ctx);
// Result should contain the unwrapped value or error.
return caughtRes.then(res => res.resultPromise);
};
})();
/**
*
* @extends Component<{ config: Config }>
*/
class Widget extends Component {
state = { inProgress: false };
shouldComponentUpdate(
/** @type {Widget['props']} */ nextProps,
/** @type {Widget['state']} */ nextState
) {
return !(this.state.inProgress && nextState.inProgress);
}
getValueProp(out = false) {
switch (this.props.config.type) {
case 'toggle':
return 'checked';
case 'datetime':
return 'valueAsNumber';
case 'range':
// Apparently can't render with `valueAsNumber` as preact property,
// but can retrieve it back.
return out ? 'valueAsNumber' : 'value';
default:
return 'value';
}
}
handleChange = async e => {
this.setState({ inProgress: true });
let value = e.target[this.getValueProp(true)];
try {
/** @type {Promise<void>} */
let uiTimeout;
await scheduleOp(context => {
// This is terrible, yes... but some configs return too quickly before they're actually updated.
// We want to wait some time before updating the UI in that case, but not block subsequent ops.
uiTimeout = new Promise(resolve => setTimeout(resolve, 800));
return context.setConfigValue(this.props.config.name, value);
});
await uiTimeout;
} catch (e) {
console.error(e);
}
this.setState({ inProgress: false });
};
render(
/** @type {Widget['props']} */ { config },
/** @type {Widget['state']} */ { inProgress }
) {
let { label, name } = config;
let id = `config-${name}`;
if (config.type === 'window' || config.type === 'section') {
return h(
'fieldset',
{ id },
h('legend', {}, label),
Object.values(config.children).map(config =>
h(Widget, { key: config.name, config })
)
);
}
let { value, readonly } = config;
let valueProp = this.getValueProp();
let attrs = {
id,
[valueProp]: value,
readonly: readonly || inProgress,
onChange: this.handleChange
};
let inputElem;
switch (config.type) {
case 'range': {
let { min, max, step } = config;
inputElem = h(EditableInput, {
type: 'number',
min,
max,
step,
...attrs
});
break;
}
case 'text':
inputElem = readonly ? value : h(EditableInput, attrs);
break;
case 'toggle': {
inputElem = h('input', {
type: 'checkbox',
...attrs
});
break;
}
case 'menu':
case 'radio': {
let { choices } = config;
inputElem = h(
'select',
attrs,
choices.map(choice =>
h(Option, {
key: choice,
value: choice,
disabled: attrs.readonly && value !== choice
})
)
);
break;
}
case 'datetime': {
inputElem = h(EditableInput, {
type: 'datetime-local',
...attrs
});
break;
}
default: {
inputElem = '(unimplemented)';
break;
}
}
return h(
'div',
{ class: 'pure-control-group' },
h('label', { for: id }, (inProgress ? '⌛ ' : '') + label),
inputElem
);
}
}
/**
* Special memoized option to work around https://github.com/preactjs/preact/issues/3171.
* @extends Component<{ value: string, disabled?: boolean }>
*/
class Option extends Component {
shouldComponentUpdate(/** @type {Option['props']} */ nextProps) {
return nextProps.value !== this.props.value;
}
render() {
return h('option', this.props, this.props.value);
}
}
/**
* Wrapper around <input /> that doesn't update it while it's in focus to allow editing.
*/
class EditableInput extends Component {
ref = createRef();
shouldComponentUpdate() {
return document.activeElement !== this.ref.current;
}
render(props) {
return h('input', Object.assign(props, { ref: this.ref }));
}
}
/** @extends Component<null, { inProgress: boolean }> */
class CaptureButton extends Component {
state = { inProgress: false };
handleCapture = async () => {
this.setState({ inProgress: true });
let file = await scheduleOp(context => context.captureImageAsFile());
let url = URL.createObjectURL(file);
Object.assign(document.createElement('a'), {
download: file.name,
href: url
}).click();
URL.revokeObjectURL(url);
this.setState({ inProgress: false });
};
render() {
return h(
Fragment,
null,
h('input', {
type: 'button',
id: 'capture',
class:
'pure-button' + (this.state.inProgress ? ' pure-button-active' : ''),
onclick: this.handleCapture,
value: `${this.state.inProgress ? '⌛' : '📷'} Capture image`
})
);
}
}
/** @typedef {{ type: 'CameraPicker' } | { type: 'Status', message: string } | { type: 'Config', config: Config }} AppState */
const INTERFACE_CLASS = 6; // PTP
const INTERFACE_SUBCLASS = 1; // MTP
/** @extends Component<null, AppState> */
class App extends Component {
state = /** @type {AppState} */ ({
type: 'Status',
message: 'Looking for cameras...'
});
constructor(...args) {
super(...args);
// @ts-ignore
navigator.usb.getDevices().then(devices => {
for (let dev of devices) {
for (let conf of dev.configurations) {
for (let intf of conf.interfaces) {
for (let alt of intf.alternates) {
if (
alt.interfaceClass === INTERFACE_CLASS &&
alt.interfaceSubclass === INTERFACE_SUBCLASS
) {
return this.connectToCamera();
}
}
}
}
}
this.setState({ type: 'CameraPicker' });
});
window.onerror = message => {
this.setState({
type: 'Status',
message: `${message}`
});
};
}
selectDevice = async () => {
// @ts-ignore
await navigator.usb.requestDevice({
filters: [
{
classCode: INTERFACE_CLASS,
subclassCode: INTERFACE_SUBCLASS
}
]
});
this.connectToCamera();
};
connectToCamera() {
prepareContext();
this.setState({ type: 'Status', message: 'Connecting...' });
(async () => {
while (true) {
await this.refreshConfig();
await new Promise(resolve => setTimeout(resolve, 100));
}
})();
}
async refreshConfig() {
let config = await scheduleOp(context => context.configToJS());
if (!isDebug) {
delete config.children.other;
}
this.setState({
type: 'Config',
config
});
}
render(/** @type {App['props']} */ props, /** @type {App['state']} */ state) {
switch (state.type) {
case 'CameraPicker':
return h(
'div',
{ class: 'center-parent' },
h('input', {
class: 'center',
type: 'button',
onclick: this.selectDevice,
value: '🔍 Select camera'
})
);
case 'Status':
return h(
'div',
{ class: 'center-parent' },
h('div', { class: 'center' }, state.message)
);
case 'Config':
return h(
'div',
{ class: 'pure-g' },
h(
'div',
{ class: 'pure-u-2-3 center-parent', id: 'canvas-holder' },
h(PreviewCanvas, {
id: 'preview-canvas',
class: 'center'
})
),
h(
'div',
{ id: 'config', class: 'pure-u-1-3' },
h(
'form',
{ class: 'pure-form pure-form-aligned' },
h(CaptureButton, null),
h(Widget, { config: state.config })
)
)
);
}
}
}
render(h(App, null), document.body);
class PreviewCanvas extends Component {
ref = createRef();
render(props) {
return h('canvas', { ...props, ref: this.ref });
}
async componentDidMount() {
// I have no idea why, but if we connect too soon, it just hangs...
await new Promise(resolve => setTimeout(resolve, 1000));
let canvas = /** @type {HTMLCanvasElement} */ (this.ref.current);
let canvasHolder = canvas.parentElement;
let canvasCtx = canvas.getContext('bitmaprenderer');
let ratio = 0;
while (true) {
try {
let blob = await scheduleOp(context => context.capturePreviewAsBlob());
// If ratio is known; decode resized image right away - it's a bit faster.
// If it isn't known, retrieve entire image to calculate ratio from its dimensions.
let img = await createImageBitmap(
blob,
ratio
? {
resizeWidth: canvas.width,
resizeHeight: canvas.height
}
: {}
);
if (!ratio) {
ratio = img.width / img.height;
function updateCanvasSize() {
let width = canvasHolder.offsetWidth - 10;
let height = canvasHolder.offsetHeight;
if (height * ratio > width) {
height = width / ratio;
} else {
width = height * ratio;
}
Object.assign(canvas, { width, height });
}
updateCanvasSize();
new ResizeObserver(updateCanvasSize).observe(canvasHolder);
}
canvasCtx.transferFromImageBitmap(img);
} catch (e) {
console.warn(e);
}
await new Promise(resolve => requestAnimationFrame(resolve));
}
}
}