react-webcam-qr-scanner
Version:
A humble implementation of a real-time QR-code scanner using WebRTC
341 lines (277 loc) • 13 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports["default"] = void 0;
var _react = _interopRequireDefault(require("react"));
var _MediaStreamManager = _interopRequireDefault(require("./MediaStreamManager"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
function _extends() { _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; }; return _extends.apply(this, arguments); }
function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }
function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }
function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest(); }
function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }
function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }
function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; }
function _iterableToArrayLimit(arr, i) { if (typeof Symbol === "undefined" || !(Symbol.iterator in Object(arr))) return; var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }
function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
function _objectWithoutProperties(source, excluded) { if (source == null) return {}; var target = _objectWithoutPropertiesLoose(source, excluded); var key, i; if (Object.getOwnPropertySymbols) { var sourceSymbolKeys = Object.getOwnPropertySymbols(source); for (i = 0; i < sourceSymbolKeys.length; i++) { key = sourceSymbolKeys[i]; if (excluded.indexOf(key) >= 0) continue; if (!Object.prototype.propertyIsEnumerable.call(source, key)) continue; target[key] = source[key]; } } return target; }
function _objectWithoutPropertiesLoose(source, excluded) { if (source == null) return {}; var target = {}; var sourceKeys = Object.keys(source); var key, i; for (i = 0; i < sourceKeys.length; i++) { key = sourceKeys[i]; if (excluded.indexOf(key) >= 0) continue; target[key] = source[key]; } return target; }
var defaults = {
constraints: {
audio: false,
video: {
facingMode: "environment"
}
},
activeCaptureSize: {
width: 1280,
height: 720
},
size: {
video: {
width: 0,
height: 0
},
capture: {
dx: 0,
dy: 0,
width: 0,
height: 0
}
}
};
var asyncRequestAnimationFrame = function asyncRequestAnimationFrame() {
return new Promise(function (res) {
return requestAnimationFrame(function (id) {
return res(id);
});
});
};
var WebcamStream = /*#__PURE__*/_react["default"].forwardRef(function (_ref, ref) {
var _ref$constraints = _ref.constraints,
constraints = _ref$constraints === void 0 ? defaults.constraints : _ref$constraints,
_ref$captureSize = _ref.captureSize,
captureSize = _ref$captureSize === void 0 ? defaults.activeCaptureSize : _ref$captureSize,
onCapture = _ref.onCapture,
onPlay = _ref.onPlay,
onPause = _ref.onPause,
onLoadedMetadata = _ref.onLoadedMetadata,
props = _objectWithoutProperties(_ref, ["constraints", "captureSize", "onCapture", "onPlay", "onPause", "onLoadedMetadata"]);
var $videoRef = _react["default"].useRef(null);
_react["default"].useImperativeHandle(ref, function () {
return $videoRef.current;
});
var _React$useState = _react["default"].useState(true),
_React$useState2 = _slicedToArray(_React$useState, 2),
visible = _React$useState2[0],
setVisible = _React$useState2[1];
var videoState = _react["default"].useRef("paused");
var updateState = _react["default"].useCallback(function (nextState) {
videoState.current = nextState;
}, []);
var mediaStreamContext = _react["default"].useMemo(function () {
return _MediaStreamManager["default"].createStreamContext(constraints);
}, [constraints, visible]);
var startStream = _react["default"].useCallback( /*#__PURE__*/_asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee() {
var stream;
return regeneratorRuntime.wrap(function _callee$(_context) {
while (1) {
switch (_context.prev = _context.next) {
case 0:
updateState("loading");
_context.next = 3;
return mediaStreamContext.getStream();
case 3:
stream = _context.sent;
if (!(stream !== null && $videoRef.current)) {
_context.next = 14;
break;
}
$videoRef.current.srcObject = stream;
$videoRef.current.playsInline = true;
$videoRef.current.muted = true;
$videoRef.current.disablePictureInPicture = true;
_context.next = 11;
return $videoRef.current.play();
case 11:
updateState("playing");
_context.next = 16;
break;
case 14:
updateState("error");
_MediaStreamManager["default"].stopStream(mediaStreamContext.id);
case 16:
case "end":
return _context.stop();
}
}
}, _callee);
})), [mediaStreamContext]);
var stopStream = _react["default"].useCallback( /*#__PURE__*/_asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee2() {
return regeneratorRuntime.wrap(function _callee2$(_context2) {
while (1) {
switch (_context2.prev = _context2.next) {
case 0:
$videoRef.current.pause();
_MediaStreamManager["default"].stopStream(mediaStreamContext.id);
updateState("paused");
case 3:
case "end":
return _context2.stop();
}
}
}, _callee2);
})), [mediaStreamContext]);
var _React$useState3 = _react["default"].useState(defaults.size),
_React$useState4 = _slicedToArray(_React$useState3, 2),
size = _React$useState4[0],
setSize = _React$useState4[1];
var graphics = _react["default"].useMemo(function () {
var canvas = document.createElement("canvas");
canvas.width = size.capture.width;
canvas.height = size.capture.height;
return canvas;
}, [size]);
var handleMetadataLoaded = _react["default"].useCallback(function (event) {
var videoWidth = event.target.videoWidth;
var videoHeight = event.target.videoHeight;
var dx = videoWidth > captureSize.width ? (videoWidth - captureSize.width) / 2 : 0;
var dy = videoHeight > captureSize.height ? (videoHeight - captureSize.height) / 2 : 0;
var captureWidth = Math.min(captureSize.width, videoWidth);
var captureHeight = Math.min(captureSize.height, videoHeight);
setSize({
video: {
width: videoWidth,
height: videoHeight
},
capture: {
dx: dx,
dy: dy,
width: captureWidth,
height: captureHeight
}
});
typeof onLoadedMetadata == 'function' && onLoadedMetadata(event);
}, [captureSize, onLoadedMetadata]);
var capturing = _react["default"].useMemo(function () {
return {
status: "idle",
start: function () {
var _start = _asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee3() {
var context, imageData;
return regeneratorRuntime.wrap(function _callee3$(_context3) {
while (1) {
switch (_context3.prev = _context3.next) {
case 0:
this.status = "running";
case 1:
if (!(this.status === "running")) {
_context3.next = 13;
break;
}
_context3.next = 4;
return asyncRequestAnimationFrame();
case 4:
if (!($videoRef.current && $videoRef.current.readyState > 1 && size.video.width > 0 && size.video.height > 0)) {
_context3.next = 11;
break;
}
context = graphics.getContext("2d");
context.drawImage($videoRef.current, size.capture.dx, size.capture.dy, size.capture.width, size.capture.height, 0, 0, size.capture.width, size.capture.height);
imageData = context.getImageData(0, 0, size.capture.width, size.capture.height);
if (!(typeof onCapture === "function")) {
_context3.next = 11;
break;
}
_context3.next = 11;
return onCapture(imageData);
case 11:
_context3.next = 1;
break;
case 13:
case "end":
return _context3.stop();
}
}
}, _callee3, this);
}));
function start() {
return _start.apply(this, arguments);
}
return start;
}(),
stop: function stop() {
this.status = "cancelled";
}
};
}, [size, graphics, onCapture]);
_react["default"].useEffect(function () {
if (capturing.status !== "running") {
capturing.start();
}
return function () {
return capturing.stop();
};
}, [capturing]);
var handlePlay = function handlePlay(event) {
capturing.start();
typeof onPlay == "function" && onPlay(event);
};
var handlePause = function handlePause(event) {
capturing.stop();
typeof onPause == "function" && onPause(event);
};
var handleVisibilityChange = _react["default"].useCallback(function (event) {
setVisible(!Boolean(event.target.hidden));
}, []);
_react["default"].useEffect(function () {
document.addEventListener("visibilitychange", handleVisibilityChange);
return function () {
document.removeEventListener("visibilitychange", handleVisibilityChange);
};
}, [handleVisibilityChange]);
_react["default"].useLayoutEffect(function () {
if (visible) {
if (videoState.current === "paused") {
startStream();
}
} else {
if (videoState.current === "playing") {
stopStream();
}
}
return function () {
stopStream();
};
}, [mediaStreamContext, visible, startStream, stopStream]);
return /*#__PURE__*/_react["default"].createElement("video", _extends({
ref: $videoRef,
onPlay: handlePlay,
onPause: handlePause,
onLoadedMetadata: handleMetadataLoaded
}, props));
});
var envSupportsWebRTC = function envSupportsWebRTC() {
return navigator && navigator.mediaDevices && navigator.mediaDevices.enumerateDevices && navigator.mediaDevices.getUserMedia;
};
var WebcamStreamWrapper = function WebcamStreamWrapper(props, ref) {
var constraints = props.constraints,
captureSize = props.captureSize,
onCapture = props.onCapture,
rest = _objectWithoutProperties(props, ["constraints", "captureSize", "onCapture"]);
if (envSupportsWebRTC()) {
return /*#__PURE__*/_react["default"].createElement(WebcamStream, _extends({
ref: ref,
constraints: constraints,
captureSize: captureSize,
onCapture: onCapture
}, rest));
} else {
return /*#__PURE__*/_react["default"].createElement("video", _extends({
ref: ref
}, rest));
}
};
var _default = /*#__PURE__*/_react["default"].forwardRef(WebcamStreamWrapper);
exports["default"] = _default;