src/browser/CameraProxy.js

/*
    Licensed to the Apache Software Foundation (ASF) under one
    or more contributor license agreements.  See the NOTICE file
    distributed with this work for additional information
    regarding copyright ownership.  The ASF licenses this file
    to you under the Apache License, Version 2.0 (the
    "License"); you may not use this file except in compliance
    with the License.  You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing,
    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.
*/

const HIGHEST_POSSIBLE_Z_INDEX = 2147483647;

function takePicture (success, error, opts) {
    if (opts && opts[2] === 1) {
        capture(success, error, opts);
    } else {
        const input = document.createElement('input');
        input.style.position = 'relative';
        input.style.zIndex = HIGHEST_POSSIBLE_Z_INDEX;
        input.className = 'cordova-camera-select';
        input.type = 'file';
        input.name = 'files[]';

        input.onchange = function (inputEvent) {
            const reader = new FileReader(); /* eslint no-undef : 0 */
            reader.onload = function (readerEvent) {
                input.parentNode.removeChild(input);

                const imageData = readerEvent.target.result;

                return success(imageData);
            };

            reader.readAsDataURL(inputEvent.target.files[0]);
        };

        document.body.appendChild(input);
    }
}

function capture (success, errorCallback, opts) {
    let localMediaStream;
    let targetWidth = opts[3];
    let targetHeight = opts[4];

    targetWidth = targetWidth === -1 ? 320 : targetWidth;
    targetHeight = targetHeight === -1 ? 240 : targetHeight;

    const video = document.createElement('video');
    const button = document.createElement('button');
    const parent = document.createElement('div');
    parent.style.position = 'relative';
    parent.style.zIndex = HIGHEST_POSSIBLE_Z_INDEX;
    parent.className = 'cordova-camera-capture';
    parent.appendChild(video);
    parent.appendChild(button);

    video.width = targetWidth;
    video.height = targetHeight;
    button.innerHTML = 'Capture!';

    button.onclick = function () {
        // create a canvas and capture a frame from video stream
        const canvas = document.createElement('canvas');
        canvas.width = targetWidth;
        canvas.height = targetHeight;
        canvas.getContext('2d').drawImage(video, 0, 0, targetWidth, targetHeight);

        // convert image stored in canvas to base64 encoded image
        const imageData = canvas.toDataURL('image/png');

        // stop video stream, remove video and button.
        // Note that MediaStream.stop() is deprecated as of Chrome 47.
        if (localMediaStream.stop) {
            localMediaStream.stop();
        } else {
            localMediaStream.getTracks().forEach(function (track) {
                track.stop();
            });
        }
        parent.parentNode.removeChild(parent);

        return success(imageData);
    };

    navigator.getUserMedia = navigator.getUserMedia ||
                             navigator.webkitGetUserMedia ||
                             navigator.mozGetUserMedia ||
                             navigator.msGetUserMedia;

    const successCallback = function (stream) {
        localMediaStream = stream;
        if ('srcObject' in video) {
            video.srcObject = localMediaStream;
        } else {
            video.src = window.URL.createObjectURL(localMediaStream);
        }
        video.play();
        document.body.appendChild(parent);
    };

    if (navigator.mediaDevices.getUserMedia) {
        navigator.mediaDevices.getUserMedia({ video: true, audio: false })
            .then(successCallback)
            .catch(errorCallback);
    } else if (navigator.getUserMedia) {
        navigator.getUserMedia({ video: true, audio: false }, successCallback, errorCallback);
    } else {
        alert('Browser does not support camera :(');
    }
}

module.exports = {
    takePicture,
    cleanup: function () {}
};

require('cordova/exec/proxy').add('Camera', module.exports);