Cross-Browser-Declarations.js

// _____________________________
// Cross-Browser-Declarations.js

// animation-frame used in WebM recording

/*jshint -W079 */
var requestAnimationFrame = window.requestAnimationFrame;
if (typeof requestAnimationFrame === 'undefined') {
    if (typeof webkitRequestAnimationFrame !== 'undefined') {
        /*global requestAnimationFrame:true */
        requestAnimationFrame = webkitRequestAnimationFrame;
    } else if (typeof mozRequestAnimationFrame !== 'undefined') {
        /*global requestAnimationFrame:true */
        requestAnimationFrame = mozRequestAnimationFrame;
    } else if (typeof msRequestAnimationFrame !== 'undefined') {
        /*global requestAnimationFrame:true */
        requestAnimationFrame = msRequestAnimationFrame;
    } else if (typeof requestAnimationFrame === 'undefined') {
        // via: https://gist.github.com/paulirish/1579671
        var lastTime = 0;

        /*global requestAnimationFrame:true */
        requestAnimationFrame = function(callback, element) {
            var currTime = new Date().getTime();
            var timeToCall = Math.max(0, 16 - (currTime - lastTime));
            var id = setTimeout(function() {
                callback(currTime + timeToCall);
            }, timeToCall);
            lastTime = currTime + timeToCall;
            return id;
        };
    }
}

/*jshint -W079 */
var cancelAnimationFrame = window.cancelAnimationFrame;
if (typeof cancelAnimationFrame === 'undefined') {
    if (typeof webkitCancelAnimationFrame !== 'undefined') {
        /*global cancelAnimationFrame:true */
        cancelAnimationFrame = webkitCancelAnimationFrame;
    } else if (typeof mozCancelAnimationFrame !== 'undefined') {
        /*global cancelAnimationFrame:true */
        cancelAnimationFrame = mozCancelAnimationFrame;
    } else if (typeof msCancelAnimationFrame !== 'undefined') {
        /*global cancelAnimationFrame:true */
        cancelAnimationFrame = msCancelAnimationFrame;
    } else if (typeof cancelAnimationFrame === 'undefined') {
        /*global cancelAnimationFrame:true */
        cancelAnimationFrame = function(id) {
            clearTimeout(id);
        };
    }
}

// WebAudio API representer
var AudioContext = window.AudioContext;

if (typeof AudioContext === 'undefined') {
    if (typeof webkitAudioContext !== 'undefined') {
        /*global AudioContext:true */
        AudioContext = webkitAudioContext;
    }

    if (typeof mozAudioContext !== 'undefined') {
        /*global AudioContext:true */
        AudioContext = mozAudioContext;
    }
}

/*jshint -W079 */
var URL = window.URL;

if (typeof URL === 'undefined' && typeof webkitURL !== 'undefined') {
    /*global URL:true */
    URL = webkitURL;
}

if (typeof navigator !== 'undefined' && typeof navigator.getUserMedia === 'undefined') { // maybe window.navigator?
    if (typeof navigator.webkitGetUserMedia !== 'undefined') {
        navigator.getUserMedia = navigator.webkitGetUserMedia;
    }

    if (typeof navigator.mozGetUserMedia !== 'undefined') {
        navigator.getUserMedia = navigator.mozGetUserMedia;
    }
}

var isEdge = navigator.userAgent.indexOf('Edge') !== -1 && (!!navigator.msSaveBlob || !!navigator.msSaveOrOpenBlob);
var isOpera = !!window.opera || navigator.userAgent.indexOf('OPR/') !== -1;
var isFirefox = navigator.userAgent.toLowerCase().indexOf('firefox') > -1 && ('netscape' in window) && / rv:/.test(navigator.userAgent);
var isChrome = (!isOpera && !isEdge && !!navigator.webkitGetUserMedia) || isElectron() || navigator.userAgent.toLowerCase().indexOf('chrome/') !== -1;

var isSafari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);

if (isSafari && !isChrome && navigator.userAgent.indexOf('CriOS') !== -1) {
    isSafari = false;
    isChrome = true;
}

var MediaStream = window.MediaStream;

if (typeof MediaStream === 'undefined' && typeof webkitMediaStream !== 'undefined') {
    MediaStream = webkitMediaStream;
}

/*global MediaStream:true */
if (typeof MediaStream !== 'undefined') {
    // override "stop" method for all browsers
    if (typeof MediaStream.prototype.stop === 'undefined') {
        MediaStream.prototype.stop = function() {
            this.getTracks().forEach(function(track) {
                track.stop();
            });
        };
    }
}

// below function via: http://goo.gl/B3ae8c
/**
 * Return human-readable file size.
 * @param {number} bytes - Pass bytes and get formatted string.
 * @returns {string} - formatted string
 * @example
 * bytesToSize(1024*1024*5) === '5 GB'
 * @see {@link https://github.com/muaz-khan/RecordRTC|RecordRTC Source Code}
 */
function bytesToSize(bytes) {
    var k = 1000;
    var sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
    if (bytes === 0) {
        return '0 Bytes';
    }
    var i = parseInt(Math.floor(Math.log(bytes) / Math.log(k)), 10);
    return (bytes / Math.pow(k, i)).toPrecision(3) + ' ' + sizes[i];
}

/**
 * @param {Blob} file - File or Blob object. This parameter is required.
 * @param {string} fileName - Optional file name e.g. "Recorded-Video.webm"
 * @example
 * invokeSaveAsDialog(blob or file, [optional] fileName);
 * @see {@link https://github.com/muaz-khan/RecordRTC|RecordRTC Source Code}
 */
function invokeSaveAsDialog(file, fileName) {
    if (!file) {
        throw 'Blob object is required.';
    }

    if (!file.type) {
        try {
            file.type = 'video/webm';
        } catch (e) {}
    }

    var fileExtension = (file.type || 'video/webm').split('/')[1];

    if (fileName && fileName.indexOf('.') !== -1) {
        var splitted = fileName.split('.');
        fileName = splitted[0];
        fileExtension = splitted[1];
    }

    var fileFullName = (fileName || (Math.round(Math.random() * 9999999999) + 888888888)) + '.' + fileExtension;

    if (typeof navigator.msSaveOrOpenBlob !== 'undefined') {
        return navigator.msSaveOrOpenBlob(file, fileFullName);
    } else if (typeof navigator.msSaveBlob !== 'undefined') {
        return navigator.msSaveBlob(file, fileFullName);
    }

    var hyperlink = document.createElement('a');
    hyperlink.href = URL.createObjectURL(file);
    hyperlink.download = fileFullName;

    hyperlink.style = 'display:none;opacity:0;color:transparent;';
    (document.body || document.documentElement).appendChild(hyperlink);

    if (typeof hyperlink.click === 'function') {
        hyperlink.click();
    } else {
        hyperlink.target = '_blank';
        hyperlink.dispatchEvent(new MouseEvent('click', {
            view: window,
            bubbles: true,
            cancelable: true
        }));
    }

    URL.revokeObjectURL(hyperlink.href);
}

/**
 * from: https://github.com/cheton/is-electron/blob/master/index.js
 **/
function isElectron() {
    // Renderer process
    if (typeof window !== 'undefined' && typeof window.process === 'object' && window.process.type === 'renderer') {
        return true;
    }

    // Main process
    if (typeof process !== 'undefined' && typeof process.versions === 'object' && !!process.versions.electron) {
        return true;
    }

    // Detect the user agent when the `nodeIntegration` option is set to true
    if (typeof navigator === 'object' && typeof navigator.userAgent === 'string' && navigator.userAgent.indexOf('Electron') >= 0) {
        return true;
    }

    return false;
}

function getTracks(stream, kind) {
    if (!stream || !stream.getTracks) {
        return [];
    }

    return stream.getTracks().filter(function(t) {
        return t.kind === (kind || 'audio');
    });
}

function setSrcObject(stream, element) {
    if ('srcObject' in element) {
        element.srcObject = stream;
    } else if ('mozSrcObject' in element) {
        element.mozSrcObject = stream;
    } else {
        element.srcObject = stream;
    }
}

/**
 * @param {Blob} file - File or Blob object.
 * @param {function} callback - Callback function.
 * @example
 * getSeekableBlob(blob or file, callback);
 * @see {@link https://github.com/muaz-khan/RecordRTC|RecordRTC Source Code}
 */
function getSeekableBlob(inputBlob, callback) {
    // EBML.js copyrights goes to: https://github.com/legokichi/ts-ebml
    if (typeof EBML === 'undefined') {
        throw new Error('Please link: https://cdn.webrtc-experiment.com/EBML.js');
    }

    var reader = new EBML.Reader();
    var decoder = new EBML.Decoder();
    var tools = EBML.tools;

    var fileReader = new FileReader();
    fileReader.onload = function(e) {
        var ebmlElms = decoder.decode(this.result);
        ebmlElms.forEach(function(element) {
            reader.read(element);
        });
        reader.stop();
        var refinedMetadataBuf = tools.makeMetadataSeekable(reader.metadatas, reader.duration, reader.cues);
        var body = this.result.slice(reader.metadataSize);
        var newBlob = new Blob([refinedMetadataBuf, body], {
            type: 'video/webm'
        });

        callback(newBlob);
    };
    fileReader.readAsArrayBuffer(inputBlob);
}

if (typeof RecordRTC !== 'undefined') {
    RecordRTC.invokeSaveAsDialog = invokeSaveAsDialog;
    RecordRTC.getTracks = getTracks;
    RecordRTC.getSeekableBlob = getSeekableBlob;
    RecordRTC.bytesToSize = bytesToSize;
    RecordRTC.isElectron = isElectron;
}