core/util/browser.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2019 The noVNC Authors
   4  * Licensed under MPL 2.0 (see LICENSE.txt)
   5  *
   6  * See README.md for usage and integration instructions.
   7  */
   8
   9 import * as Log from './logging.js';
  10
  11 // Touch detection
  12 export let isTouchDevice = ('ontouchstart' in document.documentElement) ||
  13                                  // requried for Chrome debugger
  14                                  (document.ontouchstart !== undefined) ||
  15                                  // required for MS Surface
  16                                  (navigator.maxTouchPoints > 0) ||
  17                                  (navigator.msMaxTouchPoints > 0);
  18 window.addEventListener('touchstart', function onFirstTouch() {
  19     isTouchDevice = true;
  20     window.removeEventListener('touchstart', onFirstTouch, false);
  21 }, false);
  22
  23
  24 // The goal is to find a certain physical width, the devicePixelRatio
  25 // brings us a bit closer but is not optimal.
  26 export let dragThreshold = 10 * (window.devicePixelRatio || 1);
  27
  28 let _supportsCursorURIs = false;
  29
  30 try {
  31     const target = document.createElement('canvas');
  32     target.style.cursor = 'url("data:image/x-icon;base64,AAACAAEACAgAAAIAAgA4AQAAFgAAACgAAAAIAAAAEAAAAAEAIAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAD/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////AAAAAAAAAAAAAAAAAAAAAA==") 2 2, default';
  33
  34     if (target.style.cursor.indexOf("url") === 0) {
  35         Log.Info("Data URI scheme cursor supported");
  36         _supportsCursorURIs = true;
  37     } else {
  38         Log.Warn("Data URI scheme cursor not supported");
  39     }
  40 } catch (exc) {
  41     Log.Error("Data URI scheme cursor test exception: " + exc);
  42 }
  43
  44 export const supportsCursorURIs = _supportsCursorURIs;
  45
  46 let _supportsImageMetadata = false;
  47 try {
  48     new ImageData(new Uint8ClampedArray(4), 1, 1);
  49     _supportsImageMetadata = true;
  50 } catch (ex) {
  51     // ignore failure
  52 }
  53 export const supportsImageMetadata = _supportsImageMetadata;
  54
  55 let _hasScrollbarGutter = true;
  56 try {
  57     // Create invisible container
  58     const container = document.createElement('div');
  59     container.style.visibility = 'hidden';
  60     container.style.overflow = 'scroll'; // forcing scrollbars
  61     document.body.appendChild(container);
  62
  63     // Create a div and place it in the container
  64     const child = document.createElement('div');
  65     container.appendChild(child);
  66
  67     // Calculate the difference between the container's full width
  68     // and the child's width - the difference is the scrollbars
  69     const scrollbarWidth = (container.offsetWidth - child.offsetWidth);
  70
  71     // Clean up
  72     container.parentNode.removeChild(container);
  73
  74     _hasScrollbarGutter = scrollbarWidth != 0;
  75 } catch (exc) {
  76     Log.Error("Scrollbar test exception: " + exc);
  77 }
  78 export const hasScrollbarGutter = _hasScrollbarGutter;
  79
  80 export function isMac() {
  81     return navigator && !!(/mac/i).exec(navigator.platform);
  82 }
  83
  84 export function isWindows() {
  85     return navigator && !!(/win/i).exec(navigator.platform);
  86 }
  87
  88 export function isIOS() {
  89     return navigator &&
  90            (!!(/ipad/i).exec(navigator.platform) ||
  91             !!(/iphone/i).exec(navigator.platform) ||
  92             !!(/ipod/i).exec(navigator.platform));
  93 }
  94
  95 export function isSafari() {
  96     return navigator && (navigator.userAgent.indexOf('Safari') !== -1 &&
  97                          navigator.userAgent.indexOf('Chrome') === -1);
  98 }
  99
 100 export function isIE() {
 101     return navigator && !!(/trident/i).exec(navigator.userAgent);
 102 }
 103
 104 export function isEdge() {
 105     return navigator && !!(/edge/i).exec(navigator.userAgent);
 106 }
 107
 108 export function isFirefox() {
 109     return navigator && !!(/firefox/i).exec(navigator.userAgent);
 110 }
 111