core/util/browsers.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2012 Joel Martin
   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 var 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 var _cursor_uris_supported = null;
  24
  25 export function browserSupportsCursorURIs () {
  26     if (_cursor_uris_supported === null) {
  27         try {
  28             var target = document.createElement('canvas');
  29             target.style.cursor = 'url("data:image/x-icon;base64,AAACAAEACAgAAAIAAgA4AQAAFgAAACgAAAAIAAAAEAAAAAEAIAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAD/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////AAAAAAAAAAAAAAAAAAAAAA==") 2 2, default';
  30
  31             if (target.style.cursor) {
  32                 Log.Info("Data URI scheme cursor supported");
  33                 _cursor_uris_supported = true;
  34             } else {
  35                 Log.Warn("Data URI scheme cursor not supported");
  36                 _cursor_uris_supported = false;
  37             }
  38         } catch (exc) {
  39             Log.Error("Data URI scheme cursor test exception: " + exc);
  40             _cursor_uris_supported = false;
  41         }
  42     }
  43
  44     return _cursor_uris_supported;
  45 };