| /* |
| * noVNC: HTML5 VNC client |
| * Copyright (C) 2018 The noVNC Authors |
| * Licensed under MPL 2.0 (see LICENSE.txt) |
| * |
| * See README.md for usage and integration instructions. |
| */ |
| |
| /* |
| * Cross-browser event and position routines |
| */ |
| |
| export function getPointerEvent(e) { |
| return e.changedTouches ? e.changedTouches[0] : e.touches ? e.touches[0] : e; |
| } |
| |
| export function stopEvent(e) { |
| e.stopPropagation(); |
| e.preventDefault(); |
| } |
| |
| // Emulate Element.setCapture() when not supported |
| let _captureRecursion = false; |
| let _captureElem = null; |
| function _captureProxy(e) { |
| // Recursion protection as we'll see our own event |
| if (_captureRecursion) return; |
| |
| // Clone the event as we cannot dispatch an already dispatched event |
| const newEv = new e.constructor(e.type, e); |
| |
| _captureRecursion = true; |
| _captureElem.dispatchEvent(newEv); |
| _captureRecursion = false; |
| |
| // Avoid double events |
| e.stopPropagation(); |
| |
| // Respect the wishes of the redirected event handlers |
| if (newEv.defaultPrevented) { |
| e.preventDefault(); |
| } |
| |
| // Implicitly release the capture on button release |
| if (e.type === "mouseup") { |
| releaseCapture(); |
| } |
| } |
| |
| // Follow cursor style of target element |
| function _captureElemChanged() { |
| const captureElem = document.getElementById("noVNC_mouse_capture_elem"); |
| captureElem.style.cursor = window.getComputedStyle(_captureElem).cursor; |
| } |
| |
| const _captureObserver = new MutationObserver(_captureElemChanged); |
| |
| let _captureIndex = 0; |
| |
| export function setCapture(elem) { |
| if (elem.setCapture) { |
| |
| elem.setCapture(); |
| |
| // IE releases capture on 'click' events which might not trigger |
| elem.addEventListener('mouseup', releaseCapture); |
| |
| } else { |
| // Release any existing capture in case this method is |
| // called multiple times without coordination |
| releaseCapture(); |
| |
| let captureElem = document.getElementById("noVNC_mouse_capture_elem"); |
| |
| if (captureElem === null) { |
| captureElem = document.createElement("div"); |
| captureElem.id = "noVNC_mouse_capture_elem"; |
| captureElem.style.position = "fixed"; |
| captureElem.style.top = "0px"; |
| captureElem.style.left = "0px"; |
| captureElem.style.width = "100%"; |
| captureElem.style.height = "100%"; |
| captureElem.style.zIndex = 10000; |
| captureElem.style.display = "none"; |
| document.body.appendChild(captureElem); |
| |
| // This is to make sure callers don't get confused by having |
| // our blocking element as the target |
| captureElem.addEventListener('contextmenu', _captureProxy); |
| |
| captureElem.addEventListener('mousemove', _captureProxy); |
| captureElem.addEventListener('mouseup', _captureProxy); |
| } |
| |
| _captureElem = elem; |
| _captureIndex++; |
| |
| // Track cursor and get initial cursor |
| _captureObserver.observe(elem, {attributes: true}); |
| _captureElemChanged(); |
| |
| captureElem.style.display = ""; |
| |
| // We listen to events on window in order to keep tracking if it |
| // happens to leave the viewport |
| window.addEventListener('mousemove', _captureProxy); |
| window.addEventListener('mouseup', _captureProxy); |
| } |
| } |
| |
| export function releaseCapture() { |
| if (document.releaseCapture) { |
| |
| document.releaseCapture(); |
| |
| } else { |
| if (!_captureElem) { |
| return; |
| } |
| |
| // There might be events already queued, so we need to wait for |
| // them to flush. E.g. contextmenu in Microsoft Edge |
| window.setTimeout((expected) => { |
| // Only clear it if it's the expected grab (i.e. no one |
| // else has initiated a new grab) |
| if (_captureIndex === expected) { |
| _captureElem = null; |
| } |
| }, 0, _captureIndex); |
| |
| _captureObserver.disconnect(); |
| |
| const captureElem = document.getElementById("noVNC_mouse_capture_elem"); |
| captureElem.style.display = "none"; |
| |
| window.removeEventListener('mousemove', _captureProxy); |
| window.removeEventListener('mouseup', _captureProxy); |
| } |
| } |