| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | export function defaultOnDefaultTransitionIndicator(): void | (() => void) { |
| 11 | if (typeof navigation !== 'object') { |
| 12 | // If the Navigation API is not available, then this is a noop. |
| 13 | return; |
| 14 | } |
| 15 | |
| 16 | let isCancelled = false; |
| 17 | let pendingResolve: null | (() => void) = null; |
| 18 | |
| 19 | function handleNavigate(event: NavigateEvent) { |
| 20 | if (event.canIntercept && event.info === 'react-transition') { |
| 21 | event.intercept({ |
| 22 | handler() { |
| 23 | return new Promise(resolve => (pendingResolve = resolve)); |
| 24 | }, |
| 25 | focusReset: 'manual', |
| 26 | scroll: 'manual', |
| 27 | }); |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | function handleNavigateComplete() { |
| 32 | if (pendingResolve !== null) { |
| 33 | // If this was not our navigation completing, we were probably cancelled. |
| 34 | // We'll start a new one below. |
| 35 | pendingResolve(); |
| 36 | pendingResolve = null; |
| 37 | } |
| 38 | if (!isCancelled) { |
| 39 | // Some other navigation completed but we should still be running. |
| 40 | // Start another fake one to keep the loading indicator going. |
| 41 | // There needs to be an async gap to work around https://issues.chromium.org/u/1/issues/419746417. |
| 42 | setTimeout(startFakeNavigation, 20); |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | // $FlowFixMe[incompatible-type] |
| 47 | navigation.addEventListener('navigate', handleNavigate); |
| 48 | // $FlowFixMe[incompatible-type] |
| 49 | navigation.addEventListener('navigatesuccess', handleNavigateComplete); |
| 50 | // $FlowFixMe[incompatible-type] |
| 51 | navigation.addEventListener('navigateerror', handleNavigateComplete); |
| 52 | |
| 53 | function startFakeNavigation() { |
| 54 | if (isCancelled) { |
| 55 | // We already stopped this Transition. |
| 56 | return; |
| 57 | } |
| 58 | if (navigation.transition) { |
| 59 | // There is an on-going Navigation already happening. Let's wait for it to |
| 60 | // finish before starting our fake one. |
| 61 | return; |
| 62 | } |
| 63 | // Trigger a fake navigation to the same page |
| 64 | const currentEntry = navigation.currentEntry; |
| 65 | if (currentEntry && currentEntry.url != null) { |
| 66 | navigation.navigate(currentEntry.url, { |
| 67 | state: currentEntry.getState(), |
| 68 | info: 'react-transition', // indicator to routers to ignore this navigation |
| 69 | history: 'replace', |
| 70 | }); |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | // Delay the start a bit in case this is a fast Transition. |
| 75 | setTimeout(startFakeNavigation, 100); |
| 76 | |
| 77 | return function () { |
| 78 | isCancelled = true; |
| 79 | // $FlowFixMe[incompatible-type] |
| 80 | navigation.removeEventListener('navigate', handleNavigate); |
| 81 | // $FlowFixMe[incompatible-type] |
| 82 | navigation.removeEventListener('navigatesuccess', handleNavigateComplete); |
| 83 | // $FlowFixMe[incompatible-type] |
| 84 | navigation.removeEventListener('navigateerror', handleNavigateComplete); |
| 85 | if (pendingResolve !== null) { |
| 86 | pendingResolve(); |
| 87 | pendingResolve = null; |
| 88 | } |
| 89 | }; |
| 90 | } |