hedgedoc/frontend/src/components/editor-page/renderer-pane/hooks/use-send-scroll-state.ts
Tilman Vatteroth e390c0dd15 fix(frontend): reformat source files
Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>
2022-12-04 20:59:46 +01:00

29 lines
1.3 KiB
TypeScript

/*
* SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
*
* SPDX-License-Identifier: AGPL-3.0-only
*/
import { useApplicationState } from '../../../../hooks/common/use-application-state'
import { CommunicationMessageType } from '../../../render-page/window-post-message-communicator/rendering-message'
import { useEditorToRendererCommunicator } from '../../render-context/editor-to-renderer-communicator-context-provider'
import type { ScrollState } from '../../synced-scroll/scroll-props'
import equal from 'fast-deep-equal'
import { useEffect, useRef } from 'react'
/**
* Sends the given {@link ScrollState scroll state} to the renderer if the content changed.
*
* @param scrollState The scroll state to send
*/
export const useSendScrollState = (scrollState: ScrollState | undefined): void => {
const iframeCommunicator = useEditorToRendererCommunicator()
const oldScrollState = useRef<ScrollState | undefined>(undefined)
const rendererReady = useApplicationState((state) => state.rendererStatus.rendererReady)
useEffect(() => {
if (rendererReady && scrollState && !equal(scrollState, oldScrollState.current)) {
oldScrollState.current = scrollState
iframeCommunicator.sendMessageToOtherSide({ type: CommunicationMessageType.SET_SCROLL_STATE, scrollState })
}
}, [iframeCommunicator, rendererReady, scrollState])
}