33 lines
868 B
TypeScript
33 lines
868 B
TypeScript
import React, { useEffect } from 'react'
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import state from 'state'
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import storage from 'state/storage'
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import { getCurrentCamera } from 'utils/utils'
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/**
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* When the state's camera changes, update the transform of
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* the SVG group to reflect the correct zoom and pan.
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* @param ref
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*/
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export default function useCamera(ref: React.MutableRefObject<SVGGElement>) {
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useEffect(() => {
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let prev = getCurrentCamera(state.data)
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return state.onUpdate(() => {
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const g = ref.current
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if (!g) return
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const { point, zoom } = getCurrentCamera(state.data)
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if (point !== prev.point || zoom !== prev.zoom) {
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g.setAttribute(
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'transform',
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`scale(${zoom}) translate(${point[0]} ${point[1]})`
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)
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storage.savePageState(state.data)
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prev = getCurrentCamera(state.data)
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}
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})
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}, [state])
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}
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