tldraw/hooks/useCanvasEvents.ts
2021-07-12 12:27:30 +01:00

140 lines
3.9 KiB
TypeScript

/* eslint-disable @typescript-eslint/explicit-module-boundary-types */
import { MutableRefObject, useCallback, useEffect } from 'react'
import state from 'state'
import {
fastBrushSelect,
fastDrawUpdate,
fastPanUpdate,
fastTransform,
fastTranslate,
} from 'state/hacks'
import inputs from 'state/inputs'
import Vec from 'utils/vec'
export default function useCanvasEvents(
rCanvas: MutableRefObject<SVGGElement>
) {
const handlePointerDown = useCallback(
(e: React.PointerEvent<SVGSVGElement>) => {
if (!inputs.canAccept(e.pointerId)) return
rCanvas.current.setPointerCapture(e.pointerId)
const info = inputs.pointerDown(e, 'canvas')
if (e.button === 0) {
if (inputs.isDoubleClick() && !(info.altKey || info.metaKey)) {
state.send('DOUBLE_POINTED_CANVAS', info)
}
state.send('POINTED_CANVAS', info)
} else if (e.button === 2) {
state.send('RIGHT_POINTED', info)
}
},
[]
)
const handlePointerMove = useCallback(
(e: React.PointerEvent<SVGSVGElement>) => {
if (!inputs.canAccept(e.pointerId)) return
const prev = inputs.pointer?.point
const info = inputs.pointerMove(e)
if (prev && state.isIn('selecting') && inputs.keys[' ']) {
const delta = Vec.sub(prev, info.point)
fastPanUpdate(delta)
state.send('KEYBOARD_PANNED_CAMERA', {
delta: Vec.sub(prev, info.point),
})
return
}
if (state.isIn('draw.editing')) {
fastDrawUpdate(info)
} else if (state.isIn('brushSelecting')) {
fastBrushSelect(info.point)
} else if (state.isIn('translatingSelection')) {
fastTranslate(info)
} else if (state.isIn('transformingSelection')) {
fastTransform(info)
}
state.send('MOVED_POINTER', info)
},
[]
)
const handlePointerUp = useCallback(
(e: React.PointerEvent<SVGSVGElement>) => {
if (!inputs.canAccept(e.pointerId)) return
rCanvas.current.releasePointerCapture(e.pointerId)
state.send('STOPPED_POINTING', {
id: 'canvas',
...inputs.pointerUp(e, 'canvas'),
})
},
[]
)
const handleTouchStart = useCallback((e: React.TouchEvent<SVGSVGElement>) => {
if ('safari' in window) {
e.preventDefault()
}
}, [])
useEffect(() => {
const preventGestureNavigation = (event: TouchEvent) => {
event.preventDefault()
}
const preventNavigation = (event: TouchEvent) => {
// Center point of the touch area
const touchXPosition = event.touches[0].pageX
// Size of the touch area
const touchXRadius = event.touches[0].radiusX || 0
// We set a threshold (10px) on both sizes of the screen,
// if the touch area overlaps with the screen edges
// it's likely to trigger the navigation. We prevent the
// touchstart event in that case.
if (
touchXPosition - touchXRadius < 10 ||
touchXPosition + touchXRadius > window.innerWidth - 10
) {
event.preventDefault()
}
}
rCanvas.current.addEventListener('gestureend', preventGestureNavigation)
rCanvas.current.addEventListener('gesturechange', preventGestureNavigation)
rCanvas.current.addEventListener('gesturestart', preventGestureNavigation)
rCanvas.current.addEventListener('touchstart', preventNavigation)
return () => {
rCanvas.current.removeEventListener(
'gestureend',
preventGestureNavigation
)
rCanvas.current.removeEventListener(
'gesturechange',
preventGestureNavigation
)
rCanvas.current.removeEventListener(
'gesturestart',
preventGestureNavigation
)
rCanvas.current.removeEventListener('touchstart', preventNavigation)
}
}, [])
return {
onPointerDown: handlePointerDown,
onPointerMove: handlePointerMove,
onPointerUp: handlePointerUp,
onTouchStart: handleTouchStart,
}
}