import { createContext } from 'react'
import { LEVELS, log } from '../utils'
export const ScrollerDispatch = createContext(null)
export const SCROLLABLE = 'SCROLLABLE'
export const FIXED = 'FIXED'
export const VSCROLL = 'VSCROLL'
export const VWHEEL = 'VWHEEL'
export const HSCROLL = 'HSCROLL'
export const INVALIDATE = 'INVALIDATE'
export const scrollerReducer = (state, action) => {
log('scrollerReducer', LEVELS.INFO, state, action)
const { type } = action
switch (type) {
case SCROLLABLE: {
const { scrollableBody } = action
return { ...state, scrollableBody }
}
case FIXED: {
const { fixedBody } = action
return { ...state, fixedBody }
}
case VSCROLL: {
const { scrollTop, scrolling } = action
return scrolling
? { ...state, scrolling, scrollTop, wheeling: false, deltaY: 0 }
: { ...state, scrolling: false }
}
case HSCROLL: {
const { scrollLeft, scrolling } = action
return scrolling
? { ...state, scrolling, scrollLeft }
: { ...state, scrolling: false }
}
case INVALIDATE: {
return { ...state }
}
case VWHEEL: {
const { deltaY } = action
return { ...state, wheeling: true, deltaY }
}
default:
throw new Error(`Unknown action: ${action.type}`)
}
}
Copyright 2020 Ulrich Gaal
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.