yjs/src/structs/ItemString.js
2019-04-05 19:46:18 +02:00

150 lines
3.6 KiB
JavaScript

/**
* @module structs
*/
import {
AbstractItem,
AbstractItemRef,
getItemCleanEnd,
getItemCleanStart,
getItemType,
splitItem,
changeItemRefOffset,
compareIDs,
ItemDeleted,
GC,
StructStore, Transaction, ID, AbstractType // eslint-disable-line
} from '../internals.js'
import * as encoding from 'lib0/encoding.js'
import * as decoding from 'lib0/decoding.js'
export const structStringRefNumber = 6
// TODO: we can probably try to omit rightOrigin. We can just use .right
export class ItemString extends AbstractItem {
/**
* @param {ID} id
* @param {AbstractItem | null} left
* @param {ID | null} origin
* @param {AbstractItem | null} right
* @param {ID | null} rightOrigin
* @param {AbstractType<any>} parent
* @param {string | null} parentSub
* @param {string} string
*/
constructor (id, left, origin, right, rightOrigin, parent, parentSub, string) {
super(id, left, origin, right, rightOrigin, parent, parentSub)
/**
* @type {string}
*/
this.string = string
}
/**
* @param {ID} id
* @param {AbstractItem | null} left
* @param {ID | null} origin
* @param {AbstractItem | null} right
* @param {ID | null} rightOrigin
* @param {AbstractType<any>} parent
* @param {string | null} parentSub
*/
copy (id, left, origin, right, rightOrigin, parent, parentSub) {
return new ItemString(id, left, origin, right, rightOrigin, parent, parentSub, this.string)
}
getContent () {
return this.string.split('')
}
get length () {
return this.string.length
}
/**
* @param {StructStore} store
* @param {number} diff
* @return {ItemString}
*/
splitAt (store, diff) {
/**
* @type {ItemString}
*/
// @ts-ignore
const right = splitItem(store, this, diff)
right.string = this.string.slice(diff)
this.string = this.string.slice(0, diff)
return right
}
/**
* @param {ItemString} right
* @return {boolean}
*/
mergeWith (right) {
if (compareIDs(right.origin, this.lastId) && this.right === right) {
this.string += right.string
return true
}
return false
}
/**
* @param {encoding.Encoder} encoder
* @param {number} offset
*/
write (encoder, offset) {
super.write(encoder, offset, structStringRefNumber)
encoding.writeVarString(encoder, offset === 0 ? this.string : this.string.slice(offset))
}
}
export class ItemStringRef extends AbstractItemRef {
/**
* @param {decoding.Decoder} decoder
* @param {ID} id
* @param {number} info
*/
constructor (decoder, id, info) {
super(decoder, id, info)
/**
* @type {string}
*/
this.string = decoding.readVarString(decoder)
}
get length () {
return this.string.length
}
/**
* @param {Transaction} transaction
* @param {number} offset
* @return {ItemString|GC}
*/
toStruct (transaction, offset) {
const y = transaction.y
const store = y.store
if (offset > 0) {
changeItemRefOffset(this, offset)
this.string = this.string.slice(offset)
}
let parent
if (this.parent !== null) {
const parentItem = getItemType(store, this.parent)
switch (parentItem.constructor) {
case ItemDeleted:
case GC:
return new GC(this.id, this.string.length)
}
parent = parentItem.type
} else {
// @ts-ignore
parent = y.get(this.parentYKey)
}
return new ItemString(
this.id,
this.left === null ? null : getItemCleanEnd(store, this.left),
this.left,
this.right === null ? null : getItemCleanStart(store, this.right),
this.right,
parent,
this.parentSub,
this.string
)
}
}