import { cmp, copyPos } from "../line/pos.js"
import { stretchSpansOverChange } from "../line/spans.js"
import { getBetween } from "../line/utils_line.js"
import { signal } from "../util/event.js"
import { indexOf, lst } from "../util/misc.js"
import { changeEnd } from "./change_measurement.js"
import { linkedDocs } from "./document_data.js"
import { Selection } from "./selection.js"
export function History(prev) {
// Arrays of change events and selections. Doing something adds an
// event to done and clears undo. Undoing moves events from done
// to undone, redoing moves them in the other direction.
this.done = []; this.undone = []
this.undoDepth = prev ? prev.undoDepth : Infinity
// Used to track when changes can be merged into a single undo
// event
this.lastModTime = this.lastSelTime = 0
this.lastOp = this.lastSelOp = null
this.lastOrigin = this.lastSelOrigin = null
// Used by the isClean() method
this.generation = this.maxGeneration = prev ? prev.maxGeneration : 1
}
// Create a history change event from an updateDoc-style change
// object.
export function historyChangeFromChange(doc, change) {
let histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)}
attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1)
linkedDocs(doc, doc => attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1), true)
return histChange
}
// Pop all selection events off the end of a history array. Stop at
// a change event.
function clearSelectionEvents(array) {
while (array.length) {
let last = lst(array)
if (last.ranges) array.pop()
else break
}
}
// Find the top change event in the history. Pop off selection
// events that are in the way.
function lastChangeEvent(hist, force) {
if (force) {
clearSelectionEvents(hist.done)
return lst(hist.done)
} else if (hist.done.length && !lst(hist.done).ranges) {
return lst(hist.done)
} else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
hist.done.pop()
return lst(hist.done)
}
}
// Register a change in the history. Merges changes that are within
// a single operation, or are close together with an origin that
// allows merging (starting with "+") into a single event.
export function addChangeToHistory(doc, change, selAfter, opId) {
let hist = doc.history
hist.undone.length = 0
let time = +new Date, cur
let last
if ((hist.lastOp == opId ||
hist.lastOrigin == change.origin && change.origin &&
((change.origin.charAt(0) == "+" && hist.lastModTime > time - (doc.cm ? doc.cm.options.historyEventDelay : 500)) ||
change.origin.charAt(0) == "*")) &&
(cur = lastChangeEvent(hist, hist.lastOp == opId))) {
// Merge this change into the last event
last = lst(cur.changes)
if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
// Optimized case for simple insertion -- don't want to add
// new changesets for every character typed
last.to = changeEnd(change)
} else {
// Add new sub-event
cur.changes.push(historyChangeFromChange(doc, change))
}
} else {
// Can not be merged, start a new event.
let before = lst(hist.done)
if (!before || !before.ranges)
pushSelectionToHistory(doc.sel, hist.done)
cur = {changes: [historyChangeFromChange(doc, change)],
generation: hist.generation}
hist.done.push(cur)
while (hist.done.length > hist.undoDepth) {
hist.done.shift()
if (!hist.done[0].ranges) hist.done.shift()
}
}
hist.done.push(selAfter)
hist.generation = ++hist.maxGeneration
hist.lastModTime = hist.lastSelTime = time
hist.lastOp = hist.lastSelOp = opId
hist.lastOrigin = hist.lastSelOrigin = change.origin
if (!last) signal(doc, "historyAdded")
}
function selectionEventCanBeMerged(doc, origin, prev, sel) {
let ch = origin.charAt(0)
return ch == "*" ||
ch == "+" &&
prev.ranges.length == sel.ranges.length &&
prev.somethingSelected() == sel.somethingSelected() &&
new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500)
}
// Called whenever the selection changes, sets the new selection as
// the pending selection in the history, and pushes the old pending
// selection into the 'done' array when it was significantly
// different (in number of selected ranges, emptiness, or time).
export function addSelectionToHistory(doc, sel, opId, options) {
let hist = doc.history, origin = options && options.origin
// A new event is started when the previous origin does not match
// the current, or the origins don't allow matching. Origins
// starting with * are always merged, those starting with + are
// merged when similar and close together in time.
if (opId == hist.lastSelOp ||
(origin && hist.lastSelOrigin == origin &&
(hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||
selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))
hist.done[hist.done.length - 1] = sel
else
pushSelectionToHistory(sel, hist.done)
hist.lastSelTime = +new Date
hist.lastSelOrigin = origin
hist.lastSelOp = opId
if (options && options.clearRedo !== false)
clearSelectionEvents(hist.undone)
}
export function pushSelectionToHistory(sel, dest) {
let top = lst(dest)
if (!(top && top.ranges && top.equals(sel)))
dest.push(sel)
}
// Used to store marked span information in the history.
function attachLocalSpans(doc, change, from, to) {
let existing = change["spans_" + doc.id], n = 0
doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), line => {
if (line.markedSpans)
(existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans
++n
})
}
// When un/re-doing restores text containing marked spans, those
// that have been explicitly cleared should not be restored.
function removeClearedSpans(spans) {
if (!spans) return null
let out
for (let i = 0; i < spans.length; ++i) {
if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i) }
else if (out) out.push(spans[i])
}
return !out ? spans : out.length ? out : null
}
// Retrieve and filter the old marked spans stored in a change event.
function getOldSpans(doc, change) {
let found = change["spans_" + doc.id]
if (!found) return null
let nw = []
for (let i = 0; i < change.text.length; ++i)
nw.push(removeClearedSpans(found[i]))
return nw
}
// Used for un/re-doing changes from the history. Combines the
// result of computing the existing spans with the set of spans that
// existed in the history (so that deleting around a span and then
// undoing brings back the span).
export function mergeOldSpans(doc, change) {
let old = getOldSpans(doc, change)
let stretched = stretchSpansOverChange(doc, change)
if (!old) return stretched
if (!stretched) return old
for (let i = 0; i < old.length; ++i) {
let oldCur = old[i], stretchCur = stretched[i]
if (oldCur && stretchCur) {
spans: for (let j = 0; j < stretchCur.length; ++j) {
let span = stretchCur[j]
for (let k = 0; k < oldCur.length; ++k)
if (oldCur[k].marker == span.marker) continue spans
oldCur.push(span)
}
} else if (stretchCur) {
old[i] = stretchCur
}
}
return old
}
// Used both to provide a JSON-safe object in .getHistory, and, when
// detaching a document, to split the history in two
export function copyHistoryArray(events, newGroup, instantiateSel) {
let copy = []
for (let i = 0; i < events.length; ++i) {
let event = events[i]
if (event.ranges) {
copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event)
continue
}
let changes = event.changes, newChanges = []
copy.push({changes: newChanges})
for (let j = 0; j < changes.length; ++j) {
let change = changes[j], m
newChanges.push({from: change.from, to: change.to, text: change.text})
if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {
if (indexOf(newGroup, Number(m[1])) > -1) {
lst(newChanges)[prop] = change[prop]
delete change[prop]
}
}
}
}
return copy
}
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