774 lines
27 KiB
TypeScript
774 lines
27 KiB
TypeScript
import {
|
|
type AnsiCode,
|
|
ansiCodesToString,
|
|
diffAnsiCodes,
|
|
} from '@alcalzone/ansi-tokenize'
|
|
import { logForDebugging } from '../utils/debug.js'
|
|
import type { Diff, FlickerReason, Frame } from './frame.js'
|
|
import type { Point } from './layout/geometry.js'
|
|
import {
|
|
type Cell,
|
|
CellWidth,
|
|
cellAt,
|
|
charInCellAt,
|
|
diffEach,
|
|
type Hyperlink,
|
|
isEmptyCellAt,
|
|
type Screen,
|
|
type StylePool,
|
|
shiftRows,
|
|
visibleCellAtIndex,
|
|
} from './screen.js'
|
|
import {
|
|
CURSOR_HOME,
|
|
scrollDown as csiScrollDown,
|
|
scrollUp as csiScrollUp,
|
|
RESET_SCROLL_REGION,
|
|
setScrollRegion,
|
|
} from './termio/csi.js'
|
|
import { LINK_END, link as oscLink } from './termio/osc.js'
|
|
|
|
type State = {
|
|
previousOutput: string
|
|
}
|
|
|
|
type Options = {
|
|
isTTY: boolean
|
|
stylePool: StylePool
|
|
}
|
|
|
|
const CARRIAGE_RETURN = { type: 'carriageReturn' } as const
|
|
const NEWLINE = { type: 'stdout', content: '\n' } as const
|
|
|
|
export class LogUpdate {
|
|
private state: State
|
|
|
|
constructor(private readonly options: Options) {
|
|
this.state = {
|
|
previousOutput: '',
|
|
}
|
|
}
|
|
|
|
renderPreviousOutput_DEPRECATED(prevFrame: Frame): Diff {
|
|
if (!this.options.isTTY) {
|
|
// Non-TTY output is no longer supported (string output was removed)
|
|
return [NEWLINE]
|
|
}
|
|
return this.getRenderOpsForDone(prevFrame)
|
|
}
|
|
|
|
// Called when process resumes from suspension (SIGCONT) to prevent clobbering terminal content
|
|
reset(): void {
|
|
this.state.previousOutput = ''
|
|
}
|
|
|
|
private renderFullFrame(frame: Frame): Diff {
|
|
const { screen } = frame
|
|
const lines: string[] = []
|
|
let currentStyles: AnsiCode[] = []
|
|
let currentHyperlink: Hyperlink = undefined
|
|
for (let y = 0; y < screen.height; y++) {
|
|
let line = ''
|
|
for (let x = 0; x < screen.width; x++) {
|
|
const cell = cellAt(screen, x, y)
|
|
if (cell && cell.width !== CellWidth.SpacerTail) {
|
|
// Handle hyperlink transitions
|
|
if (cell.hyperlink !== currentHyperlink) {
|
|
if (currentHyperlink !== undefined) {
|
|
line += LINK_END
|
|
}
|
|
if (cell.hyperlink !== undefined) {
|
|
line += oscLink(cell.hyperlink)
|
|
}
|
|
currentHyperlink = cell.hyperlink
|
|
}
|
|
const cellStyles = this.options.stylePool.get(cell.styleId)
|
|
const styleDiff = diffAnsiCodes(currentStyles, cellStyles)
|
|
if (styleDiff.length > 0) {
|
|
line += ansiCodesToString(styleDiff)
|
|
currentStyles = cellStyles
|
|
}
|
|
line += cell.char
|
|
}
|
|
}
|
|
// Close any open hyperlink before resetting styles
|
|
if (currentHyperlink !== undefined) {
|
|
line += LINK_END
|
|
currentHyperlink = undefined
|
|
}
|
|
// Reset styles at end of line so trimEnd doesn't leave dangling codes
|
|
const resetCodes = diffAnsiCodes(currentStyles, [])
|
|
if (resetCodes.length > 0) {
|
|
line += ansiCodesToString(resetCodes)
|
|
currentStyles = []
|
|
}
|
|
lines.push(line.trimEnd())
|
|
}
|
|
|
|
if (lines.length === 0) {
|
|
return []
|
|
}
|
|
return [{ type: 'stdout', content: lines.join('\n') }]
|
|
}
|
|
|
|
private getRenderOpsForDone(prev: Frame): Diff {
|
|
this.state.previousOutput = ''
|
|
|
|
if (!prev.cursor.visible) {
|
|
return [{ type: 'cursorShow' }]
|
|
}
|
|
return []
|
|
}
|
|
|
|
render(
|
|
prev: Frame,
|
|
next: Frame,
|
|
altScreen = false,
|
|
decstbmSafe = true,
|
|
): Diff {
|
|
if (!this.options.isTTY) {
|
|
return this.renderFullFrame(next)
|
|
}
|
|
|
|
const startTime = performance.now()
|
|
const stylePool = this.options.stylePool
|
|
|
|
// Since we assume the cursor is at the bottom on the screen, we only need
|
|
// to clear when the viewport gets shorter (i.e. the cursor position drifts)
|
|
// or when it gets thinner (and text wraps). We _could_ figure out how to
|
|
// not reset here but that would involve predicting the current layout
|
|
// _after_ the viewport change which means calcuating text wrapping.
|
|
// Resizing is a rare enough event that it's not practically a big issue.
|
|
if (
|
|
next.viewport.height < prev.viewport.height ||
|
|
(prev.viewport.width !== 0 && next.viewport.width !== prev.viewport.width)
|
|
) {
|
|
return fullResetSequence_CAUSES_FLICKER(next, 'resize', stylePool)
|
|
}
|
|
|
|
// DECSTBM scroll optimization: when a ScrollBox's scrollTop changed,
|
|
// shift content with a hardware scroll (CSI top;bot r + CSI n S/T)
|
|
// instead of rewriting the whole scroll region. The shiftRows on
|
|
// prev.screen simulates the shift so the diff loop below naturally
|
|
// finds only the rows that scrolled IN as diffs. prev.screen is
|
|
// about to become backFrame (reused next render) so mutation is safe.
|
|
// CURSOR_HOME after RESET_SCROLL_REGION is defensive — DECSTBM reset
|
|
// homes cursor per spec but terminal implementations vary.
|
|
//
|
|
// decstbmSafe: caller passes false when the DECSTBM→diff sequence
|
|
// can't be made atomic (no DEC 2026 / BSU/ESU). Without atomicity the
|
|
// outer terminal renders the intermediate state — region scrolled,
|
|
// edge rows not yet painted — a visible vertical jump on every frame
|
|
// where scrollTop moves. Falling through to the diff loop writes all
|
|
// shifted rows: more bytes, no intermediate state. next.screen from
|
|
// render-node-to-output's blit+shift is correct either way.
|
|
let scrollPatch: Diff = []
|
|
if (altScreen && next.scrollHint && decstbmSafe) {
|
|
const { top, bottom, delta } = next.scrollHint
|
|
if (
|
|
top >= 0 &&
|
|
bottom < prev.screen.height &&
|
|
bottom < next.screen.height
|
|
) {
|
|
shiftRows(prev.screen, top, bottom, delta)
|
|
scrollPatch = [
|
|
{
|
|
type: 'stdout',
|
|
content:
|
|
setScrollRegion(top + 1, bottom + 1) +
|
|
(delta > 0 ? csiScrollUp(delta) : csiScrollDown(-delta)) +
|
|
RESET_SCROLL_REGION +
|
|
CURSOR_HOME,
|
|
},
|
|
]
|
|
}
|
|
}
|
|
|
|
// We have to use purely relative operations to manipulate the cursor since
|
|
// we don't know its starting point.
|
|
//
|
|
// When content height >= viewport height AND cursor is at the bottom,
|
|
// the cursor restore at the end of the previous frame caused terminal scroll.
|
|
// viewportY tells us how many rows are in scrollback from content overflow.
|
|
// Additionally, the cursor-restore scroll pushes 1 more row into scrollback.
|
|
// We need fullReset if any changes are to rows that are now in scrollback.
|
|
//
|
|
// This early full-reset check only applies in "steady state" (not growing).
|
|
// For growing, the viewportY calculation below (with cursorRestoreScroll)
|
|
// catches unreachable scrollback rows in the diff loop instead.
|
|
const cursorAtBottom = prev.cursor.y >= prev.screen.height
|
|
const isGrowing = next.screen.height > prev.screen.height
|
|
// When content fills the viewport exactly (height == viewport) and the
|
|
// cursor is at the bottom, the cursor-restore LF at the end of the
|
|
// previous frame scrolled 1 row into scrollback. Use >= to catch this.
|
|
const prevHadScrollback =
|
|
cursorAtBottom && prev.screen.height >= prev.viewport.height
|
|
const isShrinking = next.screen.height < prev.screen.height
|
|
const nextFitsViewport = next.screen.height <= prev.viewport.height
|
|
|
|
// When shrinking from above-viewport to at-or-below-viewport, content that
|
|
// was in scrollback should now be visible. Terminal clear operations can't
|
|
// bring scrollback content into view, so we need a full reset.
|
|
// Use <= (not <) because even when next height equals viewport height, the
|
|
// scrollback depth from the previous render differs from a fresh render.
|
|
if (prevHadScrollback && nextFitsViewport && isShrinking) {
|
|
logForDebugging(
|
|
`Full reset (shrink->below): prevHeight=${prev.screen.height}, nextHeight=${next.screen.height}, viewport=${prev.viewport.height}`,
|
|
)
|
|
return fullResetSequence_CAUSES_FLICKER(next, 'offscreen', stylePool)
|
|
}
|
|
|
|
if (
|
|
prev.screen.height >= prev.viewport.height &&
|
|
prev.screen.height > 0 &&
|
|
cursorAtBottom &&
|
|
!isGrowing
|
|
) {
|
|
// viewportY = rows in scrollback from content overflow
|
|
// +1 for the row pushed by cursor-restore scroll
|
|
const viewportY = prev.screen.height - prev.viewport.height
|
|
const scrollbackRows = viewportY + 1
|
|
|
|
let scrollbackChangeY = -1
|
|
diffEach(prev.screen, next.screen, (_x, y) => {
|
|
if (y < scrollbackRows) {
|
|
scrollbackChangeY = y
|
|
return true // early exit
|
|
}
|
|
})
|
|
if (scrollbackChangeY >= 0) {
|
|
const prevLine = readLine(prev.screen, scrollbackChangeY)
|
|
const nextLine = readLine(next.screen, scrollbackChangeY)
|
|
return fullResetSequence_CAUSES_FLICKER(next, 'offscreen', stylePool, {
|
|
triggerY: scrollbackChangeY,
|
|
prevLine,
|
|
nextLine,
|
|
})
|
|
}
|
|
}
|
|
|
|
const screen = new VirtualScreen(prev.cursor, next.viewport.width)
|
|
|
|
// Treat empty screen as height 1 to avoid spurious adjustments on first render
|
|
const heightDelta =
|
|
Math.max(next.screen.height, 1) - Math.max(prev.screen.height, 1)
|
|
const shrinking = heightDelta < 0
|
|
const growing = heightDelta > 0
|
|
|
|
// Handle shrinking: clear lines from the bottom
|
|
if (shrinking) {
|
|
const linesToClear = prev.screen.height - next.screen.height
|
|
|
|
// eraseLines only works within the viewport - it can't clear scrollback.
|
|
// If we need to clear more lines than fit in the viewport, some are in
|
|
// scrollback, so we need a full reset.
|
|
if (linesToClear > prev.viewport.height) {
|
|
return fullResetSequence_CAUSES_FLICKER(
|
|
next,
|
|
'offscreen',
|
|
this.options.stylePool,
|
|
)
|
|
}
|
|
|
|
// clear(N) moves cursor UP by N-1 lines and to column 0
|
|
// This puts us at line prev.screen.height - N = next.screen.height
|
|
// But we want to be at next.screen.height - 1 (bottom of new screen)
|
|
screen.txn(prev => [
|
|
[
|
|
{ type: 'clear', count: linesToClear },
|
|
{ type: 'cursorMove', x: 0, y: -1 },
|
|
],
|
|
{ dx: -prev.x, dy: -linesToClear },
|
|
])
|
|
}
|
|
|
|
// viewportY = number of rows in scrollback (not visible on terminal).
|
|
// For shrinking: use max(prev, next) because terminal clears don't scroll.
|
|
// For growing: use prev state because new rows haven't scrolled old ones yet.
|
|
// When prevHadScrollback, add 1 for the cursor-restore LF that scrolled
|
|
// an additional row out of view at the end of the previous frame. Without
|
|
// this, the diff loop treats that row as reachable — but the cursor clamps
|
|
// at viewport top, causing writes to land 1 row off and garbling the output.
|
|
const cursorRestoreScroll = prevHadScrollback ? 1 : 0
|
|
const viewportY = growing
|
|
? Math.max(
|
|
0,
|
|
prev.screen.height - prev.viewport.height + cursorRestoreScroll,
|
|
)
|
|
: Math.max(prev.screen.height, next.screen.height) -
|
|
next.viewport.height +
|
|
cursorRestoreScroll
|
|
|
|
let currentStyleId = stylePool.none
|
|
let currentHyperlink: Hyperlink = undefined
|
|
|
|
// First pass: render changes to existing rows (rows < prev.screen.height)
|
|
let needsFullReset = false
|
|
let resetTriggerY = -1
|
|
diffEach(prev.screen, next.screen, (x, y, removed, added) => {
|
|
// Skip new rows - we'll render them directly after
|
|
if (growing && y >= prev.screen.height) {
|
|
return
|
|
}
|
|
|
|
// Skip spacers during rendering because the terminal will automatically
|
|
// advance 2 columns when we write the wide character itself.
|
|
// SpacerTail: Second cell of a wide character
|
|
// SpacerHead: Marks line-end position where wide char wraps to next line
|
|
if (
|
|
added &&
|
|
(added.width === CellWidth.SpacerTail ||
|
|
added.width === CellWidth.SpacerHead)
|
|
) {
|
|
return
|
|
}
|
|
|
|
if (
|
|
removed &&
|
|
(removed.width === CellWidth.SpacerTail ||
|
|
removed.width === CellWidth.SpacerHead) &&
|
|
!added
|
|
) {
|
|
return
|
|
}
|
|
|
|
// Skip empty cells that don't need to overwrite existing content.
|
|
// This prevents writing trailing spaces that would cause unnecessary
|
|
// line wrapping at the edge of the screen.
|
|
// Uses isEmptyCellAt to check if both packed words are zero (empty cell).
|
|
if (added && isEmptyCellAt(next.screen, x, y) && !removed) {
|
|
return
|
|
}
|
|
|
|
// If the cell outside the viewport range has changed, we need to reset
|
|
// because we can't move the cursor there to draw.
|
|
if (y < viewportY) {
|
|
needsFullReset = true
|
|
resetTriggerY = y
|
|
return true // early exit
|
|
}
|
|
|
|
moveCursorTo(screen, x, y)
|
|
|
|
if (added) {
|
|
const targetHyperlink = added.hyperlink
|
|
currentHyperlink = transitionHyperlink(
|
|
screen.diff,
|
|
currentHyperlink,
|
|
targetHyperlink,
|
|
)
|
|
const styleStr = stylePool.transition(currentStyleId, added.styleId)
|
|
if (writeCellWithStyleStr(screen, added, styleStr)) {
|
|
currentStyleId = added.styleId
|
|
}
|
|
} else if (removed) {
|
|
// Cell was removed - clear it with a space
|
|
// (This handles shrinking content)
|
|
// Reset any active styles/hyperlinks first to avoid leaking into cleared cells
|
|
const styleIdToReset = currentStyleId
|
|
const hyperlinkToReset = currentHyperlink
|
|
currentStyleId = stylePool.none
|
|
currentHyperlink = undefined
|
|
|
|
screen.txn(() => {
|
|
const patches: Diff = []
|
|
transitionStyle(patches, stylePool, styleIdToReset, stylePool.none)
|
|
transitionHyperlink(patches, hyperlinkToReset, undefined)
|
|
patches.push({ type: 'stdout', content: ' ' })
|
|
return [patches, { dx: 1, dy: 0 }]
|
|
})
|
|
}
|
|
})
|
|
if (needsFullReset) {
|
|
return fullResetSequence_CAUSES_FLICKER(next, 'offscreen', stylePool, {
|
|
triggerY: resetTriggerY,
|
|
prevLine: readLine(prev.screen, resetTriggerY),
|
|
nextLine: readLine(next.screen, resetTriggerY),
|
|
})
|
|
}
|
|
|
|
// Reset styles before rendering new rows (they'll set their own styles)
|
|
currentStyleId = transitionStyle(
|
|
screen.diff,
|
|
stylePool,
|
|
currentStyleId,
|
|
stylePool.none,
|
|
)
|
|
currentHyperlink = transitionHyperlink(
|
|
screen.diff,
|
|
currentHyperlink,
|
|
undefined,
|
|
)
|
|
|
|
// Handle growth: render new rows directly (they naturally scroll the terminal)
|
|
if (growing) {
|
|
renderFrameSlice(
|
|
screen,
|
|
next,
|
|
prev.screen.height,
|
|
next.screen.height,
|
|
stylePool,
|
|
)
|
|
}
|
|
|
|
// Restore cursor. Skipped in alt-screen: the cursor is hidden, its
|
|
// position only matters as the starting point for the NEXT frame's
|
|
// relative moves, and in alt-screen the next frame always begins with
|
|
// CSI H (see ink.tsx onRender) which resets to (0,0) regardless. This
|
|
// saves a CR + cursorMove round-trip (~6-10 bytes) every frame.
|
|
//
|
|
// Main screen: if cursor needs to be past the last line of content
|
|
// (typical: cursor.y = screen.height), emit \n to create that line
|
|
// since cursor movement can't create new lines.
|
|
if (altScreen) {
|
|
// no-op; next frame's CSI H anchors cursor
|
|
} else if (next.cursor.y >= next.screen.height) {
|
|
// Move to column 0 of current line, then emit newlines to reach target row
|
|
screen.txn(prev => {
|
|
const rowsToCreate = next.cursor.y - prev.y
|
|
if (rowsToCreate > 0) {
|
|
// Use CR to resolve pending wrap (if any) without advancing
|
|
// to the next line, then LF to create each new row.
|
|
const patches: Diff = new Array<Diff[number]>(1 + rowsToCreate)
|
|
patches[0] = CARRIAGE_RETURN
|
|
for (let i = 0; i < rowsToCreate; i++) {
|
|
patches[1 + i] = NEWLINE
|
|
}
|
|
return [patches, { dx: -prev.x, dy: rowsToCreate }]
|
|
}
|
|
// At or past target row - need to move cursor to correct position
|
|
const dy = next.cursor.y - prev.y
|
|
if (dy !== 0 || prev.x !== next.cursor.x) {
|
|
// Use CR to clear pending wrap (if any), then cursor move
|
|
const patches: Diff = [CARRIAGE_RETURN]
|
|
patches.push({ type: 'cursorMove', x: next.cursor.x, y: dy })
|
|
return [patches, { dx: next.cursor.x - prev.x, dy }]
|
|
}
|
|
return [[], { dx: 0, dy: 0 }]
|
|
})
|
|
} else {
|
|
moveCursorTo(screen, next.cursor.x, next.cursor.y)
|
|
}
|
|
|
|
const elapsed = performance.now() - startTime
|
|
if (elapsed > 50) {
|
|
const damage = next.screen.damage
|
|
const damageInfo = damage
|
|
? `${damage.width}x${damage.height} at (${damage.x},${damage.y})`
|
|
: 'none'
|
|
logForDebugging(
|
|
`Slow render: ${elapsed.toFixed(1)}ms, screen: ${next.screen.height}x${next.screen.width}, damage: ${damageInfo}, changes: ${screen.diff.length}`,
|
|
)
|
|
}
|
|
|
|
return scrollPatch.length > 0
|
|
? [...scrollPatch, ...screen.diff]
|
|
: screen.diff
|
|
}
|
|
}
|
|
|
|
function transitionHyperlink(
|
|
diff: Diff,
|
|
current: Hyperlink,
|
|
target: Hyperlink,
|
|
): Hyperlink {
|
|
if (current !== target) {
|
|
diff.push({ type: 'hyperlink', uri: target ?? '' })
|
|
return target
|
|
}
|
|
return current
|
|
}
|
|
|
|
function transitionStyle(
|
|
diff: Diff,
|
|
stylePool: StylePool,
|
|
currentId: number,
|
|
targetId: number,
|
|
): number {
|
|
const str = stylePool.transition(currentId, targetId)
|
|
if (str.length > 0) {
|
|
diff.push({ type: 'styleStr', str })
|
|
}
|
|
return targetId
|
|
}
|
|
|
|
function readLine(screen: Screen, y: number): string {
|
|
let line = ''
|
|
for (let x = 0; x < screen.width; x++) {
|
|
line += charInCellAt(screen, x, y) ?? ' '
|
|
}
|
|
return line.trimEnd()
|
|
}
|
|
|
|
function fullResetSequence_CAUSES_FLICKER(
|
|
frame: Frame,
|
|
reason: FlickerReason,
|
|
stylePool: StylePool,
|
|
debug?: { triggerY: number; prevLine: string; nextLine: string },
|
|
): Diff {
|
|
// After clearTerminal, cursor is at (0, 0)
|
|
const screen = new VirtualScreen({ x: 0, y: 0 }, frame.viewport.width)
|
|
renderFrame(screen, frame, stylePool)
|
|
return [{ type: 'clearTerminal', reason, debug }, ...screen.diff]
|
|
}
|
|
|
|
function renderFrame(
|
|
screen: VirtualScreen,
|
|
frame: Frame,
|
|
stylePool: StylePool,
|
|
): void {
|
|
renderFrameSlice(screen, frame, 0, frame.screen.height, stylePool)
|
|
}
|
|
|
|
/**
|
|
* Render a slice of rows from the frame's screen.
|
|
* Each row is rendered followed by a newline. Cursor ends at (0, endY).
|
|
*/
|
|
function renderFrameSlice(
|
|
screen: VirtualScreen,
|
|
frame: Frame,
|
|
startY: number,
|
|
endY: number,
|
|
stylePool: StylePool,
|
|
): VirtualScreen {
|
|
let currentStyleId = stylePool.none
|
|
let currentHyperlink: Hyperlink = undefined
|
|
// Track the styleId of the last rendered cell on this line (-1 if none).
|
|
// Passed to visibleCellAtIndex to enable fg-only space optimization.
|
|
let lastRenderedStyleId = -1
|
|
|
|
const { width: screenWidth, cells, charPool, hyperlinkPool } = frame.screen
|
|
|
|
let index = startY * screenWidth
|
|
for (let y = startY; y < endY; y += 1) {
|
|
// Advance cursor to this row using LF (not CSI CUD / cursor-down).
|
|
// CSI CUD stops at the viewport bottom margin and cannot scroll,
|
|
// but LF scrolls the viewport to create new lines. Without this,
|
|
// when the cursor is at the viewport bottom, moveCursorTo's
|
|
// cursor-down silently fails, creating a permanent off-by-one
|
|
// between the virtual cursor and the real terminal cursor.
|
|
if (screen.cursor.y < y) {
|
|
const rowsToAdvance = y - screen.cursor.y
|
|
screen.txn(prev => {
|
|
const patches: Diff = new Array<Diff[number]>(1 + rowsToAdvance)
|
|
patches[0] = CARRIAGE_RETURN
|
|
for (let i = 0; i < rowsToAdvance; i++) {
|
|
patches[1 + i] = NEWLINE
|
|
}
|
|
return [patches, { dx: -prev.x, dy: rowsToAdvance }]
|
|
})
|
|
}
|
|
// Reset at start of each line — no cell rendered yet
|
|
lastRenderedStyleId = -1
|
|
|
|
for (let x = 0; x < screenWidth; x += 1, index += 1) {
|
|
// Skip spacers, unstyled empty cells, and fg-only styled spaces that
|
|
// match the last rendered style (since cursor-forward produces identical
|
|
// visual result). visibleCellAtIndex handles the optimization internally
|
|
// to avoid allocating Cell objects for skipped cells.
|
|
const cell = visibleCellAtIndex(
|
|
cells,
|
|
charPool,
|
|
hyperlinkPool,
|
|
index,
|
|
lastRenderedStyleId,
|
|
)
|
|
if (!cell) {
|
|
continue
|
|
}
|
|
|
|
moveCursorTo(screen, x, y)
|
|
|
|
// Handle hyperlink
|
|
const targetHyperlink = cell.hyperlink
|
|
currentHyperlink = transitionHyperlink(
|
|
screen.diff,
|
|
currentHyperlink,
|
|
targetHyperlink,
|
|
)
|
|
|
|
// Style transition — cached string, zero allocations after warmup
|
|
const styleStr = stylePool.transition(currentStyleId, cell.styleId)
|
|
if (writeCellWithStyleStr(screen, cell, styleStr)) {
|
|
currentStyleId = cell.styleId
|
|
lastRenderedStyleId = cell.styleId
|
|
}
|
|
}
|
|
// Reset styles/hyperlinks before newline so background color doesn't
|
|
// bleed into the next line when the terminal scrolls. The old code
|
|
// reset implicitly by writing trailing unstyled spaces; now that we
|
|
// skip empty cells, we must reset explicitly.
|
|
currentStyleId = transitionStyle(
|
|
screen.diff,
|
|
stylePool,
|
|
currentStyleId,
|
|
stylePool.none,
|
|
)
|
|
currentHyperlink = transitionHyperlink(
|
|
screen.diff,
|
|
currentHyperlink,
|
|
undefined,
|
|
)
|
|
// CR+LF at end of row — \r resets to column 0, \n moves to next line.
|
|
// Without \r, the terminal cursor stays at whatever column content ended
|
|
// (since we skip trailing spaces, this can be mid-row).
|
|
screen.txn(prev => [[CARRIAGE_RETURN, NEWLINE], { dx: -prev.x, dy: 1 }])
|
|
}
|
|
|
|
// Reset any open style/hyperlink at end of slice
|
|
transitionStyle(screen.diff, stylePool, currentStyleId, stylePool.none)
|
|
transitionHyperlink(screen.diff, currentHyperlink, undefined)
|
|
|
|
return screen
|
|
}
|
|
|
|
type Delta = { dx: number; dy: number }
|
|
|
|
/**
|
|
* Write a cell with a pre-serialized style transition string (from
|
|
* StylePool.transition). Inlines the txn logic to avoid closure/tuple/delta
|
|
* allocations on every cell.
|
|
*
|
|
* Returns true if the cell was written, false if skipped (wide char at
|
|
* viewport edge). Callers MUST gate currentStyleId updates on this — when
|
|
* skipped, styleStr is never pushed and the terminal's style state is
|
|
* unchanged. Updating the virtual tracker anyway desyncs it from the
|
|
* terminal, and the next transition is computed from phantom state.
|
|
*/
|
|
function writeCellWithStyleStr(
|
|
screen: VirtualScreen,
|
|
cell: Cell,
|
|
styleStr: string,
|
|
): boolean {
|
|
const cellWidth = cell.width === CellWidth.Wide ? 2 : 1
|
|
const px = screen.cursor.x
|
|
const vw = screen.viewportWidth
|
|
|
|
// Don't write wide chars that would cross the viewport edge.
|
|
// Single-codepoint chars (CJK) at vw-2 are safe; multi-codepoint
|
|
// graphemes (flags, ZWJ emoji) need stricter threshold.
|
|
if (cellWidth === 2 && px < vw) {
|
|
const threshold = cell.char.length > 2 ? vw : vw + 1
|
|
if (px + 2 >= threshold) {
|
|
return false
|
|
}
|
|
}
|
|
|
|
const diff = screen.diff
|
|
if (styleStr.length > 0) {
|
|
diff.push({ type: 'styleStr', str: styleStr })
|
|
}
|
|
|
|
const needsCompensation = cellWidth === 2 && needsWidthCompensation(cell.char)
|
|
|
|
// On terminals with old wcwidth tables, a compensated emoji only advances
|
|
// the cursor 1 column, so the CHA below skips column x+1 without painting
|
|
// it. Write a styled space there first — on correct terminals the emoji
|
|
// glyph (width 2) overwrites it harmlessly; on old terminals it fills the
|
|
// gap with the emoji's background. Also clears any stale content at x+1.
|
|
// CHA is 1-based, so column px+1 (0-based) is CHA target px+2.
|
|
if (needsCompensation && px + 1 < vw) {
|
|
diff.push({ type: 'cursorTo', col: px + 2 })
|
|
diff.push({ type: 'stdout', content: ' ' })
|
|
diff.push({ type: 'cursorTo', col: px + 1 })
|
|
}
|
|
|
|
diff.push({ type: 'stdout', content: cell.char })
|
|
|
|
// Force terminal cursor to correct column after the emoji.
|
|
if (needsCompensation) {
|
|
diff.push({ type: 'cursorTo', col: px + cellWidth + 1 })
|
|
}
|
|
|
|
// Update cursor — mutate in place to avoid Point allocation
|
|
if (px >= vw) {
|
|
screen.cursor.x = cellWidth
|
|
screen.cursor.y++
|
|
} else {
|
|
screen.cursor.x = px + cellWidth
|
|
}
|
|
return true
|
|
}
|
|
|
|
function moveCursorTo(screen: VirtualScreen, targetX: number, targetY: number) {
|
|
screen.txn(prev => {
|
|
const dx = targetX - prev.x
|
|
const dy = targetY - prev.y
|
|
const inPendingWrap = prev.x >= screen.viewportWidth
|
|
|
|
// If we're in pending wrap state (cursor.x >= width), use CR
|
|
// to reset to column 0 on the current line without advancing
|
|
// to the next line, then issue the cursor movement.
|
|
if (inPendingWrap) {
|
|
return [
|
|
[CARRIAGE_RETURN, { type: 'cursorMove', x: targetX, y: dy }],
|
|
{ dx, dy },
|
|
]
|
|
}
|
|
|
|
// When moving to a different line, use carriage return (\r) to reset to
|
|
// column 0 first, then cursor move.
|
|
if (dy !== 0) {
|
|
return [
|
|
[CARRIAGE_RETURN, { type: 'cursorMove', x: targetX, y: dy }],
|
|
{ dx, dy },
|
|
]
|
|
}
|
|
|
|
// Standard same-line cursor move
|
|
return [[{ type: 'cursorMove', x: dx, y: dy }], { dx, dy }]
|
|
})
|
|
}
|
|
|
|
/**
|
|
* Identify emoji where the terminal's wcwidth may disagree with Unicode.
|
|
* On terminals with correct tables, the CHA we emit is a harmless no-op.
|
|
*
|
|
* Two categories:
|
|
* 1. Newer emoji (Unicode 12.0+) missing from terminal wcwidth tables.
|
|
* 2. Text-by-default emoji + VS16 (U+FE0F): the base codepoint is width 1
|
|
* in wcwidth, but VS16 triggers emoji presentation making it width 2.
|
|
* Examples: ⚔️ (U+2694), ☠️ (U+2620), ❤️ (U+2764).
|
|
*/
|
|
function needsWidthCompensation(char: string): boolean {
|
|
const cp = char.codePointAt(0)
|
|
if (cp === undefined) return false
|
|
// U+1FA70-U+1FAFF: Symbols and Pictographs Extended-A (Unicode 12.0-15.0)
|
|
// U+1FB00-U+1FBFF: Symbols for Legacy Computing (Unicode 13.0)
|
|
if ((cp >= 0x1fa70 && cp <= 0x1faff) || (cp >= 0x1fb00 && cp <= 0x1fbff)) {
|
|
return true
|
|
}
|
|
// Text-by-default emoji with VS16: scan for U+FE0F in multi-codepoint
|
|
// graphemes. Single BMP chars (length 1) and surrogate pairs without VS16
|
|
// skip this check. VS16 (0xFE0F) can't collide with surrogates (0xD800-0xDFFF).
|
|
if (char.length >= 2) {
|
|
for (let i = 0; i < char.length; i++) {
|
|
if (char.charCodeAt(i) === 0xfe0f) return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
class VirtualScreen {
|
|
// Public for direct mutation by writeCellWithStyleStr (avoids txn overhead).
|
|
// File-private class — not exposed outside log-update.ts.
|
|
cursor: Point
|
|
diff: Diff = []
|
|
|
|
constructor(
|
|
origin: Point,
|
|
readonly viewportWidth: number,
|
|
) {
|
|
this.cursor = { ...origin }
|
|
}
|
|
|
|
txn(fn: (prev: Point) => [patches: Diff, next: Delta]): void {
|
|
const [patches, next] = fn(this.cursor)
|
|
for (const patch of patches) {
|
|
this.diff.push(patch)
|
|
}
|
|
this.cursor.x += next.dx
|
|
this.cursor.y += next.dy
|
|
}
|
|
}
|