Reapply "feat(desktop): terminal pane (#5081)"

This reverts commit f9dcd979364acc5172fd0044c1c8b04dcaec9229.

1 files changed, 649 insertions, 0 deletions

diff --git a/packages/desktop/src/addons/serialize.ts b/packages/desktop/src/addons/serialize.ts
new file mode 100644
index 000000000..03899ff10
--- /dev/null
+++ b/packages/desktop/src/addons/serialize.ts
@@ -0,0 +1,649 @@
+/**
+ * SerializeAddon - Serialize terminal buffer contents
+ *
+ * Port of xterm.js addon-serialize for ghostty-web.
+ * Enables serialization of terminal contents to a string that can
+ * be written back to restore terminal state.
+ *
+ * Usage:
+ * ```typescript
+ * const serializeAddon = new SerializeAddon();
+ * term.loadAddon(serializeAddon);
+ * const content = serializeAddon.serialize();
+ * ```
+ */
+
+import type { ITerminalAddon, ITerminalCore, IBufferRange } from "ghostty-web"
+
+// ============================================================================
+// Buffer Types (matching ghostty-web internal interfaces)
+// ============================================================================
+
+interface IBuffer {
+  readonly type: "normal" | "alternate"
+  readonly cursorX: number
+  readonly cursorY: number
+  readonly viewportY: number
+  readonly baseY: number
+  readonly length: number
+  getLine(y: number): IBufferLine | undefined
+  getNullCell(): IBufferCell
+}
+
+interface IBufferLine {
+  readonly length: number
+  readonly isWrapped: boolean
+  getCell(x: number): IBufferCell | undefined
+  translateToString(trimRight?: boolean, startColumn?: number, endColumn?: number): string
+}
+
+interface IBufferCell {
+  getChars(): string
+  getCode(): number
+  getWidth(): number
+  getFgColorMode(): number
+  getBgColorMode(): number
+  getFgColor(): number
+  getBgColor(): number
+  isBold(): number
+  isItalic(): number
+  isUnderline(): number
+  isStrikethrough(): number
+  isBlink(): number
+  isInverse(): number
+  isInvisible(): number
+  isFaint(): number
+  isDim(): boolean
+}
+
+// ============================================================================
+// Types
+// ============================================================================
+
+export interface ISerializeOptions {
+  /**
+   * The row range to serialize. When an explicit range is specified, the cursor
+   * will get its final repositioning.
+   */
+  range?: ISerializeRange
+  /**
+   * The number of rows in the scrollback buffer to serialize, starting from
+   * the bottom of the scrollback buffer. When not specified, all available
+   * rows in the scrollback buffer will be serialized.
+   */
+  scrollback?: number
+  /**
+   * Whether to exclude the terminal modes from the serialization.
+   * Default: false
+   */
+  excludeModes?: boolean
+  /**
+   * Whether to exclude the alt buffer from the serialization.
+   * Default: false
+   */
+  excludeAltBuffer?: boolean
+}
+
+export interface ISerializeRange {
+  /**
+   * The line to start serializing (inclusive).
+   */
+  start: number
+  /**
+   * The line to end serializing (inclusive).
+   */
+  end: number
+}
+
+export interface IHTMLSerializeOptions {
+  /**
+   * The number of rows in the scrollback buffer to serialize, starting from
+   * the bottom of the scrollback buffer.
+   */
+  scrollback?: number
+  /**
+   * Whether to only serialize the selection.
+   * Default: false
+   */
+  onlySelection?: boolean
+  /**
+   * Whether to include the global background of the terminal.
+   * Default: false
+   */
+  includeGlobalBackground?: boolean
+  /**
+   * The range to serialize. This is prioritized over onlySelection.
+   */
+  range?: {
+    startLine: number
+    endLine: number
+    startCol: number
+  }
+}
+
+// ============================================================================
+// Helper Functions
+// ============================================================================
+
+function constrain(value: number, low: number, high: number): number {
+  return Math.max(low, Math.min(value, high))
+}
+
+function equalFg(cell1: IBufferCell, cell2: IBufferCell): boolean {
+  return cell1.getFgColorMode() === cell2.getFgColorMode() && cell1.getFgColor() === cell2.getFgColor()
+}
+
+function equalBg(cell1: IBufferCell, cell2: IBufferCell): boolean {
+  return cell1.getBgColorMode() === cell2.getBgColorMode() && cell1.getBgColor() === cell2.getBgColor()
+}
+
+function equalFlags(cell1: IBufferCell, cell2: IBufferCell): boolean {
+  return (
+    !!cell1.isInverse() === !!cell2.isInverse() &&
+    !!cell1.isBold() === !!cell2.isBold() &&
+    !!cell1.isUnderline() === !!cell2.isUnderline() &&
+    !!cell1.isBlink() === !!cell2.isBlink() &&
+    !!cell1.isInvisible() === !!cell2.isInvisible() &&
+    !!cell1.isItalic() === !!cell2.isItalic() &&
+    !!cell1.isDim() === !!cell2.isDim() &&
+    !!cell1.isStrikethrough() === !!cell2.isStrikethrough()
+  )
+}
+
+// ============================================================================
+// Base Serialize Handler
+// ============================================================================
+
+abstract class BaseSerializeHandler {
+  constructor(protected readonly _buffer: IBuffer) {}
+
+  public serialize(range: IBufferRange, excludeFinalCursorPosition?: boolean): string {
+    let oldCell = this._buffer.getNullCell()
+
+    const startRow = range.start.y
+    const endRow = range.end.y
+    const startColumn = range.start.x
+    const endColumn = range.end.x
+
+    this._beforeSerialize(endRow - startRow, startRow, endRow)
+
+    for (let row = startRow; row <= endRow; row++) {
+      const line = this._buffer.getLine(row)
+      if (line) {
+        const startLineColumn = row === range.start.y ? startColumn : 0
+        const endLineColumn = row === range.end.y ? endColumn : line.length
+        for (let col = startLineColumn; col < endLineColumn; col++) {
+          const c = line.getCell(col)
+          if (!c) {
+            continue
+          }
+          this._nextCell(c, oldCell, row, col)
+          oldCell = c
+        }
+      }
+      this._rowEnd(row, row === endRow)
+    }
+
+    this._afterSerialize()
+
+    return this._serializeString(excludeFinalCursorPosition)
+  }
+
+  protected _nextCell(_cell: IBufferCell, _oldCell: IBufferCell, _row: number, _col: number): void {}
+  protected _rowEnd(_row: number, _isLastRow: boolean): void {}
+  protected _beforeSerialize(_rows: number, _startRow: number, _endRow: number): void {}
+  protected _afterSerialize(): void {}
+  protected _serializeString(_excludeFinalCursorPosition?: boolean): string {
+    return ""
+  }
+}
+
+// ============================================================================
+// String Serialize Handler
+// ============================================================================
+
+class StringSerializeHandler extends BaseSerializeHandler {
+  private _rowIndex: number = 0
+  private _allRows: string[] = []
+  private _allRowSeparators: string[] = []
+  private _currentRow: string = ""
+  private _nullCellCount: number = 0
+  private _cursorStyle: IBufferCell
+  private _cursorStyleRow: number = 0
+  private _cursorStyleCol: number = 0
+  private _backgroundCell: IBufferCell
+  private _firstRow: number = 0
+  private _lastCursorRow: number = 0
+  private _lastCursorCol: number = 0
+  private _lastContentCursorRow: number = 0
+  private _lastContentCursorCol: number = 0
+  private _thisRowLastChar: IBufferCell
+  private _thisRowLastSecondChar: IBufferCell
+  private _nextRowFirstChar: IBufferCell
+
+  constructor(
+    buffer: IBuffer,
+    private readonly _terminal: ITerminalCore,
+  ) {
+    super(buffer)
+    this._cursorStyle = this._buffer.getNullCell()
+    this._backgroundCell = this._buffer.getNullCell()
+    this._thisRowLastChar = this._buffer.getNullCell()
+    this._thisRowLastSecondChar = this._buffer.getNullCell()
+    this._nextRowFirstChar = this._buffer.getNullCell()
+  }
+
+  protected _beforeSerialize(rows: number, start: number, _end: number): void {
+    this._allRows = new Array<string>(rows)
+    this._lastContentCursorRow = start
+    this._lastCursorRow = start
+    this._firstRow = start
+  }
+
+  protected _rowEnd(row: number, isLastRow: boolean): void {
+    // if there is colorful empty cell at line end, we must pad it back
+    if (this._nullCellCount > 0 && !equalBg(this._cursorStyle, this._backgroundCell)) {
+      this._currentRow += `\u001b[${this._nullCellCount}X`
+    }
+
+    let rowSeparator = ""
+
+    if (!isLastRow) {
+      // Enable BCE
+      if (row - this._firstRow >= this._terminal.rows) {
+        const line = this._buffer.getLine(this._cursorStyleRow)
+        const cell = line?.getCell(this._cursorStyleCol)
+        if (cell) {
+          this._backgroundCell = cell
+        }
+      }
+
+      const currentLine = this._buffer.getLine(row)!
+      const nextLine = this._buffer.getLine(row + 1)!
+
+      if (!nextLine.isWrapped) {
+        rowSeparator = "\r\n"
+        this._lastCursorRow = row + 1
+        this._lastCursorCol = 0
+      } else {
+        rowSeparator = ""
+        const thisRowLastChar = currentLine.getCell(currentLine.length - 1)
+        const thisRowLastSecondChar = currentLine.getCell(currentLine.length - 2)
+        const nextRowFirstChar = nextLine.getCell(0)
+
+        if (thisRowLastChar) this._thisRowLastChar = thisRowLastChar
+        if (thisRowLastSecondChar) this._thisRowLastSecondChar = thisRowLastSecondChar
+        if (nextRowFirstChar) this._nextRowFirstChar = nextRowFirstChar
+
+        const isNextRowFirstCharDoubleWidth = this._nextRowFirstChar.getWidth() > 1
+
+        let isValid = false
+
+        if (
+          this._nextRowFirstChar.getChars() &&
+          (isNextRowFirstCharDoubleWidth ? this._nullCellCount <= 1 : this._nullCellCount <= 0)
+        ) {
+          if (
+            (this._thisRowLastChar.getChars() || this._thisRowLastChar.getWidth() === 0) &&
+            equalBg(this._thisRowLastChar, this._nextRowFirstChar)
+          ) {
+            isValid = true
+          }
+
+          if (
+            isNextRowFirstCharDoubleWidth &&
+            (this._thisRowLastSecondChar.getChars() || this._thisRowLastSecondChar.getWidth() === 0) &&
+            equalBg(this._thisRowLastChar, this._nextRowFirstChar) &&
+            equalBg(this._thisRowLastSecondChar, this._nextRowFirstChar)
+          ) {
+            isValid = true
+          }
+        }
+
+        if (!isValid) {
+          rowSeparator = "-".repeat(this._nullCellCount + 1)
+          rowSeparator += "\u001b[1D\u001b[1X"
+
+          if (this._nullCellCount > 0) {
+            rowSeparator += "\u001b[A"
+            rowSeparator += `\u001b[${currentLine.length - this._nullCellCount}C`
+            rowSeparator += `\u001b[${this._nullCellCount}X`
+            rowSeparator += `\u001b[${currentLine.length - this._nullCellCount}D`
+            rowSeparator += "\u001b[B"
+          }
+
+          this._lastContentCursorRow = row + 1
+          this._lastContentCursorCol = 0
+          this._lastCursorRow = row + 1
+          this._lastCursorCol = 0
+        }
+      }
+    }
+
+    this._allRows[this._rowIndex] = this._currentRow
+    this._allRowSeparators[this._rowIndex++] = rowSeparator
+    this._currentRow = ""
+    this._nullCellCount = 0
+  }
+
+  private _diffStyle(cell: IBufferCell, oldCell: IBufferCell): number[] {
+    const sgrSeq: number[] = []
+    const fgChanged = !equalFg(cell, oldCell)
+    const bgChanged = !equalBg(cell, oldCell)
+    const flagsChanged = !equalFlags(cell, oldCell)
+
+    if (fgChanged || bgChanged || flagsChanged) {
+      if (this._isAttributeDefault(cell)) {
+        if (!this._isAttributeDefault(oldCell)) {
+          sgrSeq.push(0)
+        }
+      } else {
+        if (fgChanged) {
+          const color = cell.getFgColor()
+          const mode = cell.getFgColorMode()
+          if (mode === 2) {
+            // RGB
+            sgrSeq.push(38, 2, (color >>> 16) & 0xff, (color >>> 8) & 0xff, color & 0xff)
+          } else if (mode === 1) {
+            // Palette
+            if (color >= 16) {
+              sgrSeq.push(38, 5, color)
+            } else {
+              sgrSeq.push(color & 8 ? 90 + (color & 7) : 30 + (color & 7))
+            }
+          } else {
+            sgrSeq.push(39)
+          }
+        }
+        if (bgChanged) {
+          const color = cell.getBgColor()
+          const mode = cell.getBgColorMode()
+          if (mode === 2) {
+            // RGB
+            sgrSeq.push(48, 2, (color >>> 16) & 0xff, (color >>> 8) & 0xff, color & 0xff)
+          } else if (mode === 1) {
+            // Palette
+            if (color >= 16) {
+              sgrSeq.push(48, 5, color)
+            } else {
+              sgrSeq.push(color & 8 ? 100 + (color & 7) : 40 + (color & 7))
+            }
+          } else {
+            sgrSeq.push(49)
+          }
+        }
+        if (flagsChanged) {
+          if (!!cell.isInverse() !== !!oldCell.isInverse()) {
+            sgrSeq.push(cell.isInverse() ? 7 : 27)
+          }
+          if (!!cell.isBold() !== !!oldCell.isBold()) {
+            sgrSeq.push(cell.isBold() ? 1 : 22)
+          }
+          if (!!cell.isUnderline() !== !!oldCell.isUnderline()) {
+            sgrSeq.push(cell.isUnderline() ? 4 : 24)
+          }
+          if (!!cell.isBlink() !== !!oldCell.isBlink()) {
+            sgrSeq.push(cell.isBlink() ? 5 : 25)
+          }
+          if (!!cell.isInvisible() !== !!oldCell.isInvisible()) {
+            sgrSeq.push(cell.isInvisible() ? 8 : 28)
+          }
+          if (!!cell.isItalic() !== !!oldCell.isItalic()) {
+            sgrSeq.push(cell.isItalic() ? 3 : 23)
+          }
+          if (!!cell.isDim() !== !!oldCell.isDim()) {
+            sgrSeq.push(cell.isDim() ? 2 : 22)
+          }
+          if (!!cell.isStrikethrough() !== !!oldCell.isStrikethrough()) {
+            sgrSeq.push(cell.isStrikethrough() ? 9 : 29)
+          }
+        }
+      }
+    }
+
+    return sgrSeq
+  }
+
+  private _isAttributeDefault(cell: IBufferCell): boolean {
+    return (
+      cell.getFgColorMode() === 0 &&
+      cell.getBgColorMode() === 0 &&
+      !cell.isBold() &&
+      !cell.isItalic() &&
+      !cell.isUnderline() &&
+      !cell.isBlink() &&
+      !cell.isInverse() &&
+      !cell.isInvisible() &&
+      !cell.isDim() &&
+      !cell.isStrikethrough()
+    )
+  }
+
+  protected _nextCell(cell: IBufferCell, _oldCell: IBufferCell, row: number, col: number): void {
+    const isPlaceHolderCell = cell.getWidth() === 0
+
+    if (isPlaceHolderCell) {
+      return
+    }
+
+    const isEmptyCell = cell.getChars() === ""
+
+    const sgrSeq = this._diffStyle(cell, this._cursorStyle)
+
+    const styleChanged = isEmptyCell ? !equalBg(this._cursorStyle, cell) : sgrSeq.length > 0
+
+    if (styleChanged) {
+      if (this._nullCellCount > 0) {
+        if (!equalBg(this._cursorStyle, this._backgroundCell)) {
+          this._currentRow += `\u001b[${this._nullCellCount}X`
+        }
+        this._currentRow += `\u001b[${this._nullCellCount}C`
+        this._nullCellCount = 0
+      }
+
+      this._lastContentCursorRow = this._lastCursorRow = row
+      this._lastContentCursorCol = this._lastCursorCol = col
+
+      this._currentRow += `\u001b[${sgrSeq.join(";")}m`
+
+      const line = this._buffer.getLine(row)
+      const cellFromLine = line?.getCell(col)
+      if (cellFromLine) {
+        this._cursorStyle = cellFromLine
+        this._cursorStyleRow = row
+        this._cursorStyleCol = col
+      }
+    }
+
+    if (isEmptyCell) {
+      this._nullCellCount += cell.getWidth()
+    } else {
+      if (this._nullCellCount > 0) {
+        if (equalBg(this._cursorStyle, this._backgroundCell)) {
+          this._currentRow += `\u001b[${this._nullCellCount}C`
+        } else {
+          this._currentRow += `\u001b[${this._nullCellCount}X`
+          this._currentRow += `\u001b[${this._nullCellCount}C`
+        }
+        this._nullCellCount = 0
+      }
+
+      this._currentRow += cell.getChars()
+
+      this._lastContentCursorRow = this._lastCursorRow = row
+      this._lastContentCursorCol = this._lastCursorCol = col + cell.getWidth()
+    }
+  }
+
+  protected _serializeString(excludeFinalCursorPosition?: boolean): string {
+    let rowEnd = this._allRows.length
+
+    if (this._buffer.length - this._firstRow <= this._terminal.rows) {
+      rowEnd = this._lastContentCursorRow + 1 - this._firstRow
+      this._lastCursorCol = this._lastContentCursorCol
+      this._lastCursorRow = this._lastContentCursorRow
+    }
+
+    let content = ""
+
+    for (let i = 0; i < rowEnd; i++) {
+      content += this._allRows[i]
+      if (i + 1 < rowEnd) {
+        content += this._allRowSeparators[i]
+      }
+    }
+
+    if (!excludeFinalCursorPosition) {
+      // Get cursor position relative to viewport (1-indexed for ANSI)
+      // cursorY is relative to the viewport, cursorX is column position
+      const cursorRow = this._buffer.cursorY + 1 // 1-indexed
+      const cursorCol = this._buffer.cursorX + 1 // 1-indexed
+
+      // Use absolute cursor positioning (CUP - Cursor Position)
+      // This is more reliable than relative moves which depend on knowing
+      // exactly where the cursor ended up after all the content
+      content += `\u001b[${cursorRow};${cursorCol}H`
+    }
+
+    return content
+  }
+}
+
+// ============================================================================
+// SerializeAddon Class
+// ============================================================================
+
+export class SerializeAddon implements ITerminalAddon {
+  private _terminal?: ITerminalCore
+
+  /**
+   * Activate the addon (called by Terminal.loadAddon)
+   */
+  public activate(terminal: ITerminalCore): void {
+    this._terminal = terminal
+  }
+
+  /**
+   * Dispose the addon and clean up resources
+   */
+  public dispose(): void {
+    this._terminal = undefined
+  }
+
+  /**
+   * Serializes terminal rows into a string that can be written back to the
+   * terminal to restore the state. The cursor will also be positioned to the
+   * correct cell.
+   *
+   * @param options Custom options to allow control over what gets serialized.
+   */
+  public serialize(options?: ISerializeOptions): string {
+    if (!this._terminal) {
+      throw new Error("Cannot use addon until it has been loaded")
+    }
+
+    const terminal = this._terminal as any
+    const buffer = terminal.buffer
+
+    if (!buffer) {
+      return ""
+    }
+
+    const activeBuffer = buffer.active || buffer.normal
+    if (!activeBuffer) {
+      return ""
+    }
+
+    let content = options?.range
+      ? this._serializeBufferByRange(activeBuffer, options.range, true)
+      : this._serializeBufferByScrollback(activeBuffer, options?.scrollback)
+
+    // Handle alternate buffer if active and not excluded
+    if (!options?.excludeAltBuffer) {
+      const altBuffer = buffer.alternate
+      if (altBuffer && buffer.active?.type === "alternate") {
+        const alternateContent = this._serializeBufferByScrollback(altBuffer, undefined)
+        content += `\u001b[?1049h\u001b[H${alternateContent}`
+      }
+    }
+
+    return content
+  }
+
+  /**
+   * Serializes terminal content as plain text (no escape sequences)
+   * @param options Custom options to allow control over what gets serialized.
+   */
+  public serializeAsText(options?: { scrollback?: number; trimWhitespace?: boolean }): string {
+    if (!this._terminal) {
+      throw new Error("Cannot use addon until it has been loaded")
+    }
+
+    const terminal = this._terminal as any
+    const buffer = terminal.buffer
+
+    if (!buffer) {
+      return ""
+    }
+
+    const activeBuffer = buffer.active || buffer.normal
+    if (!activeBuffer) {
+      return ""
+    }
+
+    const maxRows = activeBuffer.length
+    const scrollback = options?.scrollback
+    const correctRows = scrollback === undefined ? maxRows : constrain(scrollback + this._terminal.rows, 0, maxRows)
+
+    const startRow = maxRows - correctRows
+    const endRow = maxRows - 1
+    const lines: string[] = []
+
+    for (let row = startRow; row <= endRow; row++) {
+      const line = activeBuffer.getLine(row)
+      if (line) {
+        const text = line.translateToString(options?.trimWhitespace ?? true)
+        lines.push(text)
+      }
+    }
+
+    // Trim trailing empty lines if requested
+    if (options?.trimWhitespace) {
+      while (lines.length > 0 && lines[lines.length - 1] === "") {
+        lines.pop()
+      }
+    }
+
+    return lines.join("\n")
+  }
+
+  private _serializeBufferByScrollback(buffer: IBuffer, scrollback?: number): string {
+    const maxRows = buffer.length
+    const rows = this._terminal?.rows ?? 24
+    const correctRows = scrollback === undefined ? maxRows : constrain(scrollback + rows, 0, maxRows)
+    return this._serializeBufferByRange(
+      buffer,
+      {
+        start: maxRows - correctRows,
+        end: maxRows - 1,
+      },
+      false,
+    )
+  }
+
+  private _serializeBufferByRange(
+    buffer: IBuffer,
+    range: ISerializeRange,
+    excludeFinalCursorPosition: boolean,
+  ): string {
+    const handler = new StringSerializeHandler(buffer, this._terminal!)
+    const cols = this._terminal?.cols ?? 80
+    return handler.serialize(
+      {
+        start: { x: 0, y: range.start },
+        end: { x: cols, y: range.end },
+      },
+      excludeFinalCursorPosition,
+    )
+  }
+}