[Init] Initial commit - NetMesh terminal manager

components/terminal/autocomplete/terminalStringCellWidth.ts

@@ -0,0 +1,163 @@
+/**
+ * Terminal cell-column width for autocomplete / ghost positioning.
+ *
+ * When an xterm instance is available, prefer its active Unicode provider
+ * (`15-graphemes` via UnicodeGraphemesAddon) so emoji / VS-16 clusters match
+ * the cursor advance. Fall back to a small East-Asian-Width-style classifier
+ * for unit fakes that lack `_core.unicodeService`.
+ */
+
+import type { Terminal as XTerm } from "@xterm/xterm";
+
+type UnicodeServiceLike = {
+  getStringCellWidth?: (s: string) => number;
+};
+
+type TermWithUnicodeService = {
+  _core?: {
+    unicodeService?: UnicodeServiceLike;
+  };
+};
+
+const unicodeMarkPattern = /\p{Mark}/u;
+
+function codePointCellWidth(cp: number): number {
+  // Zero-width joiners / format / variation selectors / marks — xterm
+  // folds these into the surrounding grapheme (wcwidth 0 or shouldJoin).
+  if (
+    cp === 0x00ad ||
+    cp === 0x200d ||                       // ZWJ
+    (cp >= 0x200b && cp <= 0x200f) ||     // ZWSP..RLM
+    (cp >= 0x202a && cp <= 0x202e) ||     // bidi overrides
+    (cp >= 0x2060 && cp <= 0x206f) ||     // word joiner, invisible ops
+    (cp >= 0xfe00 && cp <= 0xfe0f) ||     // Variation Selectors
+    cp === 0xfeff ||
+    (cp >= 0x1f3fb && cp <= 0x1f3ff) ||   // Emoji skin-tone modifiers
+    (cp >= 0xe0100 && cp <= 0xe01ef) ||   // Variation Selectors Supplement
+    unicodeMarkPattern.test(String.fromCodePoint(cp))
+  ) {
+    return 0;
+  }
+  if (
+    (cp >= 0x1100 && cp <= 0x115f) ||   // Hangul Jamo
+    (cp >= 0x2e80 && cp <= 0x303e) ||   // CJK Radicals, Kangxi
+    (cp >= 0x3041 && cp <= 0x33ff) ||   // Hiragana, Katakana, CJK Compat
+    (cp >= 0x3400 && cp <= 0x4dbf) ||   // CJK Extension A
+    (cp >= 0x4e00 && cp <= 0x9fff) ||   // CJK Unified Ideographs
+    (cp >= 0xa000 && cp <= 0xa4cf) ||   // Yi
+    (cp >= 0xac00 && cp <= 0xd7a3) ||   // Hangul Syllables
+    (cp >= 0xf900 && cp <= 0xfaff) ||   // CJK Compat Ideographs
+    (cp >= 0xfe30 && cp <= 0xfe4f) ||   // CJK Compat Forms
+    (cp >= 0xff00 && cp <= 0xff60) ||   // Fullwidth forms
+    (cp >= 0xffe0 && cp <= 0xffe6) ||   // Fullwidth signs
+    (cp >= 0x1f300 && cp <= 0x1faff) || // Emoji blocks
+    (cp >= 0x20000 && cp <= 0x3fffd)    // CJK Extension B-F, G
+  ) {
+    return 2;
+  }
+  return 1;
+}
+
+function graphemeCellWidth(grapheme: string): number {
+  let max = 0;
+  for (const ch of grapheme) {
+    const w = codePointCellWidth(ch.codePointAt(0) ?? 0);
+    if (w > max) max = w;
+  }
+  return max;
+}
+
+const graphemeSegmenter =
+  typeof Intl !== "undefined" && "Segmenter" in Intl
+    ? new Intl.Segmenter(undefined, { granularity: "grapheme" })
+    : null;
+
+function fallbackStringCellWidth(s: string): number {
+  if (graphemeSegmenter) {
+    let w = 0;
+    for (const { segment } of graphemeSegmenter.segment(s)) {
+      w += graphemeCellWidth(segment);
+    }
+    return w;
+  }
+  // Fallback without Segmenter: sum code-point widths (ZWJ/marks already 0).
+  let w = 0;
+  for (const ch of s) {
+    w += codePointCellWidth(ch.codePointAt(0) ?? 0);
+  }
+  return w;
+}
+
+/** Terminal cell columns occupied by `s` (wide glyphs / grapheme clusters). */
+export function stringCellWidth(
+  s: string,
+  term?: XTerm | TermWithUnicodeService | null,
+): number {
+  if (!s) return 0;
+  const unicodeService = (term as TermWithUnicodeService | null | undefined)
+    ?._core?.unicodeService;
+  const getWidth = unicodeService?.getStringCellWidth;
+  if (typeof getWidth === "function") {
+    return getWidth.call(unicodeService, s);
+  }
+  return fallbackStringCellWidth(s);
+}
+
+/**
+ * Slice a terminal line string by cell columns (xterm `cursorX` units).
+ *
+ * `translateToString()` returns characters, but `buffer.cursorX` is a cell
+ * column. Mixing them with `String#substring(cursorX)` pulls padding spaces
+ * into user input whenever the prompt contains wide glyphs (CJK paths in
+ * Windows CMD / PowerShell), which breaks autocomplete matching (#2813).
+ */
+export function sliceStringByCellColumns(
+  text: string,
+  startCell: number,
+  endCell?: number,
+  term?: XTerm | TermWithUnicodeService | null,
+): string {
+  if (!text) return "";
+  const start = Math.max(0, startCell);
+  const end = endCell === undefined ? Number.POSITIVE_INFINITY : Math.max(start, endCell);
+  if (end === 0) return "";
+
+  let cell = 0;
+  let startIndex = 0;
+  let endIndex = text.length;
+  let sawStart = false;
+
+  const advance = (segment: string, index: number, segmentLength: number): boolean => {
+    const width = stringCellWidth(segment, term);
+    const nextCell = cell + width;
+    if (!sawStart && nextCell > start) {
+      startIndex = index;
+      sawStart = true;
+    }
+    if (nextCell >= end) {
+      endIndex = nextCell === end ? index + segmentLength : index;
+      if (!sawStart) {
+        startIndex = index;
+        sawStart = true;
+      }
+      return true;
+    }
+    cell = nextCell;
+    return false;
+  };
+
+  if (graphemeSegmenter) {
+    for (const { segment, index } of graphemeSegmenter.segment(text)) {
+      if (advance(segment, index, segment.length)) break;
+    }
+  } else {
+    let index = 0;
+    for (const ch of text) {
+      if (advance(ch, index, ch.length)) break;
+      index += ch.length;
+    }
+  }
+
+  if (!sawStart) return "";
+  return text.slice(startIndex, endIndex);
+}