Function sliceSpansWindow

src/ui/diff/renderRows.tsx:60–111

Slice styled spans to one visible window while preserving color runs.

(spans: RenderSpan[], offset: number, width: number)

/** Slice styled spans to one visible window while preserving color runs. */
function sliceSpansWindow(spans: RenderSpan[], offset: number, width: number) {
  if (width <= 0) {
    return {
      spans: [] as RenderSpan[],
      usedWidth: 0,
    };
  }

  const sliced: RenderSpan[] = [];
  let remainingOffset = Math.max(0, offset);
  let remaining = width;
  let usedWidth = 0;

  for (const span of spans) {
    if (remaining <= 0) {
      break;
    }

    const spanWidth = measureTextWidth(span.text);
    if (spanWidth === 0) {
      appendRenderSpan(sliced, span);
      continue;
    }

    if (remainingOffset >= spanWidth) {
      remainingOffset -= spanWidth;
      continue;
    }

    const visible = sliceTextByWidth(span.text, remainingOffset, remaining);
    remainingOffset = 0;

    if (visible.text.length === 0) {
      continue;
    }

    const nextSpan = {
      ...span,
      text: visible.text,
    };

    appendRenderSpan(sliced, nextSpan);

    remaining -= visible.width;
    usedWidth += visible.width;
  }

  return {
    spans: sliced,
    usedWidth,
  };
}

const marker = diffRailMarker;
const addNoteBadgeText = "[+]";