fix

src/utils.ts

@@ -296,15 +296,70 @@ export function buildPrintablePages(
   };
 }
 
+/** 自动排版时允许的最小页边距 (mm) */
+export const AUTO_LAYOUT_MIN_PAGE_MARGIN_MM = 10;
+
+const AUTO_LAYOUT_MIN_MARGIN_STORAGE_KEY = 'label_designer_auto_layout_min_margin_mm';
+
+/** 读取上次自动排版使用的最小页边距 (mm) */
+export function loadAutoLayoutMinPageMarginMm(): number {
+  try {
+    const raw = localStorage.getItem(AUTO_LAYOUT_MIN_MARGIN_STORAGE_KEY);
+    if (raw === null) return AUTO_LAYOUT_MIN_PAGE_MARGIN_MM;
+    const n = Number(raw);
+    if (Number.isFinite(n) && n >= 0) return n;
+  } catch {
+    /* ignore */
+  }
+  return AUTO_LAYOUT_MIN_PAGE_MARGIN_MM;
+}
+
+/** 保存自动排版使用的最小页边距 (mm) */
+export function saveAutoLayoutMinPageMarginMm(value: number): void {
+  try {
+    localStorage.setItem(AUTO_LAYOUT_MIN_MARGIN_STORAGE_KEY, String(value));
+  } catch {
+    /* ignore */
+  }
+}
+
+/** 按最小页边距居中计算四边页边距 */
+export function computeAutoLayoutPaper(
+  paper: PaperConfig,
+  template: Pick<LabelTemplate, 'width' | 'height'>,
+  minMargin: number
+): PaperConfig {
+  const paperW = paper.orientation === 'portrait' ? paper.width : paper.height;
+  const paperH = paper.orientation === 'portrait' ? paper.height : paper.width;
+  const lw = template.width;
+  const lh = template.height;
+  const usableWInit = paperW - minMargin * 2;
+  const usableHInit = paperH - minMargin * 2;
+  const maxCols = Math.floor((usableWInit + paper.columnGap) / (lw + paper.columnGap)) || 1;
+  const maxRows = Math.floor((usableHInit + paper.rowGap) / (lh + paper.rowGap)) || 1;
+  const gridWidth = maxCols * lw + (maxCols - 1) * paper.columnGap;
+  const gridHeight = maxRows * lh + (maxRows - 1) * paper.rowGap;
+  const balancedLR = Math.max(minMargin, Math.round(((paperW - gridWidth) / 2) * 10) / 10);
+  const balancedTB = Math.max(minMargin, Math.round(((paperH - gridHeight) / 2) * 10) / 10);
+
+  return {
+    ...paper,
+    marginLeft: balancedLR,
+    marginRight: balancedLR,
+    marginTop: balancedTB,
+    marginBottom: balancedTB,
+  };
+}
+
 export const DEFAULT_PAPER_CONFIG: PaperConfig = {
   type: 'A4',
   width: 210,
   height: 297,
   orientation: 'portrait',
-  marginTop: 10,
-  marginBottom: 10,
-  marginLeft: 10,
-  marginRight: 10,
+  marginTop: AUTO_LAYOUT_MIN_PAGE_MARGIN_MM,
+  marginBottom: AUTO_LAYOUT_MIN_PAGE_MARGIN_MM,
+  marginLeft: AUTO_LAYOUT_MIN_PAGE_MARGIN_MM,
+  marginRight: AUTO_LAYOUT_MIN_PAGE_MARGIN_MM,
   columnGap: 2,
   rowGap: 2,
   flow: 'left-right-top-bottom',