fix: match legacy widget grid dimensions

apps/nextjs/src/app/[locale]/boards/(content)/_client.tsx

@@ -16,7 +16,7 @@ import { BoardSetupChecklist } from "~/components/board/board-setup-checklist";
 import {
   getBoardLaneColumnCount,
   getInitialBoardLogicalHeight,
-  getLogicalTrackSize,
+  getLogicalGridSize,
   LOGICAL_GRID_GAP,
   getRootSectionForLane,
 } from "~/components/board/layout";
@@ -61,16 +61,16 @@ export const ClientBoard = () => {
   const rightColumnCount = getBoardLaneColumnCount(currentLayout, "right");
   const laneWidths = [leftColumnCount, mainColumnCount, rightColumnCount]
     .filter((columnCount) => columnCount > 0)
-    .map(getLogicalTrackSize);
+    .map(getLogicalGridSize);
   const logicalWidth =
     laneWidths.reduce((total, width) => total + width, 0) + (laneWidths.length - 1) * LOGICAL_GRID_GAP;
   const initialLogicalHeight = getInitialBoardLogicalHeight(board, currentLayoutId);
   const representativeWidth = layoutOverrideId ? getRepresentativeLayoutWidth(currentLayout, board.layouts) : null;
   const initialAvailableWidth = Math.max(1, (representativeWidth ?? initialViewportWidth) - APP_SHELL_INLINE_PADDING);
   const gridTemplateColumns = [
-    leftColumnCount > 0 ? `${getLogicalTrackSize(leftColumnCount)}px` : null,
-    `${getLogicalTrackSize(mainColumnCount)}px`,
-    rightColumnCount > 0 ? `${getLogicalTrackSize(rightColumnCount)}px` : null,
+    leftColumnCount > 0 ? `${getLogicalGridSize(leftColumnCount)}px` : null,
+    `${getLogicalGridSize(mainColumnCount)}px`,
+    rightColumnCount > 0 ? `${getLogicalGridSize(rightColumnCount)}px` : null,
   ]
     .filter((value) => value !== null)
     .join(" ");

apps/nextjs/src/components/board/layout/README.md

@@ -2,17 +2,16 @@
 
 The board uses fixed logical units:
 
-- one `1 × 1` item is exactly `200 × 200` logical pixels;
-- the gap matches Mantine's `sm` spacing at `12` logical pixels, giving a `212` pixel track pitch;
-- multi-cell items include the gaps between their cells (`2 × 1` is `412 × 200`);
+- one grid track has a `212 × 212` logical-pixel footprint;
+- cards are inset by `10` visual pixels on every side, matching the legacy GridStack gutter;
+- multi-cell items occupy complete track footprints (`2 × 1` is `424 × 212` before the card inset);
 - the canvas is zoomed once with one uniform scale derived from its available width.
 
-Items keep the same logical dimensions at every viewport. The viewport reserves
-the painted size while the inner canvas remains at its logical dimensions, so a
-widget's `clientWidth`, `clientHeight`, and `ResizeObserver` measurements stay
-stable. The visual canvas always fits the available width, every root lane
-keeps at least one viewport of height, and edit-mode previews extend it downward
-as needed.
+Grid footprints keep the same logical dimensions at every viewport. Widget cards
+use a scale-compensated inset so their painted size and content measurements
+match the legacy responsive grid. The visual canvas always fits the available
+width, every root lane keeps at least one viewport of height, and edit-mode
+previews extend it downward as needed.
 
 The read-only renderer should:
 

apps/nextjs/src/components/board/layout/board-lanes.ts

@@ -2,7 +2,7 @@ import type { BoardLane } from "@homarr/definitions";
 import { getBoardLaneColumnCount, getRootSectionLane } from "@homarr/definitions";
 
 import type { Board, EmptySection } from "~/app/[locale]/boards/_types";
-import { getLogicalTrackSize, getLayoutRowCount, normalizeGridPlacement } from "./geometry";
+import { getLogicalGridSize, getLayoutRowCount, normalizeGridPlacement } from "./geometry";
 import { getCollapsedDisplayLayout } from "./reflow";
 import type { GridPlacement } from "./types";
 
@@ -90,5 +90,5 @@ export const getInitialBoardLogicalHeight = (board: Board, layoutId: string) =>
     return [getLayoutRowCount(displayPlacements)];
   });
 
-  return getLogicalTrackSize(Math.max(0, ...rowCounts));
+  return getLogicalGridSize(Math.max(0, ...rowCounts));
 };

apps/nextjs/src/components/board/layout/geometry.ts

@@ -10,12 +10,23 @@ export const getLogicalTrackSize = (trackCount: number) => {
   return normalizedTrackCount * LOGICAL_GRID_CELL_SIZE + (normalizedTrackCount - 1) * LOGICAL_GRID_GAP;
 };
 
+/**
+ * Returns the complete footprint occupied by grid tracks. Cards are inset
+ * inside this footprint so their visual gutters stay fixed while the canvas
+ * is scaled.
+ */
+export const getLogicalGridSize = (trackCount: number) => {
+  const normalizedTrackCount = Math.max(0, toFiniteNumber(trackCount, "trackCount"));
+
+  return normalizedTrackCount * LOGICAL_GRID_PITCH;
+};
+
 export const getLogicalItemStyle = ({ x, y, w, h }: GridCoordinates): CSSProperties => ({
   position: "absolute",
   left: x * LOGICAL_GRID_PITCH,
   top: y * LOGICAL_GRID_PITCH,
-  width: getLogicalTrackSize(w),
-  height: getLogicalTrackSize(h),
+  width: getLogicalGridSize(w),
+  height: getLogicalGridSize(h),
 });
 
 export const getLayoutRowCount = (placements: readonly GridCoordinates[]) =>
@@ -25,7 +36,7 @@ export const getGridRowCountForVisualHeight = (visualHeight: number, visualScale
   if (!Number.isFinite(visualHeight) || visualHeight <= 0) return 1;
   if (!Number.isFinite(visualScale) || visualScale <= 0) return 1;
 
-  return Math.max(1, Math.ceil((visualHeight / visualScale + LOGICAL_GRID_GAP) / LOGICAL_GRID_PITCH));
+  return Math.max(1, Math.ceil(visualHeight / visualScale / LOGICAL_GRID_PITCH));
 };
 
 export const normalizeGridPlacement = <TPlacement extends GridPlacement>(

apps/nextjs/src/components/board/sections/grid/dnd/coordinates.ts

@@ -1,4 +1,4 @@
-import { getLogicalTrackSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
+import { getLogicalGridSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
 import type { GridPlacement } from "~/components/board/layout";
 import type { GridResizeDirection } from "./types";
 
@@ -38,7 +38,7 @@ export const getSnappedGridCoordinates = ({
   target: RectangleLike;
   columnCount: number;
 }) => {
-  const logicalWidth = getLogicalTrackSize(columnCount);
+  const logicalWidth = getLogicalGridSize(columnCount);
   const visualScale = logicalWidth > 0 ? target.width / logicalWidth : 0;
   if (!Number.isFinite(visualScale) || visualScale <= 0) return null;
 

apps/nextjs/src/components/board/sections/grid/grid-editor.tsx

@@ -39,7 +39,7 @@ import { useCurrentLayout, useRequiredBoard } from "@homarr/boards/context";
 import { getWidgetName } from "@homarr/definitions";
 import { useI18n } from "@homarr/translation/client";
 
-import { getLogicalTrackSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
+import { getLogicalGridSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
 import {
   beginGridTransaction,
   cancelGridTransaction,
@@ -792,8 +792,8 @@ export default function GridEditor({
       data-grid-depth={depth}
       style={
         {
-          width: getLogicalTrackSize(columnCount),
-          height: getLogicalTrackSize(rowCount),
+          width: getLogicalGridSize(columnCount),
+          height: getLogicalGridSize(rowCount),
           "--board-grid-pitch": `${LOGICAL_GRID_PITCH}px`,
         } as CSSProperties
       }
@@ -1234,8 +1234,8 @@ const getEntryVisualScale = (element: HTMLElement | null, placement: SectionGrid
   if (!element) return null;
   const rectangle = element.getBoundingClientRect();
   const scale = {
-    x: rectangle.width / getLogicalTrackSize(placement.w),
-    y: rectangle.height / getLogicalTrackSize(placement.h),
+    x: rectangle.width / getLogicalGridSize(placement.w),
+    y: rectangle.height / getLogicalGridSize(placement.h),
   };
   return Number.isFinite(scale.x) && scale.x > 0 && Number.isFinite(scale.y) && scale.y > 0 ? scale : null;
 };

apps/nextjs/src/components/board/sections/grid/grid-preview-geometry.ts

@@ -1,4 +1,4 @@
-import { getLogicalTrackSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
+import { getLogicalGridSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
 import type { GridPlacement } from "~/components/board/layout";
 
 export interface GridPreviewDomState {
@@ -75,8 +75,8 @@ export const clearGridPreviewGeometry = (
 const applyPreviewGeometry = (element: HTMLElement, controlled: GridPlacement, preview: GridPlacement) => {
   element.style.setProperty("--board-grid-preview-x", `${(preview.x - controlled.x) * LOGICAL_GRID_PITCH}px`);
   element.style.setProperty("--board-grid-preview-y", `${(preview.y - controlled.y) * LOGICAL_GRID_PITCH}px`);
-  element.style.setProperty("--board-grid-preview-width", `${getLogicalTrackSize(preview.w)}px`);
-  element.style.setProperty("--board-grid-preview-height", `${getLogicalTrackSize(preview.h)}px`);
+  element.style.setProperty("--board-grid-preview-width", `${getLogicalGridSize(preview.w)}px`);
+  element.style.setProperty("--board-grid-preview-height", `${getLogicalGridSize(preview.h)}px`);
   element.setAttribute("data-grid-preview", "true");
   setPlacementAttributes(element, preview);
 };

apps/nextjs/src/components/board/sections/grid/grid-preview-layer.tsx

@@ -3,7 +3,7 @@
 import type { RefObject } from "react";
 import { useCallback, useLayoutEffect, useRef, useSyncExternalStore } from "react";
 
-import { getLayoutRowCount, getLogicalItemStyle, getLogicalTrackSize } from "~/components/board/layout";
+import { getLayoutRowCount, getLogicalItemStyle, getLogicalGridSize } from "~/components/board/layout";
 import type { TransactionalGridState } from "./dnd";
 import type { GridInteractionStore } from "./grid-interaction-store";
 import { clearGridPreviewGeometry, createGridPreviewDomState, syncGridPreviewGeometry } from "./grid-preview-geometry";
@@ -87,7 +87,7 @@ export const GridPreviewLayer = ({
     } else {
       delete grid.dataset.dndPreviewRevision;
     }
-    grid.style.height = `${getLogicalTrackSize(renderedRowCount)}px`;
+    grid.style.height = `${getLogicalGridSize(renderedRowCount)}px`;
 
     const viewport = grid.parentElement;
     if (viewport?.hasAttribute("data-section-id")) {
@@ -98,7 +98,7 @@ export const GridPreviewLayer = ({
       // stray value would silently blow the cap open for the rest of the session, well after any
       // drag ended, since nothing else would ever clear it back out.
       if (maxRowCount === null) {
-        viewport.style.setProperty("--board-grid-drag-height", `${getLogicalTrackSize(renderedRowCount)}px`);
+        viewport.style.setProperty("--board-grid-drag-height", `${getLogicalGridSize(renderedRowCount)}px`);
       } else {
         viewport.style.removeProperty("--board-grid-drag-height");
       }

apps/nextjs/src/components/board/sections/grid/grid-resize-outline.ts

@@ -1,4 +1,4 @@
-import { getLogicalTrackSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
+import { getLogicalGridSize, LOGICAL_GRID_PITCH } from "~/components/board/layout";
 import type { GridPlacement } from "~/components/board/layout";
 
 interface ResizeOutlinePreview {
@@ -31,8 +31,8 @@ export const createGridResizeOutlineController = (
     outline.style.position = "absolute";
     outline.style.left = `${(preview.placement.x - visualX) * LOGICAL_GRID_PITCH}px`;
     outline.style.top = `${(preview.placement.y - visualY) * LOGICAL_GRID_PITCH}px`;
-    outline.style.width = `${getLogicalTrackSize(preview.placement.w)}px`;
-    outline.style.height = `${getLogicalTrackSize(preview.placement.h)}px`;
+    outline.style.width = `${getLogicalGridSize(preview.placement.w)}px`;
+    outline.style.height = `${getLogicalGridSize(preview.placement.h)}px`;
     outline.dataset.gridResizeValid = String(preview.valid);
   };
 

apps/nextjs/src/components/board/sections/grid/section-grid.module.css

@@ -50,6 +50,10 @@
   overflow: visible;
 }
 
+.staticItem[data-type="item"] > .contentMount {
+  inset: calc(10px * var(--board-canvas-inverse-scale, 1));
+}
+
 .staticItem:has([data-board-container-label]) {
   z-index: 2;
 }

apps/nextjs/src/components/board/sections/grid/section-grid.tsx

@@ -14,7 +14,7 @@ import {
   getEditableCanvasAttributes,
   getGridRowCountForVisualHeight,
   getLayoutRowCount,
-  getLogicalTrackSize,
+  getLogicalGridSize,
   getReadonlyCanvasAttributes,
   normalizeGridPlacement,
 } from "~/components/board/layout";
@@ -138,9 +138,9 @@ export const SectionGrid = ({
   // of expanding to fit every widget, so its viewport height is capped independently of rowCount.
   const isScrollableContainer = section.kind === "container" && section.options.scrollable;
   const viewportRowCount = isScrollableContainer ? Math.max(requestedRowCount, 1) : rowCount;
-  const logicalWidth = getLogicalTrackSize(columnCount);
-  const logicalHeight = getLogicalTrackSize(rowCount);
-  const viewportHeight = getLogicalTrackSize(viewportRowCount);
+  const logicalWidth = getLogicalGridSize(columnCount);
+  const logicalHeight = getLogicalGridSize(rowCount);
+  const viewportHeight = getLogicalGridSize(viewportRowCount);
   // A collapsed container's compact coordinates are display-only. Its own
   // nested grid stays inactive until an explicit edit interaction expands it.
   const isInteractionDisabled = section.kind === "container" && collapsedSectionIds.has(section.id);