[codex] Honor min size during empty cell drag

projects/angular-gridster2/src/lib/gridsterEmptyCell.ts

@@ -228,21 +228,23 @@ export class GridsterEmptyCell {
     const item: GridsterItemConfig = {
       x: this.gridster.pixelsToPositionX(x, Math.floor, true),
       y: this.gridster.pixelsToPositionY(y, Math.floor, true),
-      cols: $options.defaultItemCols,
-      rows: $options.defaultItemRows
+      cols: Math.max($options.defaultItemCols, $options.minItemCols),
+      rows: Math.max($options.defaultItemRows, $options.minItemRows)
     };
     if (oldItem) {
-      item.cols = Math.min(Math.abs(oldItem.x - item.x) + 1, $options.emptyCellDragMaxCols);
-      item.rows = Math.min(Math.abs(oldItem.y - item.y) + 1, $options.emptyCellDragMaxRows);
-      if (oldItem.x < item.x) {
+      const cellX = item.x;
+      const cellY = item.y;
+      item.cols = Math.min(Math.max(Math.abs(oldItem.x - cellX) + 1, $options.minItemCols), $options.emptyCellDragMaxCols);
+      item.rows = Math.min(Math.max(Math.abs(oldItem.y - cellY) + 1, $options.minItemRows), $options.emptyCellDragMaxRows);
+      if (oldItem.x <= cellX) {
         item.x = oldItem.x;
-      } else if (oldItem.x - item.x > $options.emptyCellDragMaxCols - 1) {
-        item.x = this.gridster.movingItem ? this.gridster.movingItem.x : 0;
+      } else {
+        item.x = oldItem.x - item.cols + 1;
       }
-      if (oldItem.y < item.y) {
+      if (oldItem.y <= cellY) {
         item.y = oldItem.y;
-      } else if (oldItem.y - item.y > $options.emptyCellDragMaxRows - 1) {
-        item.y = this.gridster.movingItem ? this.gridster.movingItem.y : 0;
+      } else {
+        item.y = oldItem.y - item.rows + 1;
       }
     }
     if (!$options.enableOccupiedCellDrop && this.gridster.checkCollision(item)) {

projects/angular-gridster2/src/lib/tests/gridsterEmptyCell.spec.ts

@@ -0,0 +1,108 @@
+import { signal } from '@angular/core';
+
+import { Gridster } from '../gridster';
+import { GridsterEmptyCell } from '../gridsterEmptyCell';
+import { GridsterItemConfig } from '../gridsterItemConfig';
+
+const baseOptions = {
+  scale: undefined,
+  defaultItemCols: 1,
+  defaultItemRows: 1,
+  minItemCols: 6,
+  minItemRows: 5,
+  maxItemCols: 100,
+  maxItemRows: 100,
+  minItemArea: 1,
+  maxItemArea: 2500,
+  maxCols: 100,
+  maxRows: 100,
+  emptyCellDragMaxCols: 50,
+  emptyCellDragMaxRows: 50,
+  enableOccupiedCellDrop: false
+};
+
+type EmptyCellOptions = typeof baseOptions;
+
+function getMinItemCols(options: EmptyCellOptions, item: GridsterItemConfig): number {
+  return item.minItemCols === undefined ? options.minItemCols : item.minItemCols;
+}
+
+function getMinItemRows(options: EmptyCellOptions, item: GridsterItemConfig): number {
+  return item.minItemRows === undefined ? options.minItemRows : item.minItemRows;
+}
+
+function createEmptyCell(overrides: Partial<EmptyCellOptions> = {}): GridsterEmptyCell {
+  const $options = {
+    ...baseOptions,
+    ...overrides
+  };
+  const gridster = {
+    el: {
+      scrollLeft: 0,
+      scrollTop: 0,
+      getBoundingClientRect: () => ({ left: 0, top: 0 })
+    },
+    gridRenderer: {
+      getLeftMargin: () => 0,
+      getTopMargin: () => 0
+    },
+    options: signal({ scale: undefined }),
+    $options: signal($options),
+    pixelsToPositionX: (x: number) => Math.floor(x),
+    pixelsToPositionY: (y: number) => Math.floor(y),
+    checkCollision: (item: GridsterItemConfig) =>
+      item.x < 0 ||
+      item.y < 0 ||
+      item.cols < getMinItemCols($options, item) ||
+      item.rows < getMinItemRows($options, item) ||
+      item.cols > $options.maxItemCols ||
+      item.rows > $options.maxItemRows ||
+      item.x + item.cols > $options.maxCols ||
+      item.y + item.rows > $options.maxRows
+  } as unknown as Gridster;
+  return new GridsterEmptyCell(gridster);
+}
+
+function mouseAt(clientX: number, clientY: number): MouseEvent {
+  return {
+    clientX,
+    clientY,
+    preventDefault: vi.fn(),
+    stopPropagation: vi.fn()
+  } as unknown as MouseEvent;
+}
+
+describe('gridster empty cell drag', () => {
+  it('creates the initial empty cell item at the configured minimum size', () => {
+    const emptyCell = createEmptyCell();
+
+    expect(emptyCell.getValidItemFromEvent(mouseAt(2, 3))).toEqual({
+      x: 2,
+      y: 3,
+      cols: 6,
+      rows: 5
+    });
+  });
+
+  it('keeps minimum rows when dragging an empty cell item to the right', () => {
+    const emptyCell = createEmptyCell();
+
+    expect(emptyCell.getValidItemFromEvent(mouseAt(4, 3), { x: 2, y: 3, cols: 6, rows: 5 })).toEqual({
+      x: 2,
+      y: 3,
+      cols: 6,
+      rows: 5
+    });
+  });
+
+  it('keeps minimum columns when dragging an empty cell item down', () => {
+    const emptyCell = createEmptyCell();
+
+    expect(emptyCell.getValidItemFromEvent(mouseAt(2, 6), { x: 2, y: 3, cols: 6, rows: 5 })).toEqual({
+      x: 2,
+      y: 3,
+      cols: 6,
+      rows: 5
+    });
+  });
+});