🐛(frontend) fix drag-and-drop move disabled by viewport breakpoint

Drag-and-drop to move a document was disabled below a viewport
width breakpoint.
Browser zoom shrinks window.innerWidth like a narrower window
does, so zooming in on a desktop with a mouse silently disabled
moving documents, in the docs grid and in the doc tree.

A fix was made on the doc grid, but not in the tree,
we updated useResponsiveStore to tell us if the window
has coarse pointer or not (hasCoarsePointer).

Closes #2599

src/frontend/apps/impress/src/features/docs/doc-tree/components/DocTreeSubpages.tsx

@@ -3,7 +3,6 @@ import {
   TreeDataItem,
   TreeView,
   TreeViewMoveResult,
-  useResponsive,
   useTreeContext,
 } from '@gouvfr-lasuite/ui-components';
 import { useRouter } from 'next/router';
@@ -13,6 +12,7 @@ import { NodeApi } from 'react-arborist';
 import { Overlayer } from '@/components';
 import { CLASS_DOC_TITLE } from '@/docs/doc-header';
 import { Doc, useMoveDoc } from '@/docs/doc-management';
+import { useResponsiveStore } from '@/stores/useResponsiveStore';
 
 import { isDocNode, isWithinTreeItemActions } from '../utils';
 
@@ -33,7 +33,7 @@ export const DocTreeSubpages = memo(function DocTreeSubpages({
   rootNodeId,
   rootItemRef,
 }: DocTreeSubPagesProps) {
-  const { isDesktop } = useResponsive();
+  const { hasCoarsePointer } = useResponsiveStore();
   const treeContext = useTreeContext<Doc | null>();
   const { mutateAsync: moveDoc } = useMoveDoc();
   const { query } = useRouter();
@@ -70,11 +70,11 @@ export const DocTreeSubpages = memo(function DocTreeSubpages({
     ({ parentNode }: { parentNode: NodeApi<TreeDataItem<Doc>> | null }) => {
       const parentValue = parentNode?.data.value;
       if (!parentValue || !isDocNode(parentValue)) {
-        return doc.abilities.move && isDesktop;
+        return doc.abilities.move && !hasCoarsePointer;
       }
-      return parentValue.abilities.move && isDesktop;
+      return parentValue.abilities.move && !hasCoarsePointer;
     },
-    [doc.abilities.move, isDesktop],
+    [doc.abilities.move, hasCoarsePointer],
   );
 
   const canDrag = useCallback(
@@ -82,9 +82,9 @@ export const DocTreeSubpages = memo(function DocTreeSubpages({
       if (!isDocNode(node.value)) {
         return false;
       }
-      return node.value.abilities.move && isDesktop;
+      return node.value.abilities.move && !hasCoarsePointer;
     },
-    [isDesktop],
+    [hasCoarsePointer],
   );
 
   const handleRowKeyDown = useCallback(

src/frontend/apps/impress/src/features/docs/docs-grid/components/DocGridContentList.tsx

@@ -8,7 +8,6 @@ import {
 } from '@dnd-kit/core';
 import { getEventCoordinates } from '@dnd-kit/utilities';
 import { TreeViewMoveModeEnum, useModal } from '@gouvfr-lasuite/ui-components';
-import { useMediaQuery } from '@mantine/hooks';
 import dynamic from 'next/dynamic';
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { createPortal } from 'react-dom';
@@ -17,6 +16,7 @@ import { css } from 'styled-components';
 
 import { Card, Text } from '@/components';
 import { Doc, useMoveDoc, useTrans } from '@/docs/doc-management';
+import { useResponsiveStore } from '@/stores/useResponsiveStore';
 
 import { DocDragEndData, useDragAndDrop } from '../hooks/useDragAndDrop';
 
@@ -322,24 +322,18 @@ export const DraggableDocGridItem = ({
   );
 };
 
-/**
- * Browser zoom shrinks the viewport below the mobile breakpoint on a desktop,
- * so dnD depends on the pointer, not on the width. `any-pointer` also covers a
- * mouse plugged into a touch-first computer, where the primary pointer is coarse.
- */
-const FINE_POINTER_QUERY = '(any-pointer: fine)';
-
 export const DocGridContentList = ({ docs }: DocGridContentListProps) => {
-  const hasFinePointer = useMediaQuery(FINE_POINTER_QUERY);
+  const { hasCoarsePointer } = useResponsiveStore();
 
   if (docs.length === 0) {
     return null;
   }
 
-  if (hasFinePointer) {
+  if (!hasCoarsePointer) {
     return <DraggableDocGridContentList docs={docs} />;
   }
 
+  // Render a non-draggable list for touch-primary devices.
   return docs.map((doc) => (
     <DocsGridItem key={doc.id} dragMode={false} doc={doc} />
   ));

src/frontend/apps/impress/src/features/docs/docs-grid/components/__tests__/DocGridContentList.test.tsx

@@ -3,6 +3,7 @@ import type { Ref } from 'react';
 import { afterEach, describe, expect, it, vi } from 'vitest';
 
 import { Doc } from '@/docs/doc-management';
+import { useResponsiveStore } from '@/stores';
 import { AppWrapper } from '@/tests/utils';
 
 import { DocGridContentList } from '../DocGridContentList';
@@ -26,7 +27,7 @@ vi.mock('../DocsGridItem', () => ({
   ),
 }));
 
-const mockPointer = (isFine: boolean) => {
+const mockPointer = (isCoarse: boolean) => {
   Object.defineProperty(window, 'matchMedia', {
     configurable: true,
     writable: true,
@@ -34,13 +35,16 @@ const mockPointer = (isFine: boolean) => {
       addEventListener: vi.fn(),
       addListener: vi.fn(),
       dispatchEvent: vi.fn(),
-      matches: query === '(any-pointer: fine)' && isFine,
+      matches: query === '(pointer: coarse)' && isCoarse,
       media: query,
       onchange: null,
       removeEventListener: vi.fn(),
       removeListener: vi.fn(),
     })),
   });
+
+  // AppWrapper does not mount the AppProvider that wires the store.
+  return useResponsiveStore.getState().initializeResizeListener();
 };
 
 const doc = {
@@ -50,12 +54,15 @@ const doc = {
 } as Doc;
 
 describe('DocGridContentList', () => {
+  let cleanup: (() => void) | undefined;
+
   afterEach(() => {
+    cleanup?.();
     vi.restoreAllMocks();
   });
 
   it('lets a mouse drag a document whatever the viewport width', () => {
-    mockPointer(true);
+    cleanup = mockPointer(false);
 
     render(<DocGridContentList docs={[doc]} />, { wrapper: AppWrapper });
 
@@ -65,8 +72,8 @@ describe('DocGridContentList', () => {
     );
   });
 
-  it('does not make documents draggable without a fine pointer', () => {
-    mockPointer(false);
+  it('does not make documents draggable with a coarse pointer', () => {
+    cleanup = mockPointer(true);
 
     render(<DocGridContentList docs={[doc]} />, { wrapper: AppWrapper });
 

src/frontend/apps/impress/src/stores/useResponsiveStore.tsx

@@ -19,6 +19,11 @@ export interface UseResponsiveStore {
   screenWidth: number;
   setScreenSize: (size: ScreenSize) => void;
   isDesktop: boolean;
+  /**
+   * Indicates whether the primary input device has a coarse pointer (e.g., a touchscreen)
+   * rather than a fine pointer (e.g., a mouse or trackpad).
+   */
+  hasCoarsePointer: boolean;
   initializeResizeListener: () => () => void;
 }
 
@@ -28,6 +33,7 @@ const initialState = {
   isSmallMobile: false,
   isTablet: false,
   isDesktop: false,
+  hasCoarsePointer: false,
   screenSize: 'desktop' as ScreenSize,
   screenWidth: 0,
 };
@@ -38,6 +44,7 @@ export const useResponsiveStore = create<UseResponsiveStore>((set) => ({
   isMobile: initialState.isMobile,
   isSmallMobile: initialState.isSmallMobile,
   isTablet: initialState.isTablet,
+  hasCoarsePointer: initialState.hasCoarsePointer,
   screenSize: initialState.screenSize,
   screenWidth: initialState.screenWidth,
   setScreenSize: (size: ScreenSize) => set(() => ({ screenSize: size })),
@@ -107,9 +114,18 @@ export const useResponsiveStore = create<UseResponsiveStore>((set) => ({
 
     resizeHandler();
 
+    // Listen for changes to the primary input device's pointer type (coarse vs fine).
+    const coarsePointerQuery = window.matchMedia('(pointer: coarse)');
+    const pointerHandler = () => {
+      set({ hasCoarsePointer: coarsePointerQuery.matches });
+    };
+    pointerHandler();
+    coarsePointerQuery.addEventListener('change', pointerHandler);
+
     return () => {
       clearTimeout(resizeTimeout);
       window.removeEventListener('resize', debouncedResizeHandler);
+      coarsePointerQuery.removeEventListener('change', pointerHandler);
     };
   },
 }));