[AGILE-278] Move selected work packages atomically

app/components/open_project/common/border_box_list_component.sass

@@ -64,7 +64,8 @@
       &[data-batch-selected]
         border-top-color: var(--box-list-item-selected-border-color)
 
-      &:has(> .Box-card[aria-current="true"])
+      &:has(> .Box-card[aria-current="true"]),
+      &:has(> .Box-card[data-activating])
         border-top-color: var(--box-list-item-pressed-border-color)
 
   &.op-border-box-list_transparent
@@ -208,7 +209,13 @@
 // Current state: the card is open in the split screen. aria-current is
 // maintained by the backlogs--work-package controller once the URL reflects
 // the details pane; the strong border wins over a simultaneous batch selection.
-.Box-row:has(> .Box-card[aria-current="true"])
+//
+// data-activating is that controller's synchronous pressed state — the card
+// was just clicked or Enter-activated and its visit has not landed yet. It
+// is visual only (no ARIA) and reuses the pressed border so it hands over
+// seamlessly to aria-current once the URL reflects the details pane.
+.Box-row:has(> .Box-card[aria-current="true"]),
+.Box-row:has(> .Box-card[data-activating])
   @include op-box-list-item-edge-borders(var(--box-list-item-pressed-border-color))
 
 // Drag-and-drop row states, scoped to the border-box list. The global
@@ -306,6 +313,26 @@
     .-browser-firefox &
       box-shadow: none
 
+  // The stack and the lift share the one box-shadow property, so both are
+  // declared here or one replaces the other.
+  //
+  // The depth the preview writes is the batch's, uncapped: past four cards the
+  // added depth stops reading, so this default holds every deeper batch at the
+  // maximum and the shallow depths below override it.
+  &[data-preview][data-stack-depth]
+    box-shadow: op-drag-stack-shadows(), var(--shadow-floating-medium)
+
+    // Blur-free and inside the reserved overhang, so only the lift has to go.
+    .-browser-firefox &
+      box-shadow: op-drag-stack-shadows()
+
+  @for $layers from 1 through $op-drag-stack-max-layers - 1
+    &[data-preview][data-stack-depth="#{$layers}"]
+      box-shadow: op-drag-stack-shadows($layers: $layers), var(--shadow-floating-medium)
+
+      .-browser-firefox &
+        box-shadow: op-drag-stack-shadows($layers: $layers)
+
 .Box--condensed .Box-card
   padding: var(--stack-padding-condensed) var(--stack-padding-normal)
 

config/locales/js-en.yml

@@ -861,11 +861,23 @@ en:
 
     sortable_lists:
       announcements:
+        batch_too_large: "Cannot move %{count} items at once. Select no more than %{max}."
         fallback_item_label: "Item"
         fallback_list_name: "another list"
         move_failed_check_position: "Move failed. Check the item's current position."
+        # The batch keys are plural hashes so translators can add the plural
+        # categories their locale needs; the one: branch is unreachable (a
+        # one-item move announces through the singular keys).
+        move_failed_check_positions_batch:
+          other: "Move failed. Check the items' current positions."
         move_failed_rolled_back: "Move failed. %{label} returned to its previous position."
+        move_failed_rolled_back_batch:
+          other: "Move failed. %{count} items returned to their previous positions."
         moved: "%{label} moved to position %{position} of %{total}"
+        moved_batch:
+          other: "%{count} items moved to positions %{first} through %{last} of %{total}"
+        moved_batch_to_list:
+          other: "%{count} items moved to %{list}, positions %{first} through %{last} of %{total}"
         moved_to_list: "%{label} moved to %{list}, position %{position} of %{total}"
       selection:
         cleared: "Selection cleared."

frontend/AGENTS.md

@@ -7,7 +7,7 @@
   - `./src/common/` - Framework-agnostic modules (the `core-common` alias), importable from both Angular and Stimulus. Code belongs here when it depends on neither framework and both sides need it; a helper only Stimulus controllers use belongs in `./src/stimulus/helpers/` instead.
   - `./src/stimulus/` - Stimulus controllers
   - `./src/turbo/` - Turbo integration
-- `sortable-lists` batch selection is opt-in: a root enables it with a `selectionEnabled` value, and no other consumer's behavior changes. A root also sets `announcementScope`, so the shared controller's announcements speak the consumer's vocabulary instead of "item", and `selectionDescriptionId`, pointing at one shared element every selected card references via `aria-describedby`. Items declare `mobility` — `fixed`, `confined` or `free` — which gates dragging, selection eligibility, and positional moves alike. A missing value means `free`, so a consumer that renders none keeps working; an unrecognised one falls closed to `fixed` rather than handing the user controls the server will refuse. The pure selection model lives in `./src/common/batch-selection.ts` (framework-agnostic, so Angular consumers can adopt it); the DOM-facing adapter is `sortable-lists/selection.ts`, and gesture interpretation sits behind `sortable-lists/selection-orchestrator.ts`, which takes a narrow host port and imports no Stimulus. Selection identity is `(type, id)`, never the id alone: ids are unique per source table, so a nested list of another type can hold a colliding one. A root must render exactly one instance of each `(type, id)`, and an item declaring no type is refused as a candidate. A batch holds one item type — that cohort rule is orchestrator policy, not a constraint of the model, since identity namespacing and batch compatibility are different concerns. Ranges and select-all (Ctrl/Cmd+A) are both confined to the focused card's list; selecting across lists is a deliberate gap, reserved for a separate mechanism. An item belongs to its nearest ancestor root, so an independently nested root is an ownership boundary. Batch movement is not implemented: a drag still moves one card and collapses any wider selection onto it — that's a later work package.
+- `sortable-lists` batch selection is opt-in: a root enables it with a `selectionEnabled` value, and no other consumer's behavior changes. A root also sets `announcementScope`, so the shared controller's announcements speak the consumer's vocabulary instead of "item", and `selectionDescriptionId`, pointing at one shared element every selected card references via `aria-describedby`. Items declare `mobility` — `fixed`, `confined` or `free` — which gates dragging, selection eligibility, and positional moves alike. A missing value means `free`, so a consumer that renders none keeps working; an unrecognised one falls closed to `fixed` rather than handing the user controls the server will refuse. The pure selection model lives in `./src/common/batch-selection.ts` (framework-agnostic, so Angular consumers can adopt it); the DOM-facing adapter is `sortable-lists/selection.ts`, and gesture interpretation sits behind `sortable-lists/selection-orchestrator.ts`, which takes a narrow host port and imports no Stimulus. Selection identity is `(type, id)`, never the id alone: ids are unique per source table, so a nested list of another type can hold a colliding one. A root must render exactly one instance of each `(type, id)`, and an item declaring no type is refused as a candidate. A batch holds one item type — that cohort rule is orchestrator policy, not a constraint of the model, since identity namespacing and batch compatibility are different concerns. Ranges and select-all (Ctrl/Cmd+A) are both confined to the focused card's list; selecting across lists is a deliberate gap, reserved for a separate mechanism. An item belongs to its nearest ancestor root, so an independently nested root is an ownership boundary. Dragging a selected card moves the whole batch: the root freezes the drag's batch in the preview callback (`freezeDragBatch`) and marks its rows at drag start (`markDragBatch`), and a selection-enabled root with a `collectionMoveUrl` value submits ordered `ids[]` to the collection move action — for one dragged card or many. Dragging an unselected card selects it, collapsing any wider selection. A root's `moveAnnouncementScope` value keys the move announcements the same way `announcementScope` keys the selection ones.
 - `data-batch-selected` is written on the sortable item element — the row, in Backlogs — while `aria-current` is written on the card inside it. A stylesheet assuming both live on the same element will silently paint nothing while attribute assertions stay green.
 
 ## Configuration Files

frontend/src/global_styles/content/drag_and_drop.sass

@@ -25,6 +25,7 @@
 //
 // See COPYRIGHT and LICENSE files for more details.
 //++
+@use "sass:list"
 
 // The intend for this file is to become the place where all drag&drop styles are placed.
 // As there will hopefully also be a shared style for resizing, and as those two will hopefully also share some styles
@@ -45,3 +46,66 @@
 
   &:active
     cursor: grabbing
+
+// Ghost layers behind a multi-card drag preview, one per further card in the
+// batch up to the maximum. Composed into the card's own shadow by the
+// component that renders it (border_box_list_component.sass).
+$op-drag-stack-max-layers: 3 !default
+$op-drag-stack-step: 6px !default
+$op-drag-stack-ring: 1px !default
+$op-drag-stack-shade-blur: 4px !default
+$op-drag-stack-shade-color: rgba(37, 41, 46, 0.18) !default
+
+$op-drag-badge-overhang: 8px !default
+$op-drag-stack-overhang: $op-drag-stack-step * $op-drag-stack-max-layers + $op-drag-stack-shade-blur
+
+// renderDragPreview reserves the overhangs as container padding, and can only
+// do so inline (Pragmatic inline-resets the container first), so they are
+// published as custom properties rather than duplicated as numbers there.
+:root
+  --op-drag-badge-overhang: #{$op-drag-badge-overhang}
+  --op-drag-stack-overhang: #{$op-drag-stack-overhang}
+
+// Each depth emits shade, fill then ring: CSS paints a shadow list front to
+// back, so a depth's shade lands above its own fill, in the gap under the card
+// in front of it. The deepest shade reaches `step * layers + shade-blur` past
+// the right and bottom edges; the blur is under every offset, so nothing
+// reaches past the top or left.
+@function op-drag-stack-shadows($layers: $op-drag-stack-max-layers, $step: $op-drag-stack-step, $ring: $op-drag-stack-ring, $blur: $op-drag-stack-shade-blur, $shade: $op-drag-stack-shade-color)
+  $shadows: ()
+
+  @for $depth from 1 through $layers
+    $offset: $step * $depth
+    $shadows: list.append($shadows, $offset $offset $blur 0 $shade, comma)
+    $shadows: list.append($shadows, $offset $offset 0 0 var(--bgColor-default), comma)
+    $shadows: list.append($shadows, $offset $offset 0 $ring var(--borderColor-default), comma)
+
+  @return $shadows
+
+// Multi-card batch count badge on a drag preview, on Primer's Counter
+// contract plus the positioning Counter does not own and the accent skin the
+// drop indicator uses.
+//
+// Paint past the container's border box lands in Firefox's drag snapshot and
+// shifts its origin off the grab offset, so the badge sits in the padding
+// renderDragPreview writes. The right offset keeps it on the card's corner.
+.op-sortable-lists-drag-preview-batch-badge
+  position: absolute
+  top: 0
+  right: $op-drag-stack-overhang - $op-drag-badge-overhang
+  min-width: 20px
+  height: 20px
+  padding: 0 6px
+  border-radius: 999px
+  background-color: var(--bgColor-accent-emphasis)
+  color: var(--fgColor-onEmphasis)
+  font-size: 12px
+  font-weight: 600
+  line-height: 20px
+  text-align: center
+  box-shadow: var(--shadow-floating-medium)
+
+  // The blur past the container's border box would shift Firefox's snapshot
+  // origin like the overhang above.
+  .-browser-firefox &
+    box-shadow: none

frontend/src/stimulus/controllers/dynamic/backlogs/split-view-sync.controller.spec.ts

@@ -158,4 +158,39 @@ describe('Backlogs split-view-sync controller', () => {
 
     expect(refresh).not.toHaveBeenCalled();
   });
+
+  it('refreshes every cached member of a batch event, in order', async () => {
+    await renderHost();
+
+    dispatchMoved({ work_package_ids: [11, 12, 13] });
+
+    await waitFor(() => {
+      expect(id).toHaveBeenCalledWith('11');
+      expect(id).toHaveBeenCalledWith('12');
+      expect(id).toHaveBeenCalledWith('13');
+      expect(refresh).toHaveBeenCalledTimes(3);
+    });
+  });
+
+  it('skips uncached members of a batch event', async () => {
+    hasValue.mockImplementation(() => state.mock.calls.length === 2);
+    await renderHost();
+
+    dispatchMoved({ work_package_ids: [11, 12] });
+
+    await waitFor(() => {
+      expect(state).toHaveBeenCalledWith('11');
+      expect(state).toHaveBeenCalledWith('12');
+      expect(refresh).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  it('ignores an event with neither id field', async () => {
+    await renderHost();
+
+    dispatchMoved({});
+    await ctx.nextFrame();
+
+    expect(refresh).not.toHaveBeenCalled();
+  });
 });

frontend/src/stimulus/controllers/dynamic/backlogs/split-view-sync.controller.ts

@@ -53,17 +53,21 @@ export default class SplitViewSyncController extends Controller {
   // was ever opened, it will still be in the cache leading to a refresh request. The upside of this potentially
   // wasteful refresh is that when the work package is later on reopened in the split view, its information
   // is correct as well.
-  onWorkPackageMoved(event:CustomEvent<{ work_package_id?:number }>):void {
-    const workPackageId = event.detail?.work_package_id;
+  onWorkPackageMoved(event:CustomEvent<{ work_package_id?:number; work_package_ids?:number[] }>):void {
+    const detail = event.detail ?? {};
+    const ids = detail.work_package_ids
+      ?? (detail.work_package_id !== undefined ? [detail.work_package_id] : []);
     // apiV3Service is wired asynchronously via useAngularServices, so it may be absent
     // if the event somehow fires before the services resolve.
-    if (workPackageId === undefined || !this.apiV3Service) { return; }
+    if (ids.length === 0 || !this.apiV3Service) { return; }
 
-    const id = workPackageId.toString();
     const { work_packages: workPackages } = this.apiV3Service;
 
-    if (workPackages.cache.state(id).hasValue()) {
-      void workPackages.id(id).refresh();
-    }
+    ids.forEach((rawId) => {
+      const id = rawId.toString();
+      if (workPackages.cache.state(id).hasValue()) {
+        void workPackages.id(id).refresh();
+      }
+    });
   }
 }

frontend/src/stimulus/controllers/dynamic/backlogs/work-package.controller.spec.ts

@@ -177,6 +177,80 @@ describe('Backlogs work package controller', () => {
     }
   });
 
+  // The pressed state is visual only — data-activating, never ARIA — so
+  // every user gets synchronous feedback regardless of batch selection
+  // being enabled for them.
+  describe('activation feedback', () => {
+    it('shows pressed feedback synchronously on click, before any navigation', async () => {
+      const workPackage = renderWorkPackage();
+
+      await nextFrame();
+      workPackage.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+
+      expect(workPackage.hasAttribute('data-activating')).toBe(true);
+      expect(workPackage.hasAttribute('aria-current')).toBe(false);
+      expect(navigation.openSplitPane).not.toHaveBeenCalled();
+    });
+
+    it('shows pressed feedback synchronously on Enter', async () => {
+      const workPackage = renderWorkPackage();
+
+      await nextFrame();
+      keydown(workPackage, 'Enter');
+
+      expect(workPackage.hasAttribute('data-activating')).toBe(true);
+      expect(workPackage.hasAttribute('aria-current')).toBe(false);
+    });
+
+    it('clears pressed feedback when the visit lands on the card', async () => {
+      const workPackage = renderWorkPackage();
+
+      await nextFrame();
+      workPackage.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+      document.dispatchEvent(new CustomEvent('turbo:visit', {
+        detail: { url: '/projects/demo/backlogs/details/SP-42' },
+      }));
+
+      expect(workPackage.hasAttribute('data-activating')).toBe(false);
+      expect(workPackage.getAttribute('aria-current')).toBe('true');
+    });
+
+    it('clears pressed feedback when the visit lands elsewhere', async () => {
+      const workPackage = renderWorkPackage();
+
+      await nextFrame();
+      workPackage.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+      document.dispatchEvent(new CustomEvent('turbo:visit', {
+        detail: { url: '/projects/demo/backlogs' },
+      }));
+
+      expect(workPackage.hasAttribute('data-activating')).toBe(false);
+      expect(workPackage.hasAttribute('aria-current')).toBe(false);
+    });
+
+    it('clears pressed feedback when a double-click cancels the pending click', async () => {
+      const workPackage = renderWorkPackage();
+
+      await nextFrame();
+      workPackage.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+      workPackage.dispatchEvent(new MouseEvent('dblclick', { bubbles: true }));
+
+      expect(workPackage.hasAttribute('data-activating')).toBe(false);
+      expect(navigation.openFullPane).toHaveBeenCalledTimes(1);
+    });
+
+    it('clears pressed feedback when the card disconnects', async () => {
+      const workPackage = renderWorkPackage();
+
+      await nextFrame();
+      workPackage.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+      fixture.remove();
+      await nextFrame();
+
+      expect(workPackage.hasAttribute('data-activating')).toBe(false);
+    });
+  });
+
   it('marks the card as current when the URL points at it', async () => {
     const workPackage = renderWorkPackage();
 

frontend/src/stimulus/controllers/dynamic/backlogs/work-package.controller.ts

@@ -72,9 +72,16 @@ export default class WorkPackageController extends Controller<HTMLElement> imple
       clearTimeout(this.clickTimeout);
       this.clickTimeout = null;
     }
+
+    // A card that reconnects must not come back pressed.
+    this.unmarkAsActivating();
   }
 
   private syncCurrentFromUrl(locationUrl:string):void {
+    // However the visit resolved, the pressed state hands over to
+    // aria-current or to nothing.
+    this.unmarkAsActivating();
+
     const { pathname } = new URL(locationUrl, window.location.origin);
     const [, id] = DETAILS_URL_PATTERN.exec(pathname) ?? [];
     // Bookmarks and external links may still carry a numeric ID after the
@@ -88,7 +95,10 @@ export default class WorkPackageController extends Controller<HTMLElement> imple
 
   // Not set optimistically: activation waits out the double-click delay below
   // and may resolve to the full view instead, so asserting a current work
-  // package here would announce a navigation that may never happen.
+  // package here would announce a navigation that may never happen. Feedback
+  // is visual only: data-activating goes on synchronously and carries no ARIA
+  // semantics, since the card is an article and role=button was rejected in
+  // AGILE-251.
   markAsCurrent():void {
     this.element.setAttribute('aria-current', 'true');
   }
@@ -97,6 +107,14 @@ export default class WorkPackageController extends Controller<HTMLElement> imple
     this.element.removeAttribute('aria-current');
   }
 
+  markAsActivating():void {
+    this.element.setAttribute('data-activating', '');
+  }
+
+  unmarkAsActivating():void {
+    this.element.removeAttribute('data-activating');
+  }
+
   handleEvent(event:Event):void {
     switch (event.type) {
       case 'click':
@@ -119,6 +137,7 @@ export default class WorkPackageController extends Controller<HTMLElement> imple
 
     if (this.clickTimeout !== null) return;
 
+    this.markAsActivating();
     this.clickTimeout = window.setTimeout(() => {
       this.clickTimeout = null;
       this.openSplitPane();
@@ -134,6 +153,7 @@ export default class WorkPackageController extends Controller<HTMLElement> imple
     if (this.clickTimeout !== null) {
       clearTimeout(this.clickTimeout);
       this.clickTimeout = null;
+      this.unmarkAsActivating();
     }
 
     this.openFullPane();
@@ -149,6 +169,7 @@ export default class WorkPackageController extends Controller<HTMLElement> imple
 
     event.preventDefault();
 
+    this.markAsActivating();
     if (event.shiftKey) {
       this.openFullPane();
     } else {