Multiselection and container assets: create container from selection, template instances

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/editor/state.ts

@@ -6,11 +6,23 @@ import { deserializeProject, serializeProject } from '../core/store/serialize';
 
 export type Selection =
   | { kind: 'asset'; assetId: string }
-  | { kind: 'object'; sceneId: string; objectId: string }
+  /**
+   * One or more objects of a scene. `objectId` is the primary one (the last picked – the
+   * inspector shows it); `objectIds` holds the whole selection, primary included.
+   */
+  | { kind: 'object'; sceneId: string; objectId: string; objectIds: string[] }
   /** A node inside a behavior's graph. */
   | { kind: 'node'; assetId: string; nodeId: string }
   | null;
 
+/** Builds an object selection; the last id is the primary one unless given explicitly. */
+export function objectSelection(sceneId: string, objectIds: readonly string[], primary?: string): Selection {
+  const ids = [...new Set(objectIds)];
+  if (ids.length === 0) return null;
+  const objectId = primary && ids.includes(primary) ? primary : ids[ids.length - 1]!;
+  return { kind: 'object', sceneId, objectId, objectIds: ids };
+}
+
 export type EditorMode = 'edit' | 'play';
 export type SaveStatus = 'saved' | 'dirty' | 'saving' | 'error' | 'conflict';
 
@@ -169,19 +181,35 @@ export class EditorState {
   // --- selection -----------------------------------------------------------------------
 
   select(selection: Selection): void {
+    // Tolerate the short form `{ kind: 'object', sceneId, objectId }` (tests, older callers).
+    if (selection?.kind === 'object' && !selection.objectIds) selection = objectSelection(selection.sceneId, [selection.objectId]);
     if (sameSelection(this.selection, selection)) return;
     this.selection = selection;
     this.emit('selection');
   }
 
-  /** Drops a selection whose target no longer exists (after delete/undo). */
+  /** Ctrl/Shift-click: adds the object to the selection or removes it again. */
+  toggleObject(sceneId: string, objectId: string): void {
+    const s = this.selection;
+    const current = s?.kind === 'object' && s.sceneId === sceneId ? s.objectIds : [];
+    const next = current.includes(objectId) ? current.filter((id) => id !== objectId) : [...current, objectId];
+    this.select(objectSelection(sceneId, next, current.includes(objectId) ? undefined : objectId));
+  }
+
+  /** Ids of the selected scene objects (empty unless objects are selected). */
+  get selectedObjectIds(): string[] {
+    return this.selection?.kind === 'object' ? this.selection.objectIds : [];
+  }
+
+  /** Drops selected targets that no longer exist (after delete/undo). */
   private validateSelection(): void {
     const s = this.selection;
     if (!s) return;
     if (s.kind === 'asset' && !this.project.assets.some((a) => a.id === s.assetId)) this.select(null);
     if (s.kind === 'object') {
       const scene = findScene(this.project, s.sceneId);
-      if (!scene || !scene.objects.some((o) => o.id === s.objectId)) this.select(null);
+      const alive = scene ? s.objectIds.filter((id) => scene.objects.some((o) => o.id === id)) : [];
+      if (alive.length !== s.objectIds.length) this.select(objectSelection(s.sceneId, alive, s.objectId));
     }
     if (s.kind === 'node') {
       const asset = this.project.assets.find((a) => a.id === s.assetId);
@@ -225,7 +253,9 @@ function sameSelection(a: Selection, b: Selection): boolean {
   if (a === b) return true;
   if (!a || !b || a.kind !== b.kind) return false;
   if (a.kind === 'asset' && b.kind === 'asset') return a.assetId === b.assetId;
-  if (a.kind === 'object' && b.kind === 'object') return a.sceneId === b.sceneId && a.objectId === b.objectId;
+  if (a.kind === 'object' && b.kind === 'object') {
+    return a.sceneId === b.sceneId && a.objectId === b.objectId && a.objectIds.length === b.objectIds.length && a.objectIds.every((id, i) => id === b.objectIds[i]);
+  }
   if (a.kind === 'node' && b.kind === 'node') return a.assetId === b.assetId && a.nodeId === b.nodeId;
   return false;
 }