feat(view): add contextual layer controls

view/selectionSummary.ts

@@ -0,0 +1,43 @@
+import type { ImageDocument } from "@core/document";
+import type { Layer } from "@core/layer";
+import type { SelectionState } from "@editor/state";
+
+export type SelectionSummary =
+  | { type: "none" }
+  | { type: "artboard"; name: string; layerCount: number }
+  | { type: "layer"; name: string; layer: Layer }
+  | { type: "multi-layer"; count: number; layers: Layer[] };
+
+export function getSelectionSummary(document: ImageDocument, selection: SelectionState): SelectionSummary {
+  const selectedLayers = selection.layerIds.flatMap((layerId) => {
+    const layer = findLayer(document.artboards.flatMap((artboard) => artboard.layers), layerId);
+    return layer ? [layer] : [];
+  });
+
+  if (selectedLayers.length === 1 && selectedLayers[0]) {
+    return { type: "layer", name: selectedLayers[0].name, layer: selectedLayers[0] };
+  }
+
+  if (selectedLayers.length > 1) {
+    return { type: "multi-layer", count: selectedLayers.length, layers: selectedLayers };
+  }
+
+  if (selection.artboardId) {
+    const artboard = document.artboards.find((candidate) => candidate.id === selection.artboardId);
+    if (artboard) return { type: "artboard", name: artboard.name, layerCount: artboard.layers.length };
+  }
+
+  return { type: "none" };
+}
+
+function findLayer(layers: Layer[], layerId: string): Layer | undefined {
+  for (const layer of layers) {
+    if (layer.id === layerId) return layer;
+    if (layer.type === "group") {
+      const child = findLayer(layer.children, layerId);
+      if (child) return child;
+    }
+  }
+
+  return undefined;
+}