feat(input): support artboard selection

input/selection.ts

@@ -0,0 +1,35 @@
+import { commandIds } from "@commands/ids";
+import type { Dispatch } from "@commands/dispatcher";
+import type { ImageDocument } from "@core/document";
+import type { ViewportState } from "@editor/state";
+import type { PointerInputEvent } from "./pointer";
+
+export function handleArtboardSelection(options: {
+  event: PointerInputEvent;
+  document: ImageDocument;
+  viewport: ViewportState;
+  dispatch: Dispatch;
+}): boolean {
+  if (options.event.pointerType !== "mouse" || (options.event.buttons & 1) !== 1) return false;
+
+  const point = viewportPointToDocumentPoint(options.event.position, options.viewport);
+  const artboard = [...options.document.artboards].reverse().find((candidate) => {
+    const bounds = candidate.bounds;
+    return point.x >= bounds.x && point.x <= bounds.x + bounds.w && point.y >= bounds.y && point.y <= bounds.y + bounds.h;
+  });
+
+  if (!artboard) {
+    options.dispatch(commandIds.selectionClear, undefined);
+    return true;
+  }
+
+  options.dispatch(commandIds.selectionSet, { artboardId: artboard.id, layerIds: [] });
+  return true;
+}
+
+function viewportPointToDocumentPoint(point: PointerInputEvent["position"], viewport: ViewportState) {
+  return {
+    x: viewport.center.x + (point.x - viewport.size.w / 2) / viewport.zoom,
+    y: viewport.center.y + (point.y - viewport.size.h / 2) / viewport.zoom,
+  };
+}