Restore default template binding across browser sessions

核桃派软件源代码/app/static/board-startup-model.js

@@ -0,0 +1,58 @@
+export const BOARD_SESSION_KEY = "matrix-board-session-v1";
+
+function validContext(context) {
+  return context === null || (
+    context && ["template", "animation"].includes(context.type)
+    && ["id", "name", "revision", "baseline"].every((key) => typeof context[key] === "string" && context[key])
+    && typeof context.readOnly === "boolean"
+    && (context.type !== "animation" || context.readOnly)
+  );
+}
+
+export function readBoardSession(storage, draft, bootId) {
+  const raw = storage?.getItem(BOARD_SESSION_KEY);
+  if (!raw) return { bootId: null, context: null };
+  try {
+    const value = JSON.parse(raw);
+    if (value.version !== 1 || typeof value.bootId !== "string" || !validContext(value.context)) {
+      throw new Error("invalid session");
+    }
+    return {
+      bootId: value.bootId,
+      context: value.bootId === bootId && value.draft === draft ? value.context : null,
+    };
+  } catch {
+    throw new Error("画板保存绑定损坏或来自未来版本；原值已保留，请另存当前内容后处理浏览器存储。");
+  }
+}
+
+export function writeBoardSession(storage, bootId, draft, context) {
+  storage.setItem(BOARD_SESSION_KEY, JSON.stringify({ version: 1, bootId, draft, context }));
+}
+
+// Resolve only editable static defaults and the read-only demo animation.
+// Ordinary animations retain their existing explicit frame editing workflow.
+export async function loadDefaultBoard(apiJson) {
+  const reference = await apiJson("/api/display/default-content");
+  if (reference.type === "template") {
+    return { ...await apiJson(`/api/templates/${reference.id}`), type: "template" };
+  }
+  if (reference.type !== "animation" || !reference.is_demo) return null;
+  const animation = await apiJson(`/api/animations/${reference.id}/frames`);
+  const first = animation.frames[0];
+  if (!first) throw new Error("默认演示动图没有帧");
+  const frame = await apiJson(`/api/animations/${reference.id}/frames/${first.id}`);
+  return { ...animation, type: "animation", read_only: true, scene: frame.scene };
+}
+
+export async function initializeDefaultBoard({ canLoad, load, apply, retain }) {
+  if (!canLoad()) return false;
+  const content = await load();
+  if (!canLoad()) {
+    retain();
+    return false;
+  }
+  if (content) apply(content);
+  else retain();
+  return Boolean(content);
+}