Refactor (#862)

* Initial factoring out of parts of the LayerUI component

2360 → 2224 LOC

* Create a Section component

* Break up src/index.tsx

* Refactor actions to reduce duplication, fix CSS

Also consolidate icons

* Move scene/data.ts to its own directory

* Fix accidental reverts, banish further single-character variables

* ACTIVE_ELEM_COLOR → ACTIVE_ELEMENT_COLOR

* Further refactoring the icons file

* Log all errors

* Pointer Event polyfill to make the tests work

* add test hooks & fix tests

Co-authored-by: dwelle <luzar.david@gmail.com>

src/data/blob.ts

@@ -0,0 +1,47 @@
+import { getDefaultAppState } from "../appState";
+import { DataState } from "./types";
+import { restore } from "./restore";
+
+export async function loadFromBlob(blob: any) {
+  const updateAppState = (contents: string) => {
+    const defaultAppState = getDefaultAppState();
+    let elements = [];
+    let appState = defaultAppState;
+    try {
+      const data = JSON.parse(contents);
+      if (data.type !== "excalidraw") {
+        throw new Error("Cannot load invalid json");
+      }
+      elements = data.elements || [];
+      appState = { ...defaultAppState, ...data.appState };
+    } catch {
+      // Do nothing because elements array is already empty
+    }
+    return { elements, appState };
+  };
+
+  if (blob.handle) {
+    (window as any).handle = blob.handle;
+  }
+  let contents;
+  if ("text" in Blob) {
+    contents = await blob.text();
+  } else {
+    contents = await new Promise(resolve => {
+      const reader = new FileReader();
+      reader.readAsText(blob, "utf8");
+      reader.onloadend = () => {
+        if (reader.readyState === FileReader.DONE) {
+          resolve(reader.result as string);
+        }
+      };
+    });
+  }
+  const { elements, appState } = updateAppState(contents);
+  if (!elements.length) {
+    return Promise.reject("Cannot load invalid json");
+  }
+  return new Promise<DataState>(resolve => {
+    resolve(restore(elements, appState, { scrollToContent: true }));
+  });
+}