Refactor Editor and module functions (#15)

Moved all module functions to separate utils modules

Replaced standard with standard with typescript

Extracted UI elements to separate component

Reviewed-on: https://git.siklos-chaneru.duckdns.org/Siklos/svg-layout-designer-react/pulls/15

src/utils/saveload.ts

@@ -0,0 +1,54 @@
+import { findContainerById, MakeIterator } from './itertools';
+import { IEditorState } from '../Editor';
+
+/**
+ * Revive the Editor state
+ * by setting the containers references to their parent
+ * @param editorState Editor state
+ */
+export function Revive(editorState: IEditorState): void {
+  const history = editorState.history;
+  for (const state of history) {
+    if (state.MainContainer === null || state.MainContainer === undefined) {
+      continue;
+    }
+
+    const it = MakeIterator(state.MainContainer);
+    for (const container of it) {
+      const parentId = container.properties.parentId;
+      if (parentId === null) {
+        container.parent = null;
+        continue;
+      }
+      const parent = findContainerById(state.MainContainer, parentId);
+      if (parent === undefined) {
+        continue;
+      }
+      container.parent = parent;
+    }
+
+    const selected = findContainerById(state.MainContainer, state.SelectedContainerId);
+    if (selected === undefined) {
+      state.SelectedContainer = null;
+      continue;
+    }
+    state.SelectedContainer = selected;
+  }
+}
+
+export const getCircularReplacer = (): (key: any, value: object | null) => object | null | undefined => {
+  const seen = new WeakSet();
+  return (key: any, value: object | null) => {
+    if (key === 'parent') {
+      return;
+    }
+
+    if (typeof value === 'object' && value !== null) {
+      if (seen.has(value)) {
+        return;
+      }
+      seen.add(value);
+    }
+    return value;
+  };
+};