Restore removeEventListener

src/Components/Editor/Editor.tsx

@@ -42,12 +42,23 @@ const Editor: React.FunctionComponent<IEditorProps> = (props) => {
       configuration: props.configuration
     };
 
+    const funcs = new Map<string, () => void>();
     for (const event of events) {
-      editorRef.current?.addEventListener(event.name, () => event.func(editorState));
+      const func = (): void => event.func(editorState);
+      editorRef.current?.addEventListener(event.name, func);
+      funcs.set(event.name, func);
     }
 
     return () => {
       window.removeEventListener('keyup', onKeyUp);
+
+      for (const event of events) {
+        const func = funcs.get(event.name);
+        if (func === undefined) {
+          continue;
+        }
+        editorRef.current?.removeEventListener(event.name, func);
+      }
     };
   });
 

src/Components/ElementsSidebar/ElementsSidebar.tsx

@@ -97,6 +97,11 @@ export const ElementsSidebar: React.FC<IElementsSidebarProps> = (props: IElement
     );
 
     return () => {
+      elementRef.current?.removeEventListener(
+        'contextmenu',
+        onContextMenu
+      );
+
       window.removeEventListener(
         'click',
         onLeftClick