add inital attempt at cursor position preservation

src/components/textarea/textarea.tsx

@@ -1,6 +1,7 @@
-import { createEffect, createMemo, createSignal } from 'solid-js';
+import { createEffect, createMemo, createSignal, untrack } from 'solid-js';
 import { decode } from '~/utilities';
 import { debounce } from '@solid-primitives/scheduled';
+import { createSelection } from '@solid-primitives/selection';
 import { defaultChecker as spellChecker } from './spellChecker';
 import { defaultChecker as grammarChecker } from './grammarChecker';
 import css from './textarea.module.css';
@@ -15,6 +16,7 @@ interface TextareaProps {
 }
 
 export function Textarea(props: TextareaProps) {
+    const [selection, setSelection] = createSelection();
     const [value, setValue] = createSignal<string>(decode(props.value));
     const [element, setElement] = createSignal<HTMLTextAreaElement>();
 
@@ -22,6 +24,23 @@ export function Textarea(props: TextareaProps) {
         setValue(decode(props.value));
     });
 
+    createEffect(() => {
+        // For tracking
+        value();
+
+        const root = untrack(() => element());
+        const [el, start, end] = untrack(() => selection());
+
+        if (el !== root) {
+            return;
+        }
+
+        // TODO :: this needs to be calculated based on the modification done
+        const offset = 1;
+
+        setSelection([el, start + offset, end + offset]);
+    });
+
     const resize = () => {
         const el = element();
 
@@ -43,7 +62,7 @@ export function Textarea(props: TextareaProps) {
         e.stopPropagation();
         e.preventDefault();
 
-        setValue(element()!.innerText.trim());
+        setValue(element()!.textContent!);
 
         resize();
         mutate();