Implement moveNodesInsertedBeforeEndToAfterEnd

This will prevent the user typing into the decorated elements
by accident because they place cursor behind it

ts/editable/editable.ts

@@ -50,9 +50,12 @@ export class Editable extends HTMLElement {
             }
         }
 
-        return containsInlineContent(clone) && this.innerHTML.endsWith("<br>")
+        const result =
+            containsInlineContent(clone) && clone.innerHTML.endsWith("<br>")
                 ? clone.innerHTML.slice(0, -4) // trim trailing <br>
                 : clone.innerHTML;
+
+        return result;
     }
 
     connectedCallback(): void {

ts/editable/mathjax-component.ts

@@ -1,9 +1,49 @@
 import "mathjax/es5/tex-svg-full";
+import { nodeIsElement } from "lib/dom";
 
 import Mathjax_svelte from "./Mathjax.svelte";
 
+function moveNodesInsertedBeforeEndToAfterEnd(element: Element): () => void {
+    const allowedChildNodes = element.childNodes.length;
+
+    const observer = new MutationObserver(() => {
+        for (const node of [...element.childNodes].slice(allowedChildNodes)) {
+            element.removeChild(node);
+
+            let referenceNode: Node;
+
+            if (nodeIsElement(node)) {
+                referenceNode = element.insertAdjacentElement("afterend", node)!;
+            } else {
+                element.insertAdjacentText("afterend", (node as Text).wholeText);
+                referenceNode = element.nextSibling!;
+            }
+
+            if (!referenceNode) {
+                continue;
+            }
+
+            const range = document.createRange();
+            range.setStartAfter(referenceNode);
+            range.collapse(false);
+
+            const selection = document.getSelection()!;
+            selection.removeAllRanges();
+            selection.addRange(range);
+        }
+    });
+
+    observer.observe(element, { characterData: true, subtree: true });
+    return () => observer.disconnect();
+}
+
 class Mathjax extends HTMLElement {
     block: boolean = false;
+    disconnect: () => void = () => {};
+
+    constructor() {
+        super();
+    }
 
     static get observedAttributes(): string[] {
         return ["block"];
@@ -11,6 +51,11 @@ class Mathjax extends HTMLElement {
 
     connectedCallback(): void {
         this.decorate();
+        this.disconnect = moveNodesInsertedBeforeEndToAfterEnd(this);
+    }
+
+    disconnectedCallback(): void {
+        this.disconnect();
     }
 
     attributeChangedCallback(_name: string, _old: string, newValue: string): void {
@@ -41,17 +86,18 @@ class Mathjax extends HTMLElement {
 
 customElements.define("anki-mathjax", Mathjax);
 
-// TODO mathjax regex will prob. fail at double quotes
 const mathjaxTagPattern =
     /<anki-mathjax(?:[^>]*?block="(.*?)")?[^>]*?>(.*?)<\/anki-mathjax>/gsu;
 
 export function toMathjaxDelimiters(html: string): string {
     return html.replace(
         mathjaxTagPattern,
-        (_match: string, block: string | undefined, text: string) =>
+        (_match: string, block: string | undefined, text: string) => {
-            typeof block === "string" && block !== "false"
+            console.log("delim", _match, block, "text", text);
+            return typeof block === "string" && block !== "false"
                 ? `\\[${text}\\]`
-                : `\\(${text}\\)`
+                : `\\(${text}\\)`;
+        }
     );
 }
 
@@ -62,11 +108,14 @@ export function toMathjaxTags(html: string): string {
     return html
         .replace(
             mathjaxBlockDelimiterPattern,
-            (_match: string, text: string) =>
+            (_match: string, text: string) => (
-                `<anki-mathjax block="true">${text}</anki-mathjax>`
+                console.log(text), `<anki-mathjax block="true">${text}</anki-mathjax>`
+            )
         )
         .replace(
             mathjaxInlineDelimiterPattern,
-            (_match: string, text: string) => `<anki-mathjax>${text}</anki-mathjax>`
+            (_match: string, text: string) => (
+                console.log(text), `<anki-mathjax>${text}</anki-mathjax>`
+            )
         );
 }