From 85f8fc52b7a51f6c9f27ad12f2dbb42997ef84d2 Mon Sep 17 00:00:00 2001
From: Franz Liedke <franz@develophp.org>
Date: Fri, 11 Sep 2020 17:23:02 +0200
Subject: [PATCH] ComposerPostPreview: Add scroll anchoring callback

This will be needed to replace the `ReplyPlaceholderPreview` component.
---
 js/src/forum/components/ComposerPostPreview.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/js/src/forum/components/ComposerPostPreview.js b/js/src/forum/components/ComposerPostPreview.js
index 8c7a3c5c4..2be2b4dc6 100644
--- a/js/src/forum/components/ComposerPostPreview.js
+++ b/js/src/forum/components/ComposerPostPreview.js
@@ -12,10 +12,12 @@ import Component from '../../common/Component';
  *
  * - `composer` The state of the composer controlling this preview.
  * - `className` A CSS class for the element surrounding the preview.
+ * - `surround` A callback that can execute code before and after re-render, e.g. for scroll anchoring.
  */
 export default class ComposerPostPreview extends Component {
   static initAttrs(attrs) {
     attrs.className = attrs.className || '';
+    attrs.surround = attrs.surround || ((preview) => preview());
   }
 
   view() {
@@ -39,7 +41,7 @@ export default class ComposerPostPreview extends Component {
 
       preview = content;
 
-      s9e.TextFormatter.preview(preview || '', vnode.dom);
+      this.attrs.surround(() => s9e.TextFormatter.preview(preview || '', vnode.dom));
     };
     updatePreview();