From 621bae03ca66939adf00617d69ba36a7dfaf4e2e Mon Sep 17 00:00:00 2001
From: Alf Eaton <alf.eaton@overleaf.com>
Date: Wed, 3 Jan 2024 12:41:41 +0000
Subject: [PATCH] Use collapsePreambleEffect (#15866)

GitOrigin-RevId: e07a48ba5a7ca2ce30aa6933030f8eae970a65b5
---
 .../extensions/visual/skip-preamble-cursor.ts | 20 +++++++++----------
 .../visual/visual-widgets/preamble.ts         |  8 ++++++--
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/services/web/frontend/js/features/source-editor/extensions/visual/skip-preamble-cursor.ts b/services/web/frontend/js/features/source-editor/extensions/visual/skip-preamble-cursor.ts
index 52e1bf43ad..cb83c11348 100644
--- a/services/web/frontend/js/features/source-editor/extensions/visual/skip-preamble-cursor.ts
+++ b/services/web/frontend/js/features/source-editor/extensions/visual/skip-preamble-cursor.ts
@@ -6,7 +6,7 @@ import {
   StateField,
 } from '@codemirror/state'
 import { syntaxTree } from '@codemirror/language'
-import { Preamble } from './visual-widgets/preamble'
+import { collapsePreambleEffect, Preamble } from './visual-widgets/preamble'
 /**
  * A view plugin that moves the cursor from the start of the preamble into the document body when the doc is opened.
  */
@@ -63,11 +63,17 @@ export const skipPreambleWithCursor = (
       }
     }
 
-    view.dom.addEventListener('editor:collapse-preamble', escapeFromPreamble)
-
     return {
       update(update) {
-        if (!checkedOnce) {
+        if (checkedOnce) {
+          if (
+            update.transactions.some(tr =>
+              tr.effects.some(effect => effect.is(collapsePreambleEffect))
+            )
+          ) {
+            escapeFromPreamble()
+          }
+        } else {
           const { state } = update
 
           if (syntaxTree(state).length === state.doc.length) {
@@ -88,12 +94,6 @@ export const skipPreambleWithCursor = (
           }
         }
       },
-      destroy() {
-        view.dom?.removeEventListener(
-          'editor:collapse-preamble',
-          escapeFromPreamble
-        )
-      },
     }
   })
 
diff --git a/services/web/frontend/js/features/source-editor/extensions/visual/visual-widgets/preamble.ts b/services/web/frontend/js/features/source-editor/extensions/visual/visual-widgets/preamble.ts
index d7d5acc1ed..41569d3269 100644
--- a/services/web/frontend/js/features/source-editor/extensions/visual/visual-widgets/preamble.ts
+++ b/services/web/frontend/js/features/source-editor/extensions/visual/visual-widgets/preamble.ts
@@ -1,4 +1,4 @@
-import { EditorSelection } from '@codemirror/state'
+import { EditorSelection, StateEffect } from '@codemirror/state'
 import { EditorView, WidgetType } from '@codemirror/view'
 import { SyntaxNode } from '@lezer/common'
 
@@ -15,6 +15,8 @@ export type Preamble = {
   }[]
 }
 
+export const collapsePreambleEffect = StateEffect.define<boolean>()
+
 export class PreambleWidget extends WidgetType {
   constructor(public expanded: boolean) {
     super()
@@ -60,7 +62,9 @@ export class PreambleWidget extends WidgetType {
       }
       event.preventDefault()
       if (this.expanded) {
-        view.dom.dispatchEvent(new Event('editor:collapse-preamble'))
+        view.dispatch({
+          effects: collapsePreambleEffect.of(true),
+        })
       } else {
         view.dispatch({
           selection: EditorSelection.cursor(0),