From 02d75ad0190c12d29d633dbb2f1baa8cff78d4a1 Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Wed, 23 Oct 2024 22:56:16 +0200
Subject: [PATCH] fix: don't update view when it was the source of the state
 change

When the view emits and update event, the state was updated, which in turn updated the view again. That messes with things, for example the scroll positioning. This fixes that by adding a circuit breaker. Fixes #582
---
 packages/editor/src/lib/Workspace.svelte.ts | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/packages/editor/src/lib/Workspace.svelte.ts b/packages/editor/src/lib/Workspace.svelte.ts
index ea6840819b..66aca618f0 100644
--- a/packages/editor/src/lib/Workspace.svelte.ts
+++ b/packages/editor/src/lib/Workspace.svelte.ts
@@ -295,7 +295,7 @@ export class Workspace {
 			const file = files.find((file) => file.name === name) as File;
 
 			if (file) {
-				this.#update_state(file, state);
+				this.#update_state(file, state, true);
 			} else {
 				this.states.delete(name);
 			}
@@ -314,7 +314,7 @@ export class Workspace {
 		this.#reset_diagnostics();
 	}
 
-	update_file(file: File) {
+	update_file(file: File, update_view = true) {
 		if (file.name === this.#current.name) {
 			this.#current = file;
 		}
@@ -336,7 +336,7 @@ export class Workspace {
 
 		const state = this.states.get(file.name);
 		if (state) {
-			this.#update_state(file, state);
+			this.#update_state(file, state, update_view);
 		}
 
 		this.#onupdate(file);
@@ -374,10 +374,13 @@ export class Workspace {
 				if (update.docChanged) {
 					const state = this.#view!.state!;
 
-					this.update_file({
-						...this.#current,
-						contents: state.doc.toString()
-					});
+					this.update_file(
+						{
+							...this.#current,
+							contents: state.doc.toString()
+						},
+						false
+					);
 
 					// preserve undo/redo across files
 					this.states.set(this.#current.name, state);
@@ -461,7 +464,7 @@ export class Workspace {
 		this.#view?.setState(this.#get_state(this.#current));
 	}
 
-	#update_state(file: File, state: EditorState) {
+	#update_state(file: File, state: EditorState, update_view: boolean) {
 		const existing = state.doc.toString();
 
 		if (file.contents !== existing) {
@@ -481,7 +484,7 @@ export class Workspace {
 
 			this.states.set(file.name, transaction.state);
 
-			if (file === this.#current) {
+			if (update_view && file === this.#current) {
 				this.#view?.setState(transaction.state);
 			}
 		}