From 6170bca0d824d2d7c5b2be22efcfdcad58351e7b Mon Sep 17 00:00:00 2001
From: Antonella Sgarlatta <antonella@standardnotes.org>
Date: Wed, 23 Jun 2021 15:57:33 -0300
Subject: [PATCH] fix: scroll position changing when entering new line on
 editor

---
 .../javascripts/views/editor/editor_view.ts   | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/app/assets/javascripts/views/editor/editor_view.ts b/app/assets/javascripts/views/editor/editor_view.ts
index 8cb4c3559db..822c4d50e66 100644
--- a/app/assets/javascripts/views/editor/editor_view.ts
+++ b/app/assets/javascripts/views/editor/editor_view.ts
@@ -105,6 +105,7 @@ class EditorViewCtrl extends PureViewCtrl<unknown, EditorState> {
   public editorValues: EditorValues = { title: '', text: '' };
   onEditorLoad?: () => void;
 
+  private scrollPosition = 0;
   private removeAltKeyObserver?: any;
   private removeTrashKeyObserver?: any;
   private removeTabObserver?: any;
@@ -131,6 +132,8 @@ class EditorViewCtrl extends PureViewCtrl<unknown, EditorState> {
 
     this.editorMenuOnSelect = this.editorMenuOnSelect.bind(this);
     this.onPanelResizeFinish = this.onPanelResizeFinish.bind(this);
+    this.setScrollPosition = this.setScrollPosition.bind(this);
+    this.resetScrollPosition = this.resetScrollPosition.bind(this);
     this.onEditorLoad = () => {
       this.application!.getDesktopService().redoSearch();
     };
@@ -868,6 +871,20 @@ class EditorViewCtrl extends PureViewCtrl<unknown, EditorState> {
       });
   }
 
+  setScrollPosition() {
+    const editor = document.getElementById(
+      ElementIds.NoteTextEditor
+    ) as HTMLInputElement;
+    this.scrollPosition = editor.scrollTop;
+  }
+
+  resetScrollPosition() {
+    const editor = document.getElementById(
+      ElementIds.NoteTextEditor
+    ) as HTMLInputElement;
+    editor.scrollTop = this.scrollPosition;
+  }
+
   onSystemEditorLoad() {
     if (this.removeTabObserver) {
       return;
@@ -915,6 +932,9 @@ class EditorViewCtrl extends PureViewCtrl<unknown, EditorState> {
         },
       });
 
+    editor.addEventListener('scroll', this.setScrollPosition);
+    editor.addEventListener('input', this.resetScrollPosition);
+
     /**
      * Handles when the editor is destroyed,
      * (and not when our controller is destroyed.)
@@ -922,6 +942,9 @@ class EditorViewCtrl extends PureViewCtrl<unknown, EditorState> {
     angular.element(editor).one('$destroy', () => {
       this.removeTabObserver?.();
       this.removeTabObserver = undefined;
+      editor.removeEventListener('scroll', this.setScrollPosition);
+      editor.removeEventListener('scroll', this.resetScrollPosition);
+      this.scrollPosition = 0;
     });
   }
 }