From 016506b5928040050d909e14d1e6a94efe0c3c11 Mon Sep 17 00:00:00 2001
From: Rich Chiodo <rchiodo@microsoft.com>
Date: Thu, 14 Nov 2019 09:36:11 -0800
Subject: [PATCH] After pasting code, arrow keys don't navigate in a cell.

---
 news/2 Fixes/8495.md                             |  1 +
 src/datascience-ui/react-common/monacoEditor.tsx | 11 ++++++-----
 2 files changed, 7 insertions(+), 5 deletions(-)
 create mode 100644 news/2 Fixes/8495.md

diff --git a/news/2 Fixes/8495.md b/news/2 Fixes/8495.md
new file mode 100644
index 000000000000..d4d86a50faf2
--- /dev/null
+++ b/news/2 Fixes/8495.md	
@@ -0,0 +1 @@
+After pasting code, arrow keys don't navigate in a cell.
diff --git a/src/datascience-ui/react-common/monacoEditor.tsx b/src/datascience-ui/react-common/monacoEditor.tsx
index 6d2a916bcc55..9625f6cc399a 100644
--- a/src/datascience-ui/react-common/monacoEditor.tsx
+++ b/src/datascience-ui/react-common/monacoEditor.tsx
@@ -312,9 +312,9 @@ export class MonacoEditor extends React.Component<IMonacoEditorProps, IMonacoEdi
             const cursor = this.state.editor.getPosition();
             if (cursor) {
                 const top = this.state.editor.getTopForPosition(cursor.lineNumber, cursor.column);
-                const lines = this.getVisibleLines();
-                const lineTops = lines.length === this.lineTops.length ? this.lineTops : this.computeLineTops();
-                for (let i = 0; i < lines.length; i += 1) {
+                const count = this.getVisibleLineCount();
+                const lineTops = count === this.lineTops.length ? this.lineTops : this.computeLineTops();
+                for (let i = 0; i < count; i += 1) {
                     if (top <= lineTops[i]) {
                         return i;
                     }
@@ -340,10 +340,12 @@ export class MonacoEditor extends React.Component<IMonacoEditorProps, IMonacoEdi
 
     private computeLineTops(): number[] {
         const lines = this.getVisibleLines();
+
+        // Lines are not sorted by monaco, so we have to sort them by their top value
         this.lineTops = lines.map(l => {
             const match = l.style.top ? /(.+)px/.exec(l.style.top) : null;
             return match ? parseInt(match[0], 10) : Infinity;
-        });
+        }).sort((a, b) => a - b);
         return this.lineTops;
     }
 
@@ -352,7 +354,6 @@ export class MonacoEditor extends React.Component<IMonacoEditorProps, IMonacoEdi
         const visibleLineDivs = this.getVisibleLines();
         const current = this.getCurrentVisibleLine();
         if (current !== undefined && current >= 0) {
-            window.console.log(`Scrolling to line ${current}`);
             visibleLineDivs[current].scrollIntoView({ behavior: 'auto', block: 'nearest', inline: 'nearest' });
         }
     }