From 1ad0040d14234a2cc4e560aeaca22b9ca25793d4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lucas=20Lef=C3=A8vre?= <lul@odoo.com>
Date: Tue, 6 Jun 2023 10:15:01 +0000
Subject: [PATCH] [FIX] rendering: cache text width
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Computing the text width is expensive, so we cache it

Task 3354651

closes odoo/o-spreadsheet#2558

Signed-off-by: Rémi Rahir (rar) <rar@odoo.com>
---
 src/helpers/misc.ts | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/helpers/misc.ts b/src/helpers/misc.ts
index ceba5113f0..5d3f60a68b 100644
--- a/src/helpers/misc.ts
+++ b/src/helpers/misc.ts
@@ -131,13 +131,22 @@ export function getDefaultCellHeight(style: Style | undefined, numberOfLines?: n
 }
 
 export function computeTextWidth(context: CanvasRenderingContext2D, text: string, style: Style) {
-  context.save();
-  context.font = computeTextFont(style);
-  const textWidth = context.measureText(text).width;
-  context.restore();
-  return textWidth;
+  const font = computeTextFont(style);
+  if (!textWidthCache[font]) {
+    textWidthCache[font] = {};
+  }
+  if (textWidthCache[font][text] === undefined) {
+    context.save();
+    context.font = font;
+    const textWidth = context.measureText(text).width;
+    context.restore();
+    textWidthCache[font][text] = textWidth;
+  }
+  return textWidthCache[font][text];
 }
 
+const textWidthCache: Record<string, Record<string, number>> = {};
+
 export function computeTextFont(style: Style): string {
   const italic = style.italic ? "italic " : "";
   const weight = style.bold ? "bold" : DEFAULT_FONT_WEIGHT;