From 1b6e3fe05bc81ac5b24c67f8ad82ef1a467fb1e6 Mon Sep 17 00:00:00 2001
From: David Luzar <5153846+dwelle@users.noreply.github.com>
Date: Sun, 19 May 2024 22:20:40 +0200
Subject: [PATCH] feat: rerender canvas on focus (#8035)

---
 packages/excalidraw/components/App.tsx | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/packages/excalidraw/components/App.tsx b/packages/excalidraw/components/App.tsx
index d991814d4f..dc9d26efeb 100644
--- a/packages/excalidraw/components/App.tsx
+++ b/packages/excalidraw/components/App.tsx
@@ -2594,6 +2594,9 @@ class App extends React.Component<AppProps, AppState> {
       ),
       addEventListener(window, EVENT.FOCUS, () => {
         this.maybeCleanupAfterMissingPointerUp(null);
+        // browsers (chrome?) tend to free up memory a lot, which results
+        // in canvas context being cleared. Thus re-render on focus.
+        this.triggerRender(true);
       }),
     );
 
@@ -3729,8 +3732,15 @@ class App extends React.Component<AppProps, AppState> {
     },
   );
 
-  private triggerRender = () => {
-    this.setState({});
+  private triggerRender = (
+    /** force always re-renders canvas even if no change */
+    force?: boolean,
+  ) => {
+    if (force === true) {
+      this.scene.triggerUpdate();
+    } else {
+      this.setState({});
+    }
   };
 
   /**