From 81a62306afebe463a192e7d4b85f345ab007c9f7 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Wed, 10 Aug 2022 05:59:29 -0700
Subject: [PATCH] Ensure canvas device dims are > 0x0 when firing callback

See microsoft/vscode#157444
---
 src/browser/renderer/DevicePixelObserver.ts | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/browser/renderer/DevicePixelObserver.ts b/src/browser/renderer/DevicePixelObserver.ts
index 611eb910..caf1b21d 100644
--- a/src/browser/renderer/DevicePixelObserver.ts
+++ b/src/browser/renderer/DevicePixelObserver.ts
@@ -24,10 +24,12 @@ export function observeDevicePixelDimensions(element: HTMLElement, callback: (de
       return;
     }
 
-    callback(
-      entry.devicePixelContentBoxSize[0].inlineSize,
-      entry.devicePixelContentBoxSize[0].blockSize
-    );
+    // Fire the callback, ignore events where the dimensions are 0x0 as the canvas is likely hidden
+    const width = entry.devicePixelContentBoxSize[0].inlineSize;
+    const height = entry.devicePixelContentBoxSize[0].blockSize;
+    if (width > 0 && height > 0) {
+      callback(width, height);
+    }
   });
   observer.observe(element, { box: ['device-pixel-content-box'] } as any);
   return toDisposable(() => observer?.disconnect());