Can not make the hello example work

[bidzhao]

Hi there,

I followed the steps to run the hello example on my MBP with Intel cpu - MacOS 15.7.5 (24G624):

git clone https://github.com/gogpu/ui.git
cd ui/examples/hello
CGO_ENABLED=0 go run .

But unfortunately there is no window/dialog shown, only an icon on the Dock. Did I miss anything?

2026-04-23 21:01:25.111 hello[80002:21264950] NSWindow does not support utility styleMask 0x10
2026/04/23 21:01:25 INFO adapter selected name="Intel(R) Iris(TM) Plus Graphics 645" type=IntegratedGPU

[bidzhao]

Claude says (I am not sure if that is right):

This is a macOS Cocoa warning — it means the app is trying to create an NSWindow with a style mask (0x80 = NSNonactivatingPanelMask) that requires an NSPanel subclass instead of a plain NSWindow.
Why it happens:

NSNonactivatingPanelMask is a panel-only style mask — it's meant for floating utility windows that don't steal focus
Using it on a base NSWindow is technically invalid; macOS logs the warning and ignores the mask

Is it a problem?

For you as a user: No. It's a bug in the app's code, not your system
The window will still appear, just without the intended nonactivating behavior (it may steal focus when it shouldn't)

Fix (if you're the developer):
objc// Wrong
NSWindow *window = [[NSWindow alloc] initWithContentRect:frame
styleMask:NSNonactivatingPanelMask // ❌ invalid on NSWindow
...];

// Correct
NSPanel *panel = [[NSPanel alloc] initWithContentRect:frame
styleMask:NSNonactivatingPanelMask // ✅ valid on NSPanel
...];
In Swift:
swift// Use NSPanel instead of NSWindow
let panel = NSPanel(contentRect: frame,
styleMask: [.nonactivatingPanel],
backing: .buffered,
defer: false)
If you're just a user of the app, you can safely ignore this warning — it's cosmetic noise in the logs.

[AnyCPU]

@bidzhao aloha
try to run latest release, recently a lot of updates were landed for macOS Intel (built-in GPU).

Right now it has 4 major troubles (on macOS?):

• HiDPI/Retina support is partial, wrong scaling;
• Some UI table/grid rows leak when a panel is collapsed;
• Scroll areas catch events outside a window when a parent window is active;
• Huge memory leaks while rendering.

I guess I fill find a solution next week.

[AnyCPU]

@kolkov ^^ fyi

[kolkov]

@bidzhao Hi! Sorry for the late reply.

This issue should be fixed in the latest releases. We shipped several macOS fixes recently:

• goffi v0.5.1 — struct ABI fix for macOS Intel (amd64 objc_msgSend_stret)
• gogpu v0.35.0 — macOS window delegate, PUA key filter, deferred SetHitTestCallback
• ui v0.1.24 — Retina rendering fix, custom font pipeline, dependency cascade

Please try updating:

cd ui/examples/hello
go get -u ./...
CGO_ENABLED=0 go run .

The NSWindow does not support utility styleMask 0x10 warning is a cosmetic log message — it shouldn't prevent the window from appearing. If the window still doesn't show after updating, please let us know your exact versions (go list -m all | grep gogpu).

@AnyCPU Thanks for helping and for the heads up! The 4 issues you listed are tracked — HiDPI and collapse leak are already fixed in ui v0.1.24, scroll events and memory leaks we're working on.

[AnyCPU]

@kolkov

OS: macOS Intel latest with built-in GPU;
UI: 0.1.27.

commands:

cd examples/hello
go mod tidy
go get -u ./...
go run .

here is updated/corrected list of issues and related screenshots:

• HiDPI/Retina support is partial, wrong scaling;
• some UI table/grid rows leak when a panel is collapsed;
• scroll areas and other controls catch events outside a window when a parent window is active;
• huge memory leaks while rendering.

besides UI glitches, other important areas are framed by red circles on screenshots.

[AnyCPU]

to reproduce the memory leak:

• hover a touchpad/trackpad pointer over a scrollable area;
• fumble a touchpad for 10 or 20 seconds.