Native title bar causes white rectangle before window initialisation

General JUCE discussion
1

Hi everyone,
After upgrading to JUCE 8, my fullscreen DocumentWindow shows a white rectangle on startup (Windows 11) that appears before the window is fully initialised. This issue was not present in JUCE 5.

In the window constructor, setBackgroundColour(Colours::black) is called immediately. The content component paints fillAll(Colours::black) first and is set to opaque. Despite this, a white rectangle is visible for a few seconds during startup.

Setting setUsingNativeTitleBar(false) completely eliminates the issue, but I need the native title bar for proper Windows behavior.

Thanks in advance!

UI flickers white squares on Windows
Stuttery resizing when OpenGLContext is attached
2

The DemoRunner uses a native title bar do you see the same issue there?

3

@anthony-nicholls Yes, it’s also visible in DemoRunner.

white rect
white rect1132×810 12.9 KB

4

Exactly which JUCE commit are you testing?

Have you checked the current develop branch? If so, it would be interesting to know some information about the computer you’re using for testing:

  • What Windows version are you running? Do you have any updates pending?
  • What GPU is installed?
  • What GPU driver version is installed, and are there updates available?

I’d also be interested to know which behaviour is missing when you switch to a non-native titlebar.

5

@reuk I’m currently testing with JUCE 8.0.11, which I downloaded directly from the Releases section on GitHub.

The exact commit hash for the 8.0.11 release tag is c352e24 (according to the official release info on GitHub).

System details:

  • Windows version: Windows 11 24H2, OS Build 26100.7840 - no pending Windows updates for 24H2 at the moment

  • GPU: NVIDIA RTX A1000 Laptop GPU (6 GB )

  • GPU driver: 581.95 - installed automatically via Windows Update, no newer driver version is available rightnow

After switching to non-native titlebar, I have a black background without the white square, which looks much better visually.

I also tested the same build on embedded Intel Iris Xe Graphics (driver version 32.101.7077), and the white square at startup still appears in exactly the same way when using the native title bar. So the issue is not specific to the NVIDIA RTX A1000 it also reproduces on Intel integrated graphics.

6

I’ve been seeing this too. I’ve been mitigating it by deferring any slow operations until after construction with callAfterDelay.

7

@andrewj Thanks for the workaround! It looks better, but unfortunately the white square is still visible for a short moment.

8

@reuk or anyone from the JUCE team. Is this something that’s already on the radar as a known issue, or are there any plans/considerations to address this behaviour in an upcoming update or on the develop branch?

Thanks a lot for any info!

9

I don’t see this behaviour on the current develop branch. Please could you try switching to the develop branch and check whether the problem is resolved there? Thanks!

11

@reuk I’ve checked on the develop branch and in the DemoRunner the white square no longer appears. Thank you very much for your help! I really appreciate it. I’m looking forward to the next release! Would you be able to let me know which commit was responsible for removing the white square?

12

I’m not sure entirely, there have been several changes to the Direct2D drawing mechanism since 8.0.11. Although we didn’t specifically investigate this startup issue, we did fix some other issues with sluggish/glitchy resizing and repaint performance. In general the commits with these changes have the prefix Direct2D: in their titles.

13

Why not use the develop branch? The only difference between the develop branch and the master branch is that we give bigger changes a bit of time to get some exposure to people using them before merging to master. In this particular case we’re not planning anything significant before the next point release, so there’s not much benefit to waiting.