AU not centered in Studio One 5

Hi everyone, my team and I are developing a plugin and while testing we encountered this issue that we can’t fix. While the vst3 version works fine in studio one 5 and below, the au version of it doesn’t apear centered in the plugin window and this results in it going out of the window while being resized to its maximum size and as said, not centered.
Does anyone encountered this issue before and came up with a solution?
I add that the plugin works in all other DAWS perfectly, even in previous versions of studio one, such as 3 or 4, so can this be a studio one 5 bug?

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I just tried reproducing this issue with the AudioPluginDemo AU, which can be resized using a corner resizer component. I loaded it in Studio One, and was able to resize it to its maximum size smoothly with no glitches or offsets. Closing and opening the window also worked correctly when the plugin window was set to its largest size. Finally, I tried adjusting the plugin to have a larger maximum size, and then resized it to fill my 2560x1440 monitor. It still opened with the view in the correct position.

Are you using the very latest version of JUCE from the develop branch? If not, please try updating then test again. I’m not seeing any issues here, so perhaps updating will resolve the issue for you.

If that doesn’t solve the problem, then I’ll investigate further. To do so, I’ll need to be able to reproduce the problem here. Are you able to reproduce the issue with any of the JUCE example plugins? Alternatively, are you able to provide a minimal code example demonstrating the problem?

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Hi @reuk,

Thanks for your rapid response. I’m working with @fmusso on the project.

We are using the last JUCE version, yesterday tried using JUCE develop branch but nothing.

The problem isn’t when the plugin is really big but when is small. Having a width less than 400 (aprox) make it open to the left. The weird thing is that once you resize it, it immediately gets centered. So we suppose that there is some kind of call missing at the beginning, but couldn’t find what.

To repro, I created an audio plugin project from Projucer and just used in the editor constructor:

    setSize (200, 200); 
    setResizable(true, true);
    setResizeLimits(200, 200, 1000, 1000);

The problem is only on AU, Studio One 5.

Here a video:

Thanks for your time,


Thanks, I think I can reproduce the issue now. I’ll see if I can work out what’s going on.

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I’ve investigated this a bit now. I tried listening to the frame property of the JUCE AU NSView to try to find out where the host was resizing it. For some reason, the very first frameChanged notification we get from the host sets the origin of the view at (1, 81). This x coordinate snaps the view to the left hand side of the window, rather than keeping it centred. After that, the next frame change moves the view into the correct (centred) position, but afterwards the x coordinate never changes.

Inspecting the stack traces of the frame changes, none of the incorrect positions seem to be originating in JUCE code. Instead, the host seems to be setting the origin of the view’s frame incorrectly.

I also tried modifying a resizable iPlug2 example plugin to open at a very small size, and observed that it behaved in exactly the same way as the JUCE-based plugin.

Given all of this, I feel confident that the issue is in Studio One 5. It seems that the issue doesn’t affect plugin views that start with a width of around 400px, so perhaps limiting the minimum initial size of the editor to 400px would be a way to work around the issue until it is fixed in Studio One 5.

I’ll contact the support team at PreSonus and update this thread if I get a reply.


Just tried out Studio One 5.4.1 (I was testing with 5.3 previously). It appears that the behaviour is slightly improved there - editors still open off-centre, but resizing the editor causes it to become correctly centred.

Thanks, @reuk, yeah, we were testing on 5.4.1, but as you said it still opens off-centre. Once you resize it automatically correct its placement.

The weird thing is that on Studio One 3 and 4 it opens correctly.