How to make VST/AU plugin GUI notify it's host application of it's size changes?

TLDR:
I’m developing VST/AU plugin host application.
How can VST/AU plugin’s GUI notify it’s parent Component when it is being resized?


Longer description of the issue:
I’m developing VST/AU plugin host application. I want to have the plugin’s GUI to be resizable WITH some extra GUI components above/below the plugin’s own GUI.

Everything works fine and resizes correctly when I put the plugin’s GUI into a ResizableWindow using the method:
ResizableWindow::setContentNonOwned();

But I want to do the following

  • Use my own Component as parent for the plugin’s GUI.
  • Give this parent Component to ResizableWindow::setContentNonOwned().

When I do that, the plugin’s GUI resizes correctly when mouse is used and/or when the plugin itself changes it’s size. But the parent itself and the ResizableWindow don’t change their sizes anymore.

I tried creating my own ComponentBoundsConstrainer and giving that to the plugin’s GUI (i.e. AudioProcessorEditor::setConstrainer()), so I could then get information when the GUI gets resized and I could make my own Component follow the changes. But none of the methods in ComponentBoundsConstrainer get called at any point, which is odd.

How to fix this or approach this issue in a proper way?

I’ll answer my own question:

I figured out that I can simply override:
void childBoundsChanged(Component* child)

Then I get notified about the changes and things seem to work as they should now.