Design of mLayoutFunc

1

What is the rationale behind is pGraphics->SetLayoutOnResize(true) calling the same closure (mLayoutFunc), instead of having two different functions - one for layout and one for resizing?
My implementation is clearly split in two parts

if(resizing)
  SetTargetAndDrawRECTs
else
 AttachControl
2

Also, isn’t there any better way than doing this (taken from IPlugResponsiveUI)?

    auto GetBounds = [pGraphics](int ctrlIdx, const IRECT& b) {
      IRECT main = b.GetPadded(-40.f);
      IRECT keys = main.FracRectVertical(0.25, false);
      IRECT scope = main.FracRectVertical(0.75, true).GetPadded(-10.f);
      IRECT gain = scope.ReduceFromRight(100.f);
      switch (ctrlIdx) {
        case 1: return keys;
        case 2: return gain;
        case 3: return scope;
        case 0: return b;
        default: return pGraphics->GetControl(ctrlIdx)->GetRECT();
      }
    };

The main problem is that it relies on the ordinal Idx of the controls, which shouldn’t be used in a high-level function.
As a solution, for instance, each IControl could have a member closure that is called only if mLayoutOnResize is true:

void IGraphics::Resize(int w, int h, float scale, bool needsPlatformResize)
{
 [...]
    
  PlatformResize(GetDelegate()->EditorResizeFromUI(windowWidth, windowHeight, needsPlatformResize));
  ForAllControls(&IControl::OnResize);
  SetAllControlsDirty();
  DrawResize();
  
  if(mLayoutOnResize){
    ForAllControls(&IControl::LayoutFunc); //THIS
    GetDelegate()->LayoutUI(this);
  }
}