Parent panel does not invalidate width correctly in the spawn menu

[dvd_video]

Hello, I was updating my Track assembly and I wanted to add some buttons for direct convar control.

The idea is to create 3 more buttons to each slider for controlling the sign, flip and reset of each value

  asmlib.SetButtonSlider(CPanel,gsToolPrefL.."nextrol",-gnMaxOffRot, gnMaxOffRot,7,
    asmlib.GetPhrase("tool."..gsToolNameL..".nextrol_con"), asmlib.GetPhrase("tool."..gsToolNameL..".nextrol"),
      {{Text="+ | -", Click=function()
          local nV = asmlib.GetAsmVar("nextrol", "FLT")
          RunConsoleCommand(gsToolPrefL.."nextrol",-nV) end},
       {Text="< | >", Click=function()
          local nV = asmlib.GetAsmVar("nextrol", "FLT")
          RunConsoleCommand(gsToolPrefL.."nextrol",asmlib.GetSign(nV)*180) end},
       {Text="> 0 <", Click=function()
          RunConsoleCommand(gsToolPrefL.."nextrol",0) end}})

This creates a child panel that is "cPanel:AddItem(pPanel)"-ED to the tool panel "cPanel":

function SetButtonSlider(cPanel,sVar,nMin,nMax,nDec,sDsc,sTip,tBtn)
  local pPanel = vguiCreate("DPanel"); if(not IsValid(pPanel)) then
    LogInstance("Panel invalid"); return nil end
  pPanel:SetParent(cPanel)
  pPanel:InvalidateLayout(true)
  LogInstance("Panel OK")
  local sX = pPanel:GetWide()
  local vX, vY = pPanel:GetSize()
  print("SetButtonSlider", vX, vY)
  print("SetButtonSlider", pPanel:GetWide(), cPanel:GetWide())
  local sY, pY, dX, dY, mX = 50, 0, 2, 2, 10
  pPanel:SetSize(sX, sY); pY = dY
  pPanel:SetVisible(true)
  if(IsTable(tBtn) and tBtn[1]) then
    local nBtn, iCnt = #tBtn, 1
    local wB, hB = ((sX - ((nBtn + 1) * dX)) / nBtn), 20
    local bX, bY = dX, pY
    while(tBtn[iCnt]) do local vBtn = tBtn[iCnt]
      local pButton = vguiCreate("DButton"); if(not IsValid(pButton)) then
        LogInstance("Button["..iCnt.."] invalid"); return nil end
      LogInstance("Button["..iCnt.."] OK")
      pButton:SetParent(pPanel)
      pButton:SetText(tostring(vBtn.Text))
      if(vBtn.Tip) then pButton:SetTooltip(tostring(vBtn.Tip)) end
      pButton:SetPos(bX, bY)
      pButton:SetSize(wB, hB)
      pButton.DoClick = vBtn.Click
      pButton:SetVisible(true)
      bX, iCnt = (bX + (wB + dX)), (iCnt + 1)
    end; pY = pY + (dY + hB)
  end
  local pSlider = vguiCreate("DNumSlider"); if(not IsValid(pSlider)) then
    LogInstance("Slider invalid"); return nil end
  LogInstance("Slider OK")
  pSlider:SetParent(pPanel)
  pSlider:SetPos(0, pY)
  pSlider:SetSize(sX-2*dX, sY-pY-dY)
  pSlider:SetText(tostring(sDsc))
  if(sTip) then pSlider:SetTooltip(tostring(sTip)) end
  pSlider:SetMin(nMin)
  pSlider:SetMax(nMax)
  pSlider:SetDecimals(nDec)
  pSlider:SetDark(true)
  pSlider:SetConVar(sVar)
  pSlider:SetVisible(true)
  cPanel:AddItem(pPanel)
  return pPanel
end

When the game loads it outputs:
SetButtonSlider    64    24
SetButtonSlider    64    16

The log outputs:
  155 [30-12-18 14:58:07] CLIENT > TRACKASSEMBLY [LUA] SetButtonSlider: Panel OK
  156 [30-12-18 14:58:07] CLIENT > TRACKASSEMBLY [LUA] SetButtonSlider: Button[1] OK
  157 [30-12-18 14:58:07] CLIENT > TRACKASSEMBLY [LUA] SetButtonSlider: Button[2] OK
  158 [30-12-18 14:58:07] CLIENT > TRACKASSEMBLY [LUA] SetButtonSlider: Button[3] OK
  159 [30-12-18 14:58:07] CLIENT > TRACKASSEMBLY [LUA] SetButtonSlider: Slider OK

This means that all panels are created correctly, however the spawn menu looks like this
how_it_behaves.jpg

As you see the buttons are squashed, because when the game loads, it reports to my script that the panel is 64 pixels
wide instead of about:

(5.8 centimeters) * (1900 resolution width) / (41 gmod window size in centimeters) = 268.780487805 pixels.

When hard-coding the value I got the following:

https://drive.google.com/file/d/1PtMlljNwbdqxF0vAvaKa_Zm5gs_HpR2G/view?usp=sharing

When I opened the context menu I saw a slight offset on the right ( BLUE ):
https://drive.google.com/file/d/1cjkL-9YNIJLOHjvjhLPsA4lZTSUjsrUC/view?usp=sharing

How can I take the actual width of the parent panel "pPanel" and make the three buttons look the same in the context
menu and the spawn menu without the offset in blue ?

[dvd_video]

I tried "DSizeToContents" instead of a regular panel, where the position and size are inherited and the result is like this: all_options_no_resize.jpg The object is still not resizable when you drag the TOOL menu around.

[dvd_video]

This is not in the right section you can delete it.