Dynamic Frame Height

[Niketa]

I'm trying to make an options section that automatically populates a scroll frame with values in a table. However, the issue I'm having now is trying to dynamically adjust the height of the content frame (favcontent) to fit the contents that will be displayed. As of now, I can put the height as 175 for example but if there's nothing in the table then you'd be able to scroll down for that whole frame or if the contents don't fill up the entire frame, you have all that extra space to scroll down after the values are listed. Or if there are more values than space to display on the frame, then some will be cut off.

Mountaholic = {}
 
-- Create main options panel in Interface>Addons.
Mountaholic.Options = CreateFrame("Frame", nil, UIParent)
Mountaholic.Options.name = "Mountaholic"
InterfaceOptions_AddCategory(Mountaholic.Options)
 
-- Create child panel for Help text.
Mountaholic.Help = CreateFrame("Frame", nil, Mountaholic.Options)
Mountaholic.Help.name = "Help"
Mountaholic.Help.parent = Mountaholic.Options.name
InterfaceOptions_AddCategory(Mountaholic.Help)
 
-- Title font string.
local title = Mountaholic.Options:CreateFontString(nil, "OVERLAY", "GameFontNormalLarge")
      title:SetPoint("TOPLEFT", 16, -16)
      title:SetText("Mountaholic")
      
-- Favorites title.
local favtitle = Mountaholic.Options:CreateFontString(nil, "OVERLAY", "GameFontNormal")
      favtitle:SetPoint("TOPLEFT", title, "BOTTOMLEFT", 9, -20)
      favtitle:SetText("Favorite Mounts")
      
-- Favorites description.
local favdesc = Mountaholic.Options:CreateFontString(nil, "OVERLAY", "GameFontHighlightSmall")
      favdesc:SetPoint("TOPLEFT", favtitle, "BOTTOMLEFT", 0, -5)
      favdesc:SetText(favdesctxt)
      favdesc:SetWidth(575)
      favdesc:SetWordWrap(true)
      favdesc:SetJustifyH("LEFT")
 
-- Create frame for favorites.
local favframe = CreateFrame("ScrollFrame", nil, Mountaholic.Options)
      favframe:SetPoint("TOPLEFT", favdesc, "BOTTOMLEFT", 0, -20)
      favframe:SetPoint("BOTTOMRIGHT", favdesc, "BOTTOMLEFT", 575, -125)
 
local favframebg = favframe:CreateTexture(nil, "BACKGROUND")
      favframebg:SetAllPoints(favframe)
      favframebg:SetTexture(0, 0, 0, 0.4)
 
Mountaholic.Options.favscrollframe = favframe
 
local favcontent = CreateFrame("Frame", nil, scrollframea)
      favcontent:SetSize(575, 175)
    
favframe.content = favcontent
favframe:SetScrollChild(favcontent)
 
local favscrollbar = CreateFrame("Slider", nil, favframe, "UIPanelScrollBarTemplate")
      favscrollbar:SetPoint("TOPLEFT", favframe, "TOPRIGHT", -16, -16)
      favscrollbar:SetPoint("BOTTOMLEFT", favframe, "BOTTOMRIGHT", 16, 16)
      favscrollbar:SetMinMaxValues(1, favcontent:GetHeight())
      favscrollbar:SetValueStep(1)
      favscrollbar:SetValue(0)
      favscrollbar:SetWidth(16)
 
favscrollbar:SetScript("OnValueChanged", function(self, value)
    self:GetParent():SetVerticalScroll(value)
end)
 
local favscrollbarbg = favscrollbar:CreateTexture(nil, "BACKGROUND") 
      favscrollbarbg:SetAllPoints(favscrollbar) 
      favscrollbarbg:SetTexture(0, 0, 0, 0.4) 
    
Mountaholic.Options.favscrollbar = favscrollbar
 
favcontent:SetScript("OnMouseWheel", function(self, value)
    if value > 0 then
        favscrollbar:SetValue(favscrollbar:GetValue() - (favscrollbar:GetHeight()/100))
    else
        favscrollbar:SetValue(favscrollbar:GetValue() + (favscrollbar:GetHeight()/100))
    end
end)
 
-- Populate favframe.
favcontent:SetScript("OnShow", function(self, event, ...)
    local vars = {}
    local y = -10
    local numMounts, mountName = GetNumCompanions("mount"), nil
    
    for k, v in pairs(Mountaholic_Favorites) do
        for i = 1, numMounts do
            local _, creatureName, creatureSpellID = GetCompanionInfo("mount",i)
            if creatureSpellID == k then
                mountName = creatureName
                break
            end
        end
 
        vars[k.."str"] = self:CreateFontString(nil, "OVERLAY", "GameFontHighlight")
        vars[k.."str"]:SetPoint("TOPLEFT", self, "TOPLEFT", 10, y)
        vars[k.."str"]:SetText(mountName)
        vars[k.."str"]:SetWordWrap(true)
        vars[k.."str"]:SetJustifyH("LEFT")
        
        vars[k.."str2"] = self:CreateFontString(nil, "OVERLAY", "GameFontHighlight")
        vars[k.."str2"]:SetPoint("TOPLEFT", vars[k.."str"], "TOPRIGHT", 5, 0)
        vars[k.."str2"]:SetText(" |cff71C671("..k..")")
        vars[k.."str2"]:SetWordWrap(true)
        vars[k.."str2"]:SetJustifyH("LEFT")
        
        y = y - 15
    end
end)

Here's a screenshot of what I'm talking about:

[zork]

You can calculate the height of a frame based on the strings inside. You can do that by summing up the values from:

string:GetStringHeight()

After that you can apply the sum to adjust the height of your scrollframe. Once it surpases a defined max-value the height will not grow any higher.

If you have your setpoints right all your frames anchor onto the frame above. All but the first frame which is anchored to the panel itself. Thus if a frame shrinks/grows all other frames will follow automatically.