Resize a TLayout according to the number of labels in Firemonkey

here is my sample code in Firemonkey;

var
   f: integer; 
   Label1: TLabel;
   MyStringArray: TArray<String>;
   Panel1: TPanel;
   Layout1: TLayout;
begin
   Layout1.Align := TAlignLayout.Client;
   MyStringArray := ['aa','bb','cc','dd','ee','ff'];
   f:= 10;
   Layout1.BeginUpdate;
   for i := 0 to length(MyStringArray) - 1 do
   begin
        Label1 := TLabel.Create(Self);
        Label1.Name := 'Label' + i.ToString;
        Label1.Text := 'Label_' + MyStringArray[i];
        Label1.Position.Y := f;
        Label1.Align := TAlignLayout.Top;
        Label1.Parent := Layout1;
        inc(f, 15);
   end;
   Layout1.EndUpdate;
end;

MyStringArray is a dynamic array no always with the same number of elements, so I resize a TPanel (Panel1) with the contents of TLayout (Layout1) according with number of labels;

Panel1.Height := Layout1.ChildrenRect.Height

This works fine when the number of labels grows in Layout1, but when the number of labels is less, Layout1.ChildrenRect.Height has no effect and not shrinks it, height of the Layout1 always keeps the higher value.

Is there any solution or any other alternative to how to do it?, thanks Regards.

Solution

I hope that this code will help in that. I apologize for more editing, this is last, but I was trying again and the code was not entirely correct.

type
  TControlHelper = class helper for TControl
  public
    function ChildrenWidth: Single; 
    function ChildrenHeight: Single; 
  end;

function TControlHelper.ChildrenWidth: Single;
var
  VIndex: Integer;
  VControl: TControl;
  VRect: TRectF;
begin
  VRect := TRectF.Empty;
  if not ( ClipChildren or SmallSizeControl ) and ( Controls <> nil ) then
  begin
    for VIndex := GetFirstVisibleObjectIndex to GetLastVisibleObjectIndex - 1 do
    begin
      VControl := Controls[ VIndex ];
      if VControl.Visible then
        VRect := UnionRect( VRect, VControl.Margins.MarginRect( TRectF.Create( VControl.Position.Point, VControl.Width, VControl.Height ) ) );
    end;
    Result := VRect.Width + Padding.Right;
  end;
end;

function TControlHelper.ChildrenHeight: Single;
var
  VIndex: Integer;
  VControl: TControl;
  VRect: TRectF;
begin
  VRect := TRectF.Empty;
  if not ( ClipChildren or SmallSizeControl ) and ( Controls <> nil ) then
  begin
    for VIndex := GetFirstVisibleObjectIndex to GetLastVisibleObjectIndex - 1 do
    begin
      VControl := Controls[ VIndex ];
      if VControl.Visible then
        VRect := UnionRect( VRect, VControl.Margins.MarginRect( TRectF.Create( VControl.Position.Point, VControl.Width, VControl.Height ) ) );
    end;
    Result := VRect.Height + Padding.Bottom;
  end;
end;