Talk:FMX.Graphics.TCanvas.MeasureText

It is important to know that the input value of ARect is the maximum size range of the rectangle:

 procedure TCanvas.MeasureText(var ARect: TRectF; const AText: string;
 const WordWrap: Boolean; const Flags: TFillTextFlags; const ATextAlign,
 AVTextAlign: TTextAlign);
 var
   Layout: TTextLayout;
 begin
   if AText.IsEmpty then
   begin
     ARect.Right := ARect.Left;
     ARect.Bottom := ARect.Top;
     Exit;
   end;
   Layout := TTextLayoutManager.TextLayoutByCanvas(Self.ClassType).Create(Self);
   try
     Layout.BeginUpdate;
     Layout.TopLeft := ARect.TopLeft;
     Layout.MaxSize := PointF(ARect.Width, ARect.Height);
     Layout.Text := AText;
     Layout.WordWrap := WordWrap;
     Layout.HorizontalAlign := ATextAlign;
     Layout.VerticalAlign := AVTextAlign;
     Layout.Font := Self.Font;
     Layout.Color := Self.Fill.Color;
     Layout.RightToLeft := TFillTextFlag.RightToLeft in Flags;
     Layout.EndUpdate;
     ARect := Layout.TextRect;
   finally
     FreeAndNil(Layout);
   end;
 end;