You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: trackbar.go
    path of file: ./repos/govcl/samples/mp3Player
    
    the code of the file until where you have to start completion: package main

import (
	"github.com/ying32/govcl/vcl"
	"github.com/ying32/govcl/vcl/types"
)

//
type TImageTrackBar struct {
	*vcl.TPanel
	thumb      *vcl.TImage
	background *vcl.TImage
	fore       *vcl.TImage
	//max        int
	//min        int
	mouseDown bool

	position float32 // 最大100，百分比

	OnTrackChange vcl.TNotifyEvent
}

func NewImageTrackBar(owner vcl.IComponent) *TImageTrackBar {
	t := new(TImageTrackBar)
	t.TPanel = vcl.NewPanel(owner)
	t.TPanel.SetBevelOuter(types.BvNone)
	t.TPanel.SetHeigh
    
func NewImageTrackBar(owner vcl.IComponent) *TImageTrackBar {
	t := new(TImageTrackBar)
	t.TPanel = vcl.NewPanel(owner)
	t.TPanel.SetBevelOuter(types.BvNone)
	t.TPanel.SetHeight(8)
	t.TPanel.SetParentColor(true)
	t.TPanel.SetDoubleBuffered(true)

	t.background = vcl.NewImage(owner)
	t.fore = vcl.NewImage(owner)
	t.thumb = vcl.NewImage(owner)

	t.background.SetParent(t.TPanel)
	t.fore.SetParent(t.TPanel)
	t.thumb.SetParent(t.TPanel)

	t.background.SetAlign(types.AlClient)
	t.background.SetStretch(true)

	t.fore.SetWidth(100)
	t.fore.SetStretch(true)

	//t.thumb.SetAutoSize(true)
	t.thumb.SetCursor(types.CrHandPoint)

	//fmt.Println(t.thumb.)

	t.thumb.SetOnMouseDown(t.onMouseDown)
	t.thumb.SetOnMouseUp(t.onMouseUp)
	t.thumb.SetOnMouseMove(t.onMouseMove)
	return t
}