How to set seekbar 0 value in middle and style like this?

Question

I want 0 value(the base number of the ruler) in middle,and when seekbar changed,current progress to 0 value can show white like below.I use System Seekbar,and my progressDrawable xml:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/background">
        <shape android:shape="rectangle">
            <solid android:color="@color/appColorDefault" />
            <corners android:radius="2dp" />
        </shape>
    </item>
    <item android:id="@android:id/progress">
        <clip>
            <shape android:shape="rectangle">
                <solid android:color="@color/appColorAccent" />
                <corners android:radius="2dp" />
            </shape>
        </clip>
    </item>
</layer-list>

This 0 value only in start,can't in middle.How to do this?Thank you for your helps.

---

Pic update.The point is not to set it to less than 0,the key is how to display the white progress bar from current pos(eg. current is -30) to base value(0 value,in middle of the seekbar). I found a possible solution in this link:StartPointSeekBar,but this library is 2015,I'm trying it and see if it works

Answer 1

It is your charge to set the value you want with your own mapping.

For example : 0 stands for -100, 50 for 0 and 100 for 100

Answer 2

Here is answer,Same author,Github Library:StartPointSeekBar,This library can work on AndroidX,but it lacks some interfaces compared to seekbar on androidx,such as below

override fun onStartTrackingTouch(seekBar: SeekBar?) {}
override fun onStopTrackingTouch(seekBar: SeekBar?) {}