As excercise I am trying to implement a vertical SeekBar by extending AbsSeekBar. I am trying to override a few methods to account for the thumbs new positioning, however some methods aren't beeing recognized even though they are methods of AbsSeekBar. Also, when i try to use class variables which are defined in the superclass of AbsSeekBar, these also aren't beeing recognized (These variables are also not recognized when used in AbsSeekBar, but for some reason that doesn't matter). What am I missing here?

I am using Android Studio 2.1 Preview 5.
Here is some code up until one of the methods which isn't beeing recognized (when hovered over, it says "Can not resolve method 'onStartTrackingTouch()'"

```
package com.example.user.testfour;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.AbsSeekBar;
import android.widget.SeekBar;

public class VerticalSeekBar extends AbsSeekBar {

    public interface OnSeekBarChangeListener {

        void onProgressChanged(VerticalSeekBar seekBar, int progress, boolean fromUser);

        void onStartTrackingTouch(VerticalSeekBar seekBar);

        void onStopTrackingTouch(VerticalSeekBar seekBar);
    }
    private OnSeekBarChangeListener mOnSeekBarChangeListener;

    // Constructors
    public VerticalSeekBar(Context context) {this(context, null);}

    public VerticalSeekBar(Context context, AttributeSet attrs) {
        this(context, attrs, com.android.internal.R.attr.seekBarStyle);
    }

    public VerticalSeekBar(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    @Override
    void onStartTrackingTouch() {
        super.onStartTrackingTouch();
        if (mOnSeekBarChangeListener != null) {
            mOnSeekBarChangeListener.onStartTrackingTouch(this);
        }
    }
    ...
}

```

Edit: Here is some code of AbsSeekBar:

```
package android.widget;
import android.annotation.Nullable;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Insets;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.Region.Op;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.ViewConfiguration;
import android.view.accessibility.AccessibilityNodeInfo;

import com.android.internal.R;

public abstract class AbsSeekBar extends ProgressBar {
    // Lots of methods
    ...
    void onStartTrackingTouch() {
        mIsDragging = true;
    }
    ...
}

```

The SeekBar class which is part of the predefined widgets also extends AbsSeekBar and uses the exact same code for overriding the method onStartTrackingTouch(). There, the @Override is also marked as error, but it compiles without any issue. When i try to basically copy the SeekBar code, it doesn't work. Could this error be related to Android Studio or am i missing somethin elementary here?