Easy way to make scrollable views(or any views) center on in a tablet and have them scrollable by thumbs.

atts.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="CenteringView">
        <attr name="maxWidth" format="dimension|enum">
            <!-- Enums also defined in dimens -->
            <enum name="match_parent" value="-1"/>
            <enum name="wrap_content" value="-2"/>
        </attr>
    </declare-styleable>
</resources>

CenteringRecyclerView.java

package com.example;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;

import com.exmaple.CenteringWidgetDelegate;

public class CenteringRecyclerView extends RecyclerView {
    private CenteringWidgetDelegate centeringDelegate = new CenteringWidgetDelegate();

    public CenteringRecyclerView(Context context) {
        super(context);
        centeringDelegate.setupViewCentering(this, null, 0);
    }

    public CenteringRecyclerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        centeringDelegate.setupViewCentering(this, attrs, 0);
    }

    public CenteringRecyclerView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        centeringDelegate.setupViewCentering(this, attrs, defStyle);
    }

    /**
     * @param maxWidth in pixels. Set to -1 for match_parent or -2 for wrap_content.
     */
    public void setMaxWidth(int itemWidth) {
        centeringDelegate.setMaxWidth(this, itemWidth);
    }
}

CenteringWidgetDelegate.java

package com.example;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Point;
import android.support.v7.widget.RecyclerView.LayoutParams;
import android.util.AttributeSet;
import android.view.Display;
import android.view.View;
import android.view.WindowManager;

import com.example.R;

public class CenteringWidgetDelegate {

    public void setupViewCentering(View viewToCenter, AttributeSet attrs, int defStyle) {
        TypedArray tArray = viewToCenter.getContext().obtainStyledAttributes(attrs, R.styleable.CenteringView, defStyle, 0);

        int maxWith = tArray.getDimensionPixelSize(R.styleable.CenteringView_maxWidth, LayoutParams.MATCH_PARENT);
        if (!viewToCenter.isInEditMode()) {
            setMaxWidth(viewToCenter, maxWith);
        }

        tArray.recycle();
    }

    /**
     * @param maxWidth in pixels. Set to -1 for match_parent or -2 for wrap_content.
     */
    public void setMaxWidth(View view, int maxWidth) {
        if (maxWidth == -1) {
            maxWidth = LayoutParams.MATCH_PARENT;
        }

        if (maxWidth != LayoutParams.MATCH_PARENT && maxWidth != LayoutParams.WRAP_CONTENT) {
            Point screen = getScreenDimensions(view.getContext());

            int viewPadding = (screen.x - maxWidth) / 2;
            view.setPadding(
                    viewPadding + view.getPaddingLeft(),
                    view.getPaddingTop(),
                    viewPadding + view.getPaddingRight(),
                    view.getPaddingBottom());
        }
    }

    private static Point getScreenDimensions(Context context) {
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();
        Point point = new Point();
        display.getSize(point);
        return point;
    }
}

dimens.xml

<resources>
    <!-- System enums -->
    <dimen name="match_parent">-1px</dimen>
    <dimen name="wrap_content">-2px</dimen>
</resources>