Gist to set custom font to all textviews and buttons in viewgroup

FontUtils.java

import android.content.res.AssetManager;
import android.graphics.Typeface;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

public class FontUtils {

    public static Typeface getOpenSansLight(AssetManager am) {
        return Typeface.createFromAsset(am, "fonts/OpenSans-Light.ttf");
    }

    // recursively apply typeface to our textviews
    public static final void setTypeface(ViewGroup viewGroup, Typeface typeface) {
        if (viewGroup == null) return;

        int children = viewGroup.getChildCount();
        for (int i=0; i<children; i++) {
            View view = viewGroup.getChildAt(i);
            if (view instanceof ViewGroup) setTypeface((ViewGroup)view, typeface);
            if (view instanceof TextView) {
                ((TextView)view).setTypeface(typeface);
            } else if (view instanceof Button) {
                ((Button)view).setTypeface(typeface);
            }
        }
    }
}

Further usage in Fragments:

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        if(getView() instanceof ViewGroup) {
            FontUtils.setTypeface((ViewGroup) getView(), FontUtils.getOpenSansLight(getActivity().getAssets()));
        }
    }