I found the answer:
First create this class in your project:
import android.graphics.Paint;
import android.graphics.Typeface;
import android.text.TextPaint;
import android.text.style.TypefaceSpan;
public class CustomTypefaceSpan extends TypefaceSpan {
private final Typeface newType;
public CustomTypefaceSpan(String family, Typeface type) {
super(family);
newType = type;
}
@Override
public void updateDrawState(TextPaint ds) {
applyCustomTypeFace(ds, newType);
}
@Override
public void updateMeasureState(TextPaint paint) {
applyCustomTypeFace(paint, newType);
}
private static void applyCustomTypeFace(Paint paint, Typeface tf) {
int oldStyle;
Typeface old = paint.getTypeface();
if (old == null) {
oldStyle = 0;
} else {
oldStyle = old.getStyle();
}
int fake = oldStyle & ~tf.getStyle();
if ((fake & Typeface.BOLD) != 0) {
paint.setFakeBoldText(true);
}
if ((fake & Typeface.ITALIC) != 0) {
paint.setTextSkewX(-0.25f);
}
paint.setTypeface(tf);
}
}
Then add this method to your activity you want to change the font of navigation drawer menu:
private void applyFontToMenuItem(MenuItem mi) {
Typeface font = Typeface.createFromAsset(getAssets(), "ds_digi_b.TTF");
SpannableString mNewTitle = new SpannableString(mi.getTitle());
mNewTitle.setSpan(new CustomTypefaceSpan("" , font), 0 , mNewTitle.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
mi.setTitle(mNewTitle);
}
and then add call the method you just added in your activity:
navView = (NavigationView) findViewById(R.id.navView);
Menu m = navView.getMenu();
for (int i=0;i<m.size();i++) {
MenuItem mi = m.getItem(i);
//for aapplying a font to subMenu ...
SubMenu subMenu = mi.getSubMenu();
if (subMenu!=null && subMenu.size() >0 ) {
for (int j=0; j <subMenu.size();j++) {
MenuItem subMenuItem = subMenu.getItem(j);
applyFontToMenuItem(subMenuItem);
}
}
//the method we have create in activity
applyFontToMenuItem(mi);
}