How to set a custom font to the title in toolbar android

I am doing this:

toolbar = (Toolbar) findViewById(com.sports.unity.R.id.tool_bar);
setSupportActionBar(toolbar);
setTitle("hello");

I want to set a custom font for the text here in the title "hello". How to do that?

Since android.support.v7.appcompat 24.2 Toolbar has method setTitleTextAppearance and you can set its font without external textview.

create new style in styles.xml

<style name="RobotoBoldTextAppearance">
        <item name="android:fontFamily">@font/roboto_condensed_bold</item>
</style>

and use it

mToolbar.setTitleTextAppearance(this, R.style.RobotoBoldTextAppearance);

Update 2018 (kotlin version)

fun Toolbar.changeToolbarFont(){
    for (i in 0 until childCount) {
        val view = getChildAt(i)
        if (view is TextView && view.text == title) {
            view.typeface = Typeface.createFromAsset(view.context.assets, "fonts/customFont")
            break
        }
    }
}

and use it like that toolBar.changeToolbarFont()

old-post

To use a custom title in your Toolbar all you need to do is remember is that Toolbar is just a fancy ViewGroup so you can add a custom title like so:

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar_top"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:minHeight="?attr/actionBarSize"
    android:background="@color/action_bar_bkgnd"
    app:theme="@style/ToolBarTheme" >


     <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Toolbar Title"
        android:layout_gravity="center"
        android:id="@+id/toolbar_title" />


    </android.support.v7.widget.Toolbar>

This means that you can style the TextView however you would like because it's just a regular TextView. So in your activity you can access the title like so:

Toolbar toolbarTop = (Toolbar) findViewById(R.id.toolbar_top);
TextView mTitle = (TextView) toolbarTop.findViewById(R.id.toolbar_title);

And then:

Typeface khandBold = Typeface.createFromAsset(BalrogApplication.getApplication().getAssets(), "fonts/Khand-bold.ttf");

mTitle.setTypeface(khandBold);

UPDATE dynamically version

public static void changeToolbarFont(Toolbar toolbar, Activity context) {
    for (int i = 0; i < toolbar.getChildCount(); i++) {
        View view = toolbar.getChildAt(i);
        if (view instanceof TextView) {
            TextView tv = (TextView) view;
            if (tv.getText().equals(toolbar.getTitle())) {
                applyFont(tv, context);
                break;
            }
        }
    }
}

public static void applyFont(TextView tv, Activity context) {
    tv.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/customFont"));
}

and use it like that

changeToolbarFont(findViewById(R.id.app_bar), this);

I still wanted to use the Toolbars title methods (nor did I want to have a custom Toolbar class), so adding in the custom TextView inside of the Toolbar xml element didn't work for me. Instead, I used the following method to find the TextView:

public static void applyFontForToolbarTitle(Activity context){
    Toolbar toolbar = (Toolbar) context.findViewById(R.id.app_bar);
    for(int i = 0; i < toolbar.getChildCount(); i++){
        View view = toolbar.getChildAt(i);
        if(view instanceof TextView){
            TextView tv = (TextView) view;
            Typeface titleFont = Typeface.
               createFromAsset(context.getAssets(), "fonts/customFont");
            if(tv.getText().equals(toolbar.getTitle())){
                tv.setTypeface(titleFont);
                break;
            }
        }
    }
}