Android toolbar center title and custom font

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="?android: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);

The ToolBar title is stylable. Any customization you make has to be made in the theme. I'll give you an example.

Toolbar layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
    style="@style/ToolBarStyle.Event"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:minHeight="@dimen/abc_action_bar_default_height_material" />

Styles:

<style name="ToolBarStyle" parent="ToolBarStyle.Base"/>

<style name="ToolBarStyle.Base" parent="">
    <item name="popupTheme">@style/ThemeOverlay.AppCompat.Light</item>
    <item name="theme">@style/ThemeOverlay.AppCompat.Dark.ActionBar</item>
</style>

<style name="ToolBarStyle.Event" parent="ToolBarStyle">
    <item name="titleTextAppearance">@style/TextAppearance.Widget.Event.Toolbar.Title</item>
</style>

<style name="TextAppearance.Widget.Event.Toolbar.Title" parent="TextAppearance.Widget.AppCompat.Toolbar.Title">
    <!--Any text styling can be done here-->
    <item name="android:textStyle">normal</item>
    <item name="android:textSize">@dimen/event_title_text_size</item>
</style>

we don't have direct access to the ToolBar title TextView so we use reflection to access it.

  private TextView getActionBarTextView() {
    TextView titleTextView = null;

    try {
        Field f = mToolBar.getClass().getDeclaredField("mTitleTextView");
        f.setAccessible(true);
        titleTextView = (TextView) f.get(mToolBar);
    } catch (NoSuchFieldException e) {
    } catch (IllegalAccessException e) {
    }
    return titleTextView;
}

This's just to help to join all pieces using @MrEngineer13 answer with @Jonik and @Rick Sanchez comments with the right order to help to achieve title centered easly!!

The layout with TextAppearance.AppCompat.Widget.ActionBar.Title :

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay">

        <TextView
            android:id="@+id/toolbar_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"                      
            style="@style/TextAppearance.AppCompat.Widget.ActionBar.Title"
            android:layout_gravity="center" />

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

The way to achieve with the right order:

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

    setSupportActionBar(toolbar);
    mTitle.setText(toolbar.getTitle());

    getSupportActionBar().setDisplayShowTitleEnabled(false);

Please don't forget to upvote @MrEngineer13 answer !!!

Here is a sample project ToolbarCenterTitleSample

Hope to help somebody else ;)