Test custom font library with Calligraphy.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.benzneststudios.mycustomfont.MainActivity"
    android:padding="16dp">

    <TextView
        android:id="@+id/tv_hello"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!!"
        android:layout_centerHorizontal="true"
        android:textSize="36sp"/>

    <TextView
        android:text="I am developer."
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/tv_hello"
        android:textSize="36dp"
        android:layout_centerHorizontal="true"
        android:textAppearance="@style/MyFont"/>
</RelativeLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.benzneststudios.mycustomfont">

    <application
        android:name=".MyApplication"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity.java

package com.benzneststudios.mycustomfont;

import android.content.Context;
import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import uk.co.chrisjenx.calligraphy.CalligraphyContextWrapper;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        showDialog();
    }

    private void showDialog() {
        new AlertDialog.Builder(MainActivity.this)
                .setTitle("Delete this?")
                .setMessage("Are you sure you want to delete this?")
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // continue with delete
                    }
                })
                .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // do nothing
                    }
                })
                .setIcon(android.R.drawable.ic_dialog_alert)
                .show();
    }

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(CalligraphyContextWrapper.wrap(base));
    }
}

MyApplication.java

package com.benzneststudios.mycustomfont;

import android.app.Application;
import uk.co.chrisjenx.calligraphy.CalligraphyConfig;

/**
 * Created by benznest on 12-Sep-16.
 */
public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        initFont();
    }

    private void initFont() {
        CalligraphyConfig.initDefault(new CalligraphyConfig.Builder()
                .setDefaultFontPath("fonts/junegull.ttf")
                .setFontAttrId(R.attr.fontPath)
                .build()
        );
    }
}