How to set custom font for a whole application in Android?

Is it possible to set a custom font in an Android application?

I tried what is posted here, but I don't know where my extends Application class is...

Any help?

EDIT:

I tried the following:

• Add an assets folder and insert the font inside as seen here:

• Add a new class that extends from Application

• Call this new class from my AndroidManifest.xml.

• I went to my style and added it.

MyApp.java:

public class MyApp extends Application {
  @Override
  public void onCreate() {
     super.onCreate();
    FontsOverride.setDefaultFont(this, "DEFAULT", "raleway_regular.ttf");
    //  This FontsOverride comes from the example I posted above
  }
  }

AndroidManifest.xml:

<application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:supportsRtl="true"
      android:name=".MyApp"
      android:theme="@style/AppTheme">
     ....

styles.xml:

 <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="android:fontFamily">default</item>
 </style>

But my font is still not changning... any idea?

Then the MyApp class is called. But no effect on my fonts...

EDIT2: I realized that my buttons apply the custom font after I set a custom style for my buttons. Here is my custom button style:

<style name="MyButtonStyle" parent="Widget.AppCompat.Button">
    <item name="textAllCaps">false</item>
    <item name="android:textAllCaps">false</item>
</style>

And here is how it looks now:

So: my button is applying the style, but not the TextView. Any idea on why my custom font is not being applied for all items in application?

Write a class

public class MyApp extends Application{
// Put the onCreate code as you obtained from the post link you reffered
}

now next thing is in AndroidManifest.xml for the application tag give name for your application class. In this case it is MyApp

<application
android:name=".MyApp"
...
>
...
</application>

So whenever the App is opened , onCreate method of MyApp class would be invoked , and the font would be set.

Update Put font file under assets/fonts/your_font_file.ttf

Put this line under onCreate method of your application class(MyApp)

TypefaceUtil.overrideFont(getApplicationContext(), "SERIF", "fonts/your_font_file.ttf");

Source File for TypefaceUtil

public class TypefaceUtil {

    /**
     * Using reflection to override default typeface
     * NOTICE: DO NOT FORGET TO SET TYPEFACE FOR APP THEME AS DEFAULT TYPEFACE WHICH WILL BE OVERRIDDEN
     *
     * @param context                    to work with assets
     * @param defaultFontNameToOverride  for example "monospace"
     * @param customFontFileNameInAssets file name of the font from assets
     */
    public static void overrideFont(Context context, String defaultFontNameToOverride, String customFontFileNameInAssets) {

        final Typeface customFontTypeface = Typeface.createFromAsset(context.getAssets(), customFontFileNameInAssets);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Map<String, Typeface> newMap = new HashMap<String, Typeface>();
            newMap.put("serif", customFontTypeface);
            try {
                final Field staticField = Typeface.class
                        .getDeclaredField("sSystemFontMap");
                staticField.setAccessible(true);
                staticField.set(null, newMap);
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else {
            try {
                final Field defaultFontTypefaceField = Typeface.class.getDeclaredField(defaultFontNameToOverride);
                defaultFontTypefaceField.setAccessible(true);
                defaultFontTypefaceField.set(null, customFontTypeface);
            } catch (Exception e) {
                Log.e(TypefaceUtil.class.getSimpleName(), "Can not set custom font " + customFontFileNameInAssets + " instead of " + defaultFontNameToOverride);
            }
        }
    }
}

Now update your style.xml file

put the below line your style which is included for your activity in manifest file

  <item name="android:typeface">serif</item>

Hope this helps