How to change default theme font to custom font in Android Studio?

Question

Java

In the most default application theme, which is automatically applied in Android Studio for each new project, a blue panel with the name of the application is displayed on top, under the status bar. How can I edit the font on this panel?

Answer 1

Reflection to help:
https://stackoverflow.com/questions/2711858/is-it-...
The Typeface class has standard fonts defined, it is enough to override the desired values ​​and you will be happy.

public class Typeface {

    ...

    /** The default NORMAL typeface object */
    public static final Typeface DEFAULT;
    /**
     * The default BOLD typeface object. Note: this may be not actually be
     * bold, depending on what fonts are installed. Call getStyle() to know
     * for sure.
     */
    public static final Typeface DEFAULT_BOLD;
    /** The NORMAL style of the default sans serif typeface. */
    public static final Typeface SANS_SERIF;
    /** The NORMAL style of the default serif typeface. */
    public static final Typeface SERIF;
    /** The NORMAL style of the default monospace typeface. */
    public static final Typeface MONOSPACE;
    
    ...

}

You can also do something like this:

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

Then set the font in the code:

Typeface typeface = Typeface.createFromAsset(context.getAssets(), fontAssetName);
TextView toolbarTitle = (TextView) findViewById(R.id.toolbar_title);
toolbarTitle.setTypeface(typeface);

Answer 2

Android O will have the ability to use custom fonts.
The 26.0.0 Beta 1 Support Library release backports this behavior.
So you can play with it and do it normally, without reflection.