Android Oreo Font Family NPE Crash

Question

I'm using the new Android Font support introduced in API 26 and backported in version 26 of the support library.

I've created a font_family.xml of two fonts like so:

<?xml version="1.0" encoding="utf-8"?>
<font-family
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <font
        android:font="@font/regular_font"
        android:fontStyle="normal"
        android:fontWeight="400"
        app:font="@font/regular_font"
        app:fontStyle="normal"
        app:fontWeight="400"/>

    <font
        android:font="@font/bold_font"
        android:fontStyle="normal"
        android:fontWeight="700"
        app:font="@font/bold_font"
        app:fontStyle="normal"
        app:fontWeight="700"/>

</font-family>

I then set it on a TextView in my activity layout like so:

<TextView
        style="@style/TextAppearance.Display1"
        android:layout_width="wrap_content"
        android:fontFamily="@font/font_family"
        android:textStyle="bold"
        android:layout_height="wrap_content" />

This works and renders the TextView in the correct font on a Nexus 5 running Marshmallow (using the support library). But it crashes when I try to run it on a Pixel Oreo device with the following stack:

Caused by: android.view.InflateException: Binary XML file line #44: Binary XML file line #44: Error inflating class TextView
Caused by: android.view.InflateException: Binary XML file line #44: Error inflating class TextView
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.Boolean.booleanValue()' on a null object reference
    at android.support.v4.graphics.TypefaceCompatApi26Impl.abortCreation(TypefaceCompatApi26Impl.java:202)
    at android.support.v4.graphics.TypefaceCompatApi26Impl.createFromFontFamilyFilesResourceEntry(TypefaceCompatApi26Impl.java:220)
    at android.support.v4.graphics.TypefaceCompat.createFromResourcesFamilyXml(TypefaceCompat.java:116)
    at android.support.v4.content.res.ResourcesCompat.loadFont(ResourcesCompat.java:249)
    at android.support.v4.content.res.ResourcesCompat.loadFont(ResourcesCompat.java:213)
    at android.support.v4.content.res.ResourcesCompat.getFont(ResourcesCompat.java:206)
    at android.support.v7.widget.TintTypedArray.getFont(TintTypedArray.java:119)
    at android.support.v7.widget.AppCompatTextHelper.updateTypefaceAndStyle(AppCompatTextHelper.java:208)

Looks like some error with inflating the font but can't deduce much more than that.

Answer 1

I had the same problem as you. So I changed from

<font-family xmlns:android="http://schemas.android.com/apk/res/android">
    <font
        android:fontStyle="normal"
        android:fontWeight="400"
        android:font="@font/lobster_regular" />
    <font
        android:fontStyle="italic"
        android:fontWeight="400"
        android:font="@font/lobster_italic" />
</font-family>

to

<font-family xmlns:android="http://schemas.android.com/apk/res/android">
        <font
            app:fontStyle="normal"
            app:fontWeight="400"
            app:font="@font/lobster_regular" />
        <font
            app:fontStyle="italic"
            app:fontWeight="400"
            app:font="@font/lobster_italic" />
    </font-family>

inside the of my lobster_font_family.xml(v26) I made to use inside my demolayout.xml. And it's working on API 26 without a problem.