Custom Font Integration for XML Layouts

In Android development, using custom fonts can significantly enhance the visual appeal and branding of your application. While XML layouts provide a convenient way to design UI elements, integrating custom fonts into them requires specific steps. This guide will walk you through the process of integrating custom fonts into your XML layouts effectively.

Why Use Custom Fonts?

Custom fonts play a crucial role in:

• Branding: Consistent use of branded fonts enhances brand recognition.
• User Experience: Improves readability and aesthetics.
• Differentiation: Sets your app apart from the competition.

Step 1: Add Font Files to Your Project

The first step is to add your custom font files (e.g., .ttf or .otf) to your Android project. Create a font directory under the res directory and copy your font files into it.

res/
    font/
        my_custom_font_regular.ttf
        my_custom_font_bold.ttf

Step 2: Create a Font Family XML

Next, create a font family XML file that describes your font resources. This allows you to define different font styles (e.g., normal, italic, bold) within a single resource. Create a new XML file under the res/font directory (e.g., my_custom_font.xml) and define the font family:

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

    <font
        android:fontStyle="normal"
        android:fontWeight="700"
        android:font="@font/my_custom_font_bold"
        app:fontStyle="normal"
        app:fontWeight="700"
        app:font="@font/my_custom_font_bold" />
</font-family>

Explanation of attributes:

• android:fontStyle: Defines the font style (normal or italic).
• android:fontWeight: Defines the font weight (e.g., 400 for regular, 700 for bold).
• android:font: Points to the actual font file.

Step 3: Apply Custom Font to TextView in XML Layout

Now that you have defined the font family, you can apply it to a TextView in your XML layout using the fontFamily attribute. Open your layout file (e.g., activity_main.xml) and set the fontFamily attribute for the TextView:

<TextView
    android:id="@+id/myTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello, Custom Font!"
    android:fontFamily="@font/my_custom_font"
    android:textSize="20sp"/>

Step 4: Using Custom Fonts Programmatically

In some cases, you might need to apply custom fonts programmatically. Here’s how you can do it:

import android.graphics.Typeface
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.TextView
import androidx.core.content.res.ResourcesCompat

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val textView: TextView = findViewById(R.id.myTextView)

        // Load the custom font
        val typeface = ResourcesCompat.getFont(this, R.font.my_custom_font)

        // Apply the custom font to the TextView
        textView.typeface = typeface
    }
}

Explanation:

• Import necessary classes like Typeface and ResourcesCompat.
• Get a reference to the TextView.
• Use ResourcesCompat.getFont() to load the custom font.
• Apply the font to the TextView using textView.typeface = typeface.

Alternative: Using the TextAppearance Style

You can also define custom fonts within a TextAppearance style and apply this style to your TextView.

Step 1: Define the Style

Create a new style in your styles.xml file:

<style name="CustomFontTextStyle" parent="TextAppearance.AppCompat">
    <item name="android:fontFamily">@font/my_custom_font</item>
</style>

Step 2: Apply the Style to TextView

In your XML layout, apply the style to your TextView:

<TextView
    android:id="@+id/myTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello, Custom Font!"
    style="@style/CustomFontTextStyle"
    android:textSize="20sp"/>

Handling Font Downloading and Caching

For apps that need to support a wider range of devices and Android versions, downloading fonts on-demand is crucial. The FontsContract API in Android provides this functionality.

Step 1: Configure Font Request

Set up the font request with the required font provider and font name.

import android.content.Context
import android.graphics.Typeface
import android.os.Handler
import android.os.Looper
import android.provider.FontRequest
import androidx.core.content.res.FontRequestCallback
import androidx.core.provider.FontsContractCompat
import android.widget.TextView

fun setFontWithFontContract(context: Context, textView: TextView, fontName: String) {
    val fontRequest = FontRequest(
        "com.google.android.gms.fonts",
        "com.google.android.gms",
        fontName,
        R.array.com_google_android_gms_fonts_certs
    )

    val fontRequestCallback = object : FontRequestCallback() {
        override fun onTypefaceRetrieved(typeface: Typeface) {
            Handler(Looper.getMainLooper()).post {
                textView.typeface = typeface
            }
        }

        override fun onTypefaceRequestFailed(reason: Int) {
            // Handle failure here
        }
    }

    FontsContractCompat.requestFont(context, fontRequest, fontRequestCallback, Handler(Looper.getMainLooper()))
}

Step 2: Font Provider Certificate

Create a certificate array in res/values/arrays.xml. Google Fonts provider uses specific certificates which need to be declared for the font request.

<resources>
    <array name="com_google_android_gms_fonts_certs">
        <item>@array/com_google_android_gms_fonts_certs_dev</item>
    </array>
    <string-array name="com_google_android_gms_fonts_certs_dev">
        <item>
            MIIEqDCCAlCgAwIBAgIJANWFuGx90071MA0GCSqGSIb3DQEBCwUAMIHm
            MQswCQYDVQQGEwJVUzEQMA4GA1UECBMHQ2FsaWZvcm5pYTEWMBQGA1UE
            ChMNR29vZ2xlIEluYy4xODA2BgNVBAMTL0FuZHJvaWQgUmVsZWFzZSBL
            ZXkgQ2VydGlmaWNhdGUgUHJvZHVjdGlvbjCCASIwDQYJKoZIhvcNAQEB
            BQADggEPADCCAQoCggEBAKzOLK69D0jSK+hwJwKqpz5Q0datR1c6jrj
            zxMmcwlo5qJ+L7A+MlmqRKiDoUHk0mBnl+6E0QcjF1uNynLmuuT5R4c
            a7ju/63uK3+K9U6Kmeo4E0WJ/WKUwi6imzqS7gJq7WQ+sOo72eJkkmj
            wRQQJAZ0VJHfJX4jNoucLx1McPzBjnwcaEUwuxEQV+iQ9G2ieoBbGgs
            S/Q0aa0eR+xXWnfGYfOzsE6u+nMQZjV/qY+qf6nwjHdmdBy5I6EWoNc
            /eZHXjWwYf3QjUFGnOEjI6JDQrw2BpXgWcKjCfkCzOsnMTdxJRTxp6D
            ivuW4hEQ/V8KMaK0fpN2c4ydwsCAwEAAaCCAQswGgYDVR0RBBMwEYEG
            cHJvZHVjdGlvbi5hbmRyb2lkLmdvb2dsZS5jb20wDwYDVR0PAQH/BAUD
            AQEGMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQELBQADggEBAAkS
            /W0cJZg2KO8VSvwnWuVvUqcJuMPNpyllQ9c+lnaoShjbQvT17wjl1DRN
            RplOamTAmwKrktnB9GxbaNcMv8caRhcXyj8tLArUiC6jL+5l7Imv9t8V
            /NcnHsw8E+v+M7nL9KCMZ5Meqiqq5qKqSEkrn9cE+3lCtYuT3Tbz+Q+
            6mDpK/nE/c6mU+lI2j/2spkDNspv0z8qzjFm2oHqvD4wYyO9x0YyILK
            /JdjA1ineK0ynyYmB67p2B7iol8oMv2Jx+1pbV0V7KXN/s9N6KyLwU3
            EOhs+U7vWS/n9gMrS8utgJfcwXk+SHH2gxjJZXs66LmW3g0vqM8=
        </item>
    </string-array>
</resources>

Refer to official documentation for up-to-date certificates and ways to implement downloadability.

Conclusion

Integrating custom fonts in Android XML layouts significantly enhances the app’s aesthetics and user experience. Whether you’re defining fonts statically through XML or dynamically setting them in code, ensure that the fonts align with your branding guidelines. Using a font family XML provides an organized way to manage different font styles. For on-demand font requirements FontContract API offers a way for on-demand downloading.