This sample demonstrates how to use the Downloadable Fonts feature introduced in Android O. Downloadable Fonts is a feature that allows apps to request a certain font from a provider instead of bundling it or downloading it themselves. This means, there is no need to bundle the font as an asset.
There are two ways of requesting a font to download. To request a font to download from Java code, you need to create a FontRequest class first like this:
FontRequest request = new FontRequest( "com.google.android.gms.fonts", // ProviderAuthority "com.google.android.gms", // ProviderPackage query, // Query R.array.com_google_android_gms_fonts_certs); // Certificates
ProviderPackage are given by a font provider, in the case
above uses Google Play Services as a font provider.
The third parameter is a query string about the requested font. The syntax of the query is defined
by the font provider.
Then pass the request instance to the
requestFont method in the FontsContractCompat.
FontsContractCompat.requestFont(context, request, callback, handler);
The downloaded font or an error code if the request failed will be passed to the callback. The example above assumes you are using the classes from the support library. There are corresponding classes in the framework, but the feature is available back to API level 14 if you use the support library.
You can declare a downloaded font in an XML file and let the system download it for you and use it in layouts.
<font-family xmlns:app="http://schemas.android.com/apk/res-auto" app:fontProviderAuthority="com.google.android.gms.fonts" app:fontProviderPackage="com.google.android.gms" app:fontProviderQuery="Lobster Two" app:fontProviderCerts="@array/com_google_android_gms_fonts_certs"> </font-family>
By defining the requested font in an XML file and putting the
preloaded_fonts array and the
meta-data tag in the AndroidManifest, you can avoid the delay until the font is downloaded by the
<resources> <array name="preloaded_fonts" translatable="false"> <item>@font/lobster_two</item> </array> </resources>
<application > ... <meta-data android:name="preloaded_fonts" android:resource="@array/preloaded_fonts" /> ... </application>
Note that the sample uses Google Play Services as a font provider, which requires pre-released version of Google Play Services. You can sign up for the beta program so that the beta version of Google Play Services is downloaded to your device. https://developers.google.com/android/guides/beta-program If you have Google Play Services whose version number is equal or above 11.x.x, that means you have the compatible version installed. (You can confirm by navigating to Settings -> Apps -> Google Play Services)
This sample uses the Gradle build system. To build this project, use the "gradlew build" command or use "Import Project" in Android Studio.
If you've found an error in this sample, please file an issue: https://github.com/googlesamples/android-DownloadableFonts
Patches are encouraged, and may be submitted by forking this project and submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
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