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      1 Android DownloadableFonts Sample (Kotlin)
      2 ===================================
      3 
      4 This sample demonstrates how to use the Downloadable Fonts feature introduced in Android O.
      5 Downloadable Fonts is a feature that allows apps to request a certain font from a provider
      6 instead of bundling it or downloading it themselves. This means, there is no need to bundle the
      7 font as an asset.
      8 
      9 Introduction
     10 ------------
     11 
     12 There are two ways of requesting a font to download.
     13 To request a font to download from Java code, you need to create a [FontRequest][1] class first like
     14 this:
     15 ```java
     16 FontRequest request = new FontRequest(
     17     "com.google.android.gms.fonts", // ProviderAuthority
     18     "com.google.android.gms",  // ProviderPackage
     19     query,  // Query
     20     R.array.com_google_android_gms_fonts_certs); // Certificates
     21 ```
     22 The parameters `ProviderAuthority`, `ProviderPackage` are given by a font provider, in the case
     23 above uses Google Play Services as a font provider.
     24 The third parameter is a query string about the requested font. The syntax of the query is defined
     25 by the font provider.
     26 
     27 Then pass the request instance to the `requestFont` method in the [FontsContractCompat][2].
     28 ```java
     29 FontsContractCompat.requestFont(context, request, callback, handler);
     30 ```
     31 The downloaded font or an error code if the request failed will be passed to the callback.
     32 The example above assumes you are using the classes from the support library. There are
     33 corresponding classes in the framework, but the feature is available back to API level 14 if you
     34 use the support library.
     35 
     36 You can declare a downloaded font in an XML file and let the system download it for you and use it
     37 in layouts.
     38 ```xml
     39 <font-family xmlns:app="http://schemas.android.com/apk/res-auto"
     40         app:fontProviderAuthority="com.google.android.gms.fonts"
     41         app:fontProviderPackage="com.google.android.gms"
     42         app:fontProviderQuery="Lobster Two"
     43         app:fontProviderCerts="@array/com_google_android_gms_fonts_certs">
     44 </font-family>
     45 ```
     46 By defining the requested font in an XML file and putting the `preloaded_fonts` array and the
     47 meta-data tag in the AndroidManifest, you can avoid the delay until the font is downloaded by the
     48 first attempt.
     49 ```xml
     50 <resources>
     51     <array name="preloaded_fonts" translatable="false">
     52         <item>@font/lobster_two</item>
     53     </array>
     54 </resources>
     55 ```
     56 
     57 ```xml
     58 <application >
     59     ...
     60     <meta-data android:name="preloaded_fonts" android:resource="@array/preloaded_fonts" />
     61     ...
     62 </application>
     63 ```
     64 
     65 Note that the sample uses Google Play Services as a font provider, which requires pre-released
     66 version of Google Play Services.
     67 You can sign up for the beta program so that the beta version of Google Play Services is
     68 downloaded to your device. https://developers.google.com/android/guides/beta-program
     69 If you have Google Play Services whose version number is equal or above 11.x.x, that means you
     70 have the compatible version installed. (You can confirm by navigating to
     71 Settings -> Apps -> Google Play Services)
     72 
     73 [1]: https://developer.android.com/reference/android/support/v4/provider/FontRequest.html
     74 [2]: https://developer.android.com/reference/android/support/v4/provider/FontsContractCompat.html
     75 
     76 Pre-requisites
     77 --------------
     78 
     79 - Android SDK 25
     80 - Android Build Tools v25.0.3
     81 - Android Support Repository
     82 
     83 Screenshots
     84 -------------
     85 
     86 <img src="screenshots/screenshot-1.png" height="400" alt="Screenshot"/> 
     87 
     88 Getting Started
     89 ---------------
     90 
     91 This sample uses the Gradle build system. To build this project, use the
     92 "gradlew build" command or use "Import Project" in Android Studio.
     93 
     94 Support
     95 -------
     96 
     97 - Google+ Community: https://plus.google.com/communities/105153134372062985968
     98 - Stack Overflow: http://stackoverflow.com/questions/tagged/android
     99 
    100 If you've found an error in this sample, please file an issue:
    101 https://github.com/googlesamples/android-DownloadableFonts
    102 
    103 Patches are encouraged, and may be submitted by forking this project and
    104 submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
    105 
    106 License
    107 -------
    108 
    109 Copyright 2017 The Android Open Source Project, Inc.
    110 
    111 Licensed to the Apache Software Foundation (ASF) under one or more contributor
    112 license agreements.  See the NOTICE file distributed with this work for
    113 additional information regarding copyright ownership.  The ASF licenses this
    114 file to you under the Apache License, Version 2.0 (the "License"); you may not
    115 use this file except in compliance with the License.  You may obtain a copy of
    116 the License at
    117 
    118 http://www.apache.org/licenses/LICENSE-2.0
    119 
    120 Unless required by applicable law or agreed to in writing, software
    121 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    122 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
    123 License for the specific language governing permissions and limitations under
    124 the License.
    125