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      1 
      2 Android DownloadableFonts Sample
      3 ===================================
      4 
      5 This sample demonstrates how to use the Downloadable Fonts feature introduced in Android O.
      6 Downloadable Fonts is a feature that allows apps to request a certain font from a provider
      7 instead of bundling it or downloading it themselves. This means, there is no need to bundle the
      8 font as an asset.
      9 
     10 Introduction
     11 ------------
     12 
     13 There are two ways of requesting a font to download.
     14 To request a font to download from Java code, you need to create a [FontRequest][1] class first like
     15 this:
     16 ```java
     17 FontRequest request = new FontRequest(
     18     "com.google.android.gms.fonts", // ProviderAuthority
     19     "com.google.android.gms",  // ProviderPackage
     20     query,  // Query
     21     R.array.com_google_android_gms_fonts_certs); // Certificates
     22 ```
     23 The parameters `ProviderAuthority`, `ProviderPackage` are given by a font provider, in the case
     24 above uses Google Play Services as a font provider.
     25 The third parameter is a query string about the requested font. The syntax of the query is defined
     26 by the font provider.
     27 
     28 Then pass the request instance to the `requestFont` method in the [FontsContractCompat][2].
     29 ```java
     30 FontsContractCompat.requestFont(context, request, callback, handler);
     31 ```
     32 The downloaded font or an error code if the request failed will be passed to the callback.
     33 The example above assumes you are using the classes from the support library. There are
     34 corresponding classes in the framework, but the feature is available back to API level 14 if you
     35 use the support library.
     36 
     37 You can declare a downloaded font in an XML file and let the system download it for you and use it
     38 in layouts.
     39 ```xml
     40 <font-family xmlns:app="http://schemas.android.com/apk/res-auto"
     41         app:fontProviderAuthority="com.google.android.gms.fonts"
     42         app:fontProviderPackage="com.google.android.gms"
     43         app:fontProviderQuery="Lobster Two"
     44         app:fontProviderCerts="@array/com_google_android_gms_fonts_certs">
     45 </font-family>
     46 ```
     47 By defining the requested font in an XML file and putting the `preloaded_fonts` array and the
     48 meta-data tag in the AndroidManifest, you can avoid the delay until the font is downloaded by the
     49 first attempt.
     50 ```xml
     51 <resources>
     52     <array name="preloaded_fonts" translatable="false">
     53         <item>@font/lobster_two</item>
     54     </array>
     55 </resources>
     56 ```
     57 
     58 ```xml
     59 <application >
     60     ...
     61     <meta-data android:name="preloaded_fonts" android:resource="@array/preloaded_fonts" />
     62     ...
     63 </application>
     64 ```
     65 
     66 Note that the sample uses Google Play Services as a font provider, which requires pre-released
     67 version of Google Play Services.
     68 You can sign up for the beta program so that the beta version of Google Play Services is
     69 downloaded to your device. https://developers.google.com/android/guides/beta-program
     70 If you have Google Play Services whose version number is equal or above 11.x.x, that means you
     71 have the compatible version installed. (You can confirm by navigating to
     72 Settings -> Apps -> Google Play Services)
     73 
     74 [1]: https://developer.android.com/reference/android/support/v4/provider/FontRequest.html
     75 [2]: https://developer.android.com/reference/android/support/v4/provider/FontsContractCompat.html
     76 
     77 Pre-requisites
     78 --------------
     79 
     80 - Android SDK 25
     81 - Android Build Tools v25.0.3
     82 - Android Support Repository
     83 
     84 Screenshots
     85 -------------
     86 
     87 <img src="screenshots/screenshot-1.png" height="400" alt="Screenshot"/> 
     88 
     89 Getting Started
     90 ---------------
     91 
     92 This sample uses the Gradle build system. To build this project, use the
     93 "gradlew build" command or use "Import Project" in Android Studio.
     94 
     95 Support
     96 -------
     97 
     98 - Google+ Community: https://plus.google.com/communities/105153134372062985968
     99 - Stack Overflow: http://stackoverflow.com/questions/tagged/android
    100 
    101 If you've found an error in this sample, please file an issue:
    102 https://github.com/googlesamples/android-DownloadableFonts
    103 
    104 Patches are encouraged, and may be submitted by forking this project and
    105 submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
    106 
    107 License
    108 -------
    109 
    110 Copyright 2017 The Android Open Source Project, Inc.
    111 
    112 Licensed to the Apache Software Foundation (ASF) under one or more contributor
    113 license agreements.  See the NOTICE file distributed with this work for
    114 additional information regarding copyright ownership.  The ASF licenses this
    115 file to you under the Apache License, Version 2.0 (the "License"); you may not
    116 use this file except in compliance with the License.  You may obtain a copy of
    117 the License at
    118 
    119 http://www.apache.org/licenses/LICENSE-2.0
    120 
    121 Unless required by applicable law or agreed to in writing, software
    122 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    123 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
    124 License for the specific language governing permissions and limitations under
    125 the License.
    126