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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 [1]: https://developer.android.com/reference/android/support/v4/provider/FontRequest.html
     67 [2]: https://developer.android.com/reference/android/support/v4/provider/FontsContractCompat.html
     68 
     69 Pre-requisites
     70 --------------
     71 
     72 - Android SDK 27
     73 - Android Build Tools v27.0.2
     74 - Android Support Repository
     75 
     76 Screenshots
     77 -------------
     78 
     79 <img src="screenshots/screenshot-1.png" height="400" alt="Screenshot"/> 
     80 
     81 Getting Started
     82 ---------------
     83 
     84 This sample uses the Gradle build system. To build this project, use the
     85 "gradlew build" command or use "Import Project" in Android Studio.
     86 
     87 Support
     88 -------
     89 
     90 - Google+ Community: https://plus.google.com/communities/105153134372062985968
     91 - Stack Overflow: http://stackoverflow.com/questions/tagged/android
     92 
     93 If you've found an error in this sample, please file an issue:
     94 https://github.com/googlesamples/android-DownloadableFonts
     95 
     96 Patches are encouraged, and may be submitted by forking this project and
     97 submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
     98 
     99 License
    100 -------
    101 
    102 Copyright 2017 The Android Open Source Project, Inc.
    103 
    104 Licensed to the Apache Software Foundation (ASF) under one or more contributor
    105 license agreements.  See the NOTICE file distributed with this work for
    106 additional information regarding copyright ownership.  The ASF licenses this
    107 file to you under the Apache License, Version 2.0 (the "License"); you may not
    108 use this file except in compliance with the License.  You may obtain a copy of
    109 the License at
    110 
    111 http://www.apache.org/licenses/LICENSE-2.0
    112 
    113 Unless required by applicable law or agreed to in writing, software
    114 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    115 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
    116 License for the specific language governing permissions and limitations under
    117 the License.
    118