Home | History | Annotate | Download | only in DownloadableFonts 
      1 <?xml version="1.0" encoding="UTF-8"?>
      2 <!--
      3  Copyright 2017 The Android Open Source Project
      4 
      5  Licensed under the Apache License, Version 2.0 (the "License");
      6  you may not use this file except in compliance with the License.
      7  You may obtain a copy of the License at
      8 
      9      http://www.apache.org/licenses/LICENSE-2.0
     10 
     11  Unless required by applicable law or agreed to in writing, software
     12  distributed under the License is distributed on an "AS IS" BASIS,
     13  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  See the License for the specific language governing permissions and
     15  limitations under the License.
     16 -->
     17 <sample>
     18     <name>DownloadableFonts</name>
     19     <group>UI</group>
     20     <package>com.example.android.downloadablefonts</package>
     21 
     22     <strings>
     23         <intro>
     24 <![CDATA[
     25 This sample demonstrates how to use the Downloadable Fonts feature introduced in Android O.
     26 Downloadable Fonts is a feature that allows apps to request a certain font from a provider
     27 instead of bundling it or downloading it themselves. This means, there is no need to bundle the
     28 font as an asset.
     29 ]]>
     30         </intro>
     31     </strings>
     32 
     33     <template src="base-build" />
     34 
     35     <metadata>
     36         <status>PUBLISHED</status>
     37         <categories>UI</categories>
     38         <technologies>Android</technologies>
     39         <languages>Java</languages>
     40         <solutions>Mobile</solutions>
     41         <level>INTERMEDIATE</level>
     42         <icon>screenshots/icon-web.png</icon>
     43         <screenshots>
     44             <img>screenshots/screenshot-1.png</img>
     45         </screenshots>
     46         <api_refs>
     47             <android>android.provider.FontRequest</android>
     48             <android>android.support.v4.provider.FontRequest</android>
     49             <android>android.provider.FontsContractCompat</android>
     50             <android>android.support.v4.provider.FontsContractCompat</android>
     51         </api_refs>
     52 
     53         <description>
     54 <![CDATA[
     55 This sample demonstrates how to use the Downloadable Fonts feature introduced in Android O.
     56 Downloadable Fonts is a feature that allows apps to request a certain font from a provider
     57 instead of bundling it or downloading it themselves. This means, there is no need to bundle the
     58 font as an asset.
     59 ]]>
     60         </description>
     61 
     62         <intro>
     63 <![CDATA[
     64 There are two ways of requesting a font to download.
     65 To request a font to download from Java code, you need to create a [FontRequest][1] class first like
     66 this:
     67 ```java
     68 FontRequest request = new FontRequest(
     69     "com.google.android.gms.fonts", // ProviderAuthority
     70     "com.google.android.gms",  // ProviderPackage
     71     query,  // Query
     72     R.array.com_google_android_gms_fonts_certs); // Certificates
     73 ```
     74 The parameters `ProviderAuthority`, `ProviderPackage` are given by a font provider, in the case
     75 above uses Google Play Services as a font provider.
     76 The third parameter is a query string about the requested font. The syntax of the query is defined
     77 by the font provider.
     78 
     79 Then pass the request instance to the `requestFont` method in the [FontsContractCompat][2].
     80 ```java
     81 FontsContractCompat.requestFont(context, request, callback, handler);
     82 ```
     83 The downloaded font or an error code if the request failed will be passed to the callback.
     84 The example above assumes you are using the classes from the support library. There are
     85 corresponding classes in the framework, but the feature is available back to API level 14 if you
     86 use the support library.
     87 
     88 You can declare a downloaded font in an XML file and let the system download it for you and use it
     89 in layouts.
     90 ```xml
     91 <font-family xmlns:app="http://schemas.android.com/apk/res-auto"
     92         app:fontProviderAuthority="com.google.android.gms.fonts"
     93         app:fontProviderPackage="com.google.android.gms"
     94         app:fontProviderQuery="Lobster Two"
     95         app:fontProviderCerts="@array/com_google_android_gms_fonts_certs">
     96 </font-family>
     97 ```
     98 By defining the requested font in an XML file and putting the `preloaded_fonts` array and the
     99 meta-data tag in the AndroidManifest, you can avoid the delay until the font is downloaded by the
    100 first attempt.
    101 ```xml
    102 <resources>
    103     <array name="preloaded_fonts" translatable="false">
    104         <item>@font/lobster_two</item>
    105     </array>
    106 </resources>
    107 ```
    108 
    109 ```xml
    110 <application >
    111     ...
    112     <meta-data android:name="preloaded_fonts" android:resource="@array/preloaded_fonts" />
    113     ...
    114 </application>
    115 ```
    116 
    117 [1]: https://developer.android.com/reference/android/support/v4/provider/FontRequest.html
    118 [2]: https://developer.android.com/reference/android/support/v4/provider/FontsContractCompat.html
    119 ]]>
    120         </intro>
    121     </metadata>
    122 </sample>
    123