1
2Android DownloadableFonts Sample
3===================================
4
5This sample demonstrates how to use the Downloadable Fonts feature introduced in Android O.
6Downloadable Fonts is a feature that allows apps to request a certain font from a provider
7instead of bundling it or downloading it themselves. This means, there is no need to bundle the
8font as an asset.
9
10Introduction
11------------
12
13There are two ways of requesting a font to download.
14To request a font to download from Java code, you need to create a [FontRequest][1] class first like
15this:
16```java
17FontRequest 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```
23The parameters `ProviderAuthority`, `ProviderPackage` are given by a font provider, in the case
24above uses Google Play Services as a font provider.
25The third parameter is a query string about the requested font. The syntax of the query is defined
26by the font provider.
27
28Then pass the request instance to the `requestFont` method in the [FontsContractCompat][2].
29```java
30FontsContractCompat.requestFont(context, request, callback, handler);
31```
32The downloaded font or an error code if the request failed will be passed to the callback.
33The example above assumes you are using the classes from the support library. There are
34corresponding classes in the framework, but the feature is available back to API level 14 if you
35use the support library.
36
37You can declare a downloaded font in an XML file and let the system download it for you and use it
38in 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```
47By defining the requested font in an XML file and putting the `preloaded_fonts` array and the
48meta-data tag in the AndroidManifest, you can avoid the delay until the font is downloaded by the
49first 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
69Pre-requisites
70--------------
71
72- Android SDK 27
73- Android Build Tools v27.0.2
74- Android Support Repository
75
76Screenshots
77-------------
78
79<img src="screenshots/screenshot-1.png" height="400" alt="Screenshot"/>
80
81Getting Started
82---------------
83
84This sample uses the Gradle build system. To build this project, use the
85"gradlew build" command or use "Import Project" in Android Studio.
86
87Support
88-------
89
90- Google+ Community: https://plus.google.com/communities/105153134372062985968
91- Stack Overflow: http://stackoverflow.com/questions/tagged/android
92
93If you've found an error in this sample, please file an issue:
94https://github.com/googlesamples/android-DownloadableFonts
95
96Patches are encouraged, and may be submitted by forking this project and
97submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
98
99License
100-------
101
102Copyright 2017 The Android Open Source Project, Inc.
103
104Licensed to the Apache Software Foundation (ASF) under one or more contributor
105license agreements.  See the NOTICE file distributed with this work for
106additional information regarding copyright ownership.  The ASF licenses this
107file to you under the Apache License, Version 2.0 (the "License"); you may not
108use this file except in compliance with the License.  You may obtain a copy of
109the License at
110
111http://www.apache.org/licenses/LICENSE-2.0
112
113Unless required by applicable law or agreed to in writing, software
114distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
115WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
116License for the specific language governing permissions and limitations under
117the License.
118