機能と API の概要

Android 14 では、デベロッパー向けに優れた機能と API が導入されています。ここでは、アプリの機能を確認し、関連する API の使用を開始する方法について説明します。

追加、変更、削除された API の詳細なリストについては、API 差分レポートをご覧ください。追加された API について詳しくは、Android API リファレンスをご覧ください。Android 14 については、API レベル 34 で追加された API をご覧ください。プラットフォームの変更がアプリに影響する領域については、Android 14 の動作変更（Android 14 をターゲットとするアプリの場合）およびすべてのアプリについてをご確認ください。

多言語対応

アプリ別の言語設定

Android 14 expands on the per-app language features that were introduced in Android 13 (API level 33) with these additional capabilities:

  • Automatically generate an app's localeConfig: Starting with Android Studio Giraffe Canary 7 and AGP 8.1.0-alpha07, you can configure your app to support per-app language preferences automatically. Based on your project resources, the Android Gradle plugin generates the LocaleConfig file and adds a reference to it in the final manifest file, so you no longer have to create or update the file manually. AGP uses the resources in the res folders of your app modules and any library module dependencies to determine the locales to include in the LocaleConfig file.

  • Dynamic updates for an app's localeConfig: Use the setOverrideLocaleConfig() and getOverrideLocaleConfig() methods in LocaleManager to dynamically update your app's list of supported languages in the device's system settings. Use this flexibility to customize the list of supported languages per region, run A/B experiments, or provide an updated list of locales if your app utilizes server-side pushes for localization.

  • App language visibility for input method editors (IMEs): IMEs can utilize the getApplicationLocales() method to check the language of the current app and match the IME language to that language.

Grammatical Inflection API

3 billion people speak gendered languages: languages where grammatical categories—such as nouns, verbs, adjectives, and prepositions—inflect according to the gender of people and objects you talk to or about. Traditionally, many gendered languages use masculine grammatical gender as the default or generic gender.

Addressing users in the wrong grammatical gender, such as addressing women in masculine grammatical gender, can negatively impact their performance and attitude. In contrast, a UI with language that correctly reflects the user's grammatical gender can improve user engagement and provide a more personalized and natural-sounding user experience.

Android 14 では、性別で文法が変わる言語に合わせてユーザー中心の UI を構築するため、アプリをリファクタリングせずに文法上の性別への対応を追加できる Grammatical Inflection API が導入されています。

地域の設定

Regional preferences enable users to personalize temperature units, the first day of the week, and numbering systems. A European living in the United States might prefer temperature units to be in Celsius rather than Fahrenheit and for apps to treat Monday as the beginning of the week instead of the US default of Sunday.

New Android Settings menus for these preferences provide users with a discoverable and centralized location to change app preferences. These preferences also persist through backup and restore. Several APIs and intents—such as getTemperatureUnit and getFirstDayOfWeek— grant your app read access to user preferences, so your app can adjust how it displays information. You can also register a BroadcastReceiver on ACTION_LOCALE_CHANGED to handle locale configuration changes when regional preferences change.

To find these settings, open the Settings app and navigate to System > Languages & input > Regional preferences.

Regional preferences screen in Android system settings.
Temperature options for regional preferences in Android system settings.

ユーザー補助

非線形フォント スケーリングを 200% にする

Starting in Android 14, the system supports font scaling up to 200%, providing low-vision users with additional accessibility options that align with Web Content Accessibility Guidelines (WCAG).

To prevent large text elements on screen from scaling too large, the system applies a nonlinear scaling curve. This scaling strategy means that large text doesn't scale at the same rate as smaller text. Nonlinear font scaling helps preserve the proportional hierarchy between elements of different sizes while mitigating issues with linear text scaling at high degrees (such as text being cut off or text that becomes harder to read due to an extremely large display sizes).

Test your app with nonlinear font scaling

Enable the maximum font size in a device's accessibility settings to test your app.

If you already use scaled pixels (sp) units to define text sizing, then these additional options and scaling improvements are applied automatically to the text in your app. However, you should still perform UI testing with the maximum font size enabled (200%) to ensure that your app applies the font sizes correctly and can accommodate larger font sizes without impacting usability.

To enable 200% font size, follow these steps:

  1. Open the Settings app and navigate to Accessibility > Display size and text.
  2. For the Font size option, tap the plus (+) icon until the maximum font size setting is enabled, as shown in the image that accompanies this section.

Use scaled pixel (sp) units for text-sizes

Remember to always specify text sizes in sp units. When your app uses sp units, Android can apply the user's preferred text size and scale it appropriately.

Don't use sp units for padding or define view heights assuming implicit padding: with nonlinear font scaling sp dimensions might not be proportional, so 4sp + 20sp might not equal 24sp.

Convert scaled pixel (sp) units

Use TypedValue.applyDimension() to convert from sp units to pixels, and use TypedValue.deriveDimension() to convert pixels to sp. These methods apply the appropriate nonlinear scaling curve automatically.

Avoid hardcoding equations using Configuration.fontScale or DisplayMetrics.scaledDensity. Because font scaling is nonlinear, the scaledDensity field is no longer accurate. The fontScale field should be used for informational purposes only because fonts are no longer scaled with a single scalar value.

Use sp units for lineHeight

Always define android:lineHeight using sp units instead of dp, so the line height scales along with your text. Otherwise, if your text is sp but your lineHeight is in dp or px, it doesn't scale and looks cramped. TextView automatically corrects the lineHeight so that your intended proportions are preserved, but only if both textSize and lineHeight are defined in sp units.

カメラとメディア

画像のウルトラ HDR

An illustration of Standard Dynamic Range (SDR) versus High Dynamic Range (HDR) image quality.

Android 14 adds support for High Dynamic Range (HDR) images that retain more of the information from the sensor when taking a photo, which enables vibrant colors and greater contrast. Android uses the Ultra HDR format, which is fully backward compatible with JPEG images, allowing apps to seamlessly interoperate with HDR images, displaying them in Standard Dynamic Range (SDR) as needed.

Rendering these images in the UI in HDR is done automatically by the framework when your app opts in to using HDR UI for its Activity Window, either through a manifest entry or at runtime by calling Window.setColorMode(). You can also capture compressed Ultra HDR still images on supported devices. With more colors recovered from the sensor, editing in post can be more flexible. The Gainmap associated with Ultra HDR images can be used to render them using OpenGL or Vulkan.

カメラ拡張機能のズーム、フォーカス、ポストビューなど

Android 14 upgrades and improves camera extensions, allowing apps to handle longer processing times, which enables improved images using compute-intensive algorithms like low-light photography on supported devices. These features give users an even more robust experience when using camera extension capabilities. Examples of these improvements include:

センサー内ズーム

CameraCharacteristics の REQUEST_AVAILABLE_CAPABILITIES_STREAM_USE_CASE に SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW が含まれている場合、アプリは高度なセンサー機能を使用して、ストリームのユースケースが CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW に設定された RAW ターゲットで CaptureRequest を使用することで、切り抜かれた RAW ストリームに画角全体と同じピクセルを持たせることができます。リクエストのオーバーライド コントロールを実装することで、他のカメラ コントロールの準備が整う前でも、更新されたカメラでユーザーはズームを制御できます。

ロスレス USB オーディオ

Android 14 gains support for lossless audio formats for audiophile-level experiences over USB wired headsets. You can query a USB device for its preferred mixer attributes, register a listener for changes in preferred mixer attributes, and configure mixer attributes using the AudioMixerAttributes class. This class represents the format, such as channel mask, sample rate, and behavior of the audio mixer. The class allows for audio to be sent directly, without mixing, volume adjustment, or processing effects.

デベロッパーの生産性とツール

認証情報マネージャー

Android 14 adds Credential Manager as a platform API, with additional support back to Android 4.4 (API level 19) devices through a Jetpack Library using Google Play services. Credential Manager aims to make sign-in easier for users with APIs that retrieve and store credentials with user-configured credential providers. Credential Manager supports multiple sign-in methods, including username and password, passkeys, and federated sign-in solutions (such as Sign-in with Google) in a single API.

Passkeys provide many advantages. For example, passkeys are built on industry standards, can work across different operating systems and browser ecosystems, and can be used with both websites and apps.

For more information, see the Credential Manager and passkeys documentation and the blogpost about Credential Manager and passkeys.

ヘルスコネクト

Health Connect is an on-device repository for user health and fitness data. It allows users to share data between their favorite apps, with a single place to control what data they want to share with these apps.

On devices running Android versions prior to Android 14, Health Connect is available to download as an app on the Google Play store. Starting with Android 14, Health Connect is part of the platform and receives updates through Google Play system updates without requiring a separate download. With this, Health Connect can be updated frequently, and your apps can rely on Health Connect being available on devices running Android 14 or higher. Users can access Health Connect from the Settings in their device, with privacy controls integrated into the system settings.

Users can get started using Health Connect without a separate app download on devices running Android 14 or higher.
Users can control which apps have access to their health and fitness data through system settings.

Health Connect includes several new features in Android 14, such as exercise routes, allowing users to share a route of their workout which can be visualized on a map. A route is defined as a list of locations saved within a window of time, and your app can insert routes into exercise sessions, tying them together. To ensure that users have complete control over this sensitive data, users must allow sharing individual routes with other apps.

For more information, see the Health Connection documentation and the blogpost on What's new in Android Health.

OpenJDK 17 の更新

Android 14 では、最新の OpenJDK LTS リリースの機能に合わせて Android のコアライブラリを更新する取り組みが引き続き行われています。これには、アプリ デベロッパーとプラットフォーム デベロッパー向けのライブラリの更新と Java 17 言語のサポートが含まれます。

主な機能と改善点は次のとおりです。

  • 約 300 の java.base クラスを、Java 17 をサポートするように更新しました。
  • テキスト ブロック: Java プログラミング言語で複数行の文字列リテラルを記述できます。
  • instanceof: パターン マッチング: 追加の変数なしで、オブジェクトを instanceof 内で特定の型を持つものとして扱うことができます。
  • シールクラス: 拡張または実装できるクラスとインターフェースを制限できます。

Google Play システム アップデート（プロジェクト Mainline）により、6 億台を超えるデバイスが、こうした変更を含む最新の Android ランタイム（ART）アップデートを受け取ることができます。これは、さまざまなデバイスでアプリにとって一貫した安全性の高い環境を実現し、プラットフォーム リリースに依存することなく新機能をユーザーに提供するための Google の取り組みの一環です。

Java および OpenJDK は、Oracle およびその関連会社の商標または登録商標です。

アプリストアの改善

Android 14 introduces several PackageInstaller APIs that allow app stores to improve their user experience.

Request install approval before downloading

Installing or updating an app might require user approval. For example, when an installer making use of the REQUEST_INSTALL_PACKAGES permission attempts to install a new app. In prior Android versions, app stores can only request user approval after APKs are written to the install session and the session is committed.

Starting with Android 14, the requestUserPreapproval() method lets installers request user approval before committing the install session. This improvement lets an app store defer downloading any APKs until after the installation has been approved by the user. Furthermore, once a user has approved installation, the app store can download and install the app in the background without interrupting the user.

Claim responsibility for future updates

The setRequestUpdateOwnership() method allows an installer to indicate to the system that it intends to be responsible for future updates to an app it is installing. This capability enables update ownership enforcement, meaning that only the update owner is permitted to install automatic updates to the app. Update ownership enforcement helps to ensure that users receive updates only from the expected app store.

Any other installer, including those making use of the INSTALL_PACKAGES permission, must receive explicit user approval in order to install an update. If a user decides to proceed with an update from another source, update ownership is lost.

Update apps at less-disruptive times

App stores typically want to avoid updating an app that is actively in use because this leads to the app's running processes being killed, which potentially interrupts what the user was doing.

Starting with Android 14, the InstallConstraints API gives installers a way to ensure that their app updates happen at an opportune moment. For example, an app store can call the commitSessionAfterInstallConstraintsAreMet() method to make sure that an update is only committed when the user is no longer interacting with the app in question.

Seamlessly install optional splits

With split APKs, features of an app can be delivered in separate APK files, rather than as a monolithic APK. Split APKs allow app stores to optimize the delivery of different app components. For example, app stores might optimize based on the properties of the target device. The PackageInstaller API has supported splits since its introduction in API level 22.

In Android 14, the setDontKillApp() method allows an installer to indicate that the app's running processes shouldn't be killed when new splits are installed. App stores can use this feature to seamlessly install new features of an app while the user is using the app.

アプリのメタデータ バンドル

Android 14 以降では、Android パッケージ インストーラを使用して、データ セーフティ方針などのアプリのメタデータを指定して、Google Play などのアプリストア ページに追加できます。

ユーザーがデバイスのスクリーンショットを撮影したときに検出する

To create a more standardized experience for detecting screenshots, Android 14 introduces a privacy-preserving screenshot detection API. This API lets apps register callbacks on a per-activity basis. These callbacks are invoked, and the user is notified, when the user takes a screenshot while that activity is visible.

ユーザー エクスペリエンス

共有シートのカスタム アクションとランキングの改善

Android 14 updates the system sharesheet to support custom app actions and more informative preview results for users.

Add custom actions

With Android 14, your app can add custom actions to the system sharesheet it invokes.

Screenshot of custom actions on the sharesheet.

Improve ranking of Direct Share targets

Android 14 uses more signals from apps to determine the ranking of the direct share targets to provide more helpful results for the user. To provide the most useful signal for ranking, follow the guidance for improving rankings of your Direct Share targets. Communication apps can also report shortcut usage for outgoing and incoming messages.

Direct Share row in the sharesheet, as shown by 1

予測型「戻る」の組み込みアニメーションとカスタム アニメーションのサポート

Video: Predictive back animations

Android 13 introduced the predictive back-to-home animation behind a developer option. When used in a supported app with the developer option enabled, swiping back shows an animation indicating that the back gesture exits the app back to the home screen.

Android 14 includes multiple improvements and new guidance for Predictive Back:

With this Android 14 preview release, all features of Predictive Back remain behind a developer option. See the developer guide to migrate your app to predictive back, as well as the developer guide to creating custom in-app transitions.

大画面デバイス メーカーのアプリごとのオーバーライド

Per-app overrides enable device manufacturers to change the behavior of apps on large screen devices. For example, the FORCE_RESIZE_APP override instructs the system to resize the app to fit display dimensions (avoiding size compatibility mode) even if resizeableActivity="false" is set in the app manifest.

Overrides are intended to improve the user experience on large screens.

New manifest properties enable you to disable some device manufacturer overrides for your app.

大画面のユーザーのアプリごとのオーバーライド

アプリごとのオーバーライドは、大画面デバイスでのアプリの動作を変更します。たとえば、デバイス メーカーの OVERRIDE_MIN_ASPECT_RATIO_LARGE オーバーライドにより、アプリの構成に関係なく、アプリのアスペクト比が 16:9 に設定されます。

Android 14 QPR1 では、大画面デバイスで新しい設定メニューを使用して、アプリごとのオーバーライドを適用できます。

アプリの画面共有

App screen sharing enables users to share an app window instead of the entire device screen during screen content recording.

With app screen sharing, the status bar, navigation bar, notifications, and other system UI elements are excluded from the shared display. Only the content of the selected app is shared.

App screen sharing improves productivity and privacy by enabling users to run multiple apps but limit content sharing to a single app.

Google Pixel 8 Pro の Gboard での LLM を活用したスマート リプライ

12 月の Feature Drop が適用された Google Pixel 8 Pro デバイスでは、デベロッパーは、Google Tensor で動作するデバイス上の大規模言語モデル（LLM）を利用した Gboard のより高品質なスマート リプライを試すことができます。

この機能は、WhatsApp、Line、KakaoTalk の限定プレビューとして、英語（米国）で利用できます。Google Pixel 8 Pro デバイスと Gboard をキーボードとして使用する必要があります。

試してみるには、まず [設定] > [開発者向けオプション] > [AiCore 設定] > [Aicore 永続性を有効にする] でこの機能を有効にします。

次に、サポートされているアプリで会話を開くと、着信メッセージに応じて LLM を活用したスマート リプライが Gboard の候補領域に表示されます。

Gboard はオンデバイス LLM を利用して、より高品質なスマート リプライを提供します。

グラフィック

パスはクエリと補間が可能

Android's Path API is a powerful and flexible mechanism for creating and rendering vector graphics, with the ability to stroke or fill a path, construct a path from line segments or quadratic or cubic curves, perform boolean operations to get even more complex shapes, or all of these simultaneously. One limitation is the ability to find out what is actually in a Path object; the internals of the object are opaque to callers after creation.

To create a Path, you call methods such as moveTo(), lineTo(), and cubicTo() to add path segments. But there has been no way to ask that path what the segments are, so you must retain that information at creation time.

Starting in Android 14, you can query paths to find out what's inside of them. First, you need to get a PathIterator object using the Path.getPathIterator API:

Kotlin

val path = Path().apply {
    moveTo(1.0f, 1.0f)
    lineTo(2.0f, 2.0f)
    close()
}
val pathIterator = path.pathIterator

Java

Path path = new Path();
path.moveTo(1.0F, 1.0F);
path.lineTo(2.0F, 2.0F);
path.close();
PathIterator pathIterator = path.getPathIterator();

Next, you can call PathIterator to iterate through the segments one by one, retrieving all of the necessary data for each segment. This example uses PathIterator.Segment objects, which packages up the data for you:

Kotlin

for (segment in pathIterator) {
    println("segment: ${segment.verb}, ${segment.points}")
}

Java

while (pathIterator.hasNext()) {
    PathIterator.Segment segment = pathIterator.next();
    Log.i(LOG_TAG, "segment: " + segment.getVerb() + ", " + segment.getPoints());
}

PathIterator also has a non-allocating version of next() where you can pass in a buffer to hold the point data.

One of the important use cases of querying Path data is interpolation. For example, you might want to animate (or morph) between two different paths. To further simplify that use case, Android 14 also includes the interpolate() method on Path. Assuming the two paths have the same internal structure, the interpolate() method creates a new Path with that interpolated result. This example returns a path whose shape is halfway (a linear interpolation of .5) between path and otherPath:

Kotlin

val interpolatedResult = Path()
if (path.isInterpolatable(otherPath)) {
    path.interpolate(otherPath, .5f, interpolatedResult)
}

Java

Path interpolatedResult = new Path();
if (path.isInterpolatable(otherPath)) {
    path.interpolate(otherPath, 0.5F, interpolatedResult);
}

The Jetpack graphics-path library enables similar APIs for earlier versions of Android as well.

頂点シェーダーとフラグメント シェーダーを使用したカスタム メッシュ

Android has long supported drawing triangle meshes with custom shading, but the input mesh format has been limited to a few predefined attribute combinations. Android 14 adds support for custom meshes, which can be defined as triangles or triangle strips, and can, optionally, be indexed. These meshes are specified with custom attributes, vertex strides, varying, and vertex and fragment shaders written in AGSL.

The vertex shader defines the varyings, such as position and color, while the fragment shader can optionally define the color for the pixel, typically by using the varyings created by the vertex shader. If color is provided by the fragment shader, it is then blended with the current Paint color using the blend mode selected when drawing the mesh. Uniforms can be passed into the fragment and vertex shaders for additional flexibility.

Canvas 用のハードウェア バッファ レンダラ

To assist in using Android's Canvas API to draw with hardware acceleration into a HardwareBuffer, Android 14 introduces HardwareBufferRenderer. This API is particularly useful when your use case involves communication with the system compositor through SurfaceControl for low-latency drawing.