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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import '_platform_io.dart'
if (dart.library.html) '_platform_web.dart' as platform;
/// The [TargetPlatform] that matches the platform on which the framework is
/// currently executing.
/// This is the default value of [ThemeData.platform] (hence the name). Widgets
/// from the material library should use [Theme.of] to determine the current
/// platform for styling purposes, rather than using [defaultTargetPlatform].
/// Widgets and render objects at lower layers that try to emulate the
/// underlying platform can depend on [defaultTargetPlatform] directly. The
/// [dart:io.Platform] object should only be used directly when it's critical to
/// actually know the current platform, without any overrides possible (for
/// example, when a system API is about to be called).
/// In a test environment, the platform returned is []
/// regardless of the host platform. (Android was chosen because the tests were
/// originally written assuming Android-like behavior, and we added platform
/// adaptations for iOS later). Tests can check iOS behavior by using the
/// platform override APIs (such as [ThemeData.platform] in the material
/// library) or by setting [debugDefaultTargetPlatformOverride].
/// Tests can also create specific platform tests by and adding a `variant:`
/// argument to the test and using a [TargetPlatformVariant].
// When adding support for a new platform (e.g. Windows Phone, Raspberry Pi),
// first create a new value on the [TargetPlatform] enum, then add a rule for
// selecting that platform here.
// It would be incorrect to make a platform that isn't supported by
// [TargetPlatform] default to the behavior of another platform, because doing
// that would mean we'd be stuck with that platform forever emulating the other,
// and we'd never be able to introduce dedicated behavior for that platform
// (since doing so would be a big breaking change).
TargetPlatform get defaultTargetPlatform => platform.defaultTargetPlatform;
/// The platform that user interaction should adapt to target.
/// The [defaultTargetPlatform] getter returns the current platform.
enum TargetPlatform {
/// Android: <>
/// Fuchsia: <>
/// iOS: <>
/// Linux: <>
/// macOS: <>
/// Windows: <>
/// Override the [defaultTargetPlatform].
/// Setting this to null returns the [defaultTargetPlatform] to its original
/// value (based on the actual current platform).
/// Generally speaking this override is only useful for tests. To change the
/// platform that widgets resemble, consider using the platform override APIs
/// (such as [ThemeData.platform] in the material library) instead.
/// Setting [debugDefaultTargetPlatformOverride] (as opposed to, say,
/// [ThemeData.platform]) will cause unexpected and undesirable effects. For
/// example, setting this to [TargetPlatform.iOS] when the application is
/// running on Android will cause the TalkBack accessibility tool on Android to
/// be confused because it would be receiving data intended for iOS VoiceOver.
/// Similarly, setting it to [] while on iOS will cause
/// certainly widgets to work assuming the presence of a system-wide back
/// button, which will make those widgets unusable since iOS has no such button.
/// In general, therefore, this property should not be used in release builds.
TargetPlatform? debugDefaultTargetPlatformOverride;