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// Copyright 2013 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 'package:flutter/material.dart';
const Set<TargetPlatform> _desktop = <TargetPlatform>{
TargetPlatform.linux,
TargetPlatform.macOS,
TargetPlatform.windows
};
const Set<TargetPlatform> _mobile = <TargetPlatform>{
TargetPlatform.android,
TargetPlatform.fuchsia,
TargetPlatform.iOS,
};
/// A group of standard breakpoints built according to the material
/// specifications for screen width size.
///
/// See also:
///
/// * [AdaptiveScaffold], which uses some of these Breakpoints as defaults.
class Breakpoints {
/// This is a standard breakpoint that can be used as a fallthrough in the
/// case that no other breakpoint is active.
///
/// It is active from a width of -1 dp to infinity.
static const Breakpoint standard = WidthPlatformBreakpoint(begin: -1);
/// A window whose width is less than 600 dp and greater than 0 dp.
static const Breakpoint small = WidthPlatformBreakpoint(begin: 0, end: 600);
/// A window whose width is greater than 0 dp.
static const Breakpoint smallAndUp = WidthPlatformBreakpoint(begin: 0);
/// A desktop screen whose width is less than 600 dp and greater than 0 dp.
static const Breakpoint smallDesktop =
WidthPlatformBreakpoint(begin: 0, end: 600, platform: _desktop);
/// A mobile screen whose width is less than 600 dp and greater than 0 dp.
static const Breakpoint smallMobile =
WidthPlatformBreakpoint(begin: 0, end: 600, platform: _mobile);
/// A window whose width is between 600 dp and 840 dp.
static const Breakpoint medium =
WidthPlatformBreakpoint(begin: 600, end: 840);
/// A window whose width is greater than 600 dp.
static const Breakpoint mediumAndUp = WidthPlatformBreakpoint(begin: 600);
/// A desktop window whose width is between 600 dp and 840 dp.
static const Breakpoint mediumDesktop =
WidthPlatformBreakpoint(begin: 600, end: 840, platform: _desktop);
/// A mobile window whose width is between 600 dp and 840 dp.
static const Breakpoint mediumMobile =
WidthPlatformBreakpoint(begin: 600, end: 840, platform: _mobile);
/// A window whose width is greater than 840 dp.
static const Breakpoint large = WidthPlatformBreakpoint(begin: 840);
/// A desktop window whose width is greater than 840 dp.
static const Breakpoint largeDesktop =
WidthPlatformBreakpoint(begin: 840, platform: _desktop);
/// A mobile window whose width is greater than 840 dp.
static const Breakpoint largeMobile =
WidthPlatformBreakpoint(begin: 840, platform: _mobile);
}
/// A class that can be used to quickly generate [Breakpoint]s that depend on
/// the screen width and the platform.
class WidthPlatformBreakpoint extends Breakpoint {
/// Returns a const [Breakpoint] with the given constraints.
const WidthPlatformBreakpoint({this.begin, this.end, this.platform});
/// The beginning width dp value. If left null then the [Breakpoint] will have
/// no lower bound.
final double? begin;
/// The end width dp value. If left null then the [Breakpoint] will have no
/// upper bound.
final double? end;
/// A Set of [TargetPlatform]s that the [Breakpoint] will be active on. If
/// left null then it will be active on all platforms.
final Set<TargetPlatform>? platform;
@override
bool isActive(BuildContext context) {
final TargetPlatform host = Theme.of(context).platform;
final bool isRightPlatform = platform?.contains(host) ?? true;
// Null boundaries are unbounded, assign the max/min of their associated
// direction on a number line.
final double width = MediaQuery.of(context).size.width;
final double lowerBound = begin ?? double.negativeInfinity;
final double upperBound = end ?? double.infinity;
return width >= lowerBound && width < upperBound && isRightPlatform;
}
}
/// An interface to define the conditions that distinguish between types of
/// screens.
///
/// Adaptive apps usually display differently depending on the screen type: a
/// compact layout for smaller screens, or a relaxed layout for larger screens.
/// Override this class by defining `isActive` to fetch the screen property
/// (usually `MediaQuery.of`) and return true if the condition is met.
///
/// Breakpoints do not need to be exclusive because they are tested in order
/// with the last Breakpoint active taking priority.
///
/// If the condition is only based on the screen width and/or the device type,
/// use [WidthPlatformBreakpoint] to define the [Breakpoint].
///
/// See also:
///
/// * [SlotLayout.config], which uses breakpoints to dictate the layout of the
/// screen.
abstract class Breakpoint {
/// Returns a const [Breakpoint].
const Breakpoint();
/// A method that returns true based on conditions related to the context of
/// the screen such as MediaQuery.of(context).size.width.
bool isActive(BuildContext context);
}