blob: 2e43d32b56093d77aa6838fef40fa702fca0e091 [file] [log] [blame]
// Copyright 2015 The Chromium 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/cupertino.dart';
import 'package:flutter/widgets.dart';
import 'theme.dart';
// Fractional offset from 1/4 screen below the top to fully on screen.
final Tween<Offset> _kBottomUpTween = new Tween<Offset>(
begin: const Offset(0.0, 0.25),
// Used for Android and Fuchsia.
class _MountainViewPageTransition extends StatelessWidget {
Key key,
@required bool fade,
@required Animation<double> routeAnimation,
@required this.child,
}) : _positionAnimation = _kBottomUpTween.animate(new CurvedAnimation(
parent: routeAnimation, // The route's linear 0.0 - 1.0 animation.
curve: Curves.fastOutSlowIn,
_opacityAnimation = fade ? new CurvedAnimation(
parent: routeAnimation,
curve: Curves.easeIn, // Eyeballed from other Material apps.
) : const AlwaysStoppedAnimation<double>(1.0),
super(key: key);
final Animation<Offset> _positionAnimation;
final Animation<double> _opacityAnimation;
final Widget child;
Widget build(BuildContext context) {
// TODO(ianh): tell the transform to be un-transformed for hit testing
return new SlideTransition(
position: _positionAnimation,
child: new FadeTransition(
opacity: _opacityAnimation,
child: child,
/// A modal route that replaces the entire screen with a platform-adaptive
/// transition.
/// For Android, the entrance transition for the page slides the page upwards
/// and fades it in. The exit transition is the same, but in reverse.
/// The transition is adaptive to the platform and on iOS, the page slides in
/// from the right and exits in reverse. The page also shifts to the left in
/// parallax when another page enters to cover it. (These directions are flipped
/// in environments with a right-to-left reading direction.)
/// By default, when a modal route is replaced by another, the previous route
/// remains in memory. To free all the resources when this is not necessary, set
/// [maintainState] to false.
/// The `fullscreenDialog` property specifies whether the incoming page is a
/// fullscreen modal dialog. On iOS, those pages animate from the bottom to the
/// top rather than horizontally.
/// The type `T` specifies the return type of the route which can be supplied as
/// the route is popped from the stack via [Navigator.pop] by providing the
/// optional `result` argument.
/// See also:
/// * [CupertinoPageRoute], which this [PageRoute] delegates transition
/// animations to for iOS.
class MaterialPageRoute<T> extends PageRoute<T> {
/// Creates a page route for use in a material design app.
@required this.builder,
RouteSettings settings,
this.maintainState = true,
bool fullscreenDialog = false,
}) : assert(builder != null),
super(settings: settings, fullscreenDialog: fullscreenDialog) {
// ignore: prefer_asserts_in_initializer_lists ,
/// Turns on the fading of routes during page transitions.
/// This is currently disabled by default because of performance issues on
/// low-end phones. Eventually these issues will be resolved and this flag
/// will be removed.
@Deprecated('This flag will eventually be removed once the performance issues are resolved. See:')
static bool debugEnableFadingRoutes = false;
/// Builds the primary contents of the route.
final WidgetBuilder builder;
final bool maintainState;
/// A delegate PageRoute to which iOS themed page operations are delegated to.
/// It's lazily created on first use.
CupertinoPageRoute<T> get _cupertinoPageRoute {
_internalCupertinoPageRoute ??= new CupertinoPageRoute<T>(
builder: builder, // Not used.
fullscreenDialog: fullscreenDialog,
hostRoute: this,
return _internalCupertinoPageRoute;
CupertinoPageRoute<T> _internalCupertinoPageRoute;
/// Whether we should currently be using Cupertino transitions. This is true
/// if the theme says we're on iOS, or if we're in an active gesture.
bool get _useCupertinoTransitions {
return _internalCupertinoPageRoute?.popGestureInProgress == true
|| Theme.of(navigator.context).platform == TargetPlatform.iOS;
Duration get transitionDuration => const Duration(milliseconds: 300);
Color get barrierColor => null;
String get barrierLabel => null;
bool canTransitionFrom(TransitionRoute<dynamic> previousRoute) {
return previousRoute is MaterialPageRoute || previousRoute is CupertinoPageRoute;
bool canTransitionTo(TransitionRoute<dynamic> nextRoute) {
// Don't perform outgoing animation if the next route is a fullscreen dialog.
return (nextRoute is MaterialPageRoute && !nextRoute.fullscreenDialog)
|| (nextRoute is CupertinoPageRoute && !nextRoute.fullscreenDialog);
void dispose() {
Widget buildPage(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
final Widget result = new Semantics(
scopesRoute: true,
explicitChildNodes: true,
child: builder(context),
assert(() {
if (result == null) {
throw new FlutterError(
'The builder for route "${}" returned null.\n'
'Route builders must never return null.'
return true;
return result;
Widget buildTransitions(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
if (_useCupertinoTransitions) {
return _cupertinoPageRoute.buildTransitions(context, animation, secondaryAnimation, child);
} else {
return new _MountainViewPageTransition(
routeAnimation: animation,
child: child,
fade: debugEnableFadingRoutes, // ignore: deprecated_member_use
String get debugLabel => '${super.debugLabel}(${})';