firka/flutter
3
0
Fork 1
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Remove Force and SpringForce (#7532)

Browse Source 
The only client of this machinery was AnimationController.fling, but
it's easier for that function to just create the simulation it needs
directly.

Fixes #7216
This commit is contained in:
Adam Barth
2017-01-18 16:32:00 -08:00
committed by GitHub
parent 584dbe3d32
commit 7d5f172a26
4 changed files with 19 additions and 98 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
packages/flutter/lib/animation.dart
View File

@@ -15,6 +15,5 @@ export 'src/animation/animation.dart';
export 'src/animation/animation_controller.dart';
export 'src/animation/animations.dart';
export 'src/animation/curves.dart';
export 'src/animation/forces.dart';
export 'src/animation/listener_helpers.dart';
export 'src/animation/tween.dart';

25
packages/flutter/lib/src/animation/animation_controller.dart
View File

@@ -11,7 +11,6 @@ import 'package:flutter/scheduler.dart';
import 'animation.dart';
import 'curves.dart';
import 'forces.dart';
import 'listener_helpers.dart';
/// The direction in which an animation is running.
@@ -23,6 +22,17 @@ enum _AnimationDirection {
reverse,
}
final SpringDescription _kFlingSpringDescription = new SpringDescription.withDampingRatio(
mass: 1.0,
springConstant: 500.0,
ratio: 1.0,
);
const Tolerance _kFlingTolerance = const Tolerance(
velocity: double.INFINITY,
distance: 0.01,
);
/// A controller for an animation.
///
/// This class lets you perform tasks such as:
@@ -305,13 +315,16 @@ class AnimationController extends Animation<double>
return animateWith(new _RepeatingSimulation(min, max, period));
}
/// Flings the timeline with an optional force (defaults to a critically
/// damped spring within [lowerBound] and [upperBound]) and initial velocity.
/// Drives the animation with a critically damped spring (within [lowerBound] and [upperBound]) and initial velocity.
///
/// If velocity is positive, the animation will complete, otherwise it will dismiss.
Future<Null> fling({ double velocity: 1.0, Force force }) {
force ??= kDefaultSpringForce.copyWith(left: lowerBound, right: upperBound);
Future<Null> fling({ double velocity: 1.0 }) {
_direction = velocity < 0.0 ? _AnimationDirection.reverse : _AnimationDirection.forward;
return animateWith(force.release(value, velocity));
final double target = velocity < 0.0 ? lowerBound - _kFlingTolerance.distance
: upperBound + _kFlingTolerance.distance;
Simulation simulation = new SpringSimulation(_kFlingSpringDescription, value, target, velocity)
..tolerance = _kFlingTolerance;
return animateWith(simulation);
}
/// Drives the animation according to the given simulation.

75
packages/flutter/lib/src/animation/forces.dart
View File

@@ -1,75 +0,0 @@
// 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/physics.dart';
export 'package:flutter/physics.dart' show SpringDescription;
/// A factory for simulations.
abstract class Force {
/// Abstract const constructor. This constructor enables subclasses to provide
/// const constructors so that they can be used in const expressions.
const Force();
/// Creates a new physics simulation with the given initial conditions.
Simulation release(double position, double velocity);
}
/// A factory for spring-based physics simulations.
class SpringForce extends Force {
/// Creates a spring force.
///
/// The [spring], [left], and [right] arguments must not be null. The [left]
/// argument defaults to 0.0 and the [right] argument defaults to 1.0.
const SpringForce(this.spring, { this.left: 0.0, this.right: 1.0 });
/// The description of the spring to be used in the created simulations.
final SpringDescription spring;
/// Where to put the spring's resting point when releasing left.
final double left;
/// Where to put the spring's resting point when releasing right.
final double right;
/// Creates a copy of this spring force but with the given fields replaced with the new values.
SpringForce copyWith({
SpringDescription spring,
double left,
double right
}) {
return new SpringForce(
spring ?? this.spring,
left: left ?? this.left,
right: right ?? this.right
);
}
/// How pricely to terminate the simulation.
///
/// We overshoot the target by this distance, but stop the simulation when
/// the spring gets within this distance (regardless of how fast it's moving).
/// This causes the spring to settle a bit faster than it otherwise would.
static const Tolerance tolerance = const Tolerance(
velocity: double.INFINITY,
distance: 0.01
);
@override
Simulation release(double position, double velocity) {
double target = velocity < 0.0 ? this.left - tolerance.distance
: this.right + tolerance.distance;
return new SpringSimulation(spring, position, target, velocity)
..tolerance = tolerance;
}
}
final SpringDescription _kDefaultSpringDesc = new SpringDescription.withDampingRatio(
mass: 1.0,
springConstant: 500.0,
ratio: 1.0
);
/// A spring force with reasonable default values.
final SpringForce kDefaultSpringForce = new SpringForce(_kDefaultSpringDesc);

16
packages/flutter/test/animation/forces_test.dart
View File

@@ -1,16 +0,0 @@
// Copyright 2016 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_test/flutter_test.dart';
import 'package:flutter/animation.dart';
import 'package:flutter/widgets.dart';
void main() {
test('copyWith defaults to unchanged values', () {
SpringForce force = kDefaultSpringForce.copyWith();
expect(force.spring, kDefaultSpringForce.spring);
expect(force.left, kDefaultSpringForce.left);
expect(force.right, kDefaultSpringForce.right);
});
}