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[Gallery] Fix directory structure (#312)
This commit is contained in:
Pierre-Louis
GitHub
820
gallery/lib/studies/shrine/expanding_bottom_sheet.dart
Normal file
820
gallery/lib/studies/shrine/expanding_bottom_sheet.dart
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// Copyright 2019 The Flutter team. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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import 'dart:math';
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import 'package:flutter/material.dart';
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import 'package:meta/meta.dart';
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import 'package:scoped_model/scoped_model.dart';
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import 'package:gallery/layout/adaptive.dart';
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import 'package:gallery/layout/text_scale.dart';
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import 'package:gallery/l10n/gallery_localizations.dart';
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import 'package:gallery/studies/shrine/colors.dart';
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import 'package:gallery/studies/shrine/model/app_state_model.dart';
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import 'package:gallery/studies/shrine/model/product.dart';
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import 'package:gallery/studies/shrine/page_status.dart';
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import 'package:gallery/studies/shrine/shopping_cart.dart';
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// These curves define the emphasized easing curve.
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const Cubic _accelerateCurve = Cubic(0.548, 0, 0.757, 0.464);
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const Cubic _decelerateCurve = Cubic(0.23, 0.94, 0.41, 1);
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// The time at which the accelerate and decelerate curves switch off
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const _peakVelocityTime = 0.248210;
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// Percent (as a decimal) of animation that should be completed at _peakVelocityTime
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const _peakVelocityProgress = 0.379146;
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// Radius of the shape on the top start of the sheet for mobile layouts.
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const _mobileCornerRadius = 24.0;
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// Radius of the shape on the top start and bottom start of the sheet for mobile layouts.
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const _desktopCornerRadius = 12.0;
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// Width for just the cart icon and no thumbnails.
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const _cartIconWidth = 64.0;
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// Height for just the cart icon and no thumbnails.
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const _cartIconHeight = 56.0;
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// Height of a thumbnail.
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const _defaultThumbnailHeight = 40.0;
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// Gap between thumbnails.
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const _thumbnailGap = 16.0;
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// Maximum number of thumbnails shown in the cart.
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const _maxThumbnailCount = 3;
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double _thumbnailHeight(BuildContext context) {
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return _defaultThumbnailHeight * reducedTextScale(context);
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}
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double _paddedThumbnailHeight(BuildContext context) {
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return _thumbnailHeight(context) + _thumbnailGap;
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}
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class ExpandingBottomSheet extends StatefulWidget {
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const ExpandingBottomSheet({
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Key key,
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@required this.hideController,
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@required this.expandingController,
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}) : assert(hideController != null),
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assert(expandingController != null),
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super(key: key);
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final AnimationController hideController;
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final AnimationController expandingController;
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@override
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_ExpandingBottomSheetState createState() => _ExpandingBottomSheetState();
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static _ExpandingBottomSheetState of(BuildContext context,
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{bool isNullOk = false}) {
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assert(isNullOk != null);
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assert(context != null);
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final _ExpandingBottomSheetState result =
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context.findAncestorStateOfType<_ExpandingBottomSheetState>();
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if (isNullOk || result != null) {
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return result;
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}
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throw FlutterError(
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'ExpandingBottomSheet.of() called with a context that does not contain a ExpandingBottomSheet.\n');
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}
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}
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// Emphasized Easing is a motion curve that has an organic, exciting feeling.
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// It's very fast to begin with and then very slow to finish. Unlike standard
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// curves, like [Curves.fastOutSlowIn], it can't be expressed in a cubic bezier
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// curve formula. It's quintic, not cubic. But it _can_ be expressed as one
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// curve followed by another, which we do here.
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Animation<T> _getEmphasizedEasingAnimation<T>({
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@required T begin,
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@required T peak,
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@required T end,
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@required bool isForward,
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@required Animation<double> parent,
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}) {
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Curve firstCurve;
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Curve secondCurve;
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double firstWeight;
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double secondWeight;
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if (isForward) {
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firstCurve = _accelerateCurve;
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secondCurve = _decelerateCurve;
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firstWeight = _peakVelocityTime;
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secondWeight = 1 - _peakVelocityTime;
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} else {
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firstCurve = _decelerateCurve.flipped;
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secondCurve = _accelerateCurve.flipped;
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firstWeight = 1 - _peakVelocityTime;
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secondWeight = _peakVelocityTime;
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}
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return TweenSequence<T>(
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[
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TweenSequenceItem<T>(
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weight: firstWeight,
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tween: Tween<T>(
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begin: begin,
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end: peak,
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).chain(CurveTween(curve: firstCurve)),
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),
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TweenSequenceItem<T>(
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weight: secondWeight,
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tween: Tween<T>(
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begin: peak,
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end: end,
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).chain(CurveTween(curve: secondCurve)),
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),
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],
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).animate(parent);
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}
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// Calculates the value where two double Animations should be joined. Used by
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// callers of _getEmphasisedEasing<double>().
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double _getPeakPoint({double begin, double end}) {
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return begin + (end - begin) * _peakVelocityProgress;
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}
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class _ExpandingBottomSheetState extends State<ExpandingBottomSheet>
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with TickerProviderStateMixin {
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final GlobalKey _expandingBottomSheetKey =
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GlobalKey(debugLabel: 'Expanding bottom sheet');
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// The width of the Material, calculated by _widthFor() & based on the number
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// of products in the cart. 64.0 is the width when there are 0 products
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// (_kWidthForZeroProducts)
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double _width = _cartIconWidth;
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double _height = _cartIconHeight;
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// Controller for the opening and closing of the ExpandingBottomSheet
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AnimationController get _controller => widget.expandingController;
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// Animations for the opening and closing of the ExpandingBottomSheet
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Animation<double> _widthAnimation;
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Animation<double> _heightAnimation;
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Animation<double> _thumbnailOpacityAnimation;
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Animation<double> _cartOpacityAnimation;
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Animation<double> _topStartShapeAnimation;
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Animation<double> _bottomStartShapeAnimation;
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Animation<Offset> _slideAnimation;
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Animation<double> _gapAnimation;
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Animation<double> _getWidthAnimation(double screenWidth) {
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if (_controller.status == AnimationStatus.forward) {
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// Opening animation
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return Tween<double>(begin: _width, end: screenWidth).animate(
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CurvedAnimation(
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parent: _controller.view,
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curve: const Interval(0, 0.3, curve: Curves.fastOutSlowIn),
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),
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);
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} else {
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// Closing animation
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return _getEmphasizedEasingAnimation(
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begin: _width,
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peak: _getPeakPoint(begin: _width, end: screenWidth),
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end: screenWidth,
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isForward: false,
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parent: CurvedAnimation(
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parent: _controller.view, curve: const Interval(0, 0.87)),
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);
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}
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}
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Animation<double> _getHeightAnimation(double screenHeight) {
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if (_controller.status == AnimationStatus.forward) {
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// Opening animation
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return _getEmphasizedEasingAnimation(
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begin: _height,
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peak: _getPeakPoint(begin: _height, end: screenHeight),
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end: screenHeight,
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isForward: true,
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parent: _controller.view,
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);
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} else {
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// Closing animation
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return Tween<double>(
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begin: _height,
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end: screenHeight,
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).animate(
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CurvedAnimation(
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parent: _controller.view,
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curve: const Interval(0.434, 1, curve: Curves.linear), // not used
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// only the reverseCurve will be used
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reverseCurve: Interval(0.434, 1, curve: Curves.fastOutSlowIn.flipped),
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),
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);
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}
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}
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Animation<double> _getDesktopGapAnimation(double gapHeight) {
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final double _collapsedGapHeight = gapHeight;
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final double _expandedGapHeight = 0;
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if (_controller.status == AnimationStatus.forward) {
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// Opening animation
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return _getEmphasizedEasingAnimation(
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begin: _collapsedGapHeight,
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peak: _collapsedGapHeight +
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(_expandedGapHeight - _collapsedGapHeight) * _peakVelocityProgress,
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end: _expandedGapHeight,
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isForward: true,
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parent: _controller.view,
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);
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} else {
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// Closing animation
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return Tween<double>(
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begin: _collapsedGapHeight,
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end: _expandedGapHeight,
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).animate(
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CurvedAnimation(
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parent: _controller.view,
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curve: const Interval(0.434, 1), // not used
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// only the reverseCurve will be used
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reverseCurve: Interval(0.434, 1, curve: Curves.fastOutSlowIn.flipped),
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),
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);
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}
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}
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// Animation of the top-start cut corner. It's cut when closed and not cut when open.
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Animation<double> _getShapeTopStartAnimation(BuildContext context) {
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final bool isDesktop = isDisplayDesktop(context);
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final double cornerRadius =
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isDesktop ? _desktopCornerRadius : _mobileCornerRadius;
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if (_controller.status == AnimationStatus.forward) {
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return Tween<double>(begin: cornerRadius, end: 0).animate(
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CurvedAnimation(
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parent: _controller.view,
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curve: const Interval(0, 0.3, curve: Curves.fastOutSlowIn),
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),
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);
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} else {
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return _getEmphasizedEasingAnimation(
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begin: cornerRadius,
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peak: _getPeakPoint(begin: cornerRadius, end: 0),
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end: 0,
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isForward: false,
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parent: _controller.view,
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);
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}
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}
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// Animation of the bottom-start cut corner. It's cut when closed and not cut when open.
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Animation<double> _getShapeBottomStartAnimation(BuildContext context) {
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final bool isDesktop = isDisplayDesktop(context);
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final double cornerRadius = isDesktop ? _desktopCornerRadius : 0;
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if (_controller.status == AnimationStatus.forward) {
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return Tween<double>(begin: cornerRadius, end: 0).animate(
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CurvedAnimation(
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parent: _controller.view,
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curve: const Interval(0, 0.3, curve: Curves.fastOutSlowIn),
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),
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);
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} else {
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return _getEmphasizedEasingAnimation(
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begin: cornerRadius,
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peak: _getPeakPoint(begin: cornerRadius, end: 0),
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end: 0,
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isForward: false,
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parent: _controller.view,
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);
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}
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}
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Animation<double> _getThumbnailOpacityAnimation() {
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return Tween<double>(begin: 1, end: 0).animate(
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CurvedAnimation(
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parent: _controller.view,
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curve: _controller.status == AnimationStatus.forward
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? const Interval(0, 0.3)
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: const Interval(0.532, 0.766),
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),
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);
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}
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Animation<double> _getCartOpacityAnimation() {
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return CurvedAnimation(
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parent: _controller.view,
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curve: _controller.status == AnimationStatus.forward
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? const Interval(0.3, 0.6)
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: const Interval(0.766, 1),
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);
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}
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// Returns the correct width of the ExpandingBottomSheet based on the number of
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// products and the text scaling options in the cart in the mobile layout.
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double _mobileWidthFor(int numProducts, BuildContext context) {
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final double cartThumbnailGap = numProducts > 0 ? 16 : 0;
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final double thumbnailsWidth =
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min(numProducts, _maxThumbnailCount) * _paddedThumbnailHeight(context);
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final double overflowNumberWidth =
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numProducts > _maxThumbnailCount ? 30 * cappedTextScale(context) : 0;
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return _cartIconWidth +
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cartThumbnailGap +
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thumbnailsWidth +
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overflowNumberWidth;
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}
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// Returns the correct height of the ExpandingBottomSheet based on the text scaling
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// options in the mobile layout.
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double _mobileHeightFor(BuildContext context) {
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return _paddedThumbnailHeight(context);
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}
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// Returns the correct width of the ExpandingBottomSheet based on the text scaling
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// options in the desktop layout.
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double _desktopWidthFor(BuildContext context) {
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return _paddedThumbnailHeight(context) + 8;
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}
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// Returns the correct height of the ExpandingBottomSheet based on the number of
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// products and the text scaling options in the cart in the desktop layout.
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double _desktopHeightFor(int numProducts, BuildContext context) {
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final double cartThumbnailGap = numProducts > 0 ? 8 : 0;
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final double thumbnailsHeight =
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min(numProducts, _maxThumbnailCount) * _paddedThumbnailHeight(context);
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final double overflowNumberHeight =
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numProducts > _maxThumbnailCount ? 28 * reducedTextScale(context) : 0;
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return _cartIconHeight +
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cartThumbnailGap +
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thumbnailsHeight +
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overflowNumberHeight;
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}
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// Returns true if the cart is open or opening and false otherwise.
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bool get _isOpen {
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final AnimationStatus status = _controller.status;
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return status == AnimationStatus.completed ||
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status == AnimationStatus.forward;
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}
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// Opens the ExpandingBottomSheet if it's closed, otherwise does nothing.
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void open() {
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if (!_isOpen) {
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_controller.forward();
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}
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}
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// Closes the ExpandingBottomSheet if it's open or opening, otherwise does nothing.
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void close() {
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if (_isOpen) {
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_controller.reverse();
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}
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}
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// Changes the padding between the start edge of the Material and the cart icon
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// based on the number of products in the cart (padding increases when > 0
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// products.)
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EdgeInsetsDirectional _horizontalCartPaddingFor(int numProducts) {
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return (numProducts == 0)
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? const EdgeInsetsDirectional.only(start: 20, end: 8)
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: const EdgeInsetsDirectional.only(start: 32, end: 8);
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}
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// Changes the padding above and below the cart icon
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// based on the number of products in the cart (padding increases when > 0
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// products.)
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EdgeInsets _verticalCartPaddingFor(int numProducts) {
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return (numProducts == 0)
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? const EdgeInsets.only(top: 16, bottom: 16)
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: const EdgeInsets.only(top: 16, bottom: 24);
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}
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bool get _cartIsVisible => _thumbnailOpacityAnimation.value == 0;
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// We take 16 pts off of the bottom padding to ensure the collapsed shopping
|
||||
// cart is not too tall.
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double get _bottomSafeArea {
|
||||
return max(MediaQuery.of(context).viewPadding.bottom - 16, 0);
|
||||
}
|
||||
|
||||
Widget _buildThumbnails(BuildContext context, int numProducts) {
|
||||
final bool isDesktop = isDisplayDesktop(context);
|
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Widget thumbnails;
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||||
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if (isDesktop) {
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||||
thumbnails = Column(
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||||
children: [
|
||||
AnimatedPadding(
|
||||
padding: _verticalCartPaddingFor(numProducts),
|
||||
child: const Icon(Icons.shopping_cart),
|
||||
duration: const Duration(milliseconds: 225),
|
||||
),
|
||||
Container(
|
||||
width: _width,
|
||||
height: min(numProducts, _maxThumbnailCount) *
|
||||
_paddedThumbnailHeight(context),
|
||||
child: ProductThumbnailRow(),
|
||||
),
|
||||
ExtraProductsNumber(),
|
||||
],
|
||||
);
|
||||
} else {
|
||||
thumbnails = Column(
|
||||
children: [
|
||||
Row(
|
||||
children: [
|
||||
AnimatedPadding(
|
||||
padding: _horizontalCartPaddingFor(numProducts),
|
||||
child: const Icon(Icons.shopping_cart),
|
||||
duration: const Duration(milliseconds: 225),
|
||||
),
|
||||
Container(
|
||||
// Accounts for the overflow number
|
||||
width: min(numProducts, _maxThumbnailCount) *
|
||||
_paddedThumbnailHeight(context) +
|
||||
(numProducts > 0 ? _thumbnailGap : 0),
|
||||
height: _height - _bottomSafeArea,
|
||||
padding: const EdgeInsets.symmetric(vertical: 8),
|
||||
child: ProductThumbnailRow(),
|
||||
),
|
||||
ExtraProductsNumber(),
|
||||
],
|
||||
),
|
||||
],
|
||||
);
|
||||
}
|
||||
|
||||
return ExcludeSemantics(
|
||||
child: Opacity(
|
||||
opacity: _thumbnailOpacityAnimation.value,
|
||||
child: thumbnails,
|
||||
),
|
||||
);
|
||||
}
|
||||
|
||||
Widget _buildShoppingCartPage() {
|
||||
return Opacity(
|
||||
opacity: _cartOpacityAnimation.value,
|
||||
child: ShoppingCartPage(),
|
||||
);
|
||||
}
|
||||
|
||||
Widget _buildCart(BuildContext context) {
|
||||
// numProducts is the number of different products in the cart (does not
|
||||
// include multiples of the same product).
|
||||
final bool isDesktop = isDisplayDesktop(context);
|
||||
|
||||
final AppStateModel model = ScopedModel.of<AppStateModel>(context);
|
||||
final int numProducts = model.productsInCart.keys.length;
|
||||
final int totalCartQuantity = model.totalCartQuantity;
|
||||
final Size screenSize = MediaQuery.of(context).size;
|
||||
final double screenWidth = screenSize.width;
|
||||
final double screenHeight = screenSize.height;
|
||||
|
||||
final double expandedCartWidth = isDesktop
|
||||
? (360 * cappedTextScale(context)).clamp(360, screenWidth).toDouble()
|
||||
: screenWidth;
|
||||
|
||||
_width = isDesktop
|
||||
? _desktopWidthFor(context)
|
||||
: _mobileWidthFor(numProducts, context);
|
||||
_widthAnimation = _getWidthAnimation(expandedCartWidth);
|
||||
_height = isDesktop
|
||||
? _desktopHeightFor(numProducts, context)
|
||||
: _mobileHeightFor(context) + _bottomSafeArea;
|
||||
_heightAnimation = _getHeightAnimation(screenHeight);
|
||||
_topStartShapeAnimation = _getShapeTopStartAnimation(context);
|
||||
_bottomStartShapeAnimation = _getShapeBottomStartAnimation(context);
|
||||
_thumbnailOpacityAnimation = _getThumbnailOpacityAnimation();
|
||||
_cartOpacityAnimation = _getCartOpacityAnimation();
|
||||
_gapAnimation =
|
||||
isDesktop ? _getDesktopGapAnimation(116) : AlwaysStoppedAnimation(0);
|
||||
|
||||
final Widget child = Container(
|
||||
width: _widthAnimation.value,
|
||||
height: _heightAnimation.value,
|
||||
child: Material(
|
||||
animationDuration: const Duration(milliseconds: 0),
|
||||
shape: BeveledRectangleBorder(
|
||||
borderRadius: BorderRadiusDirectional.only(
|
||||
topStart: Radius.circular(_topStartShapeAnimation.value),
|
||||
bottomStart: Radius.circular(_bottomStartShapeAnimation.value),
|
||||
),
|
||||
),
|
||||
elevation: 4,
|
||||
color: shrinePink50,
|
||||
child: _cartIsVisible
|
||||
? _buildShoppingCartPage()
|
||||
: _buildThumbnails(context, numProducts),
|
||||
),
|
||||
);
|
||||
|
||||
final Widget childWithInteraction = productPageIsVisible(context)
|
||||
? Semantics(
|
||||
button: true,
|
||||
label: GalleryLocalizations.of(context)
|
||||
.shrineScreenReaderCart(totalCartQuantity),
|
||||
child: GestureDetector(
|
||||
behavior: HitTestBehavior.opaque,
|
||||
onTap: open,
|
||||
child: child,
|
||||
),
|
||||
)
|
||||
: child;
|
||||
|
||||
return Padding(
|
||||
padding: EdgeInsets.only(top: _gapAnimation.value),
|
||||
child: childWithInteraction,
|
||||
);
|
||||
}
|
||||
|
||||
// Builder for the hide and reveal animation when the backdrop opens and closes
|
||||
Widget _buildSlideAnimation(BuildContext context, Widget child) {
|
||||
final bool isDesktop = isDisplayDesktop(context);
|
||||
|
||||
if (isDesktop) {
|
||||
return child;
|
||||
} else {
|
||||
final double textDirectionScalar =
|
||||
Directionality.of(context) == TextDirection.ltr ? 1 : -1;
|
||||
|
||||
_slideAnimation = _getEmphasizedEasingAnimation(
|
||||
begin: Offset(1 * textDirectionScalar, 0),
|
||||
peak: Offset(_peakVelocityProgress * textDirectionScalar, 0),
|
||||
end: const Offset(0, 0),
|
||||
isForward: widget.hideController.status == AnimationStatus.forward,
|
||||
parent: widget.hideController,
|
||||
);
|
||||
|
||||
return SlideTransition(
|
||||
position: _slideAnimation,
|
||||
child: child,
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
@override
|
||||
Widget build(BuildContext context) {
|
||||
return AnimatedSize(
|
||||
key: _expandingBottomSheetKey,
|
||||
duration: const Duration(milliseconds: 225),
|
||||
curve: Curves.easeInOut,
|
||||
vsync: this,
|
||||
alignment: AlignmentDirectional.topStart,
|
||||
child: AnimatedBuilder(
|
||||
animation: widget.hideController,
|
||||
builder: (context, child) => AnimatedBuilder(
|
||||
animation: widget.expandingController,
|
||||
builder: (context, child) => ScopedModelDescendant<AppStateModel>(
|
||||
builder: (context, child, model) =>
|
||||
_buildSlideAnimation(context, _buildCart(context)),
|
||||
),
|
||||
),
|
||||
),
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
class ProductThumbnailRow extends StatefulWidget {
|
||||
@override
|
||||
_ProductThumbnailRowState createState() => _ProductThumbnailRowState();
|
||||
}
|
||||
|
||||
class _ProductThumbnailRowState extends State<ProductThumbnailRow> {
|
||||
final GlobalKey<AnimatedListState> _listKey = GlobalKey<AnimatedListState>();
|
||||
|
||||
// _list represents what's currently on screen. If _internalList updates,
|
||||
// it will need to be updated to match it.
|
||||
_ListModel _list;
|
||||
|
||||
// _internalList represents the list as it is updated by the AppStateModel.
|
||||
List<int> _internalList;
|
||||
|
||||
@override
|
||||
void initState() {
|
||||
super.initState();
|
||||
_list = _ListModel(
|
||||
listKey: _listKey,
|
||||
initialItems:
|
||||
ScopedModel.of<AppStateModel>(context).productsInCart.keys.toList(),
|
||||
removedItemBuilder: _buildRemovedThumbnail,
|
||||
);
|
||||
_internalList = List<int>.from(_list.list);
|
||||
}
|
||||
|
||||
Product _productWithId(int productId) {
|
||||
final AppStateModel model = ScopedModel.of<AppStateModel>(context);
|
||||
final Product product = model.getProductById(productId);
|
||||
assert(product != null);
|
||||
return product;
|
||||
}
|
||||
|
||||
Widget _buildRemovedThumbnail(
|
||||
int item, BuildContext context, Animation<double> animation) {
|
||||
return ProductThumbnail(animation, animation, _productWithId(item));
|
||||
}
|
||||
|
||||
Widget _buildThumbnail(
|
||||
BuildContext context, int index, Animation<double> animation) {
|
||||
final Animation<double> thumbnailSize =
|
||||
Tween<double>(begin: 0.8, end: 1).animate(
|
||||
CurvedAnimation(
|
||||
curve: const Interval(0.33, 1, curve: Curves.easeIn),
|
||||
parent: animation,
|
||||
),
|
||||
);
|
||||
|
||||
final Animation<double> opacity = CurvedAnimation(
|
||||
curve: const Interval(0.33, 1, curve: Curves.linear),
|
||||
parent: animation,
|
||||
);
|
||||
|
||||
return ProductThumbnail(
|
||||
thumbnailSize, opacity, _productWithId(_list[index]));
|
||||
}
|
||||
|
||||
// If the lists are the same length, assume nothing has changed.
|
||||
// If the internalList is shorter than the ListModel, an item has been removed.
|
||||
// If the internalList is longer, then an item has been added.
|
||||
void _updateLists() {
|
||||
// Update _internalList based on the model
|
||||
_internalList =
|
||||
ScopedModel.of<AppStateModel>(context).productsInCart.keys.toList();
|
||||
final Set<int> internalSet = Set<int>.from(_internalList);
|
||||
final Set<int> listSet = Set<int>.from(_list.list);
|
||||
|
||||
final Set<int> difference = internalSet.difference(listSet);
|
||||
if (difference.isEmpty) {
|
||||
return;
|
||||
}
|
||||
|
||||
for (int product in difference) {
|
||||
if (_internalList.length < _list.length) {
|
||||
_list.remove(product);
|
||||
} else if (_internalList.length > _list.length) {
|
||||
_list.add(product);
|
||||
}
|
||||
}
|
||||
|
||||
while (_internalList.length != _list.length) {
|
||||
int index = 0;
|
||||
// Check bounds and that the list elements are the same
|
||||
while (_internalList.isNotEmpty &&
|
||||
_list.length > 0 &&
|
||||
index < _internalList.length &&
|
||||
index < _list.length &&
|
||||
_internalList[index] == _list[index]) {
|
||||
index++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Widget _buildAnimatedList(BuildContext context) {
|
||||
final bool isDesktop = isDisplayDesktop(context);
|
||||
|
||||
return AnimatedList(
|
||||
key: _listKey,
|
||||
shrinkWrap: true,
|
||||
itemBuilder: _buildThumbnail,
|
||||
initialItemCount: _list.length,
|
||||
scrollDirection: isDesktop ? Axis.vertical : Axis.horizontal,
|
||||
physics: const NeverScrollableScrollPhysics(), // Cart shouldn't scroll
|
||||
);
|
||||
}
|
||||
|
||||
@override
|
||||
Widget build(BuildContext context) {
|
||||
_updateLists();
|
||||
return ScopedModelDescendant<AppStateModel>(
|
||||
builder: (context, child, model) => _buildAnimatedList(context),
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
class ExtraProductsNumber extends StatelessWidget {
|
||||
// Calculates the number to be displayed at the end of the row if there are
|
||||
// more than three products in the cart. This calculates overflow products,
|
||||
// including their duplicates (but not duplicates of products shown as
|
||||
// thumbnails).
|
||||
int _calculateOverflow(AppStateModel model) {
|
||||
final Map<int, int> productMap = model.productsInCart;
|
||||
// List created to be able to access products by index instead of ID.
|
||||
// Order is guaranteed because productsInCart returns a LinkedHashMap.
|
||||
final List<int> products = productMap.keys.toList();
|
||||
int overflow = 0;
|
||||
final int numProducts = products.length;
|
||||
for (int i = _maxThumbnailCount; i < numProducts; i++) {
|
||||
overflow += productMap[products[i]];
|
||||
}
|
||||
return overflow;
|
||||
}
|
||||
|
||||
Widget _buildOverflow(AppStateModel model, BuildContext context) {
|
||||
if (model.productsInCart.length <= _maxThumbnailCount) {
|
||||
return Container();
|
||||
}
|
||||
|
||||
final int numOverflowProducts = _calculateOverflow(model);
|
||||
// Maximum of 99 so padding doesn't get messy.
|
||||
final int displayedOverflowProducts =
|
||||
numOverflowProducts <= 99 ? numOverflowProducts : 99;
|
||||
return Container(
|
||||
child: Text(
|
||||
'+$displayedOverflowProducts',
|
||||
style: Theme.of(context).primaryTextTheme.button,
|
||||
),
|
||||
);
|
||||
}
|
||||
|
||||
@override
|
||||
Widget build(BuildContext context) {
|
||||
return ScopedModelDescendant<AppStateModel>(
|
||||
builder: (builder, child, model) => _buildOverflow(model, context),
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
class ProductThumbnail extends StatelessWidget {
|
||||
const ProductThumbnail(this.animation, this.opacityAnimation, this.product);
|
||||
|
||||
final Animation<double> animation;
|
||||
final Animation<double> opacityAnimation;
|
||||
final Product product;
|
||||
|
||||
@override
|
||||
Widget build(BuildContext context) {
|
||||
final bool isDesktop = isDisplayDesktop(context);
|
||||
|
||||
return FadeTransition(
|
||||
opacity: opacityAnimation,
|
||||
child: ScaleTransition(
|
||||
scale: animation,
|
||||
child: Container(
|
||||
width: _thumbnailHeight(context),
|
||||
height: _thumbnailHeight(context),
|
||||
decoration: BoxDecoration(
|
||||
image: DecorationImage(
|
||||
image: ExactAssetImage(
|
||||
product.assetName, // asset name
|
||||
package: product.assetPackage, // asset package
|
||||
),
|
||||
fit: BoxFit.cover,
|
||||
),
|
||||
borderRadius: const BorderRadius.all(Radius.circular(10)),
|
||||
),
|
||||
margin: isDesktop
|
||||
? const EdgeInsetsDirectional.only(start: 12, end: 12, bottom: 16)
|
||||
: const EdgeInsetsDirectional.only(start: 16),
|
||||
),
|
||||
),
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
// _ListModel manipulates an internal list and an AnimatedList
|
||||
class _ListModel {
|
||||
_ListModel({
|
||||
@required this.listKey,
|
||||
@required this.removedItemBuilder,
|
||||
Iterable<int> initialItems,
|
||||
}) : assert(listKey != null),
|
||||
assert(removedItemBuilder != null),
|
||||
_items = initialItems?.toList() ?? [];
|
||||
|
||||
final GlobalKey<AnimatedListState> listKey;
|
||||
final Widget Function(int, BuildContext, Animation<double>)
|
||||
removedItemBuilder;
|
||||
final List<int> _items;
|
||||
|
||||
AnimatedListState get _animatedList => listKey.currentState;
|
||||
|
||||
void add(int product) {
|
||||
_insert(_items.length, product);
|
||||
}
|
||||
|
||||
void _insert(int index, int item) {
|
||||
_items.insert(index, item);
|
||||
_animatedList.insertItem(index,
|
||||
duration: const Duration(milliseconds: 225));
|
||||
}
|
||||
|
||||
void remove(int product) {
|
||||
final int index = _items.indexOf(product);
|
||||
if (index >= 0) {
|
||||
_removeAt(index);
|
||||
}
|
||||
}
|
||||
|
||||
void _removeAt(int index) {
|
||||
final int removedItem = _items.removeAt(index);
|
||||
if (removedItem != null) {
|
||||
_animatedList.removeItem(index, (context, animation) {
|
||||
return removedItemBuilder(removedItem, context, animation);
|
||||
});
|
||||
}
|
||||
}
|
||||
|
||||
int get length => _items.length;
|
||||
|
||||
int operator [](int index) => _items[index];
|
||||
|
||||
int indexOf(int item) => _items.indexOf(item);
|
||||
|
||||
List<int> get list => _items;
|
||||
}
|
||||
Reference in New Issue
Block a user